Skip to main content

IGP Extensions for SR Network Resource Partition SIDs
draft-bestbar-lsr-spring-nrp-01

Document Type Active Internet-Draft (individual)
Authors Tarek Saad , Vishnu Pavan Beeram , Ran Chen , Shaofu Peng , Bin Wen , Daniele Ceccarelli
Last updated 2022-07-11
Replaces draft-bestbar-lsr-spring-sa
Stream (None)
Intended RFC status (None)
Formats
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state I-D Exists
Telechat date (None)
Responsible AD (None)
Send notices to (None)
draft-bestbar-lsr-spring-nrp-01
LSR Working Group                                                T. Saad
Internet-Draft                                               V.P. Beeram
Intended status: Standards Track                        Juniper Networks
Expires: 12 January 2023                                         R. Chen
                                                                 S. Peng
                                                         ZTE Corporation
                                                                  B. Wen
                                                                 Comcast
                                                           D. Ceccarelli
                                                                Ericsson
                                                            11 July 2022

         IGP Extensions for SR Network Resource Partition SIDs
                    draft-bestbar-lsr-spring-nrp-01

Abstract

   Segment Routing (SR) defines a set of topological "segments" within
   an IGP topology to enable steering over a specific SR path.  These
   segments are advertised by the link-state routing protocols (IS-IS
   and OSPF).

   This document describes extensions to the IS-IS and OSPF required to
   support the signaling of Resource Partition (NRP) segments that
   operate over SR-MPLS and SRv6 dataplanes.  Multiple SR NRP segments
   can be associated with the same topological element to allow offering
   of different forwarding treatments (e.g. scheduling and drop policy)
   associated with each NRP.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 12 January 2023.

Saad, et al.             Expires 12 January 2023                [Page 1]
Internet-Draft               IGP SR NRP SIDs                   July 2022

Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  NRP SIDs for SR-MPLS  . . . . . . . . . . . . . . . . . . . .   3
     3.1.  IS-IS NRP Prefix-SID Sub-TLV  . . . . . . . . . . . . . .   4
     3.2.  IS-IS NRP Adjacency-SID Sub-TLV . . . . . . . . . . . . .   5
     3.3.  IS-IS NRP per Algorithm Adjacency-SID Sub-TLV . . . . . .   6
     3.4.  IS-IS NRP LAN Adjacency-SID Sub-TLV . . . . . . . . . . .   7
     3.5.  IS-IS NRP per Algorithm LAN Adjacency-SID Sub-TLV . . . .   8
   4.  NRP SIDs for SRv6 . . . . . . . . . . . . . . . . . . . . . .   9
     4.1.  SRv6 NRP SID Sub-Sub-TLV  . . . . . . . . . . . . . . . .   9
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
     5.1.  IS-IS Consideration . . . . . . . . . . . . . . . . . . .  10
     5.2.  SRv6 IS-IS NRP SID Sub-Sub-TLV  . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   7.  Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  11
   8.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  11
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .  12
     9.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   The Segment Routing (SR) architecture [RFC8402] defines a set of
   topological "segments" within an IGP topology as means to enable
   steering over a specific SR end-to-end path.  These segments are
   advertised by the IGP link-state routing protocols (IS-IS and OSPF).
   The SR control plane can be applied to both IPv6 and MPLS data
   planes.

Saad, et al.             Expires 12 January 2023                [Page 2]
Internet-Draft               IGP SR NRP SIDs                   July 2022

   The definition of a network slice for use within the IETF and the
   characteristics of IETF network slice are specified in
   [I-D.ietf-teas-ietf-network-slice-definition].  A framework for
   reusing IETF VPN and traffic-engineering technologies to realize IETF
   network slices is discussed in [I-D.nsdt-teas-ns-framework].

   [I-D.bestbar-teas-ns-packet] introduces a Slice-Flow Aggregate as the
   collection of packets (from one or more IETF network slice traffic
   streams) that match an NRP Policy selection criteria and are offered
   the same forwarding treatment.  The NRP Policy is used to realize an
   NRP by instantiating specific control and data plane resources on
   select topological elements in an IP/MPLS network.

