L R. chen Internet-Draft Sh. Peng Intended status: Standards Track ZTE Corporation Expires: May 8, 2022 T. Saad V. Beeram Juniper Networks November 4, 2021 BGP-LS Extensions for Network Resource Partition identifier draft-chen-idr-bgp-ls-transport-slice-03 Abstract This draft defines extensions to BGP-LS protocol in order to advertise Network Resource Partition SR segments that share the same IGP computed forwarding path but offer a forwarding treatment (e.g. scheduling and drop policy) that is associated with a specific Network Resource. The draft is applicable to both SR-MPLS and SRv6 dataplanes. 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 May 8, 2022. Copyright Notice Copyright (c) 2021 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 chen, et al. Expires May 8, 2022 [Page 1] Internet-Draft BGP-LS Extensions for NRPID November 2021 to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Acronyms and Abbreviations . . . . . . . . . . . . . . . 3 3. NRPID SID for SR-MPLS . . . . . . . . . . . . . . . . . . . . 3 3.1. Node Attributes TLV . . . . . . . . . . . . . . . . . . . 3 3.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 4 3.2.1. NRPID list sub-TLV . . . . . . . . . . . . . . . . . 5 3.2.2. L2 Bundle Member NRPID TLV . . . . . . . . . . . . . 5 3.2.3. NRPID Adjacency-SID TLV . . . . . . . . . . . . . . . 6 3.2.4. NRPID LAN-Adj-SID TLV . . . . . . . . . . . . . . . . 7 3.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 8 4. NRPID SID for SRv6 . . . . . . . . . . . . . . . . . . . . . 9 4.1. Router Capabilities for NRPID . . . . . . . . . . . . . . 9 4.2. NRPID SID sub-TLV . . . . . . . . . . . . . . . . . . . . 10 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 7. Normative References . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction [I-D.bestbar-teas-ns-packet] introduces the notion of a slice aggregate which comprises of one of more IETF network slice traffic streams. It also describes the slice policy that is used to instantiate control and data plane behaviors on select topological elements associated with the Network Resource Partition that supports a slice aggregate. [I-D.bestbar-spring-scalable-ns] describes an approach to extend SR to advertiser new SID types called Network Resource Partition identifier(NRPID) SIDs. Such NRPID SIDs are used on a router to define the forwarding action for a packet (next-hop selection), as well as enforce the specific treatment (scheduling and drop policy) associated with the Slice Aggregate. [I-D.bestbar-lsr-spring-sa]describes extensions to the IS-IS that enable advertising Network Resource Partition identifier(NRPID) SR segments that share the same IGP computed forwarding path but offer a forwarding treatment (e.g. scheduling and drop policy) that is associated with a specific Slice Aggregate. chen, et al. Expires May 8, 2022 [Page 2] Internet-Draft BGP-LS Extensions for NRPID November 2021 In order to satisfy the need for applications that require topological visibility across one area or Autonomous System (AS). This document specifies extensions to the BGP Link-state address- family in order to advertise the information of Network Resource Partition SIDs. An external component (e.g., a controller) then can collect Network Resource Partition SIDs in the "northbound" direction. The draft is applicable to both SR-MPLS and SRv6 dataplanes. 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. 2.1. Terminology Slice Aggregate:a collection of packets that match a slice policy selection criteria and are given the same forwarding treatment; a slice aggregate comprises of one or more IETF network slice traffic streams; the mapping of one or more IETF network slices to a slice aggregate is maintained by the IETF Network Slice Controller. Network Resource Partition:the collection of resources that are used to support a slice aggregate. 2.2. Acronyms and Abbreviations NRPID: Network Resource Partition identifier. 3. NRPID SID for SR-MPLS BGP-LS[[RFC7752]]defines the link-state NLRI that can be a Node NLRI, a Link NLRI or a Prefix NLRI. The link-state information is mapped to BGP link-state NLRI within the BGP-LS Attribute. In addition, [I-D.ietf-idr-bgpls-inter-as-topology-ext] defines Stub Link NLRI that is used to describe the inter-as link. This document adds additional BGP-LS Attribute TLVs in order to encode Network Resource Partition information. It does not introduce any changes to the encoding of the BGP-LS NLRIs. 3.1. Node Attributes TLV The Network Resource abbribute TLV is used in order to advertise which Network Resource a router wants to take part in. The NRPID chen, et al. Expires May 8, 2022 [Page 3] Internet-Draft BGP-LS Extensions for NRPID November 2021 sub-TLV is a new TLV of the optional BGP-LS Attribute that is associated with the node NLRI. The NRPID 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 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD1 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID-1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID-n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: NRPID TLV where: Type: TBD1 (Suggested value to be assigned by IANA) Length: variable. NRPID: Network Resource Partition ID is used to indication the resources on specific link(s)/node(s) that will be traversed by a slice-aggregate. 