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<front> <front>
<title abbrev="IP Traffic Flow Security">IP-TFS: Aggregation and Fragmentati <title abbrev="IP Traffic Flow Security">Aggregation and Fragmentation Mode
on Mode for ESP and its Use for IP Traffic Flow Security</title> for Encapsulating Security Payload (ESP) and Its Use for IP Traffic Flow Securit
<author initials='C.' surname='Hopps' fullname='Christian Hopps'><organization>L y (IP-TFS)</title>
abN Consulting, L.L.C.</organization><address><email>chopps@chopps.org</email></ <seriesInfo name="RFC" value="9347"/>
address></author> <date/><abstract><t>This document describes a mechanism for a <author initials="C." surname="Hopps" fullname="Christian Hopps">
ggregation and <organization>LabN Consulting, L.L.C.</organization>
fragmentation of IP packets when they are being encapsulated in ESP <address>
payloads. This new payload type can be used for various purposes such <email>chopps@chopps.org</email>
</address>
</author>
<date year="2023" month="January"/>
<area>sec</area>
<workgroup>ipsecme</workgroup>
<abstract>
<t>This document describes a mechanism for aggregation and
fragmentation of IP packets when they are being encapsulated in Encapsulating Se
curity Payload (ESP). This new payload type can be used for various purposes, su
ch
as decreasing encapsulation overhead for small IP packets; however, as decreasing encapsulation overhead for small IP packets; however,
the focus in this document is to enhance IPsec traffic flow security the focus in this document is to enhance IP Traffic Flow Security
(IP-TFS) by adding Traffic Flow Confidentiality (TFC) to encrypted IP (IP-TFS) by adding Traffic Flow Confidentiality (TFC) to encrypted IP-encapsulat
encapsulated traffic. TFC is provided by obscuring the size and ed traffic. TFC is provided by obscuring the size and
frequency of IP traffic using a fixed-sized, constant-send-rate IPsec frequency of IP traffic using a fixed-size, constant-send-rate IPsec
tunnel. The solution allows for congestion control as well as tunnel. The solution allows for congestion control, as well as
non-constant send-rate usage.</t></abstract> </front> <middle> nonconstant send-rate usage.</t>
</abstract>
<section title="Introduction" anchor="sec-introduction"> </front>
<t>Traffic Analysis (<xref target="RFC4301"/>, <xref target="AppCrypt"/>) is the <middle>
act of extracting <section anchor="sec-introduction" numbered="true" toc="default">
<name>Introduction</name>
<t>Traffic analysis <xref target="RFC4301" format="default"/> <xref target
="AppCrypt" format="default"/> is the act of extracting
information about data being sent through a network. While directly information about data being sent through a network. While directly
obscuring the data with encryption <xref target="RFC4303"/>, the patterns in the obscuring the data with encryption <xref target="RFC4303" format="default"/>, th e patterns in the
message traffic may expose information due to variations in its shape message traffic may expose information due to variations in its shape
and timing (<xref target="RFC8546"/>, <xref target="AppCrypt"/>). Hiding the siz and timing <xref target="RFC8546" format="default"/> <xref target="AppCrypt" for
e and frequency of mat="default"/>. Hiding the size and frequency of
traffic is referred to as Traffic Flow Confidentiality (TFC) per traffic is referred to as Traffic Flow Confidentiality (TFC), per
<xref target="RFC4303"/>.</t> <xref target="RFC4303" format="default"/>.</t>
<t><xref target="RFC4303" format="default"/> provides for TFC by allowing
<t><xref target="RFC4303"/> provides for TFC by allowing padding to be added to padding to be added to encrypted
encrypted
IP packets and allowing for transmission of all-pad packets IP packets and allowing for transmission of all-pad packets
(indicated using protocol 59). This method has the major limitation (indicated using protocol 59). This method has the major limitation
that it can significantly under-utilize the available bandwidth.</t> that it can significantly underutilize the available bandwidth.</t>
<t>This document defines an aggregation and fragmentation (AGGFRAG) mode
<t>This document defines an aggregation and fragmentation (AGGFRAG) mode for ESP, as well as ESP's use for IP Traffic Flow Security (IP-TFS). This
for ESP, and its use for IP Traffic Flow Security (IP-TFS). This
solution provides for full TFC without the aforementioned bandwidth solution provides for full TFC without the aforementioned bandwidth
limitation. This is accomplished by using a constant-send-rate IPsec limitation. This is accomplished by using a constant-send-rate IPsec
<xref target="RFC4303"/> tunnel with fixed-sized encapsulating packets; however, <xref target="RFC4303" format="default"/> tunnel with fixed-size encapsulating p
these ackets; however, these
fixed-sized packets can contain partial, whole or multiple IP packets fixed-size packets can contain partial, whole, or multiple IP packets
to maximize the bandwidth of the tunnel. A non-constant send-rate is to maximize the bandwidth of the tunnel. A nonconstant send rate is
allowed, but the confidentiality properties of its use are outside allowed, but the confidentiality properties of its use are outside
the scope of this document.</t> the scope of this document.</t>
<t>For a comparison of the overhead of IP-TFS with the TFC solution
<t>For a comparison of the overhead of IP-TFS with the RFC4303 prescribed in <xref target="RFC4303" format="default"/>, see <xref target="sec-
prescribed TFC solution see <xref target="sec-comparisons-of-ip-tfs"></xref>.</t comparisons-of-ip-tfs" format="default"/>.</t>
> <t>Additionally, IP-TFS provides for operating fairly within congested
networks <xref target="RFC2914" format="default"/>. This is important for when t
<t>Additionally, IP-TFS provides for operating fairly within congested he IP-TFS user is not
networks <xref target="RFC2914"/>. This is important for when the IP-TFS user is
not
in full control of the domain through which the IP-TFS tunnel path in full control of the domain through which the IP-TFS tunnel path
flows.</t> flows.</t>
<t>The mechanisms, such as the AGGFRAG mode, defined in this document
<t>The mechanisms, such as the AGGFRAG mode, defined in this document
are generic with the intent of allowing for non-TFS uses, but such are generic with the intent of allowing for non-TFS uses, but such
uses are outside the scope of this document.</t> uses are outside the scope of this document.</t>
<section numbered="true" toc="default">
<section title="Terminology &amp; Concepts"> <name>Terminology &amp; Concepts</name>
<t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", <t>
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQU
"OPTIONAL" in this document are to be interpreted as described in BCP IRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL
14 <xref target="RFC2119"/> <xref target="RFC8174"/> when, and only when, they a NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>
ppear in all capitals, RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
as shown here.</t> "<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to
be interpreted as
<t>This document assumes familiarity with IP security concepts including described in BCP&nbsp;14 <xref target="RFC2119"/> <xref target="RFC8174"/>
TFC as described in <xref target="RFC4301"/>.</t> when, and only when, they appear in all capitals, as shown here.
</t>
</section> <t>This document assumes familiarity with IP security concepts, includin
g
</section> TFC, as described in <xref target="RFC4301" format="default"/>.</t>
</section>
<section title="The AGGFRAG Tunnel"> </section>
<t>As mentioned in <xref target="sec-introduction"></xref>, AGGFRAG mode utilize <section numbered="true" toc="default">
s an IPsec <xref target="RFC4303"/> tunnel <name>The AGGFRAG Tunnel</name>
as its transport. For the purpose of IP-TFS, fixed-sized encapsulating <t>As mentioned in <xref target="sec-introduction" format="default"/>, the
AGGFRAG mode utilizes an IPsec <xref target="RFC4303" format="default"/> tunnel
as its transport. For the purpose of IP-TFS, fixed-size encapsulating
packets are sent at a constant rate on the AGGFRAG tunnel.</t> packets are sent at a constant rate on the AGGFRAG tunnel.</t>
<t>The primary input to the tunnel algorithm is the requested bandwidth
<t>The primary input to the tunnel algorithm is the requested bandwidth
to be used by the tunnel. Two values are then required to provide for to be used by the tunnel. Two values are then required to provide for
this bandwidth use, the fixed size of the encapsulating packets, and this bandwidth use: the fixed size of the encapsulating packets and
rate at which to send them.</t> the rate at which to send them.</t>
<t>The fixed packet size <bcp14>MAY</bcp14> either be specified manually o
<t>The fixed packet size MAY either be specified manually or be r be
determined through other methods such as the Packetization Layer MTU determined through other methods, such as the Packetization Layer MTU
Discovery (PLMTUD) (<xref target="RFC4821"/>, <xref target="RFC8899"/>) or Path Discovery (PLMTUD) <xref target="RFC4821" format="default"/> <xref target="RFC88
MTU discovery (PMTUD) 99" format="default"/> or Path MTU Discovery (PMTUD)
(<xref target="RFC1191"/>, <xref target="RFC8201"/>). PMTUD is known to have iss <xref target="RFC1191" format="default"/> <xref target="RFC8201" format="default
ues so PLMTUD is "/>. PMTUD is known to have issues, so PLMTUD is
considered the more robust option. For PLMTUD, congestion control considered the more robust option. For PLMTUD, congestion control
payloads can be used as in-band probes (see <xref target="sec-congestion-control payloads can be used as in-band probes (see <xref target="sec-congestion-control
-aggfrag-payload-payload-format"></xref> and <xref target="RFC8899"/>).</t> -aggfrag-payload-payload-format" format="default"/> and <xref target="RFC8899" f
ormat="default"/>).</t>
<t>Given the encapsulating packet size and the requested bandwidth to be <t>Given the encapsulating packet size and the requested bandwidth to be
used, the corresponding packet send rate can be calculated. The used, the corresponding packet send rate can be calculated. The
packet send rate is the requested bandwidth to be used divided by the packet send rate is the requested bandwidth to be used, which is then divided by the
size of the encapsulating packet.</t> size of the encapsulating packet.</t>
<t>The egress (receiving) side of the AGGFRAG tunnel <bcp14>MUST</bcp14> a
<t>The egress (receiving) side of the AGGFRAG tunnel MUST allow for and llow for and
expect the ingress (sending) side of the AGGFRAG tunnel to vary the expect the ingress (sending) side of the AGGFRAG tunnel to vary the
size and rate of sent encapsulating packets, unless constrained by size and rate of sent encapsulating packets, unless constrained by
other policy.</t> other policy.</t>
<section numbered="true" toc="default">
<section title="Tunnel Content"> <name>Tunnel Content</name>
<t>As previously mentioned, one issue with the TFC padding solution in <t>As previously mentioned, one issue with the TFC padding solution in
<xref target="RFC4303"/> is the large amount of wasted bandwidth as only one IP <xref target="RFC4303" format="default"/> is the large amount of wasted bandwidt
h, as only one IP
packet can be sent per encapsulating packet. In order to maximize packet can be sent per encapsulating packet. In order to maximize
bandwidth, IP-TFS breaks this one-to-one association by introducing bandwidth, IP-TFS breaks this one-to-one association by introducing
an AGGFRAG mode for ESP.</t> an AGGFRAG mode for ESP.</t>
<t>The AGGFRAG mode aggregates and fragments the inner IP traffic
<t>AGGFRAG mode aggregates as well as fragments the inner IP traffic
flow into encapsulating IPsec tunnel packets. For IP-TFS, the IPsec flow into encapsulating IPsec tunnel packets. For IP-TFS, the IPsec
encapsulating tunnel packets are a fixed size. Padding is only added encapsulating tunnel packets are a fixed size. Padding is only added
to the tunnel packets if there is no data available to be sent at to the tunnel packets if there is no data available to be sent at
the time of tunnel packet transmission, or if fragmentation has been the time of tunnel packet transmission or if fragmentation has been
disabled by the receiver.</t> disabled by the receiver.</t>
<t>This is accomplished using a new Encapsulating Security Payload (ESP)
<t>This is accomplished using a new Encapsulating Security Payload (ESP, <xref target="RFC4303" format="default"/> Next Header field value AGGFRAG_PAYLOA
<xref target="RFC4303"/>) Next Header field value AGGFRAG_PAYLOAD D
(<xref target="sec-aggfrag-payload-payload"></xref>).</t> (<xref target="sec-aggfrag-payload-payload" format="default"/>).</t>
<t>Other non-IP-TFS uses of this AGGFRAG mode have been suggested, such
<t>Other non-IP-TFS uses of this AGGFRAG mode have been suggested, such
as increased performance through packet aggregation, as well as as increased performance through packet aggregation, as well as
handling MTU issues using fragmentation. These uses are not defined handling MTU issues using fragmentation. These uses are not defined
here, but are also not restricted by this document.</t> here but are also not restricted by this document.</t>
</section>
</section> <section numbered="true" toc="default">
<name>Payload Content</name>
<section title="Payload Content"> <t>The AGGFRAG_PAYLOAD payload content defined in this document
<t>The AGGFRAG_PAYLOAD payload content defined in this document consists of a 4- or 24-octet header, followed by either a partial
consists of a 4 or 24 octet header followed by either a partial data block, a full data block, or multiple partial or full data blocks.
datablock, a full datablock, or multiple partial or full datablocks.
The following diagram illustrates this payload within the ESP packet. The following diagram illustrates this payload within the ESP packet.
See <xref target="sec-aggfrag-payload-payload"></xref> for the exact formats of the See <xref target="sec-aggfrag-payload-payload" format="default"/> for the exact formats of the
AGGFRAG_PAYLOAD payload.</t> AGGFRAG_PAYLOAD payload.</t>
<figure anchor="sec-layout-of-an-aggfrag-mode-ipsec-packet">
<figure title="Layout of an AGGFRAG mode IPsec Packet" anchor="sec-layout-of-an- <name>Layout of an AGGFRAG Mode IPsec Packet</name>
aggfrag-mode-ipsec-packet"><artwork><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. Outer Encapsulating Header ... . . Outer Encapsulating Header ... .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. ESP Header... . . ESP Header... .
+---------------------------------------------------------------+ +---------------------------------------------------------------+
| [AGGFRAG sub-type/flags] : BlockOffset | | [AGGFRAG sub-type/flags] : BlockOffset |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
: [Optional Congestion Info] : : [Optional Congestion Info] :
+---------------------------------------------------------------+ +---------------------------------------------------------------+
| DataBlocks ... ~ | DataBlocks ... ~
~ ~ ~ ~
~ | ~ |
+---------------------------------------------------------------| +---------------------------------------------------------------|
. ESP Trailer... . . ESP Trailer... .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
]]></artwork></figure> ]]></artwork>
</figure>
<t>The <spanx style='verb'>BlockOffset</spanx> value is either zero or some offs <t>The <tt>BlockOffset</tt> value is either zero or some offset into or
et into or past past
the end of the <spanx style='verb'>DataBlocks</spanx> data.</t> the end of the <tt>DataBlocks</tt> data.</t>
<t>If the <tt>BlockOffset</tt> value is zero, it means that the <tt>Data
<t>If the <spanx style='verb'>BlockOffset</spanx> value is zero it means that th Blocks</tt>
e <spanx style='verb'>DataBlocks</spanx>
data begins with a new data block.</t> data begins with a new data block.</t>
<t>Conversely, if the <tt>BlockOffset</tt> value is non-zero, it points
<t>Conversely, if the <spanx style='verb'>BlockOffset</spanx> value is non-zero to the
it points to the start of the new data block, and the initial <tt>DataBlocks</tt> data
start of the new data block, and the initial <spanx style='verb'>DataBlocks</spa belongs to the data block that is still being reassembled.</t>
nx> data <t>If the <tt>BlockOffset</tt> points past the end of the <tt>DataBlocks
belongs to the data block that is still being re-assembled.</t> </tt> data,
<t>If the <spanx style='verb'>BlockOffset</spanx> points past the end of the <sp
anx style='verb'>DataBlocks</spanx> data
then the next data block occurs in a subsequent encapsulating packet.</t> then the next data block occurs in a subsequent encapsulating packet.</t>
<t>Having the <tt>BlockOffset</tt> always point at the next available da
<t>Having the <spanx style='verb'>BlockOffset</spanx> always point at the next a ta
vailable data
block allows for recovering the next inner packet in the block allows for recovering the next inner packet in the
presence of outer encapsulating packet loss.</t> presence of outer encapsulating packet loss.</t>
<t>An example AGGFRAG mode packet flow can be found in <xref target="sec
<t>An example AGGFRAG mode packet flow can be found in <xref target="sec-example -example-of-an-encapsulated-ip-packet-flow" format="default"/>.</t>
-of-an-encapsulated-ip-packet-flow"></xref>.</t> <section numbered="true" toc="default">
<name>DataBlocks</name>
<section title="Data Blocks"> <figure anchor="sec-layout-of-a-datablock">
<figure title="Layout of a DataBlock" anchor="sec-layout-of-a-datablock"><artwor <name>Layout of a Data Block</name>
k><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
+---------------------------------------------------------------+ +---------------------------------------------------------------+
| Type | rest of IPv4, IPv6 or pad. | Type | rest of IPv4, IPv6, or pad...
+-------- +--------
]]></artwork></figure> ]]></artwork>
</figure>
<t>A data block is defined by a 4-bit type code followed by the data <t>A data block is defined by a 4-bit type code, followed by the data
block data. The type values have been carefully chosen to coincide block data. The type values have been carefully chosen to coincide
with the IPv4/IPv6 version field values so that no per-data block with the IPv4/IPv6 version field values so that no per-data block type overhead
type overhead is required to encapsulate an IP packet. Likewise, the is required to encapsulate an IP packet. Likewise, the
length of the data block is extracted from the encapsulated IPv4's length of the data block is extracted from the encapsulated IPv4's
<spanx style='verb'>Total Length</spanx> or IPv6's <spanx style='verb'>Payload L <tt>Total Length</tt> or IPv6's <tt>Payload Length</tt> fields.</t>
ength</spanx> fields.</t> </section>
<section numbered="true" toc="default">
</section> <name>End Padding</name>
<t>Since a data block's type is identified in its first 4 bits, the on
<section title="End Padding"> ly
<t>Since a data block's type is identified in its first 4-bits, the only
time padding is required is when there is no data to encapsulate. For time padding is required is when there is no data to encapsulate. For
this end padding a <spanx style='verb'>Pad Data Block</spanx> is used.</t> this end padding, a <tt>Pad Data Block</tt> is used.</t>
</section>
</section> <section anchor="sec-fragmentation-sequence-numbers-and-all-pad-payloads
" numbered="true" toc="default">
<section title="Fragmentation, Sequence Numbers and All-Pad Payloads" anchor="se <name>Fragmentation, Sequence Numbers, and All-Pad Payloads</name>
c-fragmentation-sequence-numbers-and-all-pad-payloads"> <t>In order for a receiver to reassemble fragmented inner packets, the
<t>In order for a receiver to reassemble fragmented inner packets, the sender <bcp14>MUST</bcp14> send the inner packet fragments back to back in the
sender MUST send the inner packet fragments back-to-back in the
logical outer packet stream (i.e., using consecutive ESP sequence logical outer packet stream (i.e., using consecutive ESP sequence
numbers). However, the sender is allowed to insert "all-pad" payloads numbers). However, the sender is allowed to insert "all-pad" payloads
(i.e., payloads with a <spanx style='verb'>BlockOffset</spanx> of zero and a sin (i.e., payloads with a <tt>BlockOffset</tt> of zero and a single pad
gle pad data block ) in between the packets carrying the inner packet
<spanx style='verb'>DataBlock</spanx>) in between the packets carrying the inner
packet
fragment payloads. This interleaving of all-pad payloads allows the fragment payloads. This interleaving of all-pad payloads allows the
sender to always send a tunnel packet, regardless of the sender to always send a tunnel packet, regardless of the
encapsulation computational requirements.</t> encapsulation computational requirements.</t>
<t>When a receiver is reassembling an inner packet, and it receives an
<t>When a receiver is reassembling an inner packet, and it receives an
"all-pad" payload, it increments the expected sequence number that "all-pad" payload, it increments the expected sequence number that
the next inner packet fragment is expected to arrive in.</t> the next inner packet fragment is expected to arrive in.</t>
<t>Given the above, the receiver will need to handle out-of-order
<t>Given the above, the receiver will need to handle out-of-order
arrival of outer ESP packets prior to reassembly processing. ESP arrival of outer ESP packets prior to reassembly processing. ESP
already provides for optionally detecting replay attacks. Detecting already provides for optionally detecting replay attacks. Detecting
replay attacks normally utilizes a window method. A similar sequence replay attacks normally utilizes a window method. A similar sequence-number-base
number based sliding window can be used to correct re-ordering of the d
outer packet stream. Receiving a larger (newer) sequence number sliding window can be used to correct reordering of the
packet advances the window, and received older ESP packets whose outer packet stream.