   [I-D.bestbar-spring-scalable-ns] describes an approach to extend SR
   to advertise new SID types called NRP SIDs.  Such NRP SIDs are used
   by a router to define the forwarding action for a packet (next-hop
   selection), as well as to enforce the specific treatment (scheduling
   and drop policy) associated with the NRP.

   This document defines the IS-IS and OSPF specific encodings for the
   IGP-Prefix Segment, the IGP-Adjacency Segment, the IGP-LAN-Adjacency
   Segment that are required to support the signaling of SR NRP SIDs
   operating over SR-MPLS and SRv6 dataplanes.

   When the NRP segments share the same topology (and Algorithm for NRP
   Prefix-SIDs), the different NRP SIDs of the same topological element
   share the same forwarding path (i.e., IGP next-hop(s)), but are
   associated with the specific forwarding treatment (e.g. scheduling
   and drop policy) of each NRP.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  NRP SIDs for SR-MPLS

   Segment Routing can be directly instantiated on the MPLS data plane
   through the use of the Segment Routing header instantiated as a stack
   of MPLS labels defined in [RFC8402].

Saad, et al.             Expires 12 January 2023                [Page 3]
Internet-Draft               IGP SR NRP SIDs                   July 2022

3.1.  IS-IS NRP Prefix-SID Sub-TLV

   [RFC8667] defines the IS-IS Prefix Segment Identifier sub-TLV
   (Prefix-SID sub-TLV) that is applicable to SR-MPLS dataplane.  The
   Prefix-SID sub-TLV carries the Segment Routing IGP-Prefix-SID, and is
   associated with a prefix advertised by a router.

   A new IS-IS SR Network Resource Partition Prefix SID (NRP Prefix-SID)
   sub-TLV is defined to allow a router advertising a prefix to
   associate multiple NRP Prefix-SIDs to the same prefix.  The NRP
   Prefix-SIDs associated with the same prefix share the same IGP path
   to the destination prefix within the specific mapped or customized
   topology/algorithm but offer the specific QoS treatment associated
   with the specific NRP.

   The NRP ID is carried in the NRP Prefix-SID sub-TLV in order to
   associate the Prefix-SID with the specific NRP.  The NRP Prefix-SID
   sub-TLV has the following format:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |    Length     |     Flag      |   Algorithm   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             NRP-ID                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      SID/Index/Label(Variable)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 1: NRP Prefix-SID sub-TLV for SR-MPLS.

   where:

      Type: TBD1 (Suggested value to be assigned by IANA)

      Length: Variable.  Depending on the size of the SID.

      The "Flags" and "SID/Index/Label" fields are the same as the
      Prefix-SID sub-TLV [RFC8667].

      Algorithm: 1 octet.  Associated algorithm.  Algorithm values are
      defined in the IGP Algorithm Type registry

      NRP-ID: Identifies a specific NRP within the IGP domain.

   This sub-TLV MAY be present in any of the following TLVs:

      TLV-135 (Extended IPv4 reachability) defined in [RFC5305].

Saad, et al.             Expires 12 January 2023                [Page 4]
Internet-Draft               IGP SR NRP SIDs                   July 2022

      TLV-235 (Multitopology IPv4 Reachability) defined in [RFC5120].

      TLV-236 (IPv6 IP Reachability) defined in [RFC5308].

      TLV-237 (Multitopology IPv6 IP Reachability) defined in [RFC5120].

   This sub-TLV MAY appear multiple times in each TLV.

3.2.  IS-IS NRP Adjacency-SID Sub-TLV

   [RFC8667] defines the IS-IS Adjacency Segment Identifier sub-TLV
   (Adj-SID sub-TLV).  The Adj-SID sub-TLV is an optional sub-TLV
   carrying the Segment Routing IGP Adjacency-SID as defined in
   [RFC8402].

   A new SR Network Resource Partition Adjacency SID (NRP Adj-SID) sub-
   TLV is defined to allow a router to allocate and advertise multiple
   NRP Adj-SIDs towards the same IS-IS neighbor (adjacency).  The NRP
   Adj-SIDs allows a router to enforce the specific treatment associated
   with the NRP on the specific adjacency.

