<?xml version="1.0"encoding="utf-8"?>encoding="UTF-8"?> <!-- pre-edited by ST 01/30/24 --> <!DOCTYPE rfc [ <!ENTITY nbsp " "> <!ENTITY zwsp "​"> <!ENTITY nbhy "‑"> <!ENTITY wj "⁠"> ]> <rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="std" ipr="trust200902" docName="draft-ietf-detnet-mpls-oam-15" number="9546" obsoletes="" updates="" submissionType="IETF" xml:lang="en" consensus="true" tocInclude="true" tocDepth="3" symRefs="true" sortRefs="true" version="3"><!-- xml2rfc v2v3 conversion 3.6.0 --> <?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?><front> <title abbrev="OAM for DetNet over MPLS">Operations,AdministrationAdministration, and Maintenance (OAM) for DeterministicNetworksNetworking (DetNet) with the MPLS Data Plane</title> <seriesInfoname="Internet-Draft" value="draft-ietf-detnet-mpls-oam-15"/>name="RFC" value="9546"/> <author initials="G." surname="Mirsky" fullname="Greg Mirsky"> <organization>Ericsson</organization> <address> <email>gregimirsky@gmail.com</email> </address> </author> <author fullname="Mach(Guoyi) Chen" initials="M." surname="Chen"> <organization>Huawei</organization> <address><postal> <street/> <city/> <code/> <country/> </postal><email>mach.chen@huawei.com</email> </address> </author> <author fullname="Balazs Varga" initials="B." surname="Varga"> <organization>Ericsson</organization> <address> <postal> <street>Magyar Tudosok krt. 11.</street> <city>Budapest</city> <country>Hungary</country> <code>1117</code> </postal> <email>balazs.a.varga@ericsson.com</email> </address> </author><!-- <author fullname="Janos Farkas" initials="J." surname="Farkas"> <organization>Ericsson</organization> <address> <postal> <street>Magyar Tudosok krt. 11.</street> <city>Budapest</city> <country>Hungary</country> <code>1117</code> </postal> <email>janos.farkas@ericsson.com</email> </address> </author> --><date month="February" year="2024"/><area>Routing</area> <workgroup>DetNet Working Group</workgroup> <keyword>Internet-Draft</keyword><area>RTG</area> <workgroup>detnet</workgroup> <keyword>DetNet</keyword> <keyword>OAM</keyword> <abstract> <t> This document defines format and usage principles of the DeterministicNetworkNetworking (DetNet) service Associated Channel over a DetNet network with the MPLS data plane. The DetNet service Associated Channel can be used to carry test packets of active Operations, Administration, and Maintenance (OAM) protocols that are used to detect DetNet failures and measure performance metrics. </t> </abstract> </front> <middle> <section anchor="intro" numbered="true" toc="default"> <name>Introduction</name> <t> <xref target="RFC8655" format="default"/> introduces and explains DeterministicNetworksNetworking (DetNet) architecture and how the Packet Replication, Elimination, and OrderingfunctionsFunctions (PREOF) can be used to ensure a low packet drop ratio in a DetNet domain. </t> <t> Operations, Administration, and Maintenance (OAM) protocols are used to detect and localize networkdefects,defects and to monitor network performance. Some OAM functions (e.g., failure detection) are usually performed proactively in the network, while others (e.g., defect localization) are typically performed on demand. These tasks can be achieved through a combination of active and hybrid OAM methods, as classified in <xref target="RFC7799" format="default"/>. This document presents a format for active OAM in DetNet networks with the MPLS data plane. </t> <t> Also, this document defines format and usage principles of the DetNet service Associated Channel over a DetNet network with the MPLS data plane <xref target="RFC8964" format="default"/>. </t> </section> <section numbered="true" toc="default"> <name>ConventionsusedUsed inthis document</name>This Document</name> <section numbered="true" toc="default"> <name>Terminology and Acronyms</name> <t> The term "DetNet OAM"is usedin this document is used interchangeably withlonger versiona "set of OAM protocols,methodsmethods, and tools for DeterministicNetworks".Networking". </t><t>DetNet Deterministic Network</t> <t>d-ACH DetNet<dl spacing="normal"> <dt>BFD:</dt><dd>Bidirectional Forwarding