sequence numbers the window has passed by are dropped. A good choice Receiving a larger (newer) sequence number
packet advances the window, and if any older ESP packets whose
sequence numbers the window has passed by are received, then the packets are dro
pped. A good choice
for the size of this window depends on the amount of misordering the for the size of this window depends on the amount of misordering the
user is experiencing; however, a value of 3 has been suggested as a user is experiencing; however, a value of 3 has been suggested as a
default when no more informed choice exists.</t> default when no more informed choice exists.</t>
<t>As the amount of misordering that may be present is hard to predict
<t>As the amount of misordering that may be present is hard to predict, ,
the window size SHOULD be configurable by the user. Implementations the window size <bcp14>SHOULD</bcp14> be configurable by the user. Implementatio
MAY also dynamically adjust the reordering window based on actual ns
<bcp14>MAY</bcp14> also dynamically adjust the reordering window based on actual
misordering seen in arriving packets.</t> misordering seen in arriving packets.</t>
<t>Please note, when IP-TFS sends a continuous stream of packets, ther
<t>Please note, when IP-TFS sends a continuous stream of packets, there e
is no requirement for an explicit lost packet timer; however, using a is no requirement for an explicit lost packet timer; however, using a
lost packet timer is RECOMMENDED. If an implementation does not use a lost packet timer is <bcp14>RECOMMENDED</bcp14>. If an implementation does not u se a
lost packet timer and only considers an outer packet lost when the lost packet timer and only considers an outer packet lost when the
reorder window moves by it, the inner traffic can be delayed by up to reorder window moves by it, the inner traffic can be delayed by up to
the reorder window size times the per packet send rate. This the reorder window size times the per-packet send rate. This
delay could be significant for slower send rates or when larger delay could be significant for slower send rates or when larger
reorder window sizes are in use. As the lost packet timer affects reorder window sizes are in use. As the lost packet timer affects
delay of inner packet delivery, an implementation or user could choose to set it the delay of inner packet delivery, an implementation or user could choose to se t it
proportionate to the tunnel rate.</t> proportionate to the tunnel rate.</t>
<t>While ESP guarantees an increasing sequence number with subsequentl
<t>While ESP guarantees an increasing sequence number with subsequently y
sent packets, it does not actually require the sequence numbers to be sent packets, it does not actually require the sequence numbers to be
generated consecutively (e.g., sending only even numbered sequence generated consecutively (e.g., sending only even-numbered sequence
numbers would be allowed as long as they are always increasing). Gaps numbers would be allowed, as long as they are always increasing). Gaps
in the sequence numbers will not work for this document so the in the sequence numbers will not work for this document, so the
sequence number stream MUST increase monotonically by 1 for each sequence number stream <bcp14>MUST</bcp14> increase monotonically by 1 for each
subsequent packet.</t> subsequent packet.</t>
<t>When using the AGGFRAG_PAYLOAD in conjunction with replay detection
<t>When using the AGGFRAG_PAYLOAD in conjunction with replay detection, ,
the window size for both MAY be reduced to the smaller of the two the window size for both <bcp14>MAY</bcp14> be reduced to the smaller of the two
window sizes. This is because packets outside of the smaller window window sizes. This is because packets outside of the smaller window
but inside the larger would still be dropped by the mechanism with but inside the larger window would still be dropped by the mechanism with
the smaller window size. However, there is also no requirement to the smaller window size. However, there is also no requirement to
make these values the same. Indeed, in some cases, such as slow make these values the same. Indeed, in some cases, such as slow
tunnels where a very small or zero reorder window size is tunnels where a very small or zero reorder window size is
appropriate, the user may still want a large replay detection window appropriate, the user may still want a large replay detection window
to log replayed packets. Additionally, large replay windows can be to log replayed packets. Additionally, large replay windows can be
implemented with very little overhead compared to large reorder implemented with very little overhead, compared to large reorder
windows.</t> windows.</t>
<t>Finally, as sequence numbers are reset when switching Security Asso
<t>Finally, as sequence numbers are reset when switching SAs (e.g., when ciations (SAs) (e.g., when
re-keying a child SA), senders MUST NOT send initial fragments of an rekeying a Child SA), senders <bcp14>MUST NOT</bcp14> send initial fragments of
inner packet using one SA and subsequent fragments in a different SA.</t> an
inner packet using one SA and subsequent fragments in a different SA.</
<t>A note on <spanx style='verb'>BlockOffset</spanx> values, senders MUST encode t>
the <spanx style='verb'>BlockOffset</spanx> <aside>
consistent with the immediately preceding non-all-pad payload packet. <t>A note on <tt>BlockOffset</tt> values: Senders <bcp14>MUST</bcp14>
encode the <tt>BlockOffset</tt>
consistently with the immediately preceding non-all-pad payload packet.
Specifically, if the immediately preceding non-all-pad payload packet Specifically, if the immediately preceding non-all-pad payload packet
ended with a Pad Data Block, this <spanx style='verb'>BlockOffset</spanx> MUST b ended with a Pad Data Block, this <tt>BlockOffset</tt> <bcp14>MUST</bcp14> be ze
e zero, as Pad ro, as Pad
Data Blocks are never fragmented. The <spanx style='verb'>BlockOffset</spanx> MU Data Blocks are never fragmented. The <tt>BlockOffset</tt> <bcp14>MUST</bcp14> b
ST be e
consistent with the remaining size implied by the native length consistent with the remaining size implied by the length
encoding of the fragmented inner packet.</t> field from the fragmented inner packet.</t>
</aside>
<section title="Optional Extra Padding"> <section numbered="true" toc="default">
<t>When the tunnel bandwidth is not being fully utilized, a <name>Optional Extra Padding</name>
sender MAY pad-out the current encapsulating packet in order <t>When the tunnel bandwidth is not being fully utilized, a
to deliver an inner packet un-fragmented in the following outer sender <bcp14>MAY</bcp14> pad out the current encapsulating packet in order
to deliver an inner packet unfragmented in the following outer
packet. The benefit would be to avoid inner packet fragmentation in packet. The benefit would be to avoid inner packet fragmentation in
the presence of a bursty offered load (non-bursty traffic will the presence of a bursty offered load (non-bursty traffic will
naturally not fragment). Senders MAY also choose to allow naturally not fragment). Senders <bcp14>MAY</bcp14> also choose to allow
for a minimum fragment size to be configured (e.g., as a percentage for a minimum fragment size to be configured (e.g., as a percentage
of the AGGFRAG_PAYLOAD payload size) to avoid fragmentation at the of the AGGFRAG_PAYLOAD payload size) to avoid fragmentation at the
cost of tunnel bandwidth. The cost with these methods is complexity cost of tunnel bandwidth. The costs with these methods are complexity
and added delay of inner traffic. The main advantage to avoiding and an added delay of inner traffic. The main advantage to avoiding
fragmentation is to minimize inner packet loss in the presence of fragmentation is to minimize inner packet loss in the presence of
outer packet loss. When this is worthwhile (e.g., how much loss and outer packet loss. When this is worthwhile (e.g., how much loss and
what type of loss is required, given different inner traffic shapes what type of loss is required, given different inner traffic shapes
and utilization, for this to make sense), and what values to use for and utilization, for this to make sense) and what values to use for
the allowable/added delay may be worth researching but is outside the allowable/added delay may be worth researching but is outside
the scope of this document.</t> the scope of this document.</t>
<t>While use of padding to avoid fragmentation does not impact
<t>While use of padding to avoid fragmentation does not impact interoperability, if padding is used inappropriately, it can reduce the effectiv
interoperability, used inappropriately it can reduce the effective e
throughput of a tunnel. Senders implementing either of the throughput of a tunnel. Senders implementing either of the
above approaches will need to take care to not reduce the effective above approaches will need to take care to not reduce the effective
capacity, and overall utility, of the tunnel through the overuse of capacity, and overall utility, of the tunnel through the overuse of
padding.</t> padding.</t>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>Empty Payload</name>
<t>To support reporting of congestion control information (described
<section title="Empty Payload">
<t>To support reporting of congestion control information (described
later) using a non-AGGFRAG_PAYLOAD-enabled SA, it is allowed to send later) using a non-AGGFRAG_PAYLOAD-enabled SA, it is allowed to send
an AGGFRAG_PAYLOAD payload with no data blocks (i.e., the ESP payload an AGGFRAG_PAYLOAD payload with no data blocks (i.e., the ESP payload
length is equal to the AGGFRAG_PAYLOAD header length). This special length is equal to the AGGFRAG_PAYLOAD header length). This special
payload is called an empty payload.</t> payload is called an empty payload.</t>
<t>Currently, this situation is only applicable in use cases without I
<t>Currently this situation is only applicable in non-IKEv2 use cases.</t> nternet Key Exchange Protocol Version 2 (IKEv2).</t>
</section>
</section> <section numbered="true" toc="default">
<name>IP Header Value Mapping</name>
<section title="IP Header Value Mapping"> <t><xref target="RFC4301" format="default"/> provides some direction o
<t><xref target="RFC4301"/> provides some direction on when and how to map vario n when and how to map various values
us values
from an inner IP header to the outer encapsulating header, namely the from an inner IP header to the outer encapsulating header, namely the
Don't-Fragment (DF) bit (<xref target="RFC0791"/> and <xref target="RFC8200"/>), Don't Fragment (DF) bit <xref target="RFC0791" format="default"/>, the Different
the Differentiated iated
Services (DS) field <xref target="RFC2474"/> and the Explicit Congestion Notific Services (DS) field <xref target="RFC2474" format="default"/>, and the Explicit
ation Congestion Notification
(ECN) field <xref target="RFC3168"/>. Unlike <xref target="RFC4301"/>, AGGFRAG m (ECN) field <xref target="RFC3168" format="default"/>. Unlike in <xref target="R
ode may and often will be FC4301" format="default"/>, the AGGFRAG mode may, and often will, be
encapsulating more than one IP packet per ESP packet. To deal with encapsulating more than one IP packet per ESP packet. To deal with
this, these mappings are restricted further.</t> this, these mappings are restricted further.</t>
<section numbered="true" toc="default">
<section title="DF bit"> <name>DF Bit</name>
<t>AGGFRAG mode never maps the inner DF bit as it is unrelated to the <t>The AGGFRAG mode never maps the inner DF bit, as it is unrelated
AGGFRAG tunnel functionality; AGGFRAG mode never needs to IP fragment to the
the inner packets and the inner packets will not affect the AGGFRAG tunnel functionality; the AGGFRAG mode never needs to IP fragment
the inner packets, and the inner packets will not affect the
fragmentation of the outer encapsulation packets.</t> fragmentation of the outer encapsulation packets.</t>
</section>
</section> <section numbered="true" toc="default">
<name>ECN Value</name>
<section title="ECN value"> <t>The ECN value need not be mapped, as any congestion related to th
<t>The ECN value need not be mapped as any congestion related to the e
constant-send-rate IP-TFS tunnel is unrelated (by design) to the constant-send-rate IP-TFS tunnel is unrelated (by design) to the
inner traffic flow. The sender MAY still set the ECN value of inner inner traffic flow. The sender <bcp14>MAY</bcp14> still set the ECN value of inn
packets based on the normal ECN specification <xref target="RFC3168"/>, <xref ta er
rget="RFC4301"/> and packets based on the normal ECN specification <xref target="RFC3168" format="def
<xref target="RFC6040"/>.</t> ault"/> <xref target="RFC4301" format="default"/>
<xref target="RFC6040" format="default"/>.</t>
</section> </section>
<section numbered="true" toc="default">
<section title="DS field"> <name>DS Field</name>
<t>By default, the DS field SHOULD NOT be copied, although a sender MAY <t>By default, the DS field <bcp14>SHOULD NOT</bcp14> be copied, alt
hough a sender <bcp14>MAY</bcp14>
choose to allow for configuration to override this behavior. A sender choose to allow for configuration to override this behavior. A sender
SHOULD also allow the DS value to be set by configuration.</t> <bcp14>SHOULD</bcp14> also allow the DS value to be set by configuration.</t>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>IPv4 Time To Live (TTL), IPv6 Hop Limit, and ICMP Messages</name
>
<section title="IPv4 Time-To-Live (TTL), IPv6 Hop Limit, and ICMP Messages"> <t>How to modify the inner packet IPv4 TTL <xref target="RFC0791" form
<t><xref target="RFC4301"/> specifies how to modify the inner packet IPv4 TTL <x at="default"/> or
ref target="RFC0791"/> or IPv6 Hop Limit <xref target="RFC8200" format="default"/> is specified in <xref t
IPv6 Hop Limit <xref target="RFC8200"/>.</t> arget="RFC4301" format="default"/>.</t>
<t><xref target="RFC4301" format="default"/> specifies how to apply po
<t><xref target="RFC4301"/> also specifies how to apply policy to authenticated licy to authenticated and
and
unauthenticated ICMP error packets (e.g., Destination Unreachable) unauthenticated ICMP error packets (e.g., Destination Unreachable)
arriving at or being forwarded through the endpoint. In particular, arriving at or being forwarded through the endpoint, in particular,
whether to process, ignore or forward said packets. With one whether to process, ignore, or forward said packets. With the one
exception this document does not change the handling of these exception that this document does not change the handling of these
packets, they should be handled as specified in <xref target="RFC4301"/>.</t> packets, they should be handled as specified in <xref target="RFC4301" format="d
efault"/>.</t>
<t>The one way in which an AGGFRAG tunnel differs in ICMP error packet <t>The one way in which an AGGFRAG tunnel differs in ICMP error packet
mechanics is with PMTU. When fragmentation is enabled on the AGGFRAG mechanics is with PMTU. When fragmentation is enabled on the AGGFRAG
tunnel, then no ICMP "too-big" errors need to be generated for tunnel, then no ICMP "Too Big" errors need to be generated for
arriving ingress traffic as the arriving inner packets will be arriving ingress traffic, as the arriving inner packets will be
naturally fragmented by the AGGFRAG encapsultation.</t> naturally fragmented by the AGGFRAG encapsulation.</t>
<t>Otherwise, when fragmentation has been disabled on the AGGFRAG tunn
<t>Otherwise, when fragmentation has been disabled on the AGGFRAG tunnel, el,
then the treatment of arriving inner traffic exactly maps to that of then the treatment of arriving inner traffic exactly maps to that of
a non-AGGFRAG ESP tunnel. Explicitly, IPv4 with DF set and IPv6 a non-AGGFRAG ESP tunnel. Explicitly, IPv4 with DF set and IPv6
packets which cannot fit in it's own outer packet payload will packets that cannot fit in its own outer packet payload will
generate the appropriate ICMP "too-big" error as directed by <xref target="RFC43 generate the appropriate ICMP "Too Big" error, as described in <xref target="RFC
01"/>, 4301" format="default"/>,
and IPv4 packets without DF set will be IP fragmented as directed by and IPv4 packets without DF set will be IP fragmented, as described in
<xref target="RFC4301"/>.</t> <xref target="RFC4301" format="default"/>.</t>
<t>Packets egressing the tunnel continue to be handled as specified in
<t>Packets egressing the tunnel continue to be handled as specified in <xref target="RFC4301" format="default"/>.</t>
<xref target="RFC4301"/>.</t> <t>All other aspects of PMTU and the handling of ICMP "Too Big" messag
es
<t>All other aspects of PMTU and the handling of ICMP "Too Big" messages
(i.e., with regards to the outer AGGFRAG/ESP tunnel packet size) (i.e., with regards to the outer AGGFRAG/ESP tunnel packet size)
also remain unchanged from <xref target="RFC4301"/>.</t> also remain unchanged from <xref target="RFC4301" format="default"/>.</t>
</section>
</section> <section numbered="true" toc="default">
<name>Effective MTU of the Tunnel</name>
<section title="Effective MTU of the Tunnel"> <t>Unlike in <xref target="RFC4301" format="default"/>, there is norma
<t>Unlike <xref target="RFC4301"/>, there is normally no effective MTU (EMTU) on lly no effective MTU (EMTU) on an
an AGGFRAG tunnel, as all IP packet sizes are properly transmitted without
AGGFRAG tunnel as all IP packet sizes are properly transmitted without
requiring IP fragmentation prior to tunnel ingress. That said, a requiring IP fragmentation prior to tunnel ingress. That said, a
sender MAY allow for explicitly configuring an MTU for the sender <bcp14>MAY</bcp14> allow for explicitly configuring an MTU for the
tunnel.</t> tunnel.</t>
<t>If fragmentation has been disabled on the AGGFRAG tunnel, then the
<t>If fragmentation has been disabled on the AGGFRAG tunnel, then the
tunnel's EMTU and behaviors are the same as normal IPsec tunnels tunnel's EMTU and behaviors are the same as normal IPsec tunnels
<xref target="RFC4301"/>.</t> <xref target="RFC4301" format="default"/>.</t>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>Exclusive SA Use</name>
<t>This document does not specify mixed use of an
<section title="Exclusive SA Use"> AGGFRAG_PAYLOAD-enabled SA. A sender <bcp14>MUST</bcp14> only send AGGFRAG_PAYLO
<t>This document does not specify mixed use of an AD
AGGFRAG_PAYLOAD-enabled SA. A sender MUST only send AGGFRAG_PAYLOAD
payloads over an SA configured for AGGFRAG mode.</t> payloads over an SA configured for AGGFRAG mode.</t>
</section>
</section> <section numbered="true" toc="default">
<name>Modes of Operation</name>
<section title="Modes of Operation"> <t>Just as with normal IPsec/ESP SAs, AGGFRAG SAs are
<t>Just as with normal IPsec/ESP SAs, AGGFRAG SAs are
unidirectional. Bidirectional IP-TFS functionality is achieved by unidirectional. Bidirectional IP-TFS functionality is achieved by
setting up 2 AGGFRAG SAs, one in either direction.</t> setting up 2 AGGFRAG SAs, one in either direction.</t>
<t>An AGGFRAG tunnel used for IP-TFS can operate in 2 modes, a
<t>An AGGFRAG tunnel used for IP-TFS can operate in 2 modes, a
non-congestion-controlled mode and congestion-controlled mode.</t> non-congestion-controlled mode and congestion-controlled mode.</t>
<section numbered="true" toc="default">
<section title="Non-Congestion-Controlled Mode"> <name>Non-Congestion-Controlled Mode</name>
<t>In the non-congestion-controlled mode, IP-TFS sends fixed-sized <t>In the non-congestion-controlled mode, IP-TFS sends fixed-size
packets over an AGGFRAG tunnel at a constant rate. The packet send packets over an AGGFRAG tunnel at a constant rate. The packet send
rate is constant and is not automatically adjusted regardless of any rate is constant and is not automatically adjusted, regardless of any
network congestion (e.g., packet loss).</t> network congestion (e.g., packet loss).</t>
<t>For similar reasons as given in <xref target="RFC7510" format="defa
<t>For similar reasons as given in <xref target="RFC7510"/> the non-congestion-c ult"/>, the non-congestion-controlled
ontrolled mode <bcp14>MUST</bcp14> only be used where the user has full administrative con
mode MUST only be used where the user has full administrative control trol
over any path the tunnel will take, and MUST NOT be used if this is over any path the tunnel will take and <bcp14>MUST NOT</bcp14> be used if this i
s
not the case. This is required so the user can guarantee the not the case. This is required so the user can guarantee the
bandwidth and also be sure as to not be negatively affecting network bandwidth and also be sure as to not be negatively affecting network
congestion <xref target="RFC2914"/>. In this case, packet loss should be reporte d to congestion <xref target="RFC2914" format="default"/>. In this case, packet loss should be reported to
the administrator (e.g., via syslog, YANG notification, SNMP traps, the administrator (e.g., via syslog, YANG notification, SNMP traps,
etc.) so that any failures due to a lack of bandwidth can be etc.) so that any failures due to a lack of bandwidth can be
corrected. The use of circuit breakers is also RECOMMENDED (<xref target="sec-ci corrected. The use of circuit breakers is also <bcp14>RECOMMENDED</bcp14> (<xref
rcuit-breakers"></xref>).</t> target="sec-circuit-breakers" format="default"/>).</t>
<t>Users that choose the non-congestion-controlled mode need to
<t>Users that choose the non-congestion-controlled mode need to understand that this mode will send packets at a constant rate,
understand that this mode will send packets at a constant rate utilizing a constant, fixed bandwidth, and will not adjust based on
utilizing a constant fixed bandwidth and will not adjust based on
congestion. Thus, if they do not guarantee the bandwidth required by congestion. Thus, if they do not guarantee the bandwidth required by
the tunnel, the tunnel's operation, as well as the rest of their the tunnel, the tunnel's operation, as well as the rest of their
network, may be negatively impacted.</t> network, may be negatively impacted.</t>
<t>One expected use case for the non-congestion-controlled mode is to
<t>One expected use case for non-congestion-controlled mode is to
guarantee the full tunnel bandwidth is available and preferred over guarantee the full tunnel bandwidth is available and preferred over
other non-tunnel traffic. In fact, a typical site-to-site use case other non-tunnel traffic. In fact, a typical site-to-site use case
might have all of the user traffic utilizing the IP-TFS tunnel.</t> might have all of the user traffic utilizing the IP-TFS tunnel.</t>
<t>The non-congestion-controlled mode is also appropriate if ESP over
<t>Non-congestion-controlled mode is also appropriate if ESP over TCP is TCP is
in use <xref target="RFC8229"/>. However, the use of TCP is considered a highly in use <xref target="RFC9329" format="default"/>. However, the use of TCP is con
non-preferred, and a fall-back only solution for IPsec. This is also sidered a fallback-only solution for IPsec; it is highly not preferred. This is
also
one of the reasons that TCP was not chosen as the encapsulation for one of the reasons that TCP was not chosen as the encapsulation for
IP-TFS instead of AGGFRAG.</t> IP-TFS instead of AGGFRAG.</t>
</section>
</section> <section anchor="sec-congestion-controlled-mode" numbered="true" toc="de
fault">
<section title="Congestion-Controlled Mode" anchor="sec-congestion-controlled-mo <name>Congestion-Controlled Mode</name>
de"> <t>With the congestion-controlled mode, IP-TFS adapts to network
<t>With the congestion-controlled mode, IP-TFS adapts to network
congestion by lowering the packet send rate to accommodate the congestion by lowering the packet send rate to accommodate the
congestion, as well as raising the rate when congestion subsides. congestion, as well as raising the rate when congestion subsides.
