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RFC 2119 keyword, line 127: '... defined in [RFC8754]. The ingress PE MAY also classify the packet...' RFC 2119 keyword, line 145: '... specification SHOULD support the ba...' RFC 2119 keyword, line 155: '...e, or desirable, an implementation MAY...' RFC 2119 keyword, line 161: '.... This solution MAY be complemented w...' RFC 2119 keyword, line 165: '... 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 (30 July 2021) is 1001 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(See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Outdated reference: A later version (-10) exists of draft-bestbar-teas-ns-packet-03 == Outdated reference: A later version (-25) exists of draft-ietf-teas-ietf-network-slices-03 Summary: 3 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--).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: 31 January 2022 K. Raza 6 Cisco Systems, Inc. 7 D. Voyer 8 Bell Canada 9 R. Rokui 10 Nokia 11 30 July 2021 13 Stateless and Scalable Network Slice Identification for SRv6 14 draft-filsfils-spring-srv6-stateless-slice-id-04 16 Abstract 18 This document defines a stateless and scalable solution to achieve 19 network slicing with SRv6. 21 Status of This Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at https://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on 31 January 2022. 38 Copyright Notice 40 Copyright (c) 2021 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents (https://trustee.ietf.org/ 45 license-info) in effect on the date of publication of this document. 46 Please review these documents carefully, as they describe your rights 47 and restrictions with respect to this document. Code Components 48 extracted from this document must include Simplified BSD License text 49 as described in Section 4.e of the Trust Legal Provisions and are 50 provided without warranty as described in the Simplified BSD License. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 55 2. Slice Identifier . . . . . . . . . . . . . . . . . . . . . . 3 56 3. SLID Presence Indicator . . . . . . . . . . . . . . . . . . . 3 57 4. Ingress PE SLID Assignment . . . . . . . . . . . . . . . . . 3 58 5. Per-Slice Forwarding . . . . . . . . . . . . . . . . . . . . 4 59 6. Bandwidth-Allocation Slice . . . . . . . . . . . . . . . . . 4 60 7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 4 61 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 62 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 63 9.1. Normative References . . . . . . . . . . . . . . . . . . 5 64 9.2. Informative References . . . . . . . . . . . . . . . . . 5 65 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 67 1. Introduction 69 SRv6 Network Programming[RFC8986] enables the creation of overlays 70 with underlay optimization to be deployed in an SR domain[RFC8402]. 72 As defined in [RFC8754], all inter-domain packets are encapsulated 73 for the part of the packet journey that is within the SR domain. The 74 outer IPv6 header is originated by a node of the SR domain and is 75 destined to a node of the SR domain. 77 This document describes a stateless encoding of slice identification 78 in the outer IPv6 header of an SR domain. The slice identification 79 is independent of topology and the QoS/DiffServ policy of the 80 network, thus enabling scalable network slicing for SRv6 overlays. 82 The definition of network slicing in the context of networks built 83 from IETF technologies is specified in 84 [I-D.ietf-teas-ietf-network-slices]. It defines the term "IETF 85 Network Slice" and establishes the general principles of network 86 slicing in the IETF context. It also discusses the general framework 87 for requesting and operating IETF Network Slices, the characteristics 88 of an IETF Network Slice, the necessary system components and 89 interfaces, and how abstract requests can be mapped to more specific 90 technologies. The document also discusses related considerations 91 with monitoring and security. 93 2. Slice Identifier 95 The Slice Identifier (SLID) is a value encoded within the IPv6 packet 96 that allows transit routers to process the packet according to 97 network slice-based policy. An example of slice-based policy that 98 can be enforced using the SLID is described in Section 6. 100 The SLID may identify a unique IETF network slice or a group of 101 slices that share the same policy. For example, a SLID may identify 102 a slice aggregate [I-D.bestbar-teas-ns-packet]. 104 This document proposes to encode the SLID in a portion of the IPv6 105 Flow Label. 107 The precise SLID location within the IPv6 Flow Label and the number 108 of bits used to encode it are governed by local policy and uniform 109 within the SR domain. 111 3. SLID Presence Indicator 113 The SLID Presence Indicator (SPI) is set by a SLID-capable IPv6 114 source node to inform transit routers that a SLID is encoded in the 115 packet. 117 The SPI is encoded as a specific bit or range of values in the 118 Traffic Class field of the IPv6 header. 120 The encoding of the SPI in the IPv6 header is governed by local 121 policy and uniform within the SR domain. 123 4. Ingress PE SLID Assignment 125 When an ingress PE receives a packet that traverses the SR domain, it 126 encapsulates the packet in an outer IPv6 header and optional SRH as 127 defined in [RFC8754]. The ingress PE MAY also classify the packet 128 into a slice and set the slice identifier as follows: 130 * Set the SPI in the outer IPv6 header. 132 * Write the SLID in the outer IPv6 header. 134 The slice classification method is outside the scope of this 135 document. 137 5. Per-Slice Forwarding 139 Any router within the SR domain that forwards a packet with SPI bit 140 set uses the SLID to select a slice and apply per-slice policies. 142 There are many different policies that could define a slice for a 143 particular application or service. The most basic of these is 144 bandwidth-allocation, an implementation complying with this 145 specification SHOULD support the bandwidth-allocation slice as 146 defined in the next section. 148 6. Bandwidth-Allocation Slice 150 A per-slice policy is configured at each interface of each router in 151 the SR domain, with one traffic shaper per SLID. The bitrate of each 152 shaper is configured to reflect the bandwidth allocation of the per- 153 slice policy. 155 If shapers are not available, or desirable, an implementation MAY 156 configure one scheduling queue per SLID with a guaranteed bandwidth 157 equal to the bandwidth-allocation for the slice. This option allows 158 a slice to consume more bandwidth than its allocation when available. 160 Per-slice shapers or queues effectively provides a virtual port per 161 slice. This solution MAY be complemented with a per-virtual-port 162 hierarchical DiffServ policy. Within the context of one