Detection</dd> <dt>CFM:</dt><dd>Connectivity Fault Management</dd> <dt>d-ACH:</dt><dd>DetNet Associated ChannelHeader</t> <t>OAM Operations, Administration, and Maintenance</t> <t>PREOF Packet Replication, Elimination,Header</dd> <dt>DetNet:</dt><dd>Deterministic Networking</dd> <dt>DetNet Node:</dt><dd>A node that is an actor in the DetNet domain. Examples of DetNet nodes include DetNet domain edge nodes andOrdering Functions</t> <t>PW Pseudowire</t> <t>E2E End-to-end</t> <t>BFD Bidirectional Forwarding Detection</t> <t>TSN IEEE 802.1 Time-Sensitive Networking</t> <t>CFM Connectivity Fault Management</t> <t>F-Label - aDetNet nodes that perform PREOF within the DetNet domain.</dd> <dt>E2E:</dt><dd>End to end</dd> <dt>F-Label:</dt><dd>A DetNet "forwarding" label. The F-Label identifies theLSPLabel Switched Path (LSP) used to forward a DetNet flow across an MPLSPSN,Packet Switched Network (PSN), e.g., a hop-by-hop label used between label switchingrouters.</t> <t>S-Label - arouters.</dd> <dt>OAM:</dt><dd>Operations, Administration, and Maintenance</dd> <dt>PREOF:</dt><dd>Packet Replication, Elimination, and Ordering Functions</dd> <dt>PW:</dt><dd>Pseudowire</dd> <dt>S-Label:</dt><dd>A DetNet "service" label. An S-Label is used between DetNet nodes that implement the DetNet service sub-layer functions. An S-Label is also used to identify a DetNet flow at the DetNet servicesub-layer.</t> <t> Underlaysub-layer.</dd> <dt>TSN:</dt><dd>Time-Sensitive Networking</dd> <dt>Underlay Network or UnderlayLayer - theLayer:</dt><dd>The network that provides connectivity between the DetNet nodes. One example of an underlay layer is an MPLS network that providesLabel Switched Path (LSP)LSP connectivity between DetNetnodes.</t> <t>DetNet Node - a node that is an actor in the DetNet domain. Examples of DetNet nodes include DetNet domain Edge nodes, and DetNet nodes that perform PREOF within the DetNet domain.</t>nodes.</dd> </dl> </section> <section numbered="true" toc="default"><name>Keywords</name><name>Key Words</name> <t> The key words"MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY","<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>", and"OPTIONAL""<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as described inBCP 14BCP 14 <xreftarget="RFC2119" format="default"/>target="RFC2119"/> <xreftarget="RFC8174" format="default"/>target="RFC8174"/> when, and only when, they appear in all capitals, as shown here. </t> </section> </section> <section anchor="oam-data-plane" numbered="true" toc="default"> <name>Active OAM for DetNet Networks with the MPLS Data Plane</name> <t> OAM protocols and mechanisms act within the data plane of the particular networkinglayer, thuslayer; thus, it is critical that the data plane encapsulation supports OAM mechanisms that comply with the OAM requirements listed in <xref target="I-D.ietf-detnet-oam-framework" format="default"/>. </t><!-- One such example that requires special consideration is requirement #5: </t> <ul empty="true" spacing="normal"> <li> DetNet OAM packets MUST be in-band, i.e., follow precisely the same path as DetNet data plane traffic both for unidirectional and bi-directional DetNet paths. </li> </ul> --><t> Operation of a DetNet data plane with an MPLS underlay network is specified in <xref target="RFC8964"/>. Within the MPLS underlay network, DetNet flows are to be encapsulated analogous to pseudowires (PWs) as specified in <xreftarget="RFC3985"/>,target="RFC3985"/> and <xref target="RFC4385"/>. For reference, the GenericPseudowire (PW)PW MPLS Control Word (as defined in <xref target="RFC4385"/> and used with DetNet) is reproduced in <xref target="detnet-pw-cw"/>. </t> <figure anchor="detnet-pw-cw"><name>DetNet<name>Generic PW MPLS Control Word Format</name> <artwork name="" type="" align="left" alt=""><![CDATA[ 0 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 0 0 0| Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ]]></artwork> </figure> <t> PREOF in the DetNet domain is composed of a combination of nodes that perform replication and elimination functions. The Elimination sub-function always uses the S-Label in