   The NRP ID is carried in the NRP Adj-SID sub-TLV to associate it to
   the specific NRP, and has the following format:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |     Flags     |     Weight    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           NRP-ID                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      SID/Index/Label(Variable)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                 Figure 2: NRP Adj-SID sub-TLV for SR-MPLS.

   where:

      Type: TBD2 (Suggested value to be assigned by IANA)

      Length: Variable.  Depending on the size of the SID.

      The "Flags", "SID/Index/Label", and "Weight" fields are the same
      as those defined for the Adj-SID sub-TLV in [RFC8667].

      NRP-ID: Identifies a specific NRP within the IGP domain.

   This sub-TLV MAY be present in any of the following TLVs:

Saad, et al.             Expires 12 January 2023                [Page 5]
Internet-Draft               IGP SR NRP SIDs                   July 2022

      TLV-22 (Extended IS reachability) [RFC5305].

      TLV-222 (Multitopology IS) [RFC5120].

      TLV-23 (IS Neighbor Attribute) [RFC5311].

      TLV-223 (Multitopology IS Neighbor Attribute) [RFC5311].

      TLV-141 (inter-AS reachability information) [RFC5316].

   Multiple Adj-SID sub-TLVs MAY be associated with a single IS-IS
   neighbor.  This sub-TLV MAY appear multiple times in each TLV.

3.3.  IS-IS NRP per Algorithm Adjacency-SID Sub-TLV

   [I-D.ietf-lsr-algorithm-related-adjacency-sid] defines ISIS Adjacency
   Segment Identifier (Adj-SID) per Algorithm Sub-TLV.

   A new per Algorithm SR NRP Adj-SID is defined to allow a router to
   allocate and advertise multiple NRP Adj-SIDs towards the same
   adjacency.  The per Algorithm NRP Adj-SID allow the router to enforce
   the specific forwarding treatment associated with the NRP on to
   packets using that NRP Adj-SID as active segment.

   The NRP ID is carried in the NRP per Algorithm Adj-SID sub-TLV to
   associate it to the specific NRP.  The sub-TLV has the following
   format:

        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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |     Flags     |     Weight    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Algorithm   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           NRP-ID                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         SID/Label/Index (variable)            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

          Figure 3: Per Algorithm NRP Adj-SID sub-TLV for SR-MPLS.

   where:

      Type: TBD3.

      Length: 10 or 11 depending on size of the SID.

Saad, et al.             Expires 12 January 2023                [Page 6]
Internet-Draft               IGP SR NRP SIDs                   July 2022

      NRP-ID: Identifies a specific NRP within the IGP domain.

      The "Flags", "SID/Index/Label", and "Weight" fields are the same
      as those defined for the Adj-SID sub-TLV in [RFC8667].

      The "Algorithm" field is as defined in
      [I-D.ietf-lsr-algorithm-related-adjacency-sid] for the per
      Algorithm Adj-SID Sub-TLV.

3.4.  IS-IS NRP LAN Adjacency-SID Sub-TLV

   In LAN subnetworks, [RFC8667] defines the SR-MPLS LAN-Adj-SID sub-TLV
   for a router to advertise the Adj-SID of each of its neighbors.

   A new SR Network Resource Partition LAN Adjacency SID (NRP LAN-Adj-
   SID) sub-TLV is defined to allow a router to allocate and advertise
   multiple NRP LAN-Adj-SIDs towards each of its neighbors on the LAN.
   The NRP LAN-Adj-SIDs allows a router to enforce the specific
   treatment associated with the specific NRP towards a neighbor.

   The NRP ID is carried in the NRP LAN-Adj-SID sub-TLV to associate it
   to the specific NRP, and it has the following format:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |      Flags    |    Weight     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           NRP-ID                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Neighbor System-ID (ID length octets)        |
      +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   SID/Label/Index (variable)                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 4: NRP LAN Adj-SID sub-TLV for SR-MPLS.

   where:

      Type: TBD4 (Suggested value to be assigned by IANA)

      Length: Variable.  Depending on the size of the SID.

Saad, et al.             Expires 12 January 2023                [Page 7]
Internet-Draft               IGP SR NRP SIDs                   July 2022

      The "Flags" and "SID/Index/Label" fields are the same as the LAN-
      Adj-SID sub-TLV [RFC8667].