3.2. Link Attribute TLVs The following Link Attribute TLVs are are defined: chen, et al. Expires May 8, 2022 [Page 4] Internet-Draft BGP-LS Extensions for NRPID November 2021 +-------+---------------------------------------------+ | Type | Description | +-------+---------------------------------------------+ | TBD2 | NRPID list TLV | | TBD3 | L2 Bundle Member NRPID TLV | | TBD4 | NRPID Adjacency-SID TLV | | TBD5 | NRPID LAN-Adj-SID TLV | +-------+---------------------------------------------+ Table 1:The new Link Attribute TLVs These TLVs should only be added to the BGP-LS Attribute associated with the Link NLRI or Stub Link NLRI. 3.2.1. NRPID list sub-TLV The NRPID list 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 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD1 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID-1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID-n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 Type: TBD2 (Suggested value to be assigned by IANA) Length: variable. NRPID:Network Resource Partition ID is used to indication the resources on specific link(s)/node(s) that will be traversed by a slice-aggregate. 3.2.2. L2 Bundle Member NRPID TLV This TLV is used to advertise NRSP for L2 Bundle Member associated with a parent L3 adjacency which is Point-to-Point. The following format is defined for this sub-TLV: chen, et al. Expires May 8, 2022 [Page 5] Internet-Draft BGP-LS Extensions for NRPID November 2021 Type: TBD3. Length: variable. L2 Bundle Member NRPID. There MUST be one NRPID for each of the L2 Bundle Members advertised under the preceding L2 Bundle Member Attribute Descriptor. The parrent link can be configured to an IGP instance, or as an inter-as link. 3.2.3. NRPID Adjacency-SID TLV This TLV is used to advertise multiple NRPID Adj-SIDs to the controller, Adjacency-SID need to be allocated per NRPID. This information is derived from IS-IS Slice Aggregate Adjacency-SID Sub- TLV of IS-IS (section 3.2 of [I-D.bestbar-lsr-spring-sa] ). The following format is defined for this sub-TLV: 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 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD4 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Weight | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID/Index/Label(Variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3 where: Type:TBD4(Suggested value to be assigned by IANA) Length: Variable. Depending on the size of the SID. Weight: Variable. 1 octet carrying the weight used for load-balancing purposes. The use of weight is described in section 3.4 of [[RFC8402]]. NRPID: Identifies the Network Resource Partition information corresponding to the Adjacency-SID. The "Flags" and "SID/Index/Label" fields are the same as the Adjacency-SID sub-TLV [RFC8667]. chen, et al. Expires May 8, 2022 [Page 6] Internet-Draft BGP-LS Extensions for NRPID November 2021 3.2.4. NRPID LAN-Adj-SID TLV In LAN subnetworks,[ [RFC8667]]defines the LAN-Adj-SID sub-TLV for a router to advertise the Adj-SID of each of its neighbors. NRPID LAN-Adj-SID TLV is used to advertise multiple SA LAN-Adj-SIDs, Adjacency-SID need to be allocated per NRPID. This information is derived from the IS-IS Slice Aggregate LAN Adjacency-SIDs of IS-IS (section 3.3 of I-D. [I-D.bestbar-lsr-spring-sa] ). 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 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD5 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Weight | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Neighbor System-ID (ID length octets) | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID/Label/Index (variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4 where: Type:TBD5 (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 Adjacency-SID sub-TLV [RFC8667]. NRPID: Identifies the Network Resource Partition information corresponding to the LAN-Adjacency-SID. chen, et al. Expires May 8, 2022 [Page 7] Internet-Draft BGP-LS Extensions for NRPID November 2021 3.3. Prefix Attribute TLVs NRPID Prefix-SID TLV should only be added to the BGP-LS Attribute associated with the Prefix NLRI describing the prefix of the IGP node.This TLV is used to advertising multiple NRPID Prefix-SIDs.This information is derived from IS-IS Slice Aggregate Prefix-SID Sub-TLV of IS-IS (section 3.1 of [I-D.bestbar-lsr-spring-sa]). The Prefix-SID for NRPID 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 2 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD6 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flag | Algorithm | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SID/Index/Label(Variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5 where: Type:TBD6 (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: Accoridng to section "3.2. SR-Algorithm Sub-TLV" of >[RFC8667], two values can be set in this field. o 0: Shortest Path First (SPF) algorithm based on link metric. o 1: Strict Shortest Path First (SPF) algorithm