conjunction with the packet sequencing information (i.e., the Sequence Number encoded in the DetNet Control Word). The Replication sub-function uses the S-Label information only. </t> <section anchor="active-oam-data-plane" numbered="true" toc="default"> <name>DetNet Active OAM Encapsulation</name> <t> DetNet OAM, like PW OAM, uses the PW Associated Channel Header defined in <xref target="RFC4385"/>. At the same time, a DetNet PW can be viewed as a Multi-Segment PW, where DetNet service sub-layer functions are at the segment endpoints. However, DetNet service sub-layer functions operate per packet level (not per segment). These per-packet level characteristics of PREOF require additional fields for proper OAM packet processing.Encapsulation of a DetNetMPLS encapsulation <xref target="RFC8964"/> of a DetNet active OAM packet is shown in <xref target="detnet-mpls-oam-format"/>. </t> <figure anchor="detnet-mpls-oam-format"> <name>DetNet Active OAM Packet Encapsulation in the MPLS Data Plane</name> <artwork name="" type="" align="left" alt=""><![CDATA[ +---------------------------------+ | | | DetNet OAM Packet | | | +---------------------------------+ <--\ | DetNet Associated Channel Header| | +---------------------------------+ +--> DetNet active OAM | S-Label | | MPLS encapsulation +---------------------------------+ | | [ F-Label(s) ] | | +---------------------------------+ <--/ | Data-Link | +---------------------------------+ | Physical | +---------------------------------+ ]]></artwork> </figure> <t> <xref target="detnet-mpls-oam-over-ip-format" format="default"/> displays encapsulation of a test packetof an activefor a DetNet active OAM protocol in case ofMPLS-over-UDP/IPMPLS over UDP/IP <xref target="RFC9025" format="default"/>. </t> <figure anchor="detnet-mpls-oam-over-ip-format"> <name>DetNet Active OAM Packet Encapsulation inMPLS-over-UDP/IP</name>MPLS over UDP/IP</name> <artwork name="" type="" align="left" alt=""><![CDATA[ +---------------------------------+ | | | DetNet OAM Packet | | | +---------------------------------+ <--\ | DetNet Associated Channel Header| | +---------------------------------+ +--> DetNet active OAM | S-Label | | MPLS encapsulation +---------------------------------+ | | [ F-label(s) ] | | +---------------------------------+ <--+ | UDP Header | | +---------------------------------+ +--> DetNet data plane | IP Header | | IP encapsulation +---------------------------------+ <--/ | Data-Link | +---------------------------------+ | Physical | +---------------------------------+ ]]></artwork> </figure> <t> <xref target="detnet-ach-oam" format="default"/> displays the format of the DetNet Associated Channel Header (d-ACH). </t> <figure anchor="detnet-ach-oam"> <name>d-ACH Format</name> <artwork name="" type="" align="left" alt=""><![CDATA[ 0 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 0 0 1|Version|Sequence Number| Channel Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Node ID |Level| Flags |Session| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ]]></artwork> </figure><t> The<dl newline="true" spacing="normal"> <dt>The d-ACH encodes the followingfields: </t> <ul empty="true" spacing="normal"> <li> Bits 0..3 MUSTfields:</dt> <dd><dl newline="false"> <dt>Bits 0..3:</dt><dd>These <bcp14>MUST</bcp14> be 0b0001. This allows the packet to be distinguished from an IP packet <xref target="RFC4928"/> and from a DetNet data packet <xref target="RFC8964"/>.</li> <li> Version - a</dd> <dt>Version:</dt><dd>A 4-bit field. This document specifies version 0.</li> <li> Sequence Number - is an</dd> <dt>Sequence Number:</dt><dd>An unsigned circular 8-bit field. Because atest packet ofDetNet active OAM test packet includes d-ACH,Section 4.2.1 of<xreftarget="RFC8964"/>target="RFC8964" sectionFormat="of" section="4.2.1"/> does not apply to handling the Sequence Number field in DetNet OAM over the MPLS data plane. The sequence number space is circular with no restriction on the initial value. The originator DetNet nodeMUST<bcp14>MUST</bcp14> set the value of the Sequence Number field before the transmission of a packet.theThe initial valueSHOULD<bcp14>SHOULD</bcp14> be random (unpredictable). The originator nodeSHOULD<bcp14>SHOULD</bcp14> increase the value of the Sequence Number field by 1 for each active OAM packet. The originatorMAY<bcp14>MAY</bcp14> use other strategies, e.g., for negative testing of Packet Ordering Functions.