Since overhead is per packet, by allowing for maximal fixed-size Since overhead is per packet, by allowing for maximal fixed-size
packets and varying the send rate, transport overhead is minimized.</t> packets and varying the send rate, transport overhead is minimized.</t>
<t>The output of the congestion control algorithm will adjust the rate
<t>The output of the congestion control algorithm will adjust the rate
at which the ingress sends packets. While this document does not at which the ingress sends packets. While this document does not
require a specific congestion control algorithm, best current require a specific congestion control algorithm, best current
practice RECOMMENDS that the algorithm conform to <xref target="RFC5348"/>. Cong practice RECOMMENDS that the algorithm conform to <xref target="RFC5348" format=
estion "default"/>. Congestion
control principles are documented in <xref target="RFC2914"/> as well. <xref tar control principles are documented in <xref target="RFC2914" format="default"/> a
get="RFC4342"/> s well. There is an example in <xref target="RFC4342" format="default"/>
provides an example of the <xref target="RFC5348"/> algorithm which matches the of the algorithm in <xref target="RFC5348" format="default"/>, which matches the
requirements of IP-TFS (i.e., designed for fixed-size packets and send requirements of IP-TFS (i.e., designed for fixed-size packets and send
rate varied based on congestion).</t> rate varied based on congestion).</t>
<t>The required inputs for the TCP-friendly rate control algorithm
<t>The required inputs for the TCP friendly rate control algorithm described in <xref target="RFC5348" format="default"/> are the receiver's loss e
described in <xref target="RFC5348"/> are the receiver's loss event rate and the vent rate and the
sender's estimated round-trip time (RTT). These values are provided by sender's estimated round-trip time (RTT). These values are provided by
IP-TFS using the congestion information header fields described in IP-TFS using the congestion information header fields described in
<xref target="sec-congestion-information"></xref>. In particular, these values a <xref target="sec-congestion-information" format="default"/>. In particular, the
re sufficient to se values are sufficient to
implement the algorithm described in <xref target="RFC5348"/>.</t> implement the algorithm described in <xref target="RFC5348" format="default"/>.<
/t>
<t>At a minimum, the congestion information MUST be sent, from the <t>At a minimum, the congestion information <bcp14>MUST</bcp14> be sen
t, from the
receiver and from the sender, at least once per RTT. Prior to receiver and from the sender, at least once per RTT. Prior to
establishing an RTT the information SHOULD be sent constantly from establishing an RTT, the information <bcp14>SHOULD</bcp14> be sent constantly fr om
the sender and the receiver so that an RTT estimate can be the sender and the receiver so that an RTT estimate can be
established. Not receiving this information over multiple established. Not receiving this information over multiple
consecutive RTT intervals should be considered a congestion event consecutive RTT intervals should be considered a congestion event
that causes the sender to adjust its sending rate lower. For that causes the sender to adjust its sending rate lower. For
example, <xref target="RFC4342"/> calls this the "no feedback timeout" and it is example, this is called the "no feedback timeout" in <xref target="RFC4342" form
equal at="default"/>, and it is equal
to 4 RTT intervals. When a "no feedback timeout" has occurred <xref target="RFC4 to 4 RTT intervals. When a "no feedback timeout" has occurred, the sending rate
342"/> is halved, as per <xref target="RFC4342" format="default"/>.</t>
halves the sending rate.</t> <t>An implementation <bcp14>MAY</bcp14> choose to always include the c
ongestion
<t>An implementation MAY choose to always include the congestion information in its AGGFRAG payload header if it is sending it on an IP-TFS-enabl
information in its AGGFRAG payload header if sending on an IP-TFS-enabled ed
SA. Since IP-TFS normally will operate with a large packet SA. Since IP-TFS normally will operate with a large packet
size, the congestion information should represent a small portion of size, the congestion information should represent a small portion of
the available tunnel bandwidth. An implementation choosing to always the available tunnel bandwidth. An implementation choosing to always
send the data MAY also choose to only update the <spanx style='verb'>LossEventRa send the data <bcp14>MAY</bcp14> also choose to only update the <tt>LossEventRat
te</spanx> e</tt>
and <spanx style='verb'>RTT</spanx> header field values it sends every <spanx st and <tt>RTT</tt> header field values it sends every <tt>RTT</tt> through.</t>
yle='verb'>RTT</spanx> though.</t> <t>When choosing a congestion control algorithm (or a selection of
<t>When choosing a congestion control algorithm (or a selection of
algorithms), note that IP-TFS is not providing for reliable delivery algorithms), note that IP-TFS is not providing for reliable delivery
of IP traffic, and so per packet ACKs are not required and are not of IP traffic, and so per-packet acknowledgements (ACKs) are not required and ar e not
provided.</t> provided.</t>
<t>It is worth noting that the variable send rate of a
<t>It is worth noting that the variable send-rate of a congestion-controlled AGGFRAG tunnel is not private; however, this
congestion-controlled AGGFRAG tunnel, is not private; however, this send rate is being driven by network congestion, and as long as the
send-rate is being driven by network congestion, and as long as the
encapsulated (inner) traffic flow shape and timing are not directly encapsulated (inner) traffic flow shape and timing are not directly
affecting the (outer) network congestion, the variations in the affecting the (outer) network congestion, the variations in the
tunnel rate will not weaken the provided inner traffic flow tunnel rate will not weaken the provided inner traffic flow
confidentiality.</t> confidentiality.</t>
<section anchor="sec-circuit-breakers" numbered="true" toc="default">
<section title="Circuit Breakers" anchor="sec-circuit-breakers"> <name>Circuit Breakers</name>
<t>In additional to congestion control, implementations that support <t>In addition to congestion control, implementations that support t
non-congestion control mode SHOULD implement circuit breakers <xref target="RFC8 he
084"/> non-congestion-control mode <bcp14>SHOULD</bcp14> implement circuit breakers <xr
ef target="RFC8084" format="default"/>
as a recovery method of last resort. When circuit breakers are as a recovery method of last resort. When circuit breakers are
enabled an implementation SHOULD also enable congestion control enabled, an implementation <bcp14>SHOULD</bcp14> also enable congestion control
reports so that circuit breakers have information to act on.</t> reports so that circuit breakers have information to act on.</t>
<t>The pseudowire congestion considerations <xref target="RFC7893" f
<t>The pseudowire congestion considerations <xref target="RFC7893"/> are equally ormat="default"/> are equally
applicable to the mechanisms defined in this document, notably the applicable to the mechanisms defined in this document, notably the
text on inellastic traffic.</t> text on inelastic traffic.</t>
<t>One example of a simple, slow-trip circuit breaker that an
<t>One example of a simple slow-trip circuit breaker (CB) an implementation may provide would utilize 2 values: the amount of
implementation may provide would utilize 2 values, the amount of persistent loss rate required to trip the circuit breaker and the required lengt
persistent loss rate required to trip the CB, and the required length h
of time this persistent loss rate must be seen to trip the CB. These of time this persistent loss rate must be seen to trip the circuit breaker. Thes
2 value are required configuration from the user. When the CB is e
tripped the tunnel traffic is disabled, and an appropriate log 2 value are required configurations from the user. When the circuit breaker is
message or other management type alarm is triggered indicating tripped, the tunnel traffic is disabled and an appropriate log
operate intervention is required.</t> message or other management type alarm is triggered, indicating
operation intervention is required.</t>
</section> </section>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>Summary of Receiver Processing</name>
<t>An AGGFRAG-enabled SA receiver has a few tasks to perform.</t>
<section title="Summary of Receiver Processing"> <t>The receiver <bcp14>MAY</bcp14> process incoming AGGFRAG_PAYLOAD payl
<t>An AGGFRAG-enabled SA receiver has a few tasks to perform.</t> oads as soon as
they arrive, as much as it can, i.e., if the incoming AGGFRAG_PAYLOAD
<t>The receiver MAY process incoming AGGFRAG_PAYLOAD payloads as soon as
they arrive as much as it can. I.e., if the incoming AGGFRAG_PAYLOAD
packet contains complete inner packet(s), the receiver should extract packet contains complete inner packet(s), the receiver should extract
and transmit them immediately. For partial packets, the receiver needs and transmit them immediately. For partial packets, the receiver needs
to keep the partial packets in the memory until they fall out to keep the partial packets in the memory until they fall out
from the reordering window, or until the missing parts of the packets from the reordering window or until the missing parts of the packets
are received, in which case it will reassemble and transmit them. If are received, in which case, it will reassemble and transmit them. If
the AGGFRAG_PAYLOAD payload contains multiple packets they SHOULD be sent the AGGFRAG_PAYLOAD payload contains multiple packets, they <bcp14>SHOULD</bcp14
> be sent
out in the order they are in the AGGFRAG_PAYLOAD (i.e., keep the out in the order they are in the AGGFRAG_PAYLOAD (i.e., keep the
original order they were received on the other end). The cost of original order they were received on the other end). The cost of
using this method is that an amplification of out-of-order delivery using this method is that an amplification of out-of-order delivery
of inner packets can occur due to inner packet aggregation.</t> of inner packets can occur due to inner packet aggregation.</t>
<t>Instead of the method described in the previous paragraph, the
<t>Instead of the method described in the previous paragraph, the receiver <bcp14>MAY</bcp14> reorder out-of-order AGGFRAG_PAYLOAD payloads receiv
receiver MAY reorder out-of-order AGGFRAG_PAYLOAD payloads received ed
into in-sequence-order AGGFRAG_PAYLOAD payloads (<xref target="sec-fragmentation into in-sequence-order AGGFRAG_PAYLOAD payloads (<xref target="sec-fragmentation
-sequence-numbers-and-all-pad-payloads"></xref>), and only after it has an -sequence-numbers-and-all-pad-payloads" format="default"/>), and only after it h
in-order AGGFRAG_PAYLOAD payload stream would the receiver transmits as an
in-order AGGFRAG_PAYLOAD payload stream would the receiver transmit
the inner packets. Using this method will ensure the inner packets the inner packets. Using this method will ensure the inner packets
are sent in order. The cost of this method is that a lost packet will are sent in order. The cost of this method is that a lost packet will
cause a delay of up to the lost packet timer interval (or the full cause a delay of up to the lost packet timer interval (or the full
reorder window if no lost packet timer is used). Additionally, there reorder window if no lost packet timer is used). Additionally, there
can be extra burstiness in the output stream. This burstiness can can be extra burstiness in the output stream. This burstiness can
happen when a lost packet is dropped from the re-order window, happen when a lost packet is dropped from the reorder window,
and the remaining outer packets in the re-order window are immediately and the remaining outer packets in the reorder window are immediately
processed and sent out back to back.</t> processed and sent out back to back.</t>
<t>Additionally, if congestion control is enabled, the receiver sends
<t>Additionally, if congestion control is enabled, the receiver sends congestion control data (<xref target="sec-congestion-control-aggfrag-payload-pa
congestion control data (<xref target="sec-congestion-control-aggfrag-payload-pa yload-format" format="default"/>) back to the sender, as described in Sections <
yload-format"></xref>) back to the sender as described in <xref target="sec-cong xref target="sec-congestion-controlled-mode" format="counter"/>
estion-controlled-mode"></xref> and <xref target="sec-congestion-information" format="counter"/>.</t>
and <xref target="sec-congestion-information"></xref>.</t> <t>Finally, a note on receiving incorrect <tt>BlockOffset</tt> values: T
o account
<t>Finally, a note on receiving incorrect <spanx style='verb'>BlockOffset</spanx for misbehaving senders, a receiver <bcp14>SHOULD</bcp14> gracefully handle the
> values. To account case
for misbehaving senders, a receiver SHOULD gracefully handle the case where the <tt>BlockOffset</tt> of consecutive packets, and/or the inner
where the <spanx style='verb'>BlockOffset</spanx> of consecutive packets, and/or packet they share, do not agree. It <bcp14>MAY</bcp14> drop the inner packet or
the inner one or both of the outer packets.</t>
packet they share, do not agree. It MAY drop the inner packet, or one </section>
or both of the outer packets.</t> </section>
<section anchor="sec-congestion-information" numbered="true" toc="default">
</section> <name>Congestion Information</name>
<t>In order to support the congestion-controlled mode, the sender needs to
</section> know the loss event rate and to approximate the RTT <xref target="RFC5348" forma
t="default"/>. In order
<section title="Congestion Information" anchor="sec-congestion-information">
<t>In order to support the congestion-controlled mode, the sender needs to
know the loss event rate and to approximate the RTT <xref target="RFC5348"/>. In
order
to obtain these values, the receiver sends congestion control to obtain these values, the receiver sends congestion control
information on its SA back to the sender. Thus, to support information on its SA back to the sender. Thus, to support
congestion control the receiver MUST have a paired SA back to the congestion control, the receiver <bcp14>MUST</bcp14> have a paired SA back to th e
sender (this is always the case when the tunnel was created using sender (this is always the case when the tunnel was created using
IKEv2). If the SA back to the sender is a non-AGGFRAG_PAYLOAD enabled IKEv2). If the SA back to the sender is a non-AGGFRAG_PAYLOAD-enabled
SA then an AGGFRAG_PAYLOAD empty payload (i.e., header only) is used SA, then an AGGFRAG_PAYLOAD empty payload (i.e., header only) is used
to convey the information.</t> to convey the information.</t>
<t>In order to calculate a loss event rate compatible with <xref target="R
<t>In order to calculate a loss event rate compatible with <xref target="RFC5348 FC5348" format="default"/>, the
"/>, the receiver needs to have an RTT estimate. Thus, the sender
receiver needs to have a round-trip time estimate. Thus the sender communicates this estimate in the <tt>RTT</tt> header field. On startup, this
communicates this estimate in the <spanx style='verb'>RTT</spanx> header field. value will be zero, as no RTT estimate is yet known.</t>
On startup this <t>In order for the sender to estimate its <tt>RTT</tt> value, the sender
value will be zero as no RTT estimate is yet known.</t> places a timestamp value in the <tt>TVal</tt> header field. On first receipt
of this <tt>TVal</tt>, the receiver records the new <tt>TVal</tt> value, along w
<t>In order for the sender to estimate its <spanx style='verb'>RTT</spanx> value ith
, the sender the time it arrived locally. Subsequent receipt of the same <tt>TVal</tt>
places a timestamp value in the <spanx style='verb'>TVal</spanx> header field. O <bcp14>MUST NOT</bcp14> update the recorded time.</t>
n first receipt <t>When the receiver sends its congestion control header, it places this l
of this <spanx style='verb'>TVal</spanx>, the receiver records the new <spanx st atest recorded
yle='verb'>TVal</spanx> value along with <tt>TVal</tt> in the <tt>TEcho</tt> header field, along with 2 delay values: <tt
the time it arrived locally. Subsequent receipt of the same <spanx style='verb'> >Echo
TVal</spanx> Delay</tt> and <tt>Transmit Delay</tt>. The <tt>Echo Delay</tt> value is the tim
MUST NOT update the recorded time.</t> e delta
from the recorded arrival time of <tt>TVal</tt> and the current clock in
<t>When the receiver sends its congestion control header it places this latest r microseconds. The second value, <tt>Transmit Delay</tt>, is the receiver's
ecorded
<spanx style='verb'>TVal</spanx> in the <spanx style='verb'>TEcho</spanx> header
field, along with 2 delay values, <spanx style='verb'>Echo
Delay</spanx> and <spanx style='verb'>Transmit Delay</spanx>. The <spanx style='
verb'>Echo Delay</spanx> value is the time delta
from the recorded arrival time of <spanx style='verb'>TVal</spanx> and the curre
nt clock in
microseconds. The second value, <spanx style='verb'>Transmit Delay</spanx>, is t
he receiver's
current transmission delay on the tunnel (i.e., the average time current transmission delay on the tunnel (i.e., the average time
between sending packets on its half of the AGGFRAG tunnel).</t> between sending packets on its half of the AGGFRAG tunnel).</t>
<t>When the sender receives back its <tt>TVal</tt> in the <tt>TEcho</tt> h
<t>When the sender receives back its <spanx style='verb'>TVal</spanx> in the <sp eader field,
anx style='verb'>TEcho</spanx> header field
it calculates 2 RTT estimates. The first is the actual delay found by it calculates 2 RTT estimates. The first is the actual delay found by
subtracting the <spanx style='verb'>TEcho</spanx> value from its current clock a subtracting the <tt>TEcho</tt> value from its current clock and then
nd then subtracting the <tt>Echo Delay</tt> as well. The second RTT estimate is found by
subtracting <spanx style='verb'>Echo Delay</spanx> as well. The second RTT estim adding the received <tt>Transmit Delay</tt> header value to the sender's own
ate is found by
adding the received <spanx style='verb'>Transmit Delay</spanx> header value to t
he sender's own
transmission delay (i.e., the average time between sending packets on transmission delay (i.e., the average time between sending packets on
its half of the AGGFRAG tunnel). The larger of these 2 RTT estimates its half of the AGGFRAG tunnel). The larger of these 2 RTT estimates
SHOULD be used as the <spanx style='verb'>RTT</spanx> value.</t> <bcp14>SHOULD</bcp14> be used as the <tt>RTT</tt> value.</t>
<t>The two RTT estimates are required to handle different combinations of
<t>The two RTT estimates are required to handle different combinations of
faster or slower tunnel packet paths with faster or slower fixed faster or slower tunnel packet paths with faster or slower fixed
tunnel rates. Choosing the larger of the two values guarantees that tunnel rates. Choosing the larger of the two values guarantees that
the <spanx style='verb'>RTT</spanx> is never considered faster than the aggregat e transmission the <tt>RTT</tt> is never considered faster than the aggregate transmission
delay based on the IP-TFS send rate (the second estimate), as well delay based on the IP-TFS send rate (the second estimate), as well
as never being considered faster than the actual RTT along the tunnel as never being considered faster than the actual RTT along the tunnel
packet path (the first estimate).</t> packet path (the first estimate).</t>
<t>The receiver also calculates, and communicates in the <tt>LossEventRate
<t>The receiver also calculates, and communicates in the <spanx style='verb'>Los </tt>
sEventRate</spanx>
header field, the loss event rate for use by the sender. This is header field, the loss event rate for use by the sender. This is
slightly different from <xref target="RFC4342"/> which periodically sends all th e loss slightly different from <xref target="RFC4342" format="default"/>, which periodi cally sends all the loss
interval data back to the sender so that it can do the calculation. interval data back to the sender so that it can do the calculation.
See <xref target="sec-a-send-and-loss-event-rate-calculation"></xref> for a sugg See <xref target="sec-a-send-and-loss-event-rate-calculation" format="default"/>
ested way to for a suggested way to
calculate the loss event rate value. Initially this value will be calculate the loss event rate value. Initially, this value will be
zero (indicating no loss) until enough data has been collected by the zero (indicating no loss) until enough data has been collected by the
receiver to update it.</t> receiver to update it.</t>
<section anchor="sec-ecn-support" numbered="true" toc="default">
<section title="ECN Support" anchor="sec-ecn-support"> <name>ECN Support</name>
<t>In addition to normal packet loss information, AGGFRAG mode supports use <t>In addition to normal packet loss information, the AGGFRAG mode suppo
of the ECN bits in the encapsulating IP header <xref target="RFC3168"/> for rts use
of the ECN bits in the encapsulating IP header <xref target="RFC3168" format="de
fault"/> for
identifying congestion. If ECN use is enabled and a packet arrives at identifying congestion. If ECN use is enabled and a packet arrives at
the egress (receiving) side with the Congestion Experienced (CE) value set, the egress (receiving) side with the Congestion Experienced (CE) value set,
then the receiver considers that packet as being dropped, although it then the receiver considers that packet as being dropped, although it
does not drop it. The receiver MUST set the E bit in any does not drop it. The receiver <bcp14>MUST</bcp14> set the E bit in any
AGGFRAG_PAYLOAD payload header containing a <spanx style='verb'>LossEventRate</s AGGFRAG_PAYLOAD payload header containing a <tt>LossEventRate</tt> value
panx> value
derived from a CE value being considered.</t> derived from a CE value being considered.</t>
<t>In <xref target="RFC6040" format="default"/>, which updates <xref tar
<t><xref target="RFC3168"/> and <xref target="RFC4301"/>, updated by <xref targe get="RFC3168" format="default"/> and <xref target="RFC4301" format="default"/>,
t="RFC6040"/> defines behaviors for marking behaviors for marking
the outer ECN field value based on the ECN field of the inner packet. the outer ECN field value based on the ECN field of the inner packet are defined
As AGGFRAG mode may have multiple inner packets present in a single .
