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Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == The document doesn't use any RFC 2119 keywords, yet seems to have RFC 2119 boilerplate text. -- The document date (October 30, 2016) is 2733 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'ISIS-SR' is mentioned on line 166, but not defined == Unused Reference: 'RFC5440' is defined on line 233, but no explicit reference was found in the text == Outdated reference: A later version (-27) exists of draft-dhodylee-pce-pcep-ls-06 ** Downref: Normative reference to an Experimental draft: draft-dhodylee-pce-pcep-ls (ref. 'I-D.dhodylee-pce-pcep-ls') == Outdated reference: A later version (-25) exists of draft-ietf-isis-segment-routing-extensions-08 == Outdated reference: A later version (-15) exists of draft-ietf-spring-segment-routing-09 == Outdated reference: A later version (-02) exists of draft-li-spring-tunnel-segment-01 Summary: 2 errors (**), 0 flaws (~~), 8 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group Z. Li 3 Internet-Draft X. Chen 4 Intended status: Standards Track N. Wu 5 Expires: May 3, 2017 Huawei Technologies 6 October 30, 2016 8 PCEP Link-State extensions for Segment Routing 9 draft-li-pce-pcep-ls-sr-extension-01 11 Abstract 13 Segment Routing leverages source routing. A node steers a packet 14 through a controlled set of instructions, called segments, by 15 prepending the packet with an SR header. A segment can represent any 16 instruction, topological or service-based. SR allows to enforce a 17 flow through any topological path and service chain while maintaining 18 per-flow state only at the ingress node of the SR domain. 20 IGP protocols have been extended to advertise the segments. Because 21 of IGP's propagation scope limitation, it is not suited for IGP to 22 signal paths that span across AS borders. This document introduces 23 extensions of PCEP-LS to solve the problem without the similar 24 limitation. 26 Requirements Language 28 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 29 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 30 document are to be interpreted as described in RFC 2119 [RFC2119]. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on May 3, 2017. 49 Internet-DrafPCEP Link-State extensions for Segment Routing October 2016 51 Copyright Notice 53 Copyright (c) 2016 IETF Trust and the persons identified as the 54 document authors. All rights reserved. 56 This document is subject to BCP 78 and the IETF Trust's Legal 57 Provisions Relating to IETF Documents 58 (http://trustee.ietf.org/license-info) in effect on the date of 59 publication of this document. Please review these documents 60 carefully, as they describe your rights and restrictions with respect 61 to this document. Code Components extracted from this document must 62 include Simplified BSD License text as described in Section 4.e of 63 the Trust Legal Provisions and are provided without warranty as 64 described in the Simplified BSD License. 66 Table of Contents 68 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 69 2. PCEP extensions for Segment Routing . . . . . . . . . . . . . 3 70 2.1. Node Attribute TLVs . . . . . . . . . . . . . . . . . . . 3 71 2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 3 72 2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 4 73 3. Operational Considerations . . . . . . . . . . . . . . . . . 4 74 3.1. Segment Routing report . . . . . . . . . . . . . . . . . 4 75 3.2. Tunnel Segment Identifier . . . . . . . . . . . . . . . . 4 76 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 77 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 78 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 79 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 80 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 81 7.2. Informative References . . . . . . . . . . . . . . . . . 5 82 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 84 1. Introduction 86 Segment Routing [I-D.ietf-spring-segment-routing] leverages source 87 routing. A node steers a packet through a controlled set of 88 instructions, called segments, by prepending the packet with an SR 89 header. A segment can represent any instruction, topological or 90 service-based. SR allows to enforce a flow through any topological 91 path and service chain while maintaining per-flow state only at the 92 ingress node of the SR domain. 94 IGP protocols have been extended to advertise the segments. Because 95 of IGP's propagation scope limitation, it is not suited for IGP to 96 signal paths that span across AS borders. 98 Internet-DrafPCEP Link-State extensions for Segment Routing October 2016 100 In order to fulfill the need for applications that require visibility 101 of SR paths across IGP areas or even across ASes, this document 102 defines extensions for the mechanism introduced in 103 [I-D.dhodylee-pce-pcep-ls] to propagate SR information in those 104 scenarios that have no IGP SR extension or BGP-LS running. 106 2. PCEP extensions for Segment Routing 108 PCEP-LS [I-D.dhodylee-pce-pcep-ls] introduces new message type and 109 new object to accommodate link-state information in PCEP. This 110 document defines new additional TLVs to map segment routing 111 information. The value portion of these new TLVs can reuse the 112 structure defined in [I-D.ietf-isis-segment-routing-extensions]. 