</li> <li> Channel Type - is a</dd> <dt>Channel Type:</dt><dd>A 16-bitfield,field and the value of the DetNet Associated Channel Type. ItMUST<bcp14>MUST</bcp14> be one of the values listed in the IANAMPLS"MPLS Generalized Associated Channel (G-ACh) Types (including Pseudowire Associated ChannelTypes)Types)" registry <xref target="IANA-G-ACh-Types"/>.</li> <li> Node ID - is an</dd> <dt>Node ID:</dt><dd>An unsigned 20-bit field. The value of the Node ID field identifies the DetNet node that originated the packet. A DetNet nodeMUST<bcp14>MUST</bcp14> be provisioned with a Node ID that is unique in the DetNet domain. Methodsoffor distributing Node ID are outside the scope of this specification.</li> <li>Level - is a</dd> <dt>Level:</dt><dd>A 3-bit field. Semantically, the Level field isanlogousanalogous to the Maintenance Domain Level in <xref target="IEEE.802.1Q"/>. The Level field is used to cope with the "all active path forwarding" (defined by the TSN Task Group of the IEEE 802.1 WG <xref target="IEEE802.1TSNTG"/>) characteristics of the PREOF concept. A hierarchical relationship between OAM domains can be created using the Level field value, as illustrated by Figure 18.7 in <xreftarget="IEEE.802.1Q"/>.</li> <li> Flags - is atarget="IEEE.802.1Q"/>.</dd> <dt>Flags:</dt><dd>A 5-bit field. The Flags field contains five 1-bit flags. <xref target="iana-mpls-oam-flags"/> creates the IANAd-ACH Flags"DetNet Associated Channel Header (d-ACH) Flags" registry for new flags to be defined. The flags defined in this specification are presented in <xreftarget="dach-flags-fig"/>. </li> </ul>target="dach-flags-fig"/>.</dd> <dt>Session ID:</dt><dd><t>A 4-bit field. The Session field distinguishes OAM sessions originating from the same node (a given Maintenance End Point may have multiple simultaneously active OAM sessions) at the given Level. </t> <figure anchor="dach-flags-fig"> <name>DetNet Associated Channel Header Flags Field Format</name> <artwork name="" type="" align="left" alt=""><![CDATA[ 0 1 2 3 4 +-+-+-+-+-+ |U|U|U|U|U| +-+-+-+-+-+ ]]></artwork> </figure><t> U: Unused</dd> </dl> </dd> </dl> <dl spacing="normal"> <dt>U:</dt><dd>Unused and for future use.MUST<bcp14>MUST</bcp14> be 0 on transmission and ignored onreceipt.</t> <ul empty="true" spacing="normal"> <li>Session ID is a 4-bit field. The Session field distinguishes OAM sessions originating from the same node (a given Maintenance End Point may have multiple simultaneously active OAM sessions) at the given Level.</li> </ul>receipt. </dd></dl> <t>A DetNet flow, accordingAccording to <xref target="RFC8964" format="default"/>, a DetNet flow is identified by the S-Label thatMUST<bcp14>MUST</bcp14> be at the bottom of the stack. AnActiveactive OAM packetMUST<bcp14>MUST</bcp14> include d-ACH immediately following the S-Label. </t> </section> <section anchor="oam-preof-sec" numbered="true" toc="default"> <name>DetNetPacket Replication, Elimination, and Ordering FunctionsPREOF Interaction with Active OAM</name> <t> At the DetNet service sub-layer, special functions (notably PREOF)MAY<bcp14>MAY</bcp14> be applied to the particular DetNet flow to potentially reduce packet loss, improve the probability of on-time packet delivery, and ensure in-order packet delivery. PREOF relies on sequencing information in the DetNet service sub-layer. For a DetNet active OAM packet, PREOFMUST<bcp14>MUST</bcp14> use the Sequence Number field value as the source of this sequencing information. App-flow and OAM use different sequence number spaces. PREOF algorithms are executed with respect to the sequence number space identified by the flow's characteristic information. Although the Sequence Number field in d-ACH has a range from 0 through 255, it provides sufficient space because the rate of DetNet active OAMpacketpackets is significantly lower compared to the rate of DetNet packets in an App-flow; therefore, wrapping around is not an issue. </t> </section> </section><!