      NRP-ID: Identifies a specific NRP within the IGP domain.

   This sub-TLV MAY be present in any of the following TLVs:

      TLV-22 (Extended IS reachability) [RFC5305].

      TLV-222 (Multitopology IS) [RFC5120].

      TLV-23 (IS Neighbor Attribute) [RFC5311].

      TLV-223 (Multitopology IS Neighbor Attribute) [RFC5311].

   Multiple LAN-Adj-SID sub-TLVs MAY be associated with a single IS-IS
   neighbor.  This sub-TLV MAY appear multiple times in each TLV.

3.5.  IS-IS NRP per Algorithm LAN Adjacency-SID Sub-TLV

   ISIS Adjacency Segment Identifier (LAN-Adj-SID) per Algorithm Sub-TLV
   has the following format:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     Type      |     Length    |      Flags    |    Weight     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Algorithm   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           NRP-ID                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                  Neighbor System-ID (ID length octets)        |
      +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   SID/Label/Index (variable)                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

        Figure 5: Per Algorithm NRP LAN Adj-SID sub-TLV for SR-MPLS.

   where:

      Type: TBD5.

      Length: Variable.

Saad, et al.             Expires 12 January 2023                [Page 8]
Internet-Draft               IGP SR NRP SIDs                   July 2022

      The "Flags", "SID/Index/Label", "Weight", and "Neighbor System-ID"
      fields are the same as those defined for the LAN-Adj-SID sub-TLV
      in [RFC8667].

      The "Algorithm" field is as defined in
      [I-D.ietf-lsr-algorithm-related-adjacency-sid] for the per
      Algorithm LAN-Adj-SID Sub-TLV.

      Editor Note: the OSPF Sub-TLV sections will be populated in
      further update.

4.  NRP SIDs for SRv6

   Segment Routing can be directly instantiated on the IPv6 data plane
   through the use of the Segment Routing Header defined in [RFC8754].
   SRv6 refers to this SR instantiation on the IPv6 dataplane.

   The SRv6 Locator TLV was introduced in
   [I-D.ietf-lsr-isis-srv6-extensions] to advertise SRv6 Locators and
   End SIDs associated with each locator.

4.1.  SRv6 NRP SID Sub-Sub-TLV

   The SRv6 End SID sub-TLV was introduced in
   [I-D.ietf-lsr-isis-srv6-extensions] to advertise SRv6 Segment
   Identifiers (SID) with Endpoint behaviors which do not require a
   particular neighbor.

   The SRv6 End SID sub-TLV is advertised in the SRv6 Locator TLV, and
   inherits the topology/algorithm from the parent locator.  The SRv6
   End SID sub-TLV defined in [I-D.ietf-lsr-isis-srv6-extensions]
   carries optional sub-sub-TLVs.

   A new SRv6 NRP SID Sub-Sub-TLV is defined to allow a router to assign
   and advertise an SRv6 End SID that is associated with a specific NRP.
   The SRv6 SID NRP Sub-Sub-TLV allows routers to infer and enforce the
   specific treatment associated with the NRP on the selected next-hops
   along the path to the End SID destination.

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Type        |     Length    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           NRP-ID                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 6: SRv6 SID NRP Sub-Sub-TLV format for SRv6.

Saad, et al.             Expires 12 January 2023                [Page 9]
Internet-Draft               IGP SR NRP SIDs                   July 2022

   where:

      Type: TBD6

      Length: 4 octets.

      NRP-ID: Identifies a specific NRP within the IGP domain.

   ISIS SRv6 SID NRP Sub-Sub-TLV MUST NOT appear more than once in its
   parent Sub-TLV.  If it appears more than once in its parent Sub- TLV,
   the parent Sub-TLV MUST be ignored by the receiver.

   The new SRv6 SID NRP Sub-Sub-TLV is an optional Sub-Sub-TLV of:

      SRv6 End SID Sub-TLV (Section 7.2 of
      [I-D.ietf-lsr-isis-srv6-extensions])

      SRv6 End.X SID Sub-TLV (Section 8.1 of
      [I-D.ietf-lsr-isis-srv6-extensions])

      SRv6 LAN End.X SID Sub-TLV (Section 8.2 of
      [I-D.ietf-lsr-isis-srv6-extensions])

5.  IANA Considerations

   This document requests allocation for the following Sub-TLVs types.