As the AGGFRAG mode may have multiple inner packets present in a single
outer packet, and there is no obvious correct way to map these outer packet, and there is no obvious correct way to map these
multiple values to the single outer packet ECN field value, the multiple values to the single outer packet ECN field value, the
tunnel ingress endpoint SHOULD operate in the "compatibility" mode tunnel ingress endpoint <bcp14>SHOULD</bcp14> operate in the "compatibility" mod
rather than the "default" mode from RFC6040. In particular this means e,
rather than the "default" mode from <xref target="RFC6040" format="default"/>. I
n particular, this means
that the ingress (sending) endpoint of the tunnel always sets the that the ingress (sending) endpoint of the tunnel always sets the
newly constructed outer encapsulating packet header ECN field newly constructed outer encapsulating packet header ECN field
to Not-ECT <xref target="RFC6040"/>.</t> to Not-ECT <xref target="RFC6040" format="default"/>.</t>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>Configuration of AGGFRAG Tunnels for IP-TFS</name>
<t>IP-TFS is meant to be deployable with a minimal amount of
<section title="Configuration of AGGFRAG Tunnels for IP-TFS"> configuration. All IP-TFS-specific configuration should be
<t>IP-TFS is meant to be deployable with a minimal amount of
configuration. All IP-TFS specific configuration should be
specified at the unidirectional tunnel ingress (sending) side. It specified at the unidirectional tunnel ingress (sending) side. It
is intended that non-IKEv2 operation is supported, at least, with is intended that non-IKEv2 operation is supported, at least, with
local static configuration.</t> local static configuration.</t>
<t>YANG and MIB documents have been defined for IP-TFS in
<t>YANG and MIB documents have been defined for IP-TFS in <xref target="RFC9348" format="default"/> and <xref target="RFC9349" format="def
<xref target="I-D.ietf-ipsecme-yang-iptfs"/> and <xref target="I-D.ietf-ipsecme- ault"/>.</t>
mib-iptfs"/>.</t> <section numbered="true" toc="default">
<name>Bandwidth</name>
<section title="Bandwidth"> <t>Bandwidth is a local configuration option. For the
<t>Bandwidth is a local configuration option. For non-congestion-controlled mode, the bandwidth <bcp14>SHOULD</bcp14> be configure
non-congestion-controlled mode, the bandwidth SHOULD be configured. d.
For congestion-controlled mode, the bandwidth can be configured or For the congestion-controlled mode, the bandwidth can be configured or
the congestion control algorithm discovers and uses the maximum the congestion control algorithm discovers and uses the maximum
bandwidth available. No standardized configuration method is bandwidth available. No standardized configuration method is
required.</t> required.</t>
</section>
</section> <section numbered="true" toc="default">
<name>Fixed Packet Size</name>
<section title="Fixed Packet Size"> <t>The fixed packet size to be used for the tunnel encapsulation packets
<t>The fixed packet size to be used for the tunnel encapsulation packets <bcp14>MAY</bcp14> be configured manually or can be automatically determined usi
MAY be configured manually or can be automatically determined using ng
other methods such as PLMTUD (<xref target="RFC4821"/>, <xref target="RFC8899"/> other methods, such as PLMTUD <xref target="RFC4821" format="default"/> <xref ta
) or PMTUD (<xref target="RFC1191"/>, rget="RFC8899" format="default"/> or PMTUD <xref target="RFC1191" format="defaul
<xref target="RFC8201"/>). As PMTUD is known to have issues, PLMTUD is considere t"/>
d the <xref target="RFC8201" format="default"/>. As PMTUD is known to have issues, PLM
TUD is considered the
more robust option. No standardized configuration method is required.</t> more robust option. No standardized configuration method is required.</t>
</section>
</section> <section numbered="true" toc="default">
<name>Congestion Control</name>
<section title="Congestion Control"> <t>Congestion control is a local configuration option. No standardized
<t>Congestion control is a local configuration option. No standardized
configuration method is required.</t> configuration method is required.</t>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>IKEv2</name>
<section anchor="sec-use-aggfrag-notification-message" numbered="true" toc
<section title="IKEv2"> ="default">
<section title="USE_AGGFRAG Notification Message" anchor="sec-use-aggfrag-notifi <name>USE_AGGFRAG Notification Message</name>
cation-message"> <t>As mentioned previously, AGGFRAG tunnels utilize ESP payloads of type
<t>As mentioned previously AGGFRAG tunnels utilize ESP payloads of type
AGGFRAG_PAYLOAD.</t> AGGFRAG_PAYLOAD.</t>
<t>When using IKEv2, a new "USE_AGGFRAG" notification message enables
<t>When using IKEv2, a new "USE_AGGFRAG" Notification Message enables the AGGFRAG_PAYLOAD payload on a Child SA pair. The
the AGGFRAG_PAYLOAD payload on a child SA pair. The
method used is similar to how USE_TRANSPORT_MODE is negotiated, as method used is similar to how USE_TRANSPORT_MODE is negotiated, as
described in <xref target="RFC7296"/>.</t> described in <xref target="RFC7296" format="default"/>.</t>
<t>To request use of the AGGFRAG_PAYLOAD payload on the Child SA pair,
<t>To request use of the AGGFRAG_PAYLOAD payload on the Child SA pair,
the initiator includes the USE_AGGFRAG notification in an SA payload the initiator includes the USE_AGGFRAG notification in an SA payload
requesting a new Child SA (either during the initial IKE_AUTH or requesting a new Child SA (either during the initial IKE_AUTH or
during CREATE_CHILD_SA exchanges). If the request is during CREATE_CHILD_SA exchanges). If the request is
accepted then the response MUST also include a notification of type accepted, then the response <bcp14>MUST</bcp14> also include a notification of t
USE_AGGFRAG. If the responder declines the request the child SA will ype
USE_AGGFRAG. If the responder declines the request, the Child SA will
be established without AGGFRAG_PAYLOAD payload use enabled. If be established without AGGFRAG_PAYLOAD payload use enabled. If
this is unacceptable to the initiator, the initiator MUST delete the this is unacceptable to the initiator, the initiator <bcp14>MUST</bcp14> delete
child SA.</t> the
Child SA.</t>
<t>As the use of the AGGFRAG_PAYLOAD payload is currently only defined <t>As the use of the AGGFRAG_PAYLOAD payload is currently only defined
for non-transport mode tunnels, the USE_AGGFRAG notification MUST NOT for non-transport-mode tunnels, the USE_AGGFRAG notification <bcp14>MUST NOT</bc
be combined with USE_TRANSPORT notification.</t> p14>
be combined with the USE_TRANSPORT notification.</t>
<t>The USE_AGGFRAG notification contains a 1 octet payload of flags that <t>The USE_AGGFRAG notification contains a 1-octet payload of flags that
specify requirements from the sender of the notification. If any specify requirements from the sender of the notification. If any
requirement flags are not understood or cannot be supported by the requirement flags are not understood or cannot be supported by the
receiver then the receiver SHOULD NOT enable use of AGGFRAG_PAYLOAD receiver, then the receiver <bcp14>SHOULD NOT</bcp14> enable use of AGGFRAG_PAYL
(either by not responding with the USE_AGGFRAG notification, or in OAD
the case of the initiator, by deleting the child SA if the now (either by not responding with the USE_AGGFRAG notification or, in
established non-AGGFRAG_PAYLOAD using SA is unacceptable).</t> the case of the initiator, by deleting the Child SA if the now-established non-A
GGFRAG_PAYLOAD using SA is unacceptable).</t>
<t>The notification type and payload flag values are defined in <xref target="se <t>The notification type and payload flag values are defined in <xref ta
c-ikev2-use-aggfrag-notification-message"></xref>.</t> rget="sec-ikev2-use-aggfrag-notification-message" format="default"/>.</t>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>Packet and Data Formats</name>
<t>The packet and data formats defined below are generic with the intent
<section title="Packet and Data Formats">
<t>The packet and data formats defined below are generic with the intent
of allowing for non-IP-TFS uses, but such uses are outside the scope of of allowing for non-IP-TFS uses, but such uses are outside the scope of
this document.</t> this document.</t>
<section anchor="sec-aggfrag-payload-payload" numbered="true" toc="default
<section title="AGGFRAG_PAYLOAD Payload" anchor="sec-aggfrag-payload-payload"> ">
<t>ESP Next Header value: 144</t> <name>AGGFRAG_PAYLOAD Payload</name>
<t>ESP Next Header value: 144</t>
<t>An AGGFRAG payload is identified by the ESP Next Header value <t>An AGGFRAG payload is identified by the ESP Next Header value
AGGFRAG_PAYLOAD which has the value 144, which has been reserved in AGGFRAG_PAYLOAD, which has the value 144, which has been reserved in
the IP protocol numbers space. The first octet of the payload the IP protocol numbers space. The first octet of the payload
indicates the format of the remaining payload data.</t> indicates the format of the remaining payload data.</t>
<figure anchor="sec-aggfrag-payload-payload-format">
<figure title="AGGFRAG_PAYLOAD payload format" anchor="sec-aggfrag-payload-paylo <name>AGGFRAG_PAYLOAD Payload Format</name>
ad-format"><artwork><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-
| Sub-type | ... | Sub-type | ...
+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t><list style="hanging"> <dl newline="true" spacing="normal">
<t hangText="Sub-type:"><vspace/>An 8-bit value indicating the payload format.</ <dt>Sub-type:</dt>
t> <dd>An 8-bit value indicating the payload format.</dd>
</list></t> </dl>
<t>This document defines 2 payload sub-types. These payload formats
<t>This document defines 2 payload sub-types. These payload formats
are defined in the following sections.</t> are defined in the following sections.</t>
<section numbered="true" toc="default">
<section title="Non-Congestion Control AGGFRAG_PAYLOAD Payload Format"> <name>Non-Congestion-Control AGGFRAG_PAYLOAD Payload Format</name>
<t>The non-congestion control AGGFRAG_PAYLOAD payload consists of a <t>The non-congestion-control AGGFRAG_PAYLOAD payload consists of a
4-octet header followed by a variable amount of <spanx style='verb'>DataBlocks</ 4-octet header, followed by a variable amount of <tt>DataBlocks</tt> data, as
spanx> data as
shown below.</t> shown below.</t>
<figure anchor="sec-non-congestion-control-payload-format">
<figure title="Non-congestion control payload format" anchor="sec-non-congestion <name>Non-Congestion-Control Payload Format</name>
-control-payload-format"><artwork><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type (0) | Reserved | BlockOffset | | Sub-Type (0) | Reserved | BlockOffset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DataBlocks ... | DataBlocks ...
+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t><list style="hanging"> <dl newline="true" spacing="normal">
<t hangText="Sub-type:"><vspace/>An octet indicating the payload format. For thi <dt>Sub-type:</dt>
s <dd>An octet indicating the payload format. For this
non-congestion control format, the value is 0.</t> non-congestion-control format, the value is 0.</dd>
<t hangText="Reserved:"><vspace/>An octet set to 0 on generation and ignored on <dt>Reserved:</dt>
receipt.</t> <dd>An octet set to 0 on generation and ignored on
<t hangText="BlockOffset:"><vspace/>A 16-bit unsigned integer counting the numbe receipt.</dd>
r of <dt>BlockOffset:</dt>
octets of <spanx style='verb'>DataBlocks</spanx> data before the start of a <dd>A 16-bit unsigned integer counting the number of
octets of <tt>DataBlocks</tt> data before the start of a
new data block. If the start of a new data block new data block. If the start of a new data block
occurs in a subsequent payload the <spanx style='verb'>BlockOffset</spanx> occurs in a subsequent payload, the <tt>BlockOffset</tt>
will point past the end of the <spanx style='verb'>DataBlocks</spanx> data. will point past the end of the <tt>DataBlocks</tt> data.
In this case all the <spanx style='verb'>DataBlocks</spanx> data belongs to In this case, all the <tt>DataBlocks</tt> data belongs to
the current data block being assembled. When the the current data block being assembled. When the
<spanx style='verb'>BlockOffset</spanx> extends into subsequent payloads it <tt>BlockOffset</tt> extends into subsequent payloads, it
continues to only count <spanx style='verb'>DataBlocks</spanx> data (i.e., continues to only count <tt>DataBlocks</tt> data (i.e.,
it does not count subsequent packets it does not count subsequent packets of the
non-<spanx style='verb'>DataBlocks</spanx> data such as header octets).</t> non-<tt>DataBlocks</tt> data, such as header octets).</dd>
<t hangText="DataBlocks:"><vspace/>Variable number of octets that begins with th <dt>DataBlocks:</dt>
e start <dd>Variable number of octets that begins with the start
of a data block, or the continuation of a previous of a data block or the continuation of a previous
data block, followed by zero or more additional data data block, followed by zero or more additional data
blocks.</t> blocks.</dd>
</list></t> </dl>
</section>
</section> <section anchor="sec-congestion-control-aggfrag-payload-payload-format"
numbered="true" toc="default">
<section title="Congestion Control AGGFRAG_PAYLOAD Payload Format" anchor="sec-c <name>Congestion Control AGGFRAG_PAYLOAD Payload Format</name>
ongestion-control-aggfrag-payload-payload-format"> <t>The congestion control AGGFRAG_PAYLOAD payload consists of a 24-oct
<t>The congestion control AGGFRAG_PAYLOAD payload consists of a 24 et
octet header followed by a variable amount of <spanx style='verb'>DataBlocks</sp header, followed by a variable amount of <tt>DataBlocks</tt> data, as
anx> data as
shown below.</t> shown below.</t>
<figure anchor="sec-congestion-control-payload-format">
<figure title="Congestion control payload format" anchor="sec-congestion-control <name>Congestion Control Payload Format</name>
-payload-format"><artwork><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-type (1) | Reserved |P|E| BlockOffset | | Sub-type (1) | Reserved |P|E| BlockOffset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LossEventRate | | LossEventRate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RTT | Echo Delay ... | RTT | Echo Delay ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Echo Delay | Transmit Delay | ... Echo Delay | Transmit Delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TVal | | TVal |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TEcho | | TEcho |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DataBlocks ... | DataBlocks ...
+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t><list style="hanging"> <dl newline="true" spacing="normal">
<t hangText="Sub-type:"><vspace/>An octet indicating the payload format. For thi <dt>Sub-type:</dt>
s <dd>An octet indicating the payload format. For this
congestion control format, the value is 1.</t> congestion control format, the value is 1.</dd>
<t hangText="Reserved:"><vspace/>A 6-bit field set to 0 on generation and ignore <dt>Reserved:</dt>
d on <dd>A 6-bit field set to 0 on generation and ignored on
receipt.</t> receipt.</dd>
<t hangText="P:"><vspace/>A 1-bit value that if set indicates that PLMTUD probin <dt>P:</dt>
g is in <dd>A 1-bit value that, if set, indicates that PLMTUD probing is in
progress. This information can be used to avoid treating progress. This information can be used to avoid treating
missing packets as loss events by the CC algorithm when missing packets as loss events by the congestion control algorithm when
running the PLMTUD probe algorithm.</t> running the PLMTUD probe algorithm.</dd>
<t hangText="E:"><vspace/>A 1-bit value that if set indicates that Congestion Ex <dt>E:</dt>
perienced <dd>A 1-bit value that, if set, indicates that Congestion Experience
d
(CE) ECN bits were received and used in deriving the (CE) ECN bits were received and used in deriving the
reported <spanx style='verb'>LossEventRate</spanx>.</t> reported <tt>LossEventRate</tt>.</dd>
<t hangText="BlockOffset:"><vspace/>The same value as the non-congestion-control <dt>BlockOffset:</dt>
led <dd>The same value as the non-congestion-controlled
payload format value.</t> payload format value.</dd>
<t hangText="LossEventRate:"><vspace/>A 32-bit value specifying the inverse of t <dt>LossEventRate:</dt>
he <dd>A 32-bit value specifying the inverse of the
current loss event rate as calculated by the current loss event rate, as calculated by the
receiver. A value of zero indicates no loss. receiver. A value of zero indicates no loss.
Otherwise the loss event rate is Otherwise, the loss event rate is
<spanx style='verb'>1/LossEventRate</spanx>.</t> <tt>1/LossEventRate</tt>.</dd>
<t hangText="RTT:"><vspace/>A 22-bit value specifying the sender's current round <dt>RTT:</dt>
-trip <dd>A 22-bit value specifying the sender's current RTT estimate in m
time estimate in microseconds. The value MAY be zero prior icroseconds. The value <bcp14>MAY</bcp14> be zero prior
to the sender having calculated a round-trip time estimate. to the sender having calculated an RTT estimate.
The value SHOULD be set to zero on The value <bcp14>SHOULD</bcp14> be set to zero on
non-AGGFRAG_PAYLOAD-enabled SAs. If the RTT is equal to or non-AGGFRAG_PAYLOAD-enabled SAs. If the RTT is equal to or
larger than <spanx style='verb'>0x3FFFFF</spanx> the value MUST be set to <spanx larger than <tt>0x3FFFFF</tt>, the value <bcp14>MUST</bcp14> be set to <tt>0x3FF
style='verb'>0x3FFFFF</spanx>.</t> FFF</tt>.</dd>
<t hangText="Echo Delay:"><vspace/>A 21-bit value specifying the delay in micros <dt>Echo Delay:</dt>
econds <dd>A 21-bit value specifying the delay in microseconds
incurred between the receiver first receiving the <spanx style='verb'>TVal</span incurred between the receiver first receiving the <tt>TVal</tt>
x> value, which it is sending back in <tt>TEcho</tt>. If the delay
value which it is sending back in <spanx style='verb'>TEcho</spanx>. If the dela is equal to or larger than <tt>0x1FFFFF</tt>, the value <bcp14>MUST</bcp14> be
y set to <tt>0x1FFFFF</tt>.</dd>
is equal to or larger than <spanx style='verb'>0x1FFFFF</spanx> the value MUST b <dt>Transmit Delay:</dt>
e <dd>A 21-bit value specifying the transmission delay in
set to <spanx style='verb'>0x1FFFFF</spanx>.</t>
<t hangText="Transmit Delay:"><vspace/>A 21-bit value specifying the transmissio
n delay in
microseconds. This is the fixed (or average) delay on the microseconds. This is the fixed (or average) delay on the
receiver between it sending packets on the IPTFS tunnel. receiver between it sending packets on the IP-TFS tunnel.