-- <section anchor="hybrid-oam" numbered="true" toc="default"> <name>Use of Hybrid OAM in DetNet</name> <t>Hybrid OAM methods are used in performance monitoring; they are defined in <xref target="RFC7799"/> as: </t> <ul empty="true" spacing="normal"> <li>Hybrid Methods are Methods of Measurement that use a combination of Active Methods and Passive Methods.</li> </ul> <t> A hybrid measurement method may produce metrics with results that are close to the results of passive measurement, but it inevitably alters something in a data packet even if it is only the value of a designated field in the packet encapsulation. One example of such a hybrid measurement method is the Alternate Marking method described in <xref target="RFC8321"/>. Reserving a field in the DetNet Header for Alternate Marking can be useful in providing additional options to the operator-provided set of DetNet OAM tools. </t> </section> --><section anchor="oam-interworking-sec" numbered="true" toc="default"> <name>OAM Interworking Models</name> <t> Interworking of two OAM domains that utilize different networking technology can be realizedeitherby either a peering model or a tunneling model. In a peering model, OAM domains are within the corresponding network domain. When using the peering model, state changes that are detected by a Fault Management OAM protocol can be mapped from one OAM domain into another or a notification, e.g., analarm,alarm can be sent to a central controller. In the tunneling model of OAM interworking,usually,usually only one active OAM protocol is used. Its test packets are tunneled through another domain along with the data flow, thus ensuringthefate sharing among test and data packets. </t> <section anchor="ip-over-tsn-sec" numbered="true" toc="default"> <name>OAM of DetNet MPLS Interworking with OAM of TSN</name> <t>ActiveDetNet active OAM can providetheend-to-end (E2E) fault management and performance monitoring for a DetNet flow. In the case of DetNet with an MPLS data plane and an IEEE 802.1 Time-Sensitive Networking (TSN) <!--<xref target=""/>--> sub-network,thisit implies the interworking of DetNet active OAM with TSN OAM, of which the data plane aspects are specified in <xref target="RFC9037"/>. </t> <t> When the peering model (<xref target="oam-interworking-sec"/>) is used in the Connectivity Fault Management (CFM) OAM protocol <xref target="IEEE.802.1Q"/>,thenthe node that borders both TSN and DetNet MPLS domainsMUST<bcp14>MUST</bcp14> support <xref target="RFC7023" format="default"/>. <xref target="RFC7023" format="default"/> specifies the mapping of defect states between Ethernet Attachment Circuits and associated Ethernet PWs that are part of an E2E emulated Ethernetservice,service and are also applicable to E2E OAM across DetNet MPLS and TSN domains. The CFM <xref target="IEEE.802.1Q"/>or in<xref target="ITU.Y1731"/> can provide fast detection of a failure in the TSN segment of the DetNet service. In the DetNet MPLSdomain BFD (Bidirectionaldomain, Bidirectional ForwardingDetection),Detection (BFD), as specified in <xref target="RFC5880"/> and <xref target="RFC5885"/>, can be used. To provide E2E failure detection, the TSN and DetNet MPLS segments could be treated as concatenated such that the diagnostic codes (seeSection 6.8.17 of<xreftarget="RFC5880"/>) MAYtarget="RFC5880" sectionFormat="of" section="6.8.17"/>) <bcp14>MAY</bcp14> be used to inform the upstream DetNet MPLS node of afailure of theTSNsegment.segment failure. Performance monitoring can be supported by <xref target="RFC6374"/> in the DetNet MPLS and by <xref target="ITU.Y1731"/> intheTSN domains, respectively. Performance objectives for each domain should refer to metrics thatisare composable <xref target="RFC6049"/> orbeare defined for each domain separately. </t> <t> The following considerations apply when using the tunneling model of OAM interworking between DetNet MPLS and TSN domains based on general principles described inSection 4 of<xreftarget="RFC9037"/>:target="RFC9037" sectionFormat="of" section="4"/>: </t> <ul spacing="normal"> <li>Active OAM test packetsMUST<bcp14>MUST</bcp14> be mapped to the same TSN Stream ID as the monitored DetNet flow.