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RFC 2119 keyword, line 88: '... defined in [RFC8754]. The ingress PE MAY also classify the packet...' RFC 2119 keyword, line 114: '... specification SHOULD support the ba...' RFC 2119 keyword, line 124: '...e, or desirable, an implementation MAY...' RFC 2119 keyword, line 130: '.... This solution MAY be complemented w...' RFC 2119 keyword, line 134: '... SHOULD be used for queue selection....' Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (January 13, 2021) is 1171 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) No issues found here. Summary: 3 errors (**), 0 flaws (~~), 1 warning (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 SPRING C. Filsfils, Ed. 3 Internet-Draft F. Clad, Ed. 4 Intended status: Standards Track P. Camarillo 5 Expires: July 17, 2021 K. Raza 6 Cisco Systems, Inc. 7 January 13, 2021 9 Stateless and Scalable Network Slice Identification for SRv6 10 draft-filsfils-spring-srv6-stateless-slice-id-02 12 Abstract 14 This document defines a stateless and scalable solution to achieve 15 network slicing with SRv6. 17 Status of This Memo 19 This Internet-Draft is submitted in full conformance with the 20 provisions of BCP 78 and BCP 79. 22 Internet-Drafts are working documents of the Internet Engineering 23 Task Force (IETF). Note that other groups may also distribute 24 working documents as Internet-Drafts. The list of current Internet- 25 Drafts is at https://datatracker.ietf.org/drafts/current/. 27 Internet-Drafts are draft documents valid for a maximum of six months 28 and may be updated, replaced, or obsoleted by other documents at any 29 time. It is inappropriate to use Internet-Drafts as reference 30 material or to cite them other than as "work in progress." 32 This Internet-Draft will expire on July 17, 2021. 34 Copyright Notice 36 Copyright (c) 2021 IETF Trust and the persons identified as the 37 document authors. All rights reserved. 39 This document is subject to BCP 78 and the IETF Trust's Legal 40 Provisions Relating to IETF Documents 41 (https://trustee.ietf.org/license-info) in effect on the date of 42 publication of this document. Please review these documents 43 carefully, as they describe your rights and restrictions with respect 44 to this document. Code Components extracted from this document must 45 include Simplified BSD License text as described in Section 4.e of 46 the Trust Legal Provisions and are provided without warranty as 47 described in the Simplified BSD License. 49 Table of Contents 51 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 52 2. Slice Identifier . . . . . . . . . . . . . . . . . . . . . . 2 53 3. Ingress PE SLID Assignment . . . . . . . . . . . . . . . . . 2 54 4. Per-Slice Forwarding . . . . . . . . . . . . . . . . . . . . 3 55 5. Bandwidth-Allocation Slice . . . . . . . . . . . . . . . . . 3 56 6. Backward Compatibility . . . . . . . . . . . . . . . . . . . 3 57 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 58 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 59 8.1. Normative References . . . . . . . . . . . . . . . . . . 4 60 8.2. Informative References . . . . . . . . . . . . . . . . . 4 61 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 63 1. Introduction 65 SRv6 Network Programming[I-D.ietf-spring-srv6-network-programming] 66 enables the creation of overlays with underlay optimization to be 67 deployed in an SR domain[RFC8402]. 69 As defined in [RFC8754], all inter-domain packets are encapsulated 70 for the part of the packet journey that is within the SR domain. The 71 outer IPv6 header is originated by a node of the SR domain and is 72 destined to a node of the SR domain. 74 This document describes a stateless encoding of slice identification 75 in the outer IPv6 header of an SR domain. The slice identification 76 is independent of topology and the QoS/DiffServ policy of the 77 network, thus enabling scalable network slicing for SRv6 overlays. 79 2. Slice Identifier 81 Each network slice in an SR domain is uniquely identified by an 8-bit 82 Slice Identifier (SLID). 