If the delay is equal to or larger than <spanx style='verb'>0x1FFFFF</spanx> the If the delay is equal to or larger than <tt>0x1FFFFF</tt>, the
value MUST be set to <spanx style='verb'>0x1FFFFF</spanx>.</t> value <bcp14>MUST</bcp14> be set to <tt>0x1FFFFF</tt>.</dd>
<t hangText="TVal:"><vspace/>An opaque 32-bit value that will be echoed back by <dt>TVal:</dt>
the <dd>An opaque, 32-bit value that will be echoed back by the
receiver in later packets in the <spanx style='verb'>TEcho</spanx> field, along receiver in later packets in the <tt>TEcho</tt> field, along with
with an <tt>Echo Delay</tt> value of how long that echo took.</dd>
an <spanx style='verb'>Echo Delay</spanx> value of how long that echo took.</t> <dt>TEcho:</dt>
<t hangText="TEcho:"><vspace/>The opaque 32-bit value from a received packet's < <dd>The opaque, 32-bit value from a received packet's <tt>TVal</tt>
spanx style='verb'>TVal</spanx> field. The received <tt>TVal</tt> is placed in <tt>TEcho</tt>, along with
field. The received <spanx style='verb'>TVal</spanx> is placed in <spanx style=' an <tt>Echo Delay</tt> value indicating how long it has been since
verb'>TEcho</spanx> along with receiving the <tt>TVal</tt> value.</dd>
an <spanx style='verb'>Echo Delay</spanx> value indicating how long it has been <dt>DataBlocks:</dt>
since <dd>Variable number of octets that begins with the start
receiving the <spanx style='verb'>TVal</spanx> value.</t> of a data block or the continuation of a previous
<t hangText="DataBlocks:"><vspace/>Variable number of octets that begins with th
e start
of a data block, or the continuation of a previous
data block, followed by zero or more additional data data block, followed by zero or more additional data
blocks. For the special case of sending congestion blocks. For the special case of sending congestion
control information on a non-IP-TFS enabled SA this control information on a non-IP-TFS-enabled SA, this
field MUST be empty (i.e., be zero octets long).</t> field <bcp14>MUST</bcp14> be empty (i.e., be zero octets long).</dd>
</list></t> </dl>
</section>
</section> <section numbered="true" toc="default">
<name>Data Blocks</name>
<section title="Data Blocks"> <figure anchor="sec-data-block-format">
<figure title="Data Block format" anchor="sec-data-block-format"><artwork><![CDA <name>Data Block Format</name>
TA[ <artwork name="" type="" align="left" alt=""><![CDATA[
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | IPv4, IPv6 or pad... | Type | IPv4, IPv6, or pad...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t><list style="hanging"> <dl newline="true" spacing="normal">
<t hangText="Type:"><vspace/>A 4-bit field where 0x0 identifies a pad data block <dt>Type:</dt>
, 0x4 <dd>A 4-bit field where 0x0 identifies a Pad Data Block, 0x4
indicates an IPv4 data block, and 0x6 indicates an IPv6 indicates an IPv4 data block, and 0x6 indicates an IPv6
data block.</t> data block.</dd>
</list></t> </dl>
<section numbered="true" toc="default">
<section title="IPv4 Data Block"> <name>IPv4 Data Block</name>
<figure title="IPv4 Data Block format" anchor="sec-ipv4-data-block-format"><artw <figure anchor="sec-ipv4-data-block-format">
ork><![CDATA[ <name>IPv4 Data Block Format</name>
<artwork name="" type="" align="left" alt=""><![CDATA[
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x4 | IHL | TypeOfService | TotalLength | | 0x4 | IHL | TypeOfService | TotalLength |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Rest of the inner packet ... | Rest of the inner packet ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t>These values are the actual values within the encapsulated IPv4 <t>These values are the actual values within the encapsulated IPv4
header. In other words, the start of this data block is the start of header. In other words, the start of this data block is the start of
the encapsulated IP packet.</t> the encapsulated IP packet.</t>
<dl newline="true" spacing="normal">
<t><list style="hanging"> <dt>Type:</dt>
<t hangText="Type:"><vspace/>A 4-bit value of 0x4 indicating IPv4 (i.e., first n <dd>A 4-bit value of 0x4 indicating IPv4 (i.e., first nibble of
ibble of the IPv4 packet).</dd>
the IPv4 packet).</t> <dt>TotalLength:</dt>
<t hangText="TotalLength:"><vspace/>The 16-bit unsigned integer "Total Length" f <dd>The 16-bit unsigned integer "Total Length" field of
ield of the IPv4 inner packet.</dd>
the IPv4 inner packet.</t> </dl>
</list></t> </section>
<section numbered="true" toc="default">
</section> <name>IPv6 Data Block</name>
<figure anchor="sec-ipv6-data-block-format">
<section title="IPv6 Data Block"> <name>IPv6 Data Block Format</name>
<figure title="IPv6 Data Block format" anchor="sec-ipv6-data-block-format"><artw <artwork name="" type="" align="left" alt=""><![CDATA[
ork><![CDATA[
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x6 | TrafficClass | FlowLabel | | 0x6 | TrafficClass | FlowLabel |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PayloadLength | Rest of the inner packet ... | PayloadLength | Rest of the inner packet ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t>These values are the actual values within the encapsulated IPv6 <t>These values are the actual values within the encapsulated IPv6
header. In other words, the start of this data block is the start of header. In other words, the start of this data block is the start of
the encapsulated IP packet.</t> the encapsulated IP packet.</t>
<dl newline="true" spacing="normal">
<t><list style="hanging"> <dt>Type:</dt>
<t hangText="Type:"><vspace/>A 4-bit value of 0x6 indicating IPv6 (i.e., first n <dd>A 4-bit value of 0x6 indicating IPv6 (i.e., first nibble of
ibble of the IPv6 packet).</dd>
the IPv6 packet).</t> <dt>PayloadLength:</dt>
<t hangText="PayloadLength:"><vspace/>The 16-bit unsigned integer "Payload Lengt <dd>The 16-bit unsigned integer "Payload Length" field
h" field of the inner IPv6 inner packet.</dd>
of the inner IPv6 inner packet.</t> </dl>
</list></t> </section>
<section numbered="true" toc="default">
</section> <name>Pad Data Block</name>
<figure anchor="sec-pad-data-block-format">
<section title="Pad Data Block"> <name>Pad Data Block Format</name>
<figure title="Pad Data Block format" anchor="sec-pad-data-block-format"><artwor <artwork name="" type="" align="left" alt=""><![CDATA[
k><![CDATA[
1 2 3 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x0 | Padding ... | 0x0 | Padding ...
+-+-+-+-+-+-+-+-+-+-+- +-+-+-+-+-+-+-+-+-+-+-
]]></artwork></figure> ]]></artwork>
</figure>
<t><list style="hanging"> <dl newline="true" spacing="normal">
<t hangText="Type:"><vspace/>A 4-bit value of 0x0 indicating a padding data bloc <dt>Type:</dt>
k.</t> <dd>A 4-bit value of 0x0 indicating a padding data block.</dd>
<t hangText="Padding:"><vspace/>Extends to end of the encapsulating packet.</t> <dt>Padding:</dt>
</list></t> <dd>Extends to end of the encapsulating packet.</dd>
</dl>
</section> </section>
</section>
</section> <section anchor="sec-ikev2-use-aggfrag-notification-message" numbered="t
rue" toc="default">
<section title="IKEv2 USE_AGGFRAG Notification Message" anchor="sec-ikev2-use-ag <name>IKEv2 USE_AGGFRAG Notification Message</name>
gfrag-notification-message"> <t>As discussed in <xref target="sec-use-aggfrag-notification-message"
<t>As discussed in <xref target="sec-use-aggfrag-notification-message"></xref>, format="default"/>, a notification
a notification
message USE_AGGFRAG is used to negotiate use of the ESP AGGFRAG_PAYLOAD message USE_AGGFRAG is used to negotiate use of the ESP AGGFRAG_PAYLOAD
Next Header value.</t> Next Header value.</t>
<t>The USE_AGGFRAG Notification Message State Type is 16442.</t>
<t>The USE_AGGFRAG Notification Message State Type is 16442</t> <t>The notification payload contains 1 octet of requirement flags. The
re
<t>The notification payload contains 1 octet of requirement flags. There
are currently 2 requirement flags defined. This may be revised by are currently 2 requirement flags defined. This may be revised by
later specifications.</t> later specifications.</t>
<figure anchor="sec-use-aggfrag-requirement-flags">
<figure title="USE_AGGFRAG requirement flags" anchor="sec-use-aggfrag-requiremen <name>USE_AGGFRAG Requirement Flags</name>
t-flags"><artwork><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|0|0|0|0|0|0|C|D| |0|0|0|0|0|0|C|D|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
]]></artwork></figure> ]]></artwork>
</figure>
<t><list style="hanging"> <dl newline="true" spacing="normal">
<t hangText="0:"><vspace/>6 bits - Reserved MUST be zero on send, unless defined <dt>0:</dt>
by <dd>6 bits - Reserved <bcp14>MUST</bcp14> be zero on send, unless de
later specifications.</t> fined by
<t hangText="C:"><vspace/>Congestion Control bit. If set, then the sender is req later specifications.</dd>
uiring <dt>C:</dt>
that congestion control information MUST be returned to it <dd>Congestion Control bit. If set, then the sender is requiring
periodically as defined in <xref target="sec-congestion-information"></xref>.</t that congestion control information <bcp14>MUST</bcp14> be returned to it
> periodically, as defined in <xref target="sec-congestion-information" format="de
<t hangText="D:"><vspace/>Don't Fragment bit. If set, indicates the sender of th fault"/>.</dd>
e notify <dt>D:</dt>
<dd>Don't Fragment bit. If set, it indicates the sender of the notif
y
message does not support receiving packet fragments (i.e., inner message does not support receiving packet fragments (i.e., inner
packets MUST be sent using a single <spanx style='verb'>Data Block</spanx>). Thi packets <bcp14>MUST</bcp14> be sent using a single <tt>Data Block</tt>). This va
s value only lue only
applies to what the sender is capable of receiving; the sender MAY applies to what the sender is capable of receiving; the sender <bcp14>MAY</bcp14
>
still send packet fragments unless similarly restricted by the still send packet fragments unless similarly restricted by the
receiver in its USE_AGGFRAG notification.</t> receiver in its USE_AGGFRAG notification.</dd>
</list></t> </dl>
</section>
</section> </section>
</section>
</section> <section numbered="true" toc="default">
<name>IANA Considerations</name>
</section> <section numbered="true" toc="default">
<name>ESP Next Header Value</name>
<section title="IANA Considerations"> <t>IANA has
<section title="ESP Next Header Value"> allocated an IP protocol number from the "Protocol Numbers - Assigned
<t>Per the INT area directors direction, this document requests IANA Internet Protocol Numbers" registry as follows.</t>
allocate an IP protocol number from "Protocol Numbers - Assigned <dl newline="false" spacing="compact">
Internet Protocol Numbers" registry</t> <dt>Decimal:</dt>
<dd>144</dd>
<t><list style="hanging"> <dt>Keyword:</dt>
<t hangText="Decimal:"><vspace/>144</t> <dd>AGGFRAG</dd>
<t hangText="Keyword:"><vspace/>AGGFRAG</t> <dt>Protocol:</dt>
<t hangText="Protocol:"><vspace/>AGGFRAG encapsulation payload for ESP (TEMPORAR <dd>AGGFRAG encapsulation payload for ESP</dd>
Y - registered 2022-08-26, document sent to IESG Evaluation 2022-07-14)</t> <dt>Reference:</dt>
<t hangText="Reference:"><vspace/>This document</t> <dd>RFC 9347</dd>
</list></t> </dl>
</section>
</section> <section numbered="true" toc="default">
<name>AGGFRAG_PAYLOAD Sub-Types</name>
<section title="AGGFRAG_PAYLOAD Sub-Type Registry"> <t>IANA has created a registry called "AGGFRAG_PAYLOAD
<t>This document requests IANA create a registry called "AGGFRAG_PAYLOAD Sub-Types" under a new category named "ESP AGGFRAG_PAYLOAD".
Sub-Type Registry" under a new category named "ESP AGGFRAG_PAYLOAD Parameters".
The registration policy for this registry is "Expert Review" The registration policy for this registry is "Expert Review"
(<xref target="RFC8126"/> and <xref target="RFC7120"/>).</t> <xref target="RFC8126" format="default"/> <xref target="RFC7120" format="default
"/>.</t>
<t><list style="hanging"> <dl newline="false" spacing="compact">
<t hangText="Name:"><vspace/>AGGFRAG_PAYLOAD Sub-Type Registry</t> <dt>Name:</dt>
<t hangText="Description:"><vspace/>AGGFRAG_PAYLOAD Payload Formats.</t> <dd>AGGFRAG_PAYLOAD Sub-Types</dd>
<t hangText="Reference:"><vspace/>This document</t> <dt>Description:</dt>
</list></t> <dd>AGGFRAG_PAYLOAD Payload Formats</dd>
<dt>Reference:</dt>
<t>This initial content for this registry is as follows:</t> <dd>RFC 9347</dd>
</dl>
<figure><artwork><![CDATA[ <t>This initial content for this registry is as follows:</t>
Sub-Type Name Reference <table align="center">
0 Non-Congestion Control Format This document <name>AGGFRAG_PAYLOAD Sub-Types</name>
1 Congestion Control Format This document <thead>
3-255 Reserved <tr>
]]></artwork></figure> <th>Sub-Type</th>
<th>Name</th>
</section> <th>Reference</th>
</tr>
<section title="USE_AGGFRAG Notify Message Status Type"> </thead>
<t>This document requests a status type USE_AGGFRAG be allocated from <tbody>
<tr>
<td>0</td>
<td>Non-Congestion-Control Format</td>
<td>RFC 9347</td>
</tr>
<tr>
<td>1</td>
<td>Congestion Control Format</td>
<td>RFC 9347</td>
</tr>
<tr>
<td>3-255</td>
<td>Reserved</td>
<td></td>
</tr>
</tbody>
</table>
</section>
<section numbered="true" toc="default">
<name>USE_AGGFRAG Notify Message Status Type</name>
<t>IANA has allocated a status type USE_AGGFRAG from
the "IKEv2 Notify Message Types - Status Types" registry.</t> the "IKEv2 Notify Message Types - Status Types" registry.</t>
<dl newline="false" spacing="compact">
<t><list style="hanging"> <dt>Decimal:</dt>
<t hangText="Decimal:"><vspace/>16442</t> <dd>16442</dd>
<t hangText="Name:"><vspace/>USE_AGGFRAG</t> <dt>Name:</dt>
<t hangText="Reference:"><vspace/>This document</t> <dd>USE_AGGFRAG</dd>
</list></t> <dt>Reference:</dt>
<dd>RFC 9347</dd>
</section> </dl>
</section>
</section> </section>
<section numbered="true" toc="default">
<section title="Implementation Status"> <name>Security Considerations</name>
<t>[ RFC Ed.: please remove this entire section as well as the reference to <t>This document describes an aggregation and fragmentation mechanism to
RFC7942 prior to publication. ]</t>
<t>[Section added during IESG review to help with evaluation]</t>
<t>This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in <xref target="RFC7942"/>
. The
description of implementations in this section is intended to assist
the IETF in its decision processes in progressing drafts to RFCs.
Please note that the listing of any individual implementation here
does not imply endorsement by the IETF. This is not intended as, and
must not be construed to be, a catalog of available implementations
or their features. Readers are advised to note that other
implementations may exist.</t>
<t>According to RFC 7942, "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature. It
is up to the individual working groups to use this information as
they see fit".</t>
<t>Currently the author and contributors are aware of 1 full and completed
implementation and 1 underway implementation of IP-TFS as defined in
this document. These 2 are described below.</t>
<section title="Reference Implementation - VPP + Strongswan">
<t>The entire IP-TFS protocol including congestion control mode has been
implemented in VPP (Vector Packet Processor), and published to github
with an Open Source (Apache 2) License. VPP is a highly efficient
forwarding plane implemented in user-space utlizing direct control
and polling of physical devices to provide high speed low-latency
forwarding in Linux. By pinning packet processing threads directly to
CPU cores for their exclusive use a high degree of control is given
to the protocol designer.</t>
<t>The IKEv2 additions were implemented in Strongswan and are licensed
using the GNU public license used by the Strongswan project.</t>
<t>Finally, an extensive automation suite was also created and is
included with the open source implementation, which tests the
functionality as well as the performance of the implementation, and
most importantly verifies, through precise timing tracing and
time-stamping, the decoupling of the users offered load from the
tunnel packets (i.e., the Traffic Flow Security).</t>
<t>The verification process utilized the <eref target="https://trex-tgn.cisco.co
m/">TREX</eref> packet generator for high
bandwidth testing as well as other tools such as iperf. The test
hardware included large servers with 10GE, 40GE and 100GE network
interfaces, as well as small SoC (system on a chip) network
appliances, and also cloud deployments.</t>
<t>Tested IP-TFS tunnel rates ranged from 10M all the way to 10GE on the
small network appliance, for the large servers multiple 10GE tunnel
rates were tested as well.</t>
<t>Offered loads included partial, full and oversubscribed bandwidths
from various flow types consisting of small packets, large packets,
random sized packets, sequential sized packets, and multiple IMIX
variations sized flows. Timing analysis was done with variable rate
traffic, impulse traffic and random bursty traffic.</t>
<t>The quality of the reference implementation should be considered
production level as it underwent extensive testing and verification.</t>
<t>The organization responsible for this implementation is LabN
Consulting, L.L.C.</t>
<t>URLs to the implementation follow.</t>
<t><list style="symbols">
<t><eref target="https://github.com/LabNConsulting/vpp/tree/labn-stable/2009-pub
lic">VPP+IPTFS</eref>, <eref target="https://github.com/LabNConsulting/vpp/tree/
labn-stable/2009-public/src/plugins/iptfs">iptfs plugin</eref></t>
<t><eref target="https://github.com/LabNConsulting/strongswan/tree/labn-5.8-publ
ic">Strongswan IKEv2</eref></t>
</list></t>
<t>The implementation was last updated April, 2021.</t>
</section>
<section title="In Progress Linux Kernel Implementation.">
<t>A second open source implementation has begun by LabN Consulting
L.L.C., within the Linux IPsec xfrm stack. Development has also been
coordinated with the Linux IPsec community, and was being
worked by the same during the most recent IETF 114 hackathon.</t>
<t>Currently the quality is alpha level with aggregation-only complete and
fragmentation support underway with congestion control to follow.</t>
<t>This implementation is licensed under the GNU public license and can
be found at the following URLs</t>
<t><list style="symbols">
<t>development environment: <eref target="https://github.com/LabNConsulting/iptf
s-dev"/></t>
<t>linux kernel source: <eref target="https://github.com/LabNConsulting/iptfs-li
nux"/></t>
<t>iproute2 source: <eref target="https://github.com/LabNConsulting/iptfs-iprout
e2"/></t>
</list></t>
</section>
</section>
<section title="Security Considerations">
<t>This document describes an aggregation and fragmentation mechanism to
efficiently implement TFC for IP traffic. This approach is expected to reduce efficiently implement TFC for IP traffic. This approach is expected to reduce
the efficacy of traffic analysis on IPsec communication. Other than the efficacy of traffic analysis on IPsec communication. Other than
the additional security afforded by using this mechanism, IP-TFS the additional security afforded by using this mechanism, IP-TFS
utilizes the security protocols <xref target="RFC4303"/> and <xref target="RFC72 96"/> and so their utilizes the security protocols <xref target="RFC4303" format="default"/> and <x ref target="RFC7296" format="default"/>, and so their
security considerations apply to IP-TFS as well.</t> security considerations apply to IP-TFS as well.</t>
<t>As noted in <xref target="sec-ecn-support" format="default"/>, the ECN
<t>As noted in <xref target="sec-ecn-support"></xref>, the ECN bits are not prot bits are not protected by IPsec and
ected by IPsec and thus may constitute a covert channel. For this reason, ECN use <bcp14>SHOULD
thus may constitute a covert channel. For this reason, ECN use SHOULD NOT</bcp14> be enabled by default.</t>
NOT be enabled by default.</t> <t>As noted previously in <xref target="sec-congestion-controlled-mode" fo
rmat="default"/>, for TFC to be
<t>As noted previously in <xref target="sec-congestion-controlled-mode"></xref>,
for TFC to be
maintained, the encapsulated traffic flow should not be maintained, the encapsulated traffic flow should not be
affecting network congestion in a predictable way, and if it would be, affecting network congestion in a predictable way, and if it would be,
then non-congestion-controlled mode use should be considered instead.</t> then non-congestion-controlled mode use should be considered instead.</t>
</section>
</middle>
<back>
<references>
<name>References</name>
<references>
<name>Normative References</name>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2
119.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4
303.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7
296.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
174.xml"/>
</references>
<references>
<name>Informative References</name>
</section> <reference anchor="AppCrypt">
<front>
</middle> <title>Applied Cryptography: Protocols, Algorithms, and Source Code
<back> in C</title>
<references title="Normative References"> <author initials="B." surname="Schneier" fullname="Bruce Schneier">
<organization/>
<reference anchor='RFC2119' target='https://www.rfc-editor.org/info/rfc2119'> </author>
<front> <date year="1996"/>
<title>Key words for use in RFCs to Indicate Requirement Levels</title> </front>
<author initials='S.' surname='Bradner' fullname='S. Bradner'><organization /></ </reference>
author>
<date year='1997' month='March' />
<abstract><t>In many standards track documents several words are used to signify
the requirements in the specification. These words are often capitalized. This
document defines these words as they should be interpreted in IETF documents.