</li> <li>Active OAM test packetsMUST<bcp14>MUST</bcp14> betreatedprocessed in the TSN domain based onitstheir S-Label and Class of Service marking (the Traffic Class field value).</li> </ul> <t> Mapping between a DetNet flow and TSN Stream in the TSN sub-network is described inSection 4.1 of<xreftarget="RFC9037"/>.target="RFC9037" sectionFormat="of" section="4.1"/>. The mapping has to be done only on the edge node of the TSN sub-network, and intermediate TSN nodes do not need to recognize the S-Label. An edge node has two components: </t> <ol> <li>A passive Stream identification function.</li> <li>An active Stream identification function.</li> </ol> <t>The first component identifies the DetNet flow (using Clause 6.8 of <xref target="IEEE.802.1CBdb"/>), and the second component creates the TSN Stream by manipulating the Ethernet header. That manipulation simplifies the identification of the TSN Stream in the intermediate TSN nodes by avoiding the need for them to look outside of the Ethernet header. DetNet MPLS OAM packets use the same S-Label as the DetNet flow data packets. The above-described mapping function treats these OAM packets as data packets of the DetNet flow. As a result, DetNet MPLS OAM packets arefate-sharingfate sharing within the TSN sub-network. As an example of the mapping between DetNet MPLS and TSN, see Annex C.1 of <xref target="IEEE.802.1CBdb"/> that, in support of <xref target="RFC9037"/>, describes how to match MPLS DetNet flows and achieve TSNStreams can be achieved.Streams. </t> <t> Note that the tunneling model of the OAM interworking requires that the remote peer of the E2E OAM domain supports the active OAM protocol selected on the ingress endpoint. For example, if BFD is used for proactive path continuity monitoring in the DetNet MPLS domain, BFD support (as defined in <xref target="RFC5885"/>) is necessary at any TSN endpoint of the DetNet service. </t> </section> <section anchor="ip-over-ip-sec" numbered="true" toc="default"> <name>OAM of DetNet MPLS Interworking with OAM of DetNet IP</name> <t> Interworking between active OAM segments in DetNet MPLS and DetNet IP domains can also be realized using either the peering model or the tunneling model, as discussed in <xref target="ip-over-tsn-sec" format="default"/>. Using the same protocol, e.g.,BFD,BFD over both segments, simplifies the mapping of errors in the peering model. For example, respective BFD sessions in DetNet MPLS and DetNet IP domains can be in a concatenated relationship as described inSection 6.8.17 of<xreftarget="RFC5880"/>.target="RFC5880" sectionFormat="of" section="6.8.17"/>. To provide performance monitoring over a DetNet IP domain,STAMPthe Simple Two-way Active Measurement Protocol (STAMP) <xref target="RFC8762"/> and its extensions <xref target="RFC8972"/> can be used to measure packet loss and packet delay metrics. Such performance metrics can be used to calculate composable metrics <xref target="RFC6049"/> within DetNet MPLS and DetNet IP domains to reflect the end-to-end DetNet service performance. </t> </section> </section> <section anchor="iana-considerations" numbered="true" toc="default"> <name>IANA Considerations</name> <section anchor="iana-mpls-oam-flags" numbered="true" toc="default"> <name>DetNet Associated Channel Header (d-ACH) Flags Registry</name><t> This document describes a new IANA-managed registry to identify d-ACH Flags bits. The registration procedure is "IETF Review" <xref target="RFC8126"/>. The registry name is<t>IANA has created the "DetNet Associated Channel Header (d-ACH)Flags". IANA should treatFlags" registry within the "DetNet Associated Channel Header (d-ACH) Flags"as the name of theregistry group. The registration procedure is "IETF Review" <xref target="RFC8126"/>. There are five flags in thefive-bit5-bit Flags field,definedas defined in <xref target="iana-dach-flags-tbl"/>. </t> <table anchor="iana-dach-flags-tbl" align="center"> <name>DetNet Associated Channel Header (d-ACH)Flags</name>Flags