5.1.  IS-IS Consideration

   Table 1 summarizes registrations made in the "Sub-TLVs for TLV
   135,235,226 and 237 registry".

          +==============+========================+=============+
          | Sub-TLV Type | Description            | Reference   |
          +==============+========================+=============+
          | TBD1         | NRP Prefix-SID Sub-TLV | Section 3.1 |
          +--------------+------------------------+-------------+

                                  Table 1

      Table 1: Summary of Sub-TLV registrations for TLVs 135,235,226 and
                            237 (to be assigned by IANA).

   Table 2 summarizes registrations made in the "Sub-TLVs for TLV 22,
   23, 25, 141, 222, and 223" registry.

Saad, et al.             Expires 12 January 2023               [Page 10]
Internet-Draft               IGP SR NRP SIDs                   July 2022

     +==============+==================================+=============+
     | Sub-TLV Type | Description                      | Reference   |
     +==============+==================================+=============+
     | TBD2         | NRP Adj-SID Sub-TLV              | Section 3.2 |
     +--------------+----------------------------------+-------------+
     | TBD3         | NRP LAN-Adj-SID Sub-TLV          | Section 3.4 |
     +--------------+----------------------------------+-------------+
     | TBD4         | NRP Per Algo Adj-SID Sub-TLV     | Section 3.3 |
     +--------------+----------------------------------+-------------+
     | TBD5         | NRP Per Algo LAN-Adj-SID Sub-TLV | Section 3.5 |
     +--------------+----------------------------------+-------------+

                                  Table 2

     Table 2: Summary of Sub-TLV registrations for TLVs 22, 23, 25, 141,
                           222, and 223 (to be assigned by IANA).

5.2.  SRv6 IS-IS NRP SID Sub-Sub-TLV

   The below is a request to allocate a new sub-sub-TLV type from the
   "sub-sub-TLVs for SRv6 End SID and SRv6 End.X SID" registry:

      Type: TBD5 (to be assigned by IANA).  Reference: Section 4.1

6.  Security Considerations

   TBD.

7.  Acknowledgement

   The authors would like to thank Swamy SRK, and Prabhu Raj Villadathu
   Karunakaran for their review of this document, and for providing
   valuable feedback on it.

8.  Contributors

   The following individuals contributed to this document:

Saad, et al.             Expires 12 January 2023               [Page 11]
Internet-Draft               IGP SR NRP SIDs                   July 2022

      Colby Barth
      Juniper Networks
      Email: cbarth@juniper.net

      Srihari R.  Sangli
      Juniper Networks
      Email: ssangli@juniper.net

      Chandra Ramachandran
      Juniper Networks
      Email: csekar@juniper.net

9.  References

9.1.  Normative References

   [I-D.bestbar-spring-scalable-ns]
              Saad, T., Beeram, V. P., Chen, R., Peng, S., Wen, B., and
              D. Ceccarelli, "Scalable Network Slicing over SR
              Networks", Work in Progress, Internet-Draft, draft-
              bestbar-spring-scalable-ns-02, 16 September 2021,
              <https://www.ietf.org/archive/id/draft-bestbar-spring-
              scalable-ns-02.txt>.

   [I-D.bestbar-teas-ns-packet]
              Saad, T., Beeram, V. P., Dong, J., Wen, B., Ceccarelli,
              D., Halpern, J., Peng, S., Chen, R., Liu, X., Contreras,
              L. M., Rokui, R., and L. Jalil, "Realizing Network Slices
              in IP/MPLS Networks", Work in Progress, Internet-Draft,
              draft-bestbar-teas-ns-packet-10, 5 May 2022,
              <https://www.ietf.org/archive/id/draft-bestbar-teas-ns-
              packet-10.txt>.