This document specifies an Internet Best Current Practices for the Internet Comm
unity, and requests discussion and suggestions for improvements.</t></abstract>
</front>
<seriesInfo name='BCP' value='14'/>
<seriesInfo name='RFC' value='2119'/>
<seriesInfo name='DOI' value='10.17487/RFC2119'/>
</reference>
<reference anchor='RFC4303' target='https://www.rfc-editor.org/info/rfc4303'>
<front>
<title>IP Encapsulating Security Payload (ESP)</title>
<author initials='S.' surname='Kent' fullname='S. Kent'><organization /></author
>
<date year='2005' month='December' />
<abstract><t>This document describes an updated version of the Encapsulating Sec
urity Payload (ESP) protocol, which is designed to provide a mix of security ser
vices in IPv4 and IPv6. ESP is used to provide confidentiality, data origin aut
hentication, connectionless integrity, an anti-replay service (a form of partial
sequence integrity), and limited traffic flow confidentiality. This document o
bsoletes RFC 2406 (November 1998). [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='4303'/>
<seriesInfo name='DOI' value='10.17487/RFC4303'/>
</reference>
<reference anchor='RFC7296' target='https://www.rfc-editor.org/info/rfc7296'>
<front>
<title>Internet Key Exchange Protocol Version 2 (IKEv2)</title>
<author initials='C.' surname='Kaufman' fullname='C. Kaufman'><organization /></
author>
<author initials='P.' surname='Hoffman' fullname='P. Hoffman'><organization /></
author>
<author initials='Y.' surname='Nir' fullname='Y. Nir'><organization /></author>
<author initials='P.' surname='Eronen' fullname='P. Eronen'><organization /></au
thor>
<author initials='T.' surname='Kivinen' fullname='T. Kivinen'><organization /></
author>
<date year='2014' month='October' />
<abstract><t>This document describes version 2 of the Internet Key Exchange (IKE
) protocol. IKE is a component of IPsec used for performing mutual authenticati
on and establishing and maintaining Security Associations (SAs). This document
obsoletes RFC 5996, and includes all of the errata for it. It advances IKEv2 to
be an Internet Standard.</t></abstract>
</front>
<seriesInfo name='STD' value='79'/>
<seriesInfo name='RFC' value='7296'/>
<seriesInfo name='DOI' value='10.17487/RFC7296'/>
</reference>
<reference anchor='RFC8174' target='https://www.rfc-editor.org/info/rfc8174'>
<front>
<title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
<author initials='B.' surname='Leiba' fullname='B. Leiba'><organization /></auth
or>
<date year='2017' month='May' />
<abstract><t>RFC 2119 specifies common key words that may be used in protocol s
pecifications. This document aims to reduce the ambiguity by clarifying that on
ly UPPERCASE usage of the key words have the defined special meanings.</t></abs
tract>
</front>
<seriesInfo name='BCP' value='14'/>
<seriesInfo name='RFC' value='8174'/>
<seriesInfo name='DOI' value='10.17487/RFC8174'/>
</reference>
</references>
<references title="Informative References">
<reference anchor="AppCrypt">
<front>
<title>Applied Cryptography: Protocols, Algorithms, and Source Code in C</title>
<author initials='B.' surname='Schneier' fullname='Bruce Schneier'><organization
/></author>
<date day="1" month="11" year="2017"/>
</front>
</reference>
<reference anchor='RFC0791' target='https://www.rfc-editor.org/info/rfc791'>
<front>
<title>Internet Protocol</title>
<author initials='J.' surname='Postel' fullname='J. Postel'><organization /></au
thor>
<date year='1981' month='September' />
</front>
<seriesInfo name='STD' value='5'/>
<seriesInfo name='RFC' value='791'/>
<seriesInfo name='DOI' value='10.17487/RFC0791'/>
</reference>
<reference anchor='RFC1191' target='https://www.rfc-editor.org/info/rfc1191'>
<front>
<title>Path MTU discovery</title>
<author initials='J.' surname='Mogul' fullname='J. Mogul'><organization /></auth
or>
<author initials='S.' surname='Deering' fullname='S. Deering'><organization /></
author>
<date year='1990' month='November' />
<abstract><t>This memo describes a technique for dynamically discovering the max
imum transmission unit (MTU) of an arbitrary internet path. It specifies a smal
l change to the way routers generate one type of ICMP message. For a path that
passes through a router that has not been so changed, this technique might not d
iscover the correct Path MTU, but it will always choose a Path MTU as accurate a
s, and in many cases more accurate than, the Path MTU that would be chosen by cu
rrent practice. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='1191'/>
<seriesInfo name='DOI' value='10.17487/RFC1191'/>
</reference>
<reference anchor='RFC2474' target='https://www.rfc-editor.org/info/rfc2474'>
<front>
<title>Definition of the Differentiated Services Field (DS Field) in the IPv4 an
d IPv6 Headers</title>
<author initials='K.' surname='Nichols' fullname='K. Nichols'><organization /></
author>
<author initials='S.' surname='Blake' fullname='S. Blake'><organization /></auth
or>
<author initials='F.' surname='Baker' fullname='F. Baker'><organization /></auth
or>
<author initials='D.' surname='Black' fullname='D. Black'><organization /></auth
or>
<date year='1998' month='December' />
<abstract><t>This document defines the IP header field, called the DS (for diffe
rentiated services) field. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='2474'/>
<seriesInfo name='DOI' value='10.17487/RFC2474'/>
</reference>
<reference anchor='RFC2914' target='https://www.rfc-editor.org/info/rfc2914'>
<front>
<title>Congestion Control Principles</title>
<author initials='S.' surname='Floyd' fullname='S. Floyd'><organization /></auth
or>
<date year='2000' month='September' />
<abstract><t>The goal of this document is to explain the need for congestion con
trol in the Internet, and to discuss what constitutes correct congestion control
. This document specifies an Internet Best Current Practices for the Internet C
ommunity, and requests discussion and suggestions for improvements.</t></abstrac
t>
</front>
<seriesInfo name='BCP' value='41'/>
<seriesInfo name='RFC' value='2914'/>
<seriesInfo name='DOI' value='10.17487/RFC2914'/>
</reference>
<reference anchor='RFC3168' target='https://www.rfc-editor.org/info/rfc3168'>
<front>
<title>The Addition of Explicit Congestion Notification (ECN) to IP</title>
<author initials='K.' surname='Ramakrishnan' fullname='K. Ramakrishnan'><organiz
ation /></author>
<author initials='S.' surname='Floyd' fullname='S. Floyd'><organization /></auth
or>
<author initials='D.' surname='Black' fullname='D. Black'><organization /></auth
or>
<date year='2001' month='September' />
<abstract><t>This memo specifies the incorporation of ECN (Explicit Congestion N
otification) to TCP and IP, including ECN's use of two bits in the IP header. [
STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='3168'/>
<seriesInfo name='DOI' value='10.17487/RFC3168'/>
</reference>
<reference anchor='RFC4301' target='https://www.rfc-editor.org/info/rfc4301'>
<front>
<title>Security Architecture for the Internet Protocol</title>
<author initials='S.' surname='Kent' fullname='S. Kent'><organization /></author
>
<author initials='K.' surname='Seo' fullname='K. Seo'><organization /></author>
<date year='2005' month='December' />
<abstract><t>This document describes an updated version of the &quot;Security Ar
chitecture for IP&quot;, which is designed to provide security services for traf
fic at the IP layer. This document obsoletes RFC 2401 (November 1998). [STANDA
RDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='4301'/>
<seriesInfo name='DOI' value='10.17487/RFC4301'/>
</reference>
<reference anchor='RFC4342' target='https://www.rfc-editor.org/info/rfc4342'>
<front>
<title>Profile for Datagram Congestion Control Protocol (DCCP) Congestion Contro
l ID 3: TCP-Friendly Rate Control (TFRC)</title>
<author initials='S.' surname='Floyd' fullname='S. Floyd'><organization /></auth
or>
<author initials='E.' surname='Kohler' fullname='E. Kohler'><organization /></au
thor>
<author initials='J.' surname='Padhye' fullname='J. Padhye'><organization /></au
thor>
<date year='2006' month='March' />
<abstract><t>This document contains the profile for Congestion Control Identifie
r 3, TCP-Friendly Rate Control (TFRC), in the Datagram Congestion Control Protoc
ol (DCCP). CCID 3 should be used by senders that want a TCP-friendly sending ra
te, possibly with Explicit Congestion Notification (ECN), while minimizing abrup
t rate changes. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='4342'/>
<seriesInfo name='DOI' value='10.17487/RFC4342'/>
</reference>
<reference anchor='RFC4821' target='https://www.rfc-editor.org/info/rfc4821'>
<front>
<title>Packetization Layer Path MTU Discovery</title>
<author initials='M.' surname='Mathis' fullname='M. Mathis'><organization /></au
thor>
<author initials='J.' surname='Heffner' fullname='J. Heffner'><organization /></
author>
<date year='2007' month='March' />
<abstract><t>This document describes a robust method for Path MTU Discovery (PMT
UD) that relies on TCP or some other Packetization Layer to probe an Internet pa
th with progressively larger packets. This method is described as an extension
to RFC 1191 and RFC 1981, which specify ICMP-based Path MTU Discovery for IP ver
sions 4 and 6, respectively. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='4821'/>
<seriesInfo name='DOI' value='10.17487/RFC4821'/>
</reference>
<reference anchor='RFC5348' target='https://www.rfc-editor.org/info/rfc5348'>
<front>
<title>TCP Friendly Rate Control (TFRC): Protocol Specification</title>
<author initials='S.' surname='Floyd' fullname='S. Floyd'><organization /></auth
or>
<author initials='M.' surname='Handley' fullname='M. Handley'><organization /></
author>
<author initials='J.' surname='Padhye' fullname='J. Padhye'><organization /></au
thor>
<author initials='J.' surname='Widmer' fullname='J. Widmer'><organization /></au
thor>
<date year='2008' month='September' />
<abstract><t>This document specifies TCP Friendly Rate Control (TFRC). TFRC is
a congestion control mechanism for unicast flows operating in a best-effort Inte
rnet environment. It is reasonably fair when competing for bandwidth with TCP f
lows, but has a much lower variation of throughput over time compared with TCP,
making it more suitable for applications such as streaming media where a relativ
ely smooth sending rate is of importance.</t><t>This document obsoletes RFC 3448
and updates RFC 4342. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='5348'/>
<seriesInfo name='DOI' value='10.17487/RFC5348'/>
</reference>
<reference anchor='RFC6040' target='https://www.rfc-editor.org/info/rfc6040'>
<front>
<title>Tunnelling of Explicit Congestion Notification</title>
<author initials='B.' surname='Briscoe' fullname='B. Briscoe'><organization /></
author>
<date year='2010' month='November' />
<abstract><t>This document redefines how the explicit congestion notification (E
CN) field of the IP header should be constructed on entry to and exit from any I
P-in-IP tunnel. On encapsulation, it updates RFC 3168 to bring all IP-in-IP tun
nels (v4 or v6) into line with RFC 4301 IPsec ECN processing. On decapsulation,
it updates both RFC 3168 and RFC 4301 to add new behaviours for previously unus
ed combinations of inner and outer headers. The new rules ensure the ECN field
is correctly propagated across a tunnel whether it is used to signal one or two
severity levels of congestion; whereas before, only one severity level was suppo
rted. Tunnel endpoints can be updated in any order without affecting pre-existi
ng uses of the ECN field, thus ensuring backward compatibility. Nonetheless, op
erators wanting to support two severity levels (e.g., for pre-congestion notific
ation -- PCN) can require compliance with this new specification. A thorough an
alysis of the reasoning for these changes and the implications is included. In
the unlikely event that the new rules do not meet a specific need, RFC 4774 give
s guidance on designing alternate ECN semantics, and this document extends that
to include tunnelling issues. [STANDARDS-TRACK]</t></abstract>
</front>
<seriesInfo name='RFC' value='6040'/>
<seriesInfo name='DOI' value='10.17487/RFC6040'/>
</reference>
<reference anchor='RFC7120' target='https://www.rfc-editor.org/info/rfc7120'>
<front>
<title>Early IANA Allocation of Standards Track Code Points</title>
<author initials='M.' surname='Cotton' fullname='M. Cotton'><organization /></au
thor>
<date year='2014' month='January' />
<abstract><t>This memo describes the process for early allocation of code points
by IANA from registries for which &quot;Specification Required&quot;, &quot;RFC
Required&quot;, &quot;IETF Review&quot;, or &quot;Standa
rds Action&quot; policies apply. This process can be used to alleviate the prob
lem where code point allocation is needed to facilitate desired or required impl
ementation and deployment experience prior to publication of an RFC, which would
normally trigger code point allocation. The procedures in this document are in
tended to apply only to IETF Stream documents.</t></abstract>
</front>
<seriesInfo name='BCP' value='100'/>
<seriesInfo name='RFC' value='7120'/>
<seriesInfo name='DOI' value='10.17487/RFC7120'/>
</reference>
<reference anchor='RFC7510' target='https://www.rfc-editor.org/info/rfc7510'>
<front>
<title>Encapsulating MPLS in UDP</title>
<author initials='X.' surname='Xu' fullname='X. Xu'><organization /></author>
<author initials='N.' surname='Sheth' fullname='N. Sheth'><organization /></auth
or>
<author initials='L.' surname='Yong' fullname='L. Yong'><organization /></author
>
<author initials='R.' surname='Callon' fullname='R. Callon'><organization /></au
thor>
<author initials='D.' surname='Black' fullname='D. Black'><organization /></auth
or>
<date year='2015' month='April' />
<abstract><t>This document specifies an IP-based encapsulation for MPLS, called
MPLS-in-UDP for situations where UDP (User Datagram Protocol) encapsulation is p
referred to direct use of MPLS, e.g., to enable UDP-based ECMP (Equal-Cost Multi
path) or link aggregation. The MPLS- in-UDP encapsulation technology must only
be deployed within a single network (with a single network operator) or networks
of an adjacent set of cooperating network operators where traffic is managed to
avoid congestion, rather than over the Internet where congestion control is req
uired. Usage restrictions apply to MPLS-in-UDP usage for traffic that is not co
ngestion controlled and to UDP zero checksum usage with IPv6.</t></abstract>
</front>
<seriesInfo name='RFC' value='7510'/>
<seriesInfo name='DOI' value='10.17487/RFC7510'/>
</reference>
<reference anchor='RFC7893' target='https://www.rfc-editor.org/info/rfc7893'>
<front>
<title>Pseudowire Congestion Considerations</title>
<author initials='Y(J)' surname='Stein' fullname='Y(J) Stein'><organization /></
author>
<author initials='D.' surname='Black' fullname='D. Black'><organization /></auth
or>
<author initials='B.' surname='Briscoe' fullname='B. Briscoe'><organization /></
author>
<date year='2016' month='June' />
<abstract><t>Pseudowires (PWs) have become a common mechanism for tunneling traf
fic and may be found in unmanaged scenarios competing for network resources both
with other PWs and with non-PW traffic, such as TCP/IP flows. Thus, it is wort
hwhile specifying under what conditions such competition is acceptable, i.e., th
e PW traffic does not significantly harm other traffic or contribute more than i
t should to congestion. We conclude that PWs transporting responsive traffic be
have as desired without the need for additional mechanisms. For inelastic PWs (
such as Time Division Multiplexing (TDM) PWs), we derive a bound under which suc
h PWs consume no more network capacity than a TCP flow. For TDM PWs, we find th
at the level of congestion at which the PW can no longer deliver acceptable TDM
service is never significantly greater, and is typically much lower, than this b
ound. Therefore, as long as the PW is shut down when it can no longer deliver ac
ceptable TDM service, it will never do significantly more harm than even a singl
e TCP flow. If the TDM service does not automatically shut down, a mechanism to
block persistently unacceptable TDM pseudowires is required.</t></abstract>
</front>
<seriesInfo name='RFC' value='7893'/>
<seriesInfo name='DOI' value='10.17487/RFC7893'/>
</reference>
<reference anchor='RFC7942' target='https://www.rfc-editor.org/info/rfc7942'>
<front>
<title>Improving Awareness of Running Code: The Implementation Status Section</t
itle>
<author initials='Y.' surname='Sheffer' fullname='Y. Sheffer'><organization /></
author>
<author initials='A.' surname='Farrel' fullname='A. Farrel'><organization /></au
thor>
<date year='2016' month='July' />
<abstract><t>This document describes a simple process that allows authors of Int
ernet-Drafts to record the status of known implementations by including an Imple
mentation Status section. This will allow reviewers and working groups to assig
n due consideration to documents that have the benefit of running code, which ma
y serve as evidence of valuable experimentation and feedback that have made the
implemented protocols more mature.</t><t>This process is not mandatory. Authors
of Internet-Drafts are encouraged to consider using the process for their docum
ents, and working groups are invited to think about applying the process to all
of their protocol specifications. This document obsoletes RFC 6982, advancing i
t to a Best Current Practice.</t></abstract>
</front>
<seriesInfo name='BCP' value='205'/>
<seriesInfo name='RFC' value='7942'/>
<seriesInfo name='DOI' value='10.17487/RFC7942'/>
</reference>
<reference anchor='RFC8084' target='https://www.rfc-editor.org/info/rfc8084'>
<front>
<title>Network Transport Circuit Breakers</title>
<author initials='G.' surname='Fairhurst' fullname='G. Fairhurst'><organization
/></author>
<date year='2017' month='March' />
<abstract><t>This document explains what is meant by the term &quot;network tran
sport Circuit Breaker&quot;. It describes the need for
Circuit Breakers (CBs) for network tunnels and applications when using non-cong
estion- controlled traffic and explains where CBs are, and are not, needed. It a
lso defines requirements for building a CB and the expected outcomes of using a
CB within the Internet.</t></abstract>
</front>
<seriesInfo name='BCP' value='208'/>
<seriesInfo name='RFC' value='8084'/>
<seriesInfo name='DOI' value='10.17487/RFC8084'/>
</reference>
<reference anchor='RFC8126' target='https://www.rfc-editor.org/info/rfc8126'>
<front>
<title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
<author initials='M.' surname='Cotton' fullname='M. Cotton'><organization /></au
thor>
<author initials='B.' surname='Leiba' fullname='B. Leiba'><organization /></auth
or>
<author initials='T.' surname='Narten' fullname='T. Narten'><organization /></au
thor>
<date year='2017' month='June' />
<abstract><t>Many protocols make use of points of extensibility that use constan
ts to identify various protocol parameters. To ensure that the values in these
fields do not have conflicting uses and to promote interoperability, their alloc
ations are often coordinated by a central record keeper. For IETF protocols, th
at role is filled by the Internet Assigned Numbers Authority (IANA).</t><t>To ma
ke assignments in a given registry prudently, guidance describing the conditions
under which new values should be assigned, as well as when and how modification
s to existing values can be made, is needed. This document defines a framework
for the documentation of these guidelines by specification authors, in order to
assure that the provided guidance for the IANA Considerations is clear and addre
sses the various issues that are likely in the operation of a registry.</t><t>Th
is is the third edition of this document; it obsoletes RFC 5226.</t></abstract>
</front>
<seriesInfo name='BCP' value='26'/>
<seriesInfo name='RFC' value='8126'/>
<seriesInfo name='DOI' value='10.17487/RFC8126'/>
</reference>
<reference anchor='RFC8200' target='https://www.rfc-editor.org/info/rfc8200'>
<front>
<title>Internet Protocol, Version 6 (IPv6) Specification</title>
<author initials='S.' surname='Deering' fullname='S. Deering'><organization /></
author>
<author initials='R.' surname='Hinden' fullname='R. Hinden'><organization /></au
thor>
<date year='2017' month='July' />
<abstract><t>This document specifies version 6 of the Internet Protocol (IPv6).