Registry</name> <thead> <tr> <th align="left">Bit</th> <th align="center">Description</th><th align="left">Reference</th></tr> </thead> <tbody> <tr> <td align="left">0-4</td> <td align="center">Unassigned</td><td align="left">This document</td></tr> </tbody> </table> </section> </section> <section anchor="security-considerations" numbered="true" toc="default"> <name>Security Considerations</name> <t> Security considerations discussed in DetNet specifications <xref target="RFC8655"/>, <xreftarget="RFC9055"/>, <xreftarget="RFC8964"/>, <xref target="RFC9055"/>, and <xref target="I-D.ietf-detnet-oam-framework"/> are applicable to this document. Security concerns and issues related to MPLS OAM tools like LSP Ping <xreftarget="RFC8029"/>,target="RFC8029"/> and BFD over PW <xref target="RFC5885"/> also apply to this specification. </t> </section><section anchor="ack" numbered="true" toc="default"> <name>Acknowledgment</name> <t> Authors extend their appreciation to Pascal Thubert for his insightful comments and productive discussion that helped to improve the document. The authors are enormously grateful to Janos Farkas for his detailed comments and the inspiring discussion that made this document clearer and stronger. The authors recognize helpful reviews and suggestions from Andrew Malis, David Black, Tianran Zhou, and Kiran Makhijani. And special thanks are addressed to Ethan Grossman for his fantastic help in improving the document. </t> </section></middle> <back><!-- References split into informative and normative --><displayreference target="I-D.ietf-detnet-oam-framework" to="OAM-FRAMEWORK"/> <references> <name>References</name> <references> <name>Normative References</name> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <!-- <?rfc include="reference.RFC.5586"?> <?rfc include="reference.RFC.6423"?> -->href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7023.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7023.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8655.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8655.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8964.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8964.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9025.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9025.xml"/> </references> <references><name>Informational<name>Informative References</name> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7799.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.7799.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6374.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6374.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3985.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3985.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4385.xml"/> <!--href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4385.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8321.xml"/> -->href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4928.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4928.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5880.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5880.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5885.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5885.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8029.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8029.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8762.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8762.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8972.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8972.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9055.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9055.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9037.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9037.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/> <xi:includehref="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6049.xml"/> <xi:include href="https://datatracker.ietf.org/doc/bibxml3/draft-ietf-detnet-oam-framework.xml"/>href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6049.xml"/> <!