| rfc9015v3.txt | rfc9015.txt | |||
|---|---|---|---|---|
| skipping to change at line 391 ¶ | skipping to change at line 391 ¶ | |||
| administrator. | administrator. | |||
| It is envisaged that the majority of SFT values used will be assigned | It is envisaged that the majority of SFT values used will be assigned | |||
| from the First Come First Served space in the registry. This will | from the First Come First Served space in the registry. This will | |||
| ensure interoperability, especially in situations where software and | ensure interoperability, especially in situations where software and | |||
| hardware from different vendors are deployed in the same networks, or | hardware from different vendors are deployed in the same networks, or | |||
| when networks are merged. However, operators of private networks may | when networks are merged. However, operators of private networks may | |||
| choose to develop their own SFs and manage the configuration and | choose to develop their own SFs and manage the configuration and | |||
| operation of their network through their own list of SFT values. | operation of their network through their own list of SFT values. | |||
| This document also introduces a new BGP AFI/SAFI (values to be | This document also introduces a new BGP AFI/SAFI (values 31 and 9, | |||
| assigned by IANA) for "SFC Routes". Two SFC Route Types are defined | respectively) for "SFC Routes". Two SFC Route Types are defined by | |||
| by this document: the Service Function Instance Route (SFIR) and the | this document: the Service Function Instance Route (SFIR) and the | |||
| Service Function Path Route (SFPR). As detailed in Section 3, the | Service Function Path Route (SFPR). As detailed in Section 3, the | |||
| Route Type is indicated by a subfield in the Network Layer | Route Type is indicated by a subfield in the Network Layer | |||
| Reachability Information (NLRI). | Reachability Information (NLRI). | |||
| * The SFIR is advertised by the node that provides access to the | * The SFIR is advertised by the node that provides access to the | |||
| service function instance (i.e., the SFF). The SFIR describes a | service function instance (i.e., the SFF). The SFIR describes a | |||
| particular instance of a particular SF (i.e., an SFI) and the way | particular instance of a particular SF (i.e., an SFI) and the way | |||
| to forward a packet to it through the underlay network, i.e., IP | to forward a packet to it through the underlay network, i.e., IP | |||
| address and encapsulation information. | address and encapsulation information. | |||
| skipping to change at line 571 ¶ | skipping to change at line 571 ¶ | |||
| 2. Service Function Path Route (SFPR) | 2. Service Function Path Route (SFPR) | |||
| An SFIR is used to identify an SFI. An SFPR defines a sequence of | An SFIR is used to identify an SFI. An SFPR defines a sequence of | |||
| SFs (each of which has at least one instance advertised in an SFIR) | SFs (each of which has at least one instance advertised in an SFIR) | |||
| that form an SFP. | that form an SFP. | |||
| The detailed encoding and procedures for these Route Types are | The detailed encoding and procedures for these Route Types are | |||
| described in subsequent sections. | described in subsequent sections. | |||
| The SFC NLRI is carried in BGP [RFC4271] using BGP Multiprotocol | The SFC NLRI is carried in BGP [RFC4271] using BGP Multiprotocol | |||
| Extensions [RFC4760] with an Address Family Identifier (AFI) of TBD1 | Extensions [RFC4760] with an Address Family Identifier (AFI) of 31 | |||
| and a Subsequent Address Family Identifier (SAFI) of TBD2. The | and a Subsequent Address Family Identifier (SAFI) of 9. The "NLRI" | |||
| "NLRI" field in the MP_REACH_NLRI/MP_UNREACH_NLRI attribute contains | field in the MP_REACH_NLRI/MP_UNREACH_NLRI attribute contains the SFC | |||
| the SFC NLRI, encoded as specified above. | NLRI, encoded as specified above. | |||
| In order for two BGP speakers to exchange SFC NLRIs, they MUST use | In order for two BGP speakers to exchange SFC NLRIs, they MUST use | |||
| BGP capabilities advertisements to ensure that they both are capable | BGP capabilities advertisements to ensure that they both are capable | |||
| of properly processing such NLRIs. This is done as specified in | of properly processing such NLRIs. This is done as specified in | |||
| [RFC4760], by using capability code 1 (Multiprotocol BGP) with an AFI | [RFC4760], by using capability code 1 (Multiprotocol BGP) with an AFI | |||
| of TBD1 and a SAFI of TBD2. | of 31 and a SAFI of 9. | |||
| The "nexthop" field of the MP_REACH_NLRI attribute of the SFC NLRI | The "nexthop" field of the MP_REACH_NLRI attribute of the SFC NLRI | |||
| MUST be set to a loopback address of the advertising SFF. | MUST be set to a loopback address of the advertising SFF. | |||