It obsoletes RFC 2460.</t></abstract>
</front>
<seriesInfo name='STD' value='86'/>
<seriesInfo name='RFC' value='8200'/>
<seriesInfo name='DOI' value='10.17487/RFC8200'/>
</reference>
<reference anchor='RFC8201' target='https://www.rfc-editor.org/info/rfc8201'>
<front>
<title>Path MTU Discovery for IP version 6</title>
<author initials='J.' surname='McCann' fullname='J. McCann'><organization /></au
thor>
<author initials='S.' surname='Deering' fullname='S. Deering'><organization /></
author>
<author initials='J.' surname='Mogul' fullname='J. Mogul'><organization /></auth
or>
<author initials='R.' surname='Hinden' fullname='R. Hinden' role='editor'><organ
ization /></author>
<date year='2017' month='July' />
<abstract><t>This document describes Path MTU Discovery (PMTUD) for IP version 6
. It is largely derived from RFC 1191, which describes Path MTU Discovery for IP
version 4. It obsoletes RFC 1981.</t></abstract>
</front>
<seriesInfo name='STD' value='87'/>
<seriesInfo name='RFC' value='8201'/>
<seriesInfo name='DOI' value='10.17487/RFC8201'/>
</reference>
<reference anchor='RFC8229' target='https://www.rfc-editor.org/info/rfc8229'> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.0
<front> 791.xml"/>
<title>TCP Encapsulation of IKE and IPsec Packets</title> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.1
<author initials='T.' surname='Pauly' fullname='T. Pauly'><organization /></auth 191.xml"/>
or> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2
<author initials='S.' surname='Touati' fullname='S. Touati'><organization /></au 474.xml"/>
thor> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2
<author initials='R.' surname='Mantha' fullname='R. Mantha'><organization /></au 914.xml"/>
thor> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3
<date year='2017' month='August' /> 168.xml"/>
<abstract><t>This document describes a method to transport Internet Key Exchange <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4
Protocol (IKE) and IPsec packets over a TCP connection for traversing network m 301.xml"/>
iddleboxes that may block IKE negotiation over UDP. This method, referred to as <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4
&quot;TCP encapsulation&quot;, involves sending both IKE packets for Security A 342.xml"/>
ssociation establishment and Encapsulating Security Payload (ESP) packets over a <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4
TCP connection. This method is intended to be used as a fallback option when I 821.xml"/>
KE cannot be negotiated over UDP.</t></abstract> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5
</front> 348.xml"/>
<seriesInfo name='RFC' value='8229'/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6
<seriesInfo name='DOI' value='10.17487/RFC8229'/> 040.xml"/>
</reference> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7
120.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7
510.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7
893.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
084.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
126.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
200.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
201.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9
329.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
546.xml"/>
<xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8
899.xml"/>
<reference anchor='RFC8546' target='https://www.rfc-editor.org/info/rfc8546'> <reference anchor='RFC9349' target='https://www.rfc-editor.org/info/rfc9349'>
<front> <front>
<title>The Wire Image of a Network Protocol</title> <title>Definitions of Managed Objects for IP Traffic Flow Security</title>
<author initials='B.' surname='Trammell' fullname='B. Trammell'><organization /> <author initials="D." surname="Fedyk" fullname="Don Fedyk">
</author> <organization>LabN Consulting, L.L.C.</organization>
<author initials='M.' surname='Kuehlewind' fullname='M. Kuehlewind'><organizatio </author>
n /></author> <author initials="E." surname="Kinzie" fullname="Eric Kinzie">
<date year='2019' month='April' /> <organization>LabN Consulting, L.L.C.</organization>
<abstract><t>This document defines the wire image, an abstraction of the informa </author>
tion available to an on-path non-participant in a networking protocol. This abs <date month="January" year="2023"/>
traction is intended to shed light on the implications that increased encryption
has for network functions that use the wire image.</t></abstract>
</front> </front>
<seriesInfo name='RFC' value='8546'/> <seriesInfo name="RFC" value="9349"/>
<seriesInfo name='DOI' value='10.17487/RFC8546'/> <seriesInfo name="DOI" value="10.17487/RFC9349"/>
</reference> </reference>
<reference anchor='RFC8899' target='https://www.rfc-editor.org/info/rfc8899'> <reference anchor='RFC9348' target='https://www.rfc-editor.org/info/rfc9348'>
<front> <front>
<title>Packetization Layer Path MTU Discovery for Datagram Transports</title> <title>A YANG Data Model for IP Traffic Flow Security</title>
<author initials='G.' surname='Fairhurst' fullname='G. Fairhurst'><organization <author initials="D." surname="Fedyk" fullname="Don Fedyk">
/></author> <organization>LabN Consulting, L.L.C.</organization>
<author initials='T.' surname='Jones' fullname='T. Jones'><organization /></auth </author>
or> <author initials="C." surname="Hopps" fullname="Christian Hopps">
<author initials='M.' surname='Tüxen' fullname='M. Tüxen'><organization /></auth <organization>LabN Consulting, L.L.C.</organization>
or> </author>
<author initials='I.' surname='Rüngeler' fullname='I. Rüngeler'><organization /> <date month="January" year="2023"/>
</author>
<author initials='T.' surname='Völker' fullname='T. Völker'><organization /></au
thor>
<date year='2020' month='September' />
<abstract><t>This document specifies Datagram Packetization Layer Path MTU Disco
very (DPLPMTUD). This is a robust method for Path MTU Discovery (PMTUD) for data
gram Packetization Layers (PLs). It allows a PL, or a datagram application that
uses a PL, to discover whether a network path can support the current size of da
tagram. This can be used to detect and reduce the message size when a sender en
counters a packet black hole. It can also probe a network path to discover wheth
er the maximum packet size can be increased. This provides functionality for da
tagram transports that is equivalent to the PLPMTUD specification for TCP, speci
fied in RFC 4821, which it updates. It also updates the UDP Usage Guidelines to
refer to this method for use with UDP datagrams and updates SCTP.</t><t>The docu
ment provides implementation notes for incorporating Datagram PMTUD into IETF da
tagram transports or applications that use datagram transports.</t><t>This speci
fication updates RFC 4960, RFC 4821, RFC 6951, RFC 8085, and RFC 8261.</t></abst
ract>
</front> </front>
<seriesInfo name='RFC' value='8899'/> <seriesInfo name="RFC" value="9348"/>
<seriesInfo name='DOI' value='10.17487/RFC8899'/> <seriesInfo name="DOI" value="10.17487/RFC9348"/>
</reference>
<reference anchor="I-D.ietf-ipsecme-mib-iptfs" target="https://www.ietf.org/arch
ive/id/draft-ietf-ipsecme-mib-iptfs-03.txt">
<front>
<title>Definitions of Managed Objects for IP Traffic Flow Security</title>
<author fullname="Don Fedyk">
<organization>LabN Consulting, L.L.C.</organization>
</author>
<author fullname="Eric Kinzie">
<organization>LabN Consulting, L.L.C.</organization>
</author>
<date day="18" month="November" year="2021"/>
<abstract>
<t>This document describes managed objects for the the management of IP Tr
affic Flow Security additions to IKEv2 and IPsec. This document provides a read
only version of the objects defined in the YANG module for the same purpose.</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-ipsecme-mib-iptfs-03"/>
</reference>
<reference anchor="I-D.ietf-ipsecme-yang-iptfs" target="https://www.ietf.org/arc
hive/id/draft-ietf-ipsecme-yang-iptfs-10.txt">
<front>
<title>A YANG Data Model for IP Traffic Flow Security</title>
<author fullname="Don Fedyk">
<organization>LabN Consulting, L.L.C.</organization>
</author>
<author fullname="Christian Hopps">
<organization>LabN Consulting, L.L.C.</organization>
</author>
<date day="31" month="August" year="2022"/>
<abstract>
<t>This document describes a YANG module for the management of IP Traffic
Flow Security additions to IKEv2 and IPsec.</t>
</abstract>
</front>
<seriesInfo name="Internet-Draft" value="draft-ietf-ipsecme-yang-iptfs-10"/>
</reference> </reference>
</references>
<section title="Example of An Encapsulated IP Packet Flow" anchor="sec-example-o </references>
f-an-encapsulated-ip-packet-flow"> </references>
<t>Below, an example inner IP packet flow within the encapsulating tunnel <section anchor="sec-example-of-an-encapsulated-ip-packet-flow" numbered="tr
ue" toc="default">
<name>Example of an Encapsulated IP Packet Flow</name>
<t>Below, an example inner IP packet flow within the encapsulating tunnel
packet stream is shown. Notice how encapsulated IP packets can start packet stream is shown. Notice how encapsulated IP packets can start
and end anywhere, and more than one or less than 1 may occur in a and end anywhere, and more than one or less than one may occur in a
single encapsulating packet.</t> single encapsulating packet.</t>
<figure anchor="sec-inner-and-outer-packet-flow">
<figure title="Inner and outer packet flow" anchor="sec-inner-and-outer-packet-f <name>Inner and Outer Packet Flow</name>
low"><artwork><![CDATA[ <artwork name="" type="" align="left" alt=""><![CDATA[
Offset: 0 Offset: 100 Offset: 2000 Offset: 600 Offset: 0 Offset: 100 Offset: 2000 Offset: 600
[ ESP1 (1404) ][ ESP2 (1404) ][ ESP3 (1404) ][ ESP4 (1404) ] [ ESP1 (1404) ][ ESP2 (1404) ][ ESP3 (1404) ][ ESP4 (1404) ]
[--750--][--750--][60][-240-][--3000----------------------][pad] [--750--][--750--][60][-240-][--3000----------------------][pad]
]]></artwork></figure> ]]></artwork>
</figure>
<t>Each outer encapsulating ESPupayload space is a fixed-size of 1404 <t>Each outer encapsulating ESP space is a fixed size of 1404
octets the first 4 octets of which contains the AGGFRAG header. octets, the first 4 octets of which contain the AGGFRAG header.
The encapsulated IP packet flow (lengths include IP header and The encapsulated IP packet flow (lengths include the IP header and
payload) is as follows: a 750-octet packet, a 750-octet packet, a payload) is as follows: a 750-octet packet, a 750-octet packet, a
60-octet packet, a 240-octet packet, a 3000-octet packet.</t> 60-octet packet, a 240-octet packet, and a 3000-octet packet.</t>
<t>The <tt>BlockOffset</tt> values in the 4 AGGFRAG payload headers for th
<t>The <spanx style='verb'>BlockOffset</spanx> values in the 4 AGGFRAG payload h is
eaders for this packet flow would thus be: 0, 100, 2000, and 600, respectively. The first
packet flow would thus be: 0, 100, 2000, 600 respectively. The first encapsulating packet (ESP1) has a zero <tt>BlockOffset</tt>, which points at the
encapsulating packet (ESP1) has a zero <spanx style='verb'>BlockOffset</spanx> w
hich points at the
IP data block immediately following the AGGFRAG header. The following IP data block immediately following the AGGFRAG header. The following
packet's (ESP2) <spanx style='verb'>BlockOffset</spanx> points inward 100 octets to the start of the packet's (ESP2) <tt>BlockOffset</tt> points inward 100 octets to the start of th e
60-octet data block. The third encapsulating packet (ESP3) contains the 60-octet data block. The third encapsulating packet (ESP3) contains the
middle portion of the 3000-octet data block so the offset points past middle portion of the 3000-octet data block, so the offset points past
its end and into the fourth encapsulating packet. The fourth packet's its end and into the fourth encapsulating packet. The fourth packet's
(ESP4) offset is 600, pointing at the padding which follows the (ESP4) offset is 600, pointing at the padding that follows the
completion of the continued 3000-octet packet.</t> completion of the continued 3000-octet packet.</t>
</section>
</section> <section anchor="sec-a-send-and-loss-event-rate-calculation" numbered="true"
toc="default">
<section title="A Send and Loss Event Rate Calculation" anchor="sec-a-send-and-l <name>A Send and Loss Event Rate Calculation</name>
oss-event-rate-calculation"> <t>The current best practice indicates that congestion control <bcp14>SHOU
<t>The current best practice indicates that congestion control SHOULD be LD</bcp14> be
done in a TCP-friendly way. A TCP-friendly congestion control algorithm done in a TCP-friendly way. A TCP-friendly congestion control algorithm
is described in <xref target="RFC5348"/>. For this IP-TFS use case (as with <xre f target="RFC4342"/>), the is described in <xref target="RFC5348" format="default"/>. For this IP-TFS use c ase (as with <xref target="RFC4342" format="default"/>), the
(fixed) packet size is used as the segment size for the algorithm. The (fixed) packet size is used as the segment size for the algorithm. The
main formula in the algorithm for the send rate is then as follows:</t> main formula in the algorithm for the send rate is then as follows:</t>
<artwork name="" type="" align="left" alt=""><![CDATA[
<figure><artwork><![CDATA[
1 1
X = ----------------------------------------------- X = -----------------------------------------------
R * (sqrt(2*p/3) + 12*sqrt(3*p/8)*p*(1+32*p^2)) R * (sqrt(2*p/3) + 12*sqrt(3*p/8)*p*(1+32*p^2))
]]></artwork></figure> ]]></artwork>
<t><tt>X</tt> is the send rate in packets per second, <tt>R</tt> is the
<t>Where <spanx style='verb'>X</spanx> is the send rate in packets per second, < RTT estimate, and <tt>p</tt> is the loss event rate (the inverse
spanx style='verb'>R</spanx> is the
round trip time estimate and <spanx style='verb'>p</spanx> is the loss event rat
e (the inverse
of which is provided by the receiver).</t> of which is provided by the receiver).</t>
<t>In addition, the algorithm in <xref target="RFC5348" format="default"/>
<t>In addition, the algorithm in <xref target="RFC5348"/> also uses an <spanx st also uses an <tt>X_recv</tt> value (the
yle='verb'>X_recv</spanx> value (the receiver's receive rate). For IP-TFS, one <bcp14>MAY</bcp14> set this value acco
receiver's receive rate). For IP-TFS one MAY set this value according to rding to
the sender's current tunnel send-rate (<spanx style='verb'>X</spanx>).</t> the sender's current tunnel send rate (<tt>X</tt>).</t>
<t>The IP-TFS receiver, having the RTT estimate from the sender, can use t
<t>The IP-TFS receiver, having the RTT estimate from the sender can use the he
same method as described in <xref target="RFC5348"/> and <xref target="RFC4342"/ same method as described in <xref target="RFC5348" format="default"/> and <xref
> to collect the loss target="RFC4342" format="default"/> to collect the loss
intervals and calculate the loss event rate value using the weighted intervals and calculate the loss event rate value using the weighted
average as indicated. The receiver communicates the inverse of this average as indicated. The receiver communicates the inverse of this
value back to the sender in the AGGFRAG_PAYLOAD payload header field value back to the sender in the AGGFRAG_PAYLOAD payload header field
<spanx style='verb'>LossEventRate</spanx>.</t> <tt>LossEventRate</tt>.</t>
<t>The IP-TFS sender now has both the <tt>R</tt> and <tt>p</tt> values and
<t>The IP-TFS sender now has both the <spanx style='verb'>R</spanx> and <spanx s can calculate
tyle='verb'>p</spanx> values and can calculate the correct sending rate. If following <xref target="RFC5348" format="default"/>
the correct sending rate. If following <xref target="RFC5348"/>, the sender shou , the sender should also
ld also
use the slow start mechanism described therein when the IP-TFS SA is use the slow start mechanism described therein when the IP-TFS SA is
first established.</t> first established.</t>
</section>
</section> <section anchor="sec-comparisons-of-ip-tfs" numbered="true" toc="default">
<name>Comparisons of IP-TFS</name>
<section title="Comparisons of IP-TFS" anchor="sec-comparisons-of-ip-tfs"> <section numbered="true" toc="default">
<name>Comparing Overhead</name>
<section title="Comparing Overhead"> <t>For comparing overhead, the overhead of ESP for both normal and AGGFR
<t>For comparing overhead, the overhead of ESP for both normal and AGGFRAG AG
tunnel packets must be calculated, and so an algorithm for encryption tunnel packets must be calculated, and so an algorithm for encryption
and authentication must be chosen. For the data below AES-GCM-256 was and authentication must be chosen. For the data below, AES-GCM-256 was
selected. This leads to an IP+ESP overhead of 54.</t> selected. This leads to an IP+ESP overhead of 54.</t>
<artwork name="" type="" align="left" alt=""><![CDATA[
<figure><artwork><![CDATA[
54 = 20 (IP) + 8 (ESPH) + 2 (ESPF) + 8 (IV) + 16 (ICV) 54 = 20 (IP) + 8 (ESPH) + 2 (ESPF) + 8 (IV) + 16 (ICV)
]]></artwork></figure> ]]></artwork>
<t>Additionally, for IP-TFS, non-congestion-control AGGFRAG_PAYLOAD
<t>Additionally, for IP-TFS, non-congestion control AGGFRAG_PAYLOAD headers were chosen, which adds 4 octets, for a total overhead of 58.</t>
headers were chosen which adds 4 octets for a total overhead of 58.</t> <section numbered="true" toc="default">
<name>IP-TFS Overhead</name>
<section title="IP-TFS Overhead"> <t>For comparison, the overhead of an AGGFRAG payload is 58 octets per
<t>For comparison, the overhead of an AGGFRAG payload is 58 octets per outer pac outer packet.
ket.
Therefore, the octet overhead per inner packet is 58 divided by the Therefore, the octet overhead per inner packet is 58 divided by the
number of outer packets required (fractions allowed). The overhead number of outer packets required (fractions allowed). The overhead
as a percentage of inner packet size is a constant based on the Outer as a percentage of inner packet size is a constant based on the Outer
MTU size.</t> MTU size.</t>
<artwork name="" type="" align="left" alt=""><![CDATA[
<figure><artwork><![CDATA[
OH = 58 / Outer Payload Size / Inner Packet Size OH = 58 / Outer Payload Size / Inner Packet Size
OH % of Inner Packet Size = 100 * OH / Inner Packet Size OH % of Inner Packet Size = 100 * OH / Inner Packet Size
OH % of Inner Packet Size = 5800 / Outer Payload Size OH % of Inner Packet Size = 5800 / Outer Payload Size
]]></artwork></figure> ]]></artwork>
<table anchor="sec-ip-tfs-overhead-as-percentage-of-inner-packet-size"
<figure title="IP-TFS Overhead as Percentage of Inner Packet Size" anchor="sec-i align="center">
p-tfs-overhead-as-percentage-of-inner-packet-size"><artwork><![CDATA[ <name>IP-TFS Overhead as Percentage of Inner Packet Size</name>
Type IP-TFS IP-TFS IP-TFS <thead>
MTU 576 1500 9000 <tr>
PSize 518 1442 8942 <th>Type</th>
------------------------------- <th>IP-TFS</th>
40 11.20% 4.02% 0.65% <th>IP-TFS</th>
576 11.20% 4.02% 0.65% <th>IP-TFS</th>
1500 11.20% 4.02% 0.65% </tr>
9000 11.20% 4.02% 0.65% <tr>
]]></artwork></figure> <th>MTU</th>
<th>576</th>
</section> <th>1500</th>
<th>9000</th>
<section title="ESP with Padding Overhead"> </tr>
<t>The overhead per inner packet for constant-send-rate padded ESP <tr>
(i.e., traditional IPsec TFC) is 36 octets plus any padding, unless <th>PSize</th>
<th>518</th>
<th>1442</th>
<th>8942</th>
</tr>
</thead>
<tbody>
<tr>
<td>40</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65% </td>
</tr>
<tr>
<td>576</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>1500</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>9000</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
</tbody>
</table>
</section>
<section numbered="true" toc="default">
<name>ESP with Padding Overhead</name>
<t>The overhead per inner packet for constant-send-rate-padded ESP
(i.e., original IPsec TFC) is 36 octets plus any padding, unless
fragmentation is required.</t> fragmentation is required.</t>
<t>When fragmentation of the inner packet is required to fit in the
<t>When fragmentation of the inner packet is required to fit in the
outer IPsec packet, overhead is the number of outer packets required outer IPsec packet, overhead is the number of outer packets required
to carry the fragmented inner packet times both the inner IP overhead to carry the fragmented inner packet times both the inner IP Overhead