   [I-D.ietf-lsr-algorithm-related-adjacency-sid]
              Peng, S., Chen, R., Talaulikar, K., and P. Psenak,
              "Algorithm Related IGP-Adjacency SID Advertisement", Work
              in Progress, Internet-Draft, draft-ietf-lsr-algorithm-
              related-adjacency-sid-02, 18 January 2022,
              <https://www.ietf.org/archive/id/draft-ietf-lsr-algorithm-
              related-adjacency-sid-02.txt>.

   [I-D.ietf-lsr-isis-srv6-extensions]
              Psenak, P., Filsfils, C., Bashandy, A., Decraene, B., and
              Z. Hu, "IS-IS Extensions to Support Segment Routing over
              IPv6 Dataplane", Work in Progress, Internet-Draft, draft-
              ietf-lsr-isis-srv6-extensions-18, 20 October 2021,
              <https://www.ietf.org/archive/id/draft-ietf-lsr-isis-srv6-
              extensions-18.txt>.

Saad, et al.             Expires 12 January 2023               [Page 12]
Internet-Draft               IGP SR NRP SIDs                   July 2022

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120,
              DOI 10.17487/RFC5120, February 2008,
              <https://www.rfc-editor.org/info/rfc5120>.

   [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
              Engineering", RFC 5305, DOI 10.17487/RFC5305, October
              2008, <https://www.rfc-editor.org/info/rfc5305>.

   [RFC5308]  Hopps, C., "Routing IPv6 with IS-IS", RFC 5308,
              DOI 10.17487/RFC5308, October 2008,
              <https://www.rfc-editor.org/info/rfc5308>.

   [RFC5311]  McPherson, D., Ed., Ginsberg, L., Previdi, S., and M.
              Shand, "Simplified Extension of Link State PDU (LSP) Space
              for IS-IS", RFC 5311, DOI 10.17487/RFC5311, February 2009,
              <https://www.rfc-editor.org/info/rfc5311>.

   [RFC5316]  Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in
              Support of Inter-Autonomous System (AS) MPLS and GMPLS
              Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316,
              December 2008, <https://www.rfc-editor.org/info/rfc5316>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8402]  Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
              July 2018, <https://www.rfc-editor.org/info/rfc8402>.

   [RFC8667]  Previdi, S., Ed., Ginsberg, L., Ed., Filsfils, C.,
              Bashandy, A., Gredler, H., and B. Decraene, "IS-IS
              Extensions for Segment Routing", RFC 8667,
              DOI 10.17487/RFC8667, December 2019,
              <https://www.rfc-editor.org/info/rfc8667>.

   [RFC8754]  Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
              Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
              (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
              <https://www.rfc-editor.org/info/rfc8754>.

Saad, et al.             Expires 12 January 2023               [Page 13]
Internet-Draft               IGP SR NRP SIDs                   July 2022

9.2.  Informative References

   [I-D.ietf-teas-ietf-network-slice-definition]
              Rokui, R., Homma, S., Makhijani, K., Contreras, L. M., and
              J. Tantsura, "Definition of IETF Network Slices", Work in
              Progress, Internet-Draft, draft-ietf-teas-ietf-network-
              slice-definition-01, 22 February 2021,
              <https://www.ietf.org/archive/id/draft-ietf-teas-ietf-
              network-slice-definition-01.txt>.

   [I-D.nsdt-teas-ns-framework]
              Gray, E. and J. Drake, "Framework for IETF Network
              Slices", Work in Progress, Internet-Draft, draft-nsdt-
              teas-ns-framework-05, 2 February 2021,
              <https://www.ietf.org/archive/id/draft-nsdt-teas-ns-
              framework-05.txt>.

Authors' Addresses

   Tarek Saad
   Juniper Networks
   Email: tsaad@juniper.net

   Vishnu Pavan Beeram
   Juniper Networks
   Email: vbeeram@juniper.net

   Ran Chen
   ZTE Corporation
   Email: chen.ran@zte.com.cn

   Shaofu Peng
   ZTE Corporation
   Email: peng.shaofu@zte.com.cn

   Bin Wen
   Comcast
   Email: Bin_Wen@cable.comcast.com

   Daniele Ceccarelli
   Ericsson
   Email: daniele.ceccarelli@ericsson.com

Saad, et al.             Expires 12 January 2023               [Page 14]