| 3.1. Service Function Instance Route (SFIR) | 3.1. Service Function Instance Route (SFIR) | |||
| Figure 3 shows the Route Type specific NLRI of the SFIR. | Figure 3 shows the Route Type specific NLRI of the SFIR. | |||
| +--------------------------------------------+ | +--------------------------------------------+ | |||
| | Route Distinguisher (RD) (8 octets) | | | Route Distinguisher (RD) (8 octets) | | |||
| skipping to change at line 1678 ¶ | skipping to change at line 1678 ¶ | |||
| Note that, according to [RFC8955], a given flow-specification update | Note that, according to [RFC8955], a given flow-specification update | |||
| may include multiple of these action Extended Communities. If a | may include multiple of these action Extended Communities. If a | |||
| given action extended community does not contain an installed SFPR | given action extended community does not contain an installed SFPR | |||
| with the specified {SPI, SI, SFT}, it MUST NOT be used for | with the specified {SPI, SI, SFT}, it MUST NOT be used for | |||
| dispositioning the packets of the specified flow. | dispositioning the packets of the specified flow. | |||
| The normal case of packet classification for service function | The normal case of packet classification for service function | |||
| chaining will see a packet enter the SFP at its first hop. In this | chaining will see a packet enter the SFP at its first hop. In this | |||
| case, the SI in the Extended Community is superfluous, and the SFT | case, the SI in the Extended Community is superfluous, and the SFT | |||
| may also be unnecessary. To allow these cases to be handled, a | may also be unnecessary. To allow these cases to be handled, a | |||
| special meaning is assigned to a SI of zero (not a valid value) and | special meaning is assigned to an SI of zero (not a valid value) and | |||
| an SFT of zero (a reserved value in the registry -- see | an SFT of zero (a reserved value in the registry -- see | |||
| Section 10.5). | Section 10.5). | |||
| * If an SFC Classifiers Extended Community is received with SI = 0, | * If an SFC Classifiers Extended Community is received with SI = 0, | |||
| then it means that the first hop of the SFP indicated by the SPI | then it means that the first hop of the SFP indicated by the SPI | |||
| MUST be used. | MUST be used. | |||
| * If an SFC Classifiers Extended Community is received with SFT = 0, | * If an SFC Classifiers Extended Community is received with SFT = 0, | |||
| then there are two subcases: | then there are two subcases: | |||
| skipping to change at line 2741 ¶ | skipping to change at line 2741 ¶ | |||
| mechanisms described in this document: | mechanisms described in this document: | |||
| * That modifications to active SFPs not be made. | * That modifications to active SFPs not be made. | |||
| * That SPIs not be immediately reused. | * That SPIs not be immediately reused. | |||
| 10. IANA Considerations | 10. IANA Considerations | |||
| 10.1. New BGP AF/SAFI | 10.1. New BGP AF/SAFI | |||
| IANA maintains a registry of "Address Family Numbers". IANA is | IANA maintains the "Address Family Numbers" registry. IANA has | |||
| requested to assign a new Address Family Number from the "Standards | assigned a new Address Family Number from the "Standards Action" | |||
| Action" range called "BGP SFC" (TBD1 in this document), with this | range called "BGP SFC" (31), with this document as a reference. | |||
| document as a reference. | ||||
| IANA maintains a registry of "Subsequent Address Family Identifiers | IANA maintains the "Subsequent Address Family Identifiers (SAFI) | |||
| (SAFI) Parameters". IANA is requested to assign a new SAFI value | Parameters" registry. IANA has assigned a new SAFI value from the | |||
| from the "Standards Action" range called "BGP SFC" (TBD2 in this | "Standards Action" range called "BGP SFC" (9), with this document as | |||
| document), with this document as a reference. | a reference. | |||
| 10.2. "SFP attribute" BGP Path Attribute | 10.2. "SFP attribute" BGP Path Attribute | |||
| IANA maintains a registry of "Border Gateway Protocol (BGP) | IANA maintains a registry of "Border Gateway Protocol (BGP) | |||
| Parameters" with a subregistry of "BGP Path Attributes". IANA has | Parameters" with a subregistry of "BGP Path Attributes". IANA has | |||
| assigned a new Path attribute called "SFP attribute" with a value of | assigned a new Path attribute called "SFP attribute" with a value of | |||
| 37 and with this document as a reference. | 37 and with this document as a reference. | |||
| 10.3. "SFP Attribute TLVs" Registry | 10.3. "SFP Attribute TLVs" Registry | |||
| End of changes. 6 change blocks. | ||||
| 17 lines changed or deleted | 16 lines changed or added | |||
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