-- [I-D.ietf-detnet-oam-framework] IESG State: RFC Ed Queue as of 2/21/24. Entered long way to get the correct initials--> <reference anchor="I-D.ietf-detnet-oam-framework" target="https://datatracker.ietf.org/doc/html/draft-ietf-detnet-oam-framework-11"> <front> <title>Framework of Operations, Administration and Maintenance (OAM) for Deterministic Networking (DetNet)</title> <author fullname="Greg Mirsky" initials="G." surname="Mirsky"> <organization>Ericsson</organization> </author> <author fullname="Fabrice Theoleyre" initials="F." surname="Theoleyre"> <organization>CNRS</organization> </author> <author fullname="Georgios Z. Papadopoulos" initials="G. Z." surname="Papadopoulos"> <organization>IMT Atlantique</organization> </author> <author fullname="Carlos J. Bernardos" initials="CJ." surname="Bernardos"> <organization>Universidad Carlos III de Madrid</organization> </author> <author fullname="Balazs Varga" initials="B." surname="Varga"> <organization>Ericsson</organization> </author> <author fullname="János Farkas" initials="J." surname="Farkas"> <organization>Ericsson</organization> </author> <date day="8" month="January" year="2024"/> </front> <seriesInfo name="Internet-Draft" value="draft-ietf-detnet-oam-framework-11"/> </reference> <reference anchor="IEEE.802.1CBdb"> <front> <title>IEEE Standard for Local and metropolitan area networks--Frame Replication and Elimination forReliability AmendmentReliability--Amendment 2: Extended Stream Identification Functions</title> <author> <organization>IEEE</organization> </author> <date month="December" year="2021"/> </front> <seriesInfoname="IEEE" value="802.1CBdb"/>name="IEEE Std" value="802.1CBdb-2021"/> </reference> <reference anchor="IEEE.802.1Q"> <front><title>Bridges<title>IEEE Standard for Local and Metropolitan Area Network--Bridges and Bridged Networks</title> <author> <organization>IEEE</organization> </author> <dateyear="2014"/>month="July" year="2018"/> </front> <seriesInfoname="IEEE" value="802.1Q"/>name="IEEE Std" value="802.1Q-2018"/> <seriesInfo name="DOI" value="10.1109/IEEESTD.2018.8403927"/> </reference> <reference anchor="IEEE802.1TSNTG" target="https://1.ieee802.org/tsn/" quoteTitle="true" derivedAnchor="IEEE802.1TSNTG"> <front> <title>Time-Sensitive Networking (TSN) Task Group</title> <author><organization showOnFrontPage="true">IEEE</organization><organization>IEEE 802.1</organization> </author> </front><seriesInfo name="IEEE" value="802.1Q"/><refcontent>TSN Standards</refcontent> </reference> <reference anchor="ITU.Y1731"> <front><title>OAM<title>Operation, administration and maintenance (OAM) functions and mechanisms forEthernet based Networks</title>Ethernet-based networks</title> <author> <organization>ITU-T</organization> </author> <datemonth="November" year="2013"/>month="June" year="2023"/> </front> <seriesInfo name="ITU-T Recommendation" value="G.8013/Y.1731"/> </reference> <reference anchor="IANA-G-ACh-Types"target="https://www.iana.org/assignments/g-ach-parameters/g-ach-parameters.xhtml#mpls-g-ach-types">target="https://www.iana.org/assignments/g-ach-parameters/"> <front> <title>MPLS Generalized Associated Channel (G-ACh) Types (including Pseudowire Associated Channel Types)</title> <author> <organization>IANA</organization> </author> </front> </reference> </references> </references> <section anchor="ack" numbered="false" toc="default"> <name>Acknowledgments</name> <t> The authors extend their appreciation to <contact fullname="Pascal Thubert"/> for his insightful comments and productive discussion that helped to improve the document. The authors are enormously grateful to <contact fullname="János Farkas"/> for his detailed comments and the inspiring discussion that made this document clearer and stronger. The authors recognize helpful reviews and suggestions from <contact fullname="Andrew Malis"/>, <contact fullname="David Black"/>, <contact fullname="Tianran Zhou"/>, and <contact fullname="Kiran Makhijani"/>. And special thanks to <contact fullname="Ethan Grossman"/> for his fantastic help in improving the document. </t> </section> </back> </rfc>