(20) and the outer packet overhead (54) minus the initial inner IP (20) and the outer packet overhead (54) minus the initial inner IP
overhead plus any required tail padding in the last encapsulation Overhead plus any required tail padding in the last encapsulation
packet. The required tail padding is the number of required packets packet. The required tail padding is the number of required packets
times the difference of the Outer Payload Size and the IP Overhead times the difference of the Outer Payload Size and the IP Overhead
minus the Inner Payload Size. So:</t> minus the Inner Payload Size. So:</t>
<artwork name="" type="" align="left" alt=""><![CDATA[
<figure><artwork><![CDATA[
Inner Payload Size = IP Packet Size - IP Overhead Inner Payload Size = IP Packet Size - IP Overhead
Outer Payload Size = MTU - IPsec Overhead Outer Payload Size = MTU - IPsec Overhead
Inner Payload Size Inner Payload Size
NF0 = ---------------------------------- NF0 = ----------------------------------
Outer Payload Size - IP Overhead Outer Payload Size - IP Overhead
NF = CEILING(NF0) NF = CEILING(NF0)
OH = NF * (IP Overhead + IPsec Overhead) OH = NF * (IP Overhead + IPsec Overhead)
- IP Overhead - IP Overhead
+ NF * (Outer Payload Size - IP Overhead) + NF * (Outer Payload Size - IP Overhead)
- Inner Payload Size - Inner Payload Size
OH = NF * (IPsec Overhead + Outer Payload Size) OH = NF * (IPsec Overhead + Outer Payload Size)
- (IP Overhead + Inner Payload Size) - (IP Overhead + Inner Payload Size)
OH = NF * (IPsec Overhead + Outer Payload Size) OH = NF * (IPsec Overhead + Outer Payload Size)
- Inner Packet Size - Inner Packet Size
]]></artwork></figure> ]]></artwork>
</section>
</section> </section>
<section numbered="true" toc="default">
</section> <name>Overhead Comparison</name>
<t>The following tables collect the overhead values for some common L3
<section title="Overhead Comparison">
<t>The following tables collect the overhead values for some common L3
MTU sizes in order to compare them. The first table is the number of MTU sizes in order to compare them. The first table is the number of
octets of overhead for a given L3 MTU sized packet. The second table octets of overhead for a given L3 MTU-sized packet. The second table
is the percentage of overhead in the same MTU sized packet.</t> is the percentage of overhead in the same MTU-sized packet.</t>
<table anchor="sec-overhead-comparison-in-octets" align="center">
<t></t> <name>Overhead Comparison in Octets</name>
<thead>
<figure title="Overhead comparison in octets" anchor="sec-overhead-comparison-in <tr>
-octets"><artwork><![CDATA[ <th>Type</th>
Type ESP+Pad ESP+Pad ESP+Pad IP-TFS IP-TFS IP-TFS <th>ESP+Pad</th>
L3 MTU 576 1500 9000 576 1500 9000 <th>ESP+Pad</th>
PSize 522 1446 8946 518 1442 8942 <th>ESP+Pad</th>
----------------------------------------------------------- <th>IP-TFS</th>
40 482 1406 8906 4.5 1.6 0.3 <th>IP-TFS</th>
128 394 1318 8818 14.3 5.1 0.8 <th>IP-TFS</th>
256 266 1190 8690 28.7 10.3 1.7 </tr>
518 4 928 8428 58.0 20.8 3.4 <tr>
576 576 870 8370 64.5 23.2 3.7 <th>L3 MTU</th>
1442 286 4 7504 161.5 58.0 9.4 <th>576</th>
1500 228 1500 7446 168.0 60.3 9.7 <th>1500</th>
8942 1426 1558 4 1001.2 359.7 58.0 <th>9000</th>
9000 1368 1500 9000 1007.7 362.0 58.4 <th>576</th>
]]></artwork></figure> <th>1500</th>
<th>9000</th>
<figure title="Overhead as Percentage of Inner Packet Size" anchor="sec-overhead </tr>
-as-percentage-of-inner-packet-size"><artwork><![CDATA[ <tr>
Type ESP+Pad ESP+Pad ESP+Pad IP-TFS IP-TFS IP-TFS <th>PSize</th>
MTU 576 1500 9000 576 1500 9000 <th>522</th>
PSize 522 1446 8946 518 1442 8942 <th>1446</th>
----------------------------------------------------------- <th>8946</th>
40 1205.0% 3515.0% 22265.0% 11.20% 4.02% 0.65% <th>518</th>
128 307.8% 1029.7% 6889.1% 11.20% 4.02% 0.65% <th>1442</th>
256 103.9% 464.8% 3394.5% 11.20% 4.02% 0.65% <th>8942 </th>
518 0.8% 179.2% 1627.0% 11.20% 4.02% 0.65% </tr>
576 100.0% 151.0% 1453.1% 11.20% 4.02% 0.65% </thead>
1442 19.8% 0.3% 520.4% 11.20% 4.02% 0.65% <tbody>
1500 15.2% 100.0% 496.4% 11.20% 4.02% 0.65% <tr>
8942 15.9% 17.4% 0.0% 11.20% 4.02% 0.65% <td>40</td>
9000 15.2% 16.7% 100.0% 11.20% 4.02% 0.65% <td>482</td>
]]></artwork></figure> <td>1406</td>
<td>8906</td>
</section> <td>4.5</td>
<td>1.6</td>
<section title="Comparing Available Bandwidth"> <td>0.3</td>
<t>Another way to compare the two solutions is to look at the amount of </tr>
<tr>
<td>128</td>
<td>394</td>
<td>1318</td>
<td>8818</td>
<td>14.3</td>
<td>5.1</td>
<td>0.8</td>
</tr>
<tr>
<td>256</td>
<td>266</td>
<td>1190</td>
<td>8690</td>
<td>28.7</td>
<td>10.3</td>
<td>1.7</td>
</tr>
<tr>
<td>518</td>
<td>4</td>
<td>928</td>
<td>8428</td>
<td>58.0</td>
<td>20.8</td>
<td>3.4 </td>
</tr>
<tr>
<td>576</td>
<td>576</td>
<td>870</td>
<td>8370</td>
<td>64.5</td>
<td>23.2</td>
<td>3.7</td>
</tr>
<tr>
<td>1442</td>
<td>286</td>
<td>4</td>
<td>7504</td>
<td>161.5</td>
<td>58.0</td>
<td>9.4</td>
</tr>
<tr>
<td>1500</td>
<td>228</td>
<td>1500</td>
<td>7446</td>
<td>168.0</td>
<td>60.3</td>
<td>9.7</td>
</tr>
<tr>
<td>8942</td>
<td>1426</td>
<td>1558</td>
<td>4</td>
<td>1001.2</td>
<td>359.7</td>
<td>58.0</td>
</tr>
<tr>
<td>9000</td>
<td>1368</td>
<td>1500</td>
<td>9000</td>
<td>1007.7</td>
<td>362.0</td>
<td>58.4</td>
</tr>
</tbody>
</table>
<table anchor="sec-overhead-as-percentage-of-inner-packet-size" align="c
enter">
<name>Overhead as Percentage of Inner Packet Size</name>
<thead>
<tr>
<th>Type</th>
<th>ESP+Pad</th>
<th>ESP+Pad</th>
<th>ESP+Pad</th>
<th>IP-TFS</th>
<th>IP-TFS</th>
<th>IP-TFS</th>
</tr>
<tr>
<th>MTU</th>
<th>576</th>
<th>1500</th>
<th>9000</th>
<th>576</th>
<th>1500</th>
<th>9000</th>
</tr>
<tr>
<th>PSize</th>
<th>522</th>
<th>1446</th>
<th>8946</th>
<th>518</th>
<th>1442</th>
<th>8942</th>
</tr>
</thead>
<tbody>
<tr>
<td>40</td>
<td>1205.0%</td>
<td>3515.0%</td>
<td>22265.0%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>128</td>
<td>307.8%</td>
<td>1029.7%</td>
<td>6889.1%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>256</td>
<td>103.9%</td>
<td>464.8%</td>
<td>3394.5%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>518</td>
<td>0.8%</td>
<td>179.2%</td>
<td>1627.0%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>576</td>
<td>100.0%</td>
<td>151.0%</td>
<td>1453.1%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>1442</td>
<td>19.8%</td>
<td>0.3%</td>
<td>520.4%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>1500</td>
<td>15.2%</td>
<td>100.0%</td>
<td>496.4%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>8942</td>
<td>15.9%</td>
<td>17.4%</td>
<td>0.0%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
<tr>
<td>9000</td>
<td>15.2%</td>
<td>16.7%</td>
<td>100.0%</td>
<td>11.20%</td>
<td>4.02%</td>
<td>0.65%</td>
</tr>
</tbody>
</table>
</section>
<section numbered="true" toc="default">
<name>Comparing Available Bandwidth</name>
<t>Another way to compare the two solutions is to look at the amount of
available bandwidth each solution provides. The following sections available bandwidth each solution provides. The following sections
consider and compare the percentage of available bandwidth. For the consider and compare the percentage of available bandwidth. For the
sake of providing a well-understood baseline normal (unencrypted) sake of providing a well-understood baseline, normal (unencrypted)
Ethernet as well as normal ESP values are included.</t> Ethernet and normal ESP values are included.</t>
<section numbered="true" toc="default">
<section title="Ethernet"> <name>Ethernet</name>
<t>In order to calculate the available bandwidth the per packet overhead <t>In order to calculate the available bandwidth, the per-packet overh
ead
is calculated first. The total overhead of Ethernet is 14+4 octets of is calculated first. The total overhead of Ethernet is 14+4 octets of
header and CRC plus an additional 20 octets of framing (preamble, header and Cyclic Redundancy Check (CRC) plus an additional 20 octets of framing (preamble,
start, and inter-packet gap), for a total of 38 octets. Additionally, start, and inter-packet gap), for a total of 38 octets. Additionally,
the minimum payload is 46 octets.</t> the minimum payload is 46 octets.</t>
<table anchor="sec-l2-octets-per-packet" align="center">
<figure title="L2 Octets Per Packet" anchor="sec-l2-octets-per-packet"><artwork> <name>L2 Octets Per Packet</name>
<![CDATA[ <thead>
Size E + P E + P E + P IPTFS IPTFS IPTFS Enet ESP <tr>
MTU 590 1514 9014 590 1514 9014 any any <th>Size</th>
OH 92 92 92 96 96 96 38 74 <th>E + P</th>
------------------------------------------------------------ <th>E + P</th>
40 614 1538 9038 47 42 40 84 114 <th>E + P</th>
128 614 1538 9038 151 136 129 166 202 <th>IPTFS</th>
256 614 1538 9038 303 273 258 294 330 <th>IPTFS</th>
518 614 1538 9038 614 552 523 574 610 <th>IPTFS</th>
576 1228 1538 9038 682 614 582 614 650 <th>Enet</th>
1442 1842 1538 9038 1709 1538 1457 1498 1534 <th>ESP</th>
1500 1842 3076 9038 1777 1599 1516 1538 1574 </tr>
8942 11052 10766 9038 10599 9537 9038 8998 9034 <tr>
9000 11052 10766 18076 10667 9599 9096 9038 9074 <th>MTU</th>
]]></artwork></figure> <th>590</th>
<th>1514</th>
<figure title="Packets Per Second on 10G Ethernet" anchor="sec-packets-per-secon <th>9014</th>
d-on-10g-ethernet"><artwork><![CDATA[ <th>590</th>
Size E + P E + P E + P IPTFS IPTFS IPTFS Enet ESP <th>1514</th>
MTU 590 1514 9014 590 1514 9014 any any <th>9014</th>
OH 92 92 92 96 96 96 38 74 <th>any</th>
-------------------------------------------------------------- <th>any</th>
40 2.0M 0.8M 0.1M 26.4M 29.3M 30.9M 14.9M 11.0M </tr>
128 2.0M 0.8M 0.1M 8.2M 9.2M 9.7M 7.5M 6.2M <tr>
256 2.0M 0.8M 0.1M 4.1M 4.6M 4.8M 4.3M 3.8M <th>OH</th>
518 2.0M 0.8M 0.1M 2.0M 2.3M 2.4M 2.2M 2.1M <th>92</th>
576 1.0M 0.8M 0.1M 1.8M 2.0M 2.1M 2.0M 1.9M <th>92</th>
1442 678K 812K 138K 731K 812K 857K 844K 824K <th>92</th>
1500 678K 406K 138K 703K 781K 824K 812K 794K <th>96</th>
8942 113K 116K 138K 117K 131K 138K 139K 138K <th>96</th>
9000 113K 116K 69K 117K 130K 137K 138K 137K <th>96</th>
]]></artwork></figure> <th>38</th>
<th>74</th>
<figure title="Percentage of Bandwidth on 10G Ethernet" anchor="sec-percentage-o </tr>
f-bandwidth-on-10g-ethernet"><artwork><![CDATA[ </thead>
Size E + P E + P E + P IPTFS IPTFS IPTFS Enet ESP <tbody>
590 1514 9014 590 1514 9014 any any <tr>
92 92 92 96 96 96 38 74 <td>40</td>
40 6.51% 2.60% 0.44% 84.36% 93.76% 98.94% 47.62% 35.09% <td>614</td>
128 20.85% 8.32% 1.42% 84.36% 93.76% 98.94% 77.11% 63.37% <td>1538</td>
256 41.69% 16.64% 2.83% 84.36% 93.76% 98.94% 87.07% 77.58% <td>9038</td>
518 84.36% 33.68% 5.73% 84.36% 93.76% 98.94% 93.17% 87.50% <td>47</td>
576 46.91% 37.45% 6.37% 84.36% 93.76% 98.94% 93.81% 88.62% <td>42</td>
1442 78.28% 93.76% 15.95% 84.36% 93.76% 98.94% 97.43% 95.12% <td>40</td>
1500 81.43% 48.76% 16.60% 84.36% 93.76% 98.94% 97.53% 95.30% <td>84</td>
8942 80.91% 83.06% 98.94% 84.36% 93.76% 98.94% 99.58% 99.18% <td>114</td>
9000 81.43% 83.60% 49.79% 84.36% 93.76% 98.94% 99.58% 99.18% </tr>
]]></artwork></figure> <tr>
<td>128</td>
<t>A sometimes unexpected result of using an AGGFRAG tunnel (or any packet <td>614</td>
<td>1538</td>
<td>9038</td>
<td>151</td>
<td>136</td>
<td>129</td>
<td>166</td>
<td>202</td>
</tr>
<tr>
<td>256</td>
<td>614</td>
<td>1538</td>
<td>9038</td>
<td>303</td>
<td>273</td>
<td>258</td>
<td>294</td>
<td>330</td>
</tr>
<tr>
<td>518</td>
<td>614</td>
<td>1538</td>
<td>9038</td>
<td>614</td>
<td>552</td>
<td>523</td>
<td>574</td>
<td>610</td>
</tr>
<tr>
<td>576</td>
<td>1228</td>
<td>1538</td>
<td>9038</td>
<td>682</td>
<td>614</td>
<td>582</td>
<td>614</td>
<td>650</td>
</tr>
<tr>
<td>1442</td>
<td>1842</td>
<td>1538</td>
<td>9038</td>
<td>1709</td>
<td>1538</td>
<td>1457</td>
<td>1498</td>
<td>1534</td>
</tr>
<tr>
<td>1500</td>
<td>1842</td>
<td>3076</td>
<td>9038</td>
<td>1777</td>
<td>1599</td>
<td>1516</td>
<td>1538</td>
<td>1574</td>
</tr>
<tr>
<td>8942</td>
<td>11052</td>
<td>10766</td>
<td>9038</td>
<td>10599</td>
<td>9537</td>
<td>9038</td>
<td>8998</td>
<td>9034</td>
</tr>
<tr>
<td>9000</td>
<td>11052</td>
<td>10766</td>
<td>18076</td>
<td>10667</td>
<td>9599</td>
<td>9096</td>
<td>9038</td>
<td>9074</td>
</tr>
</tbody>
</table>
<table anchor="sec-packets-per-second-on-10g-ethernet">
<name>Packets Per Second on 10G Ethernet</name>
<thead>
<tr>
<th>Size</th>
<th>E + P</th>
<th>E + P</th>
<th>E + P</th>
<th>IPTFS</th>
<th>IPTFS</th>
<th>IPTFS</th>
<th>Enet</th>
<th>ESP</th>
</tr>
<tr>
<th>MTU</th>
<th>590</th>
<th>1514</th>
<th>9014</th>
<th>590</th>
<th>1514</th>
<th>9014</th>
<th>any</th>
<th>any</th>
</tr>
<tr>
<th>OH</th>
<th>92</th>
<th>92</th>
<th>92</th>
<th>96</th>
<th>96</th>
<th>96</th>
<th>38</th>
<th>74</th>
</tr>
</thead>
<tbody>
<tr>
<td>40</td>
<td>2.0M</td>
<td>0.8M</td>
<td>0.1M</td>
<td>26.4M</td>
<td>29.3M</td>
<td>30.9M</td>
<td>14.9M</td>
<td>11.0M</td>
</tr>
<tr>
<td>128</td>
<td>2.0M</td>
<td>0.8M</td>
<td>0.1M</td>
<td>8.2M</td>
<td>9.2M</td>
<td>9.7M</td>
<td>7.5M</td>
<td>6.2M</td>
</tr>
<tr>
<td>256</td>
<td>2.0M</td>
<td>0.8M</td>
<td>0.1M</td>
<td>4.1M</td>
<td>4.6M</td>
<td>4.8M</td>
<td>4.3M</td>
<td>3.8M</td>
</tr>
<tr>
<td>518</td>
<td>2.0M</td>
<td>0.8M</td>
<td>0.1M</td>
<td>2.0M</td>
<td>2.3M</td>
<td>2.4M</td>
<td>2.2M</td>
<td>2.1M</td>
</tr>
<tr>
<td>576</td>
<td>1.0M</td>
<td>0.8M</td>
<td>0.1M</td>
<td>1.8M</td>
<td>2.0M</td>
<td>2.1M</td>
<td>2.0M</td>
<td>1.9M</td>
</tr>
<tr>
<td>1442</td>
<td>678K</td>
<td>812K</td>
<td>138K</td>
<td>731K</td>
<td>812K</td>
<td>857K</td>
<td>844K</td>
<td>824K</td>
</tr>
<tr>
<td>1500</td>
<td>678K</td>
<td>406K</td>
<td>138K</td>
<td>703K</td>
<td>781K</td>
<td>824K</td>
<td>812K</td>
<td>794K</td>
</tr>
<tr>
<td>8942</td>
<td>113K</td>
<td>116K</td>
<td>138K</td>
<td>117K</td>
<td>131K</td>
<td>138K</td>
<td>139K</td>
<td>138K</td>
</tr>
<tr>
<td>9000</td>
<td>113K</td>
<td>116K</td>
<td>69K</td>
<td>117K</td>
<td>130K</td>
<td>137K</td>
<td>138K</td>
<td>137K</td>
</tr>
</tbody>
</table>
<table anchor="sec-percentage-of-bandwidth-on-10g-ethernet" align="cen
ter">
<name>Percentage of Bandwidth on 10G Ethernet</name>
<thead>
<tr>
<th>Size</th>
<th>E + P</th>
<th>E + P</th>
<th>E + P</th>
<th>IP-TFS</th>
<th>IP-TFS</th>
<th>IP-TFS</th>
<th>Enet</th>
<th>ESP</th>
</tr>
<tr>
<th>MTU</th>
<th>590</th>
<th>1514</th>
<th>9014</th>
<th>590</th>
<th>1514</th>
<th>9014</th>
<th>any</th>
<th>any</th>
</tr>
<tr>
<th>OH</th>
<th>92</th>
<th>92</th>
<th>92</th>
<th>96</th>
<th>96</th>
<th>96</th>
<th>38</th>
<th>74</th>
</tr>
</thead>
<tbody>
<tr>
<td>40</td>
<td>6.51%</td>
<td>2.60%</td>
<td>0.44%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>47.62%</td>
<td>35.09%</td>
</tr>
<tr>
<td>128</td>
<td>20.85%</td>
<td>8.32%</td>
<td>1.42%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>77.11%</td>
<td>63.37%</td>
</tr>
<tr>
<td>256</td>
<td>41.69%</td>
<td>16.64%</td>
<td>2.83%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>87.07%</td>
<td>77.58%</td>
</tr>
<tr>
<td>518</td>
<td>84.36%</td>
<td>33.68%</td>
<td>5.73%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>93.17%</td>
<td>87.50%</td>
</tr>
<tr>
<td>576</td>
<td>46.91%</td>
<td>37.45%</td>
<td>6.37%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>93.81%</td>
<td>88.62%</td>
</tr>
<tr>
<td>1442</td>
<td>78.28%</td>
<td>93.76%</td>
<td>15.95%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>97.43%</td>
<td>95.12%</td>
</tr>
<tr>
<td>1500</td>
<td>81.43%</td>
<td>48.76%</td>
<td>16.60%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>97.53%</td>
<td>95.30%</td>
</tr>
<tr>
<td>8942</td>
<td>80.91%</td>
<td>83.06%</td>
<td>98.94%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>99.58%</td>
<td>99.18%</td>
</tr>
<tr>
<td>9000</td>
<td>81.43%</td>
<td>83.60%</td>
<td>49.79%</td>
<td>84.36%</td>
<td>93.76%</td>
<td>98.94%</td>
<td>99.58%</td>
<td>99.18%</td>
</tr>
</tbody>
</table>
<t>A sometimes unexpected result of using an AGGFRAG tunnel (or any pa
cket
aggregating tunnel) is that, for small- to medium-sized packets, the aggregating tunnel) is that, for small- to medium-sized packets, the
available bandwidth is actually greater than native Ethernet. This is available bandwidth is actually greater than plain Ethernet. This is
due to the reduction in Ethernet framing overhead. This increased due to the reduction in Ethernet framing overhead. This increased
bandwidth is paid for with an increase in latency. This latency is bandwidth is paid for with an increase in latency. This latency is
the time to send the unrelated octets in the outer tunnel frame. The the time to send the unrelated octets in the outer tunnel frame. The
following table illustrates the latency for some common values on a following table illustrates the latency for some common values on a
10G Ethernet link. The table also includes latency introduced by 10G Ethernet link. The table also includes latency introduced by
padding if using ESP with padding.</t> padding if using ESP with padding.</t>
<table anchor="sec-added-latency" align="center">
<figure title="Added Latency" anchor="sec-added-latency"><artwork><![CDATA[ <name>Added Latency</name>
ESP+Pad ESP+Pad IP-TFS IP-TFS <thead>
1500 9000 1500 9000 <tr>
<th>Size</th>
------------------------------------------ <th>ESP+Pad</th>
40 1.12 us 7.12 us 1.17 us 7.17 us <th>ESP+Pad</th>
128 1.05 us 7.05 us 1.10 us 7.10 us <th>IP-TFS</th>
256 0.95 us 6.95 us 1.00 us 7.00 us <th>IP-TFS</th>
518 0.74 us 6.74 us 0.79 us 6.79 us </tr>
576 0.70 us 6.70 us 0.74 us 6.74 us <tr>
1442 0.00 us 6.00 us 0.05 us 6.05 us <th>MTU</th>
1500 1.20 us 5.96 us 0.00 us 6.00 us <th>1500</th>
]]></artwork></figure> <th>9000</th>
<th>1500</th>
<t>Notice that the latency values are very similar between the two <th>9000</th>
</tr>
</thead>
<tbody>
<tr>
<td>40</td>
<td>1.12 us</td>
<td>7.12 us</td>
<td>1.17 us</td>
<td>7.17 us</td>
</tr>
<tr>
<td>128</td>
<td>1.05 us</td>
<td>7.05 us</td>
<td>1.10 us</td>
<td>7.10 us</td>
</tr>
<tr>
<td>256</td>
<td>0.95 us</td>
<td>6.95 us</td>
<td>1.00 us</td>
<td>7.00 us</td>
</tr>
<tr>
<td>518</td>
<td>0.74 us</td>
<td>6.74 us</td>
<td>0.79 us</td>
<td>6.79 us</td>
</tr>
<tr>
<td>576</td>
<td>0.70 us</td>
<td>6.70 us</td>
<td>0.74 us</td>
<td>6.74 us</td>
</tr>
<tr>
<td>1442</td>
<td>0.00 us</td>
<td>6.00 us</td>
<td>0.05 us</td>
<td>6.05 us</td>
</tr>
<tr>
<td>1500</td>
<td>1.20 us</td>
<td>5.96 us</td>
<td>0.00 us</td>
<td>6.00 us</td>
</tr>
</tbody>
</table>
<t>Notice that the latency values are very similar between the two
solutions; however, whereas IP-TFS provides for constant high solutions; however, whereas IP-TFS provides for constant high
bandwidth, in some cases even exceeding native Ethernet, ESP with bandwidth, in some cases even exceeding plain Ethernet, ESP with
padding often greatly reduces available bandwidth.</t> padding often greatly reduces available bandwidth.</t>
</section>
</section> </section>
</section>
</section> <section numbered="false" toc="default">
<name>Acknowledgements</name>
</section> <t>We would like to thank <contact fullname="Don Fedyk"/> for help in revi
ewing and editing
<section title="Acknowledgements"> this work. We would also like to thank <contact fullname="Michael Richardson"/>,
<t>We would like to thank Don Fedyk for help in reviewing and editing <contact fullname="Sean
this work. We would also like to thank Michael Richardson, Sean Turner"/>, <contact fullname="Valery Smyslov"/>, and <contact fullname="Tero Kiv
Turner, Valery Smyslov and Tero Kivinen for reviews and many inen"/> for reviews and many
suggestions for improvements, as well as Joseph Touch for the suggestions for improvements, as well as <contact fullname="Joseph Touch"/> for
the
transport area review and suggested improvements.</t> transport area review and suggested improvements.</t>
</section>
</section> <section numbered="false" toc="default">
<name>Contributors</name>
<section title="Contributors"> <t>The following person made significant contributions to this document.</
<t>The following people made significant contributions to this document.</t> t>
<contact fullname="Lou Berger">
<figure><artwork><![CDATA[ <organization>LabN Consulting, L.L.C.</organization>
Lou Berger <address>
LabN Consulting, L.L.C. <email>lberger@labn.net</email>
</address>
Email: lberger@labn.net </contact>
]]></artwork></figure> </section>
</section>
</back> </back>
</rfc> </rfc>
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