114 2.1. Node Attribute TLVs 116 Some new optional, non-transitive node attribute TLVs are defined for 117 carrying segment routing information and are listed below: 119 +--------------+-----------------------+----------+-----------------------+ 120 |TLV Code Point| Description | Length | Value defined | 121 +--------------+-----------------------+----------+-----------------------+ 122 | TBD1 | SID/Label Binding | variable | [ISIS-SR]#section2.4 | 123 +--------------+-----------------------+----------+-----------------------+ 124 | TBD2 | SR-Capabilities | variable | [ISIS-SR]#section3.1 | 125 +--------------+-----------------------+----------+-----------------------+ 126 | TBD3 | SR-Algorithm | variable | [ISIS-SR]#section3.2 | 127 +--------------+-----------------------+----------+-----------------------+ 129 [ISIS-SR]: https://datatracker.ietf.org/doc/draft-ietf-isis-segment- 130 routing-extensions/ 132 Table 1: Node Attribute TLVs 134 2.2. Link Attribute TLVs 136 Some new optional, non-transitive link attribute TLVs are defined for 137 carrying segment routing information and are listed below: 139 +--------------+-----------------------+----------+-----------------------+ 140 |TLV Code Point| Description | Length | Value defined | 141 +--------------+-----------------------+----------+-----------------------+ 142 | TBD4 | Adjacency Segment | variable | [ISIS-SR]#section2.2.1| 143 +--------------+-----------------------+----------+-----------------------+ 144 | TBD5 | LAN Adjacency Segment | variable | [ISIS-SR]#section2.2.2| 145 +--------------+-----------------------+----------+-----------------------+ 146 | TBD6 | Tunnel Segment | variable | | 147 +--------------+-----------------------+----------+-----------------------+ 148 Internet-DrafPCEP Link-State extensions for Segment Routing October 2016 150 [ISIS-SR]: https://datatracker.ietf.org/doc/draft-ietf-isis-segment- 151 routing-extensions/ 153 Table 2: Link Attribute TLVs 155 2.3. Prefix Attribute TLVs 157 A new optional, non-transitive link attribute TLVs are defined for 158 carrying segment routing information and are listed below: 160 +--------------+-----------------------+----------+-----------------------+ 161 |TLV Code Point| Description | Length | Value defined | 162 +--------------+-----------------------+----------+-----------------------+ 163 | TBD7 | Prefix Segment | variable | [ISIS-SR]#section2.1.2| 164 +--------------+-----------------------+----------+-----------------------+ 166 [ISIS-SR]: https://datatracker.ietf.org/doc/draft-ietf-isis-segment- 167 routing-extensions/ 169 Table 3: Prefix Attribute TLVs 171 3. Operational Considerations 173 3.1. Segment Routing report 175 The procedure for segment routing information reporting from PCC to 176 PCE will follow those defined in [I-D.dhodylee-pce-pcep-ls]. 178 3.2. Tunnel Segment Identifier 180 Tunnel Segment introduced in [I-D.li-spring-tunnel-segment] is used 181 to identify a tunnel of any kind in a segment routing network. It is 182 originated by the tunnel ingress node and one SID is allocated and 183 attached to it either locally or globally. 185 4. IANA Considerations 187 TBD. 189 5. Security Considerations 191 TBD. 193 6. Acknowledgements 195 TBD. 197 Internet-DrafPCEP Link-State extensions for Segment Routing October 2016 199 7. References 201 7.1. Normative References 203 [I-D.dhodylee-pce-pcep-ls] 204 Dhody, D., Lee, Y., and D. Ceccarelli, "PCEP Extension for 205 Distribution of Link-State and TE Information.", draft- 206 dhodylee-pce-pcep-ls-06 (work in progress), September 207 2016. 209 [I-D.ietf-isis-segment-routing-extensions] 210 Previdi, S., Filsfils, C., Bashandy, A., Gredler, H., 211 Litkowski, S., Decraene, B., and j. jefftant@gmail.com, 212 "IS-IS Extensions for Segment Routing", draft-ietf-isis- 213 segment-routing-extensions-08 (work in progress), October 214 2016. 216 [I-D.ietf-spring-segment-routing] 217 Filsfils, C., Previdi, S., Decraene, B., Litkowski, S., 218 and R. Shakir, "Segment Routing Architecture", draft-ietf- 219 spring-segment-routing-09 (work in progress), July 2016. 221 [I-D.li-spring-tunnel-segment] 222 Li, Z. and N. Wu, "Tunnel Segment in Segment Routing", 223 draft-li-spring-tunnel-segment-01 (work in progress), 224 March 2016. 226 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 227 Requirement Levels", BCP 14, RFC 2119, 228 DOI 10.17487/RFC2119, March 1997, 229 . 231 7.2. Informative References 233 [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation 234 Element (PCE) Communication Protocol (PCEP)", RFC 5440, 235 DOI 10.17487/RFC5440, March 2009, 236 . 238 Authors' Addresses 240 Zhenbin Li 241 Huawei Technologies 242 Huawei Bld., No.156 Beiqing Rd. 243 Beijing 100095 244 China 246 Email: lizhenbin@huawei.com 248 Internet-DrafPCEP Link-State extensions for Segment Routing October 2016 250 Xia Chen 251 Huawei Technologies 252 Huawei Bld., No.156 Beiqing Rd. 253 Beijing 100095 254 China 256 Email: jescia.chenxia@huawei.com 258 Nan Wu 259 Huawei Technologies 260 Huawei Bld., No.156 Beiqing Rd. 261 Beijing 100095 262 China 264 Email: eric.wu@huawei.com