based on link metric. Note that[I-D.ietf-lsr-flex-algo]also allows user to define other algorithm values, i.e., FA-id within [128, 255], for the purpose of constraint based path computation.However, an FA-id algorithm value MUST not be set in this field, the reason is that FA-id has not semantic local within AII. chen, et al. Expires May 8, 2022 [Page 8] Internet-Draft BGP-LS Extensions for NRPID November 2021 NRPID: Identifies the NRPID information corresponding to the Prefix- SID. 4. NRPID SID for SRv6 SRv6 attributes with an IPv6 prefix are advertised using the new BGP- LS Attribute TLVs defined in this section and associated with the BGP-LS Prefix NLRI. 4.1. Router Capabilities for NRPID This BGP-LS Attribute TLV is used to announce which NRPID a router wants to take part in. The Router Capabilities for NRPID 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=TBD7 | Length | Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID-1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ...... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID-n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1 where: Type: TBD7. Length: variable. Number:Number of slice-aggregate which share the same topology. NRPID: Network Resource Partition ID is used to indication the resources on specific link(s)/node(s) that will be traversed by a slice-aggregate. chen, et al. Expires May 8, 2022 [Page 9] Internet-Draft BGP-LS Extensions for NRPID November 2021 4.2. NRPID SID sub-TLV The SRv6 Locator TLV was introduced in [I-D.ietf-idr-bgpls-srv6-ext] to advertise SRv6 Locators and additional attributes for the given SRv6 Locator. A new NRPID SID sub-TLV under the SRv6 Locator TLV is defined to advertise an Locator that is associated with a specific NRPID. The NRPID SRv6 Locator 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=TBD8 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | NRPID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6 where: Type: TBD8 Length: 4 octets. NRPID: Identifies the NRPID information corresponding to an Locator. The new NRPID SID sub-TLV is an optional Sub-TLV of: SRv6 End.X SID TLV (Section 4.1 of [I-D.ietf-idr-bgpls-srv6-ext]. SRv6 LAN End.X SID TLV (Section 4.2 of [I-D.ietf-idr-bgpls-srv6-ext]. 5. IANA Considerations TBD. 6. Acknowledgements TBD chen, et al. Expires May 8, 2022 [Page 10] Internet-Draft BGP-LS Extensions for NRPID November 2021 7. Normative References [I-D.bestbar-lsr-spring-sa] Saad, T., Beeram, V. P., Chen, R., Peng, S., Wen, B., and D. Ceccarelli, "IGP Extensions for SR Slice Aggregate SIDs", draft-bestbar-lsr-spring-sa-01 (work in progress), September 2021. [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", draft-bestbar-spring-scalable-ns-02 (work in progress), September 2021. [I-D.bestbar-teas-ns-packet] Saad, T., Beeram, V. P., Wen, B., Ceccarelli, D., Halpern, J., Peng, S., Chen, R., Liu, X., Contreras, L. M., and R. Rokui, "Realizing Network Slices in IP/MPLS Networks", draft-bestbar-teas-ns-packet-04 (work in progress), October 2021. [I-D.ietf-idr-bgpls-inter-as-topology-ext] Wang, A., Chen, H., Talaulikar, K., and S. Zhuang, "BGP-LS Extension for Inter-AS Topology Retrieval", draft-ietf- idr-bgpls-inter-as-topology-ext-10 (work in progress), October 2021. [I-D.ietf-idr-bgpls-srv6-ext] Dawra, G., Filsfils, C., Talaulikar, K., Chen, M., Bernier, D., and B. Decraene, "BGP Link State Extensions for SRv6", draft-ietf-idr-bgpls-srv6-ext-08 (work in progress), June 2021. [I-D.ietf-lsr-flex-algo] Psenak, P., Hegde, S., Filsfils, C., Talaulikar, K., and A. Gulko, "IGP Flexible Algorithm", draft-ietf-lsr-flex- algo-18 (work in progress), October 2021. [I-D.ietf-spring-segment-routing-policy] Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and P. Mattes, "Segment Routing Policy Architecture", draft- ietf-spring-segment-routing-policy-14 (work in progress), October 2021. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . chen, et al. Expires May 8, 2022 [Page 11] Internet-Draft BGP-LS Extensions for NRPID November 2021 [RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P. Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", RFC 4915, DOI 10.17487/RFC4915, June 2007, . [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, . [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, . [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and S. Ray, "North-Bound Distribution of Link-State and Traffic Engineering (TE) Information Using BGP", RFC 7752, DOI 10.17487/RFC7752, March 2016, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [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, . [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, . Authors' Addresses Ran Chen ZTE Corporation No.50 Software Avenue, Yuhuatai District Nanjing China Email: chen.ran@zte.com.cn chen, et al. Expires May 8, 2022 [Page 12] Internet-Draft BGP-LS Extensions for NRPID November 2021 Shaofu ZTE Corporation No.68 Zijinghua Road, Yuhuatai District Nanjing China Email: peng.shaofu@zte.com.cn Tarek Saad Juniper Networks Email: tsaad@juniper.net Shaofu Juniper Networks Email: vbeeram@juniper.net chen, et al. Expires May 8, 2022 [Page 13]