84 3. Ingress PE SLID Assignment 86 When an ingress PE receives a packet that traverses the SR domain, it 87 encapsulates the packet in an outer IPv6 header and optional SRH as 88 defined in [RFC8754]. The ingress PE MAY also classify the packet 89 into a slice and set the slice identifier as follows: 91 o Set the SPI bit (SLID Presence Indicator) in the Traffic Class 92 field of the outer IPv6 header. 94 o Write this SLID in the 8 most significant bits of the Flow Label 95 field of the outer IPv6 header. The remaining 12 bits of the Flow 96 Label field were set as described in section 5.5 of [RFC8754] for 97 inter-domain packets. 99 The slice classification method is outside the scope of this 100 document. 102 The choice of the SPI bit from within the IPv6 Traffic Class field is 103 a domain-wide configuration and is outside the scope of this 104 document. 106 4. Per-Slice Forwarding 108 Any router within the SR domain that forwards a packet with SPI bit 109 set uses the SLID to select a slice and apply per-slice policies. 111 There are many different policies that could define a slice for a 112 particular application or service. The most basic of these is 113 bandwidth-allocation, an implementation complying with this 114 specification SHOULD support the bandwidth-allocation slice as 115 defined in the next section. 117 5. Bandwidth-Allocation Slice 119 A per-slice policy is configured at each interface of each router in 120 the SR domain, with one traffic shaper per SLID. The bitrate of each 121 shaper is configured to reflect the bandwidth allocation of the per- 122 slice policy. 124 If shapers are not available, or desirable, an implementation MAY 125 configure one scheduling queue per SLID with a guaranteed bandwidth 126 equal to the bandwidth-allocation for the slice. This option allows 127 a slice to consume more bandwidth than its allocation when available. 129 Per-slice shapers or queues effectively provides a virtual port per 130 slice. This solution MAY be complemented with a per-virtual-port 131 hierarchical DiffServ policy. Within the context of one specific 132 slice, packets are further classified into children DiffServ queues 133 which hang from the virtual port. The DSCP value in the IPv6 header 134 SHOULD be used for queue selection. 136 6. Backward Compatibility 138 The Flow Label usage described in this document is consistent with 139 [RFC6437] and [RFC6438]. 141 PE routers that do not set the SPI bit do not enable the SLID 142 semantic of the Flow Label bits. Hence, SLID-aware routers would not 143 attempt to classify these packets into a slice. 145 Any router that does not process the SPI nor the SLID forwards 146 packets as usual. 148 7. Acknowledgements 150 The authors would like to thank Darren Dukes, Ketan Talaulikar, Jisu 151 Bhattacharya, John Bettink, and Aman Manot for their insightful 152 feedback on this document. 154 8. References 156 8.1. Normative References 158 [I-D.ietf-spring-srv6-network-programming] 159 Filsfils, C., Camarillo, P., Leddy, J., Voyer, D., 160 Matsushima, S., and Z. Li, "SRv6 Network Programming", 161 draft-ietf-spring-srv6-network-programming-28 (work in 162 progress), December 2020. 164 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 165 Decraene, B., Litkowski, S., and R. Shakir, "Segment 166 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 167 July 2018, . 169 [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., 170 Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header 171 (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, 172 . 174 8.2. Informative References 176 [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, 177 "IPv6 Flow Label Specification", RFC 6437, 178 DOI 10.17487/RFC6437, November 2011, 179 . 181 [RFC6438] Carpenter, B. and S. Amante, "Using the IPv6 Flow Label 182 for Equal Cost Multipath Routing and Link Aggregation in 183 Tunnels", RFC 6438, DOI 10.17487/RFC6438, November 2011, 184 . 186 Authors' Addresses 188 Clarence Filsfils (editor) 189 Cisco Systems, Inc. 190 Belgium 192 Email: cf@cisco.com 193 Francois Clad (editor) 194 Cisco Systems, Inc. 195 France 197 Email: fclad@cisco.com 199 Pablo Camarillo 200 Cisco Systems, Inc. 201 Spain 203 Email: pcamaril@cisco.com 205 Kamran Raza 206 Cisco Systems, Inc. 207 Canada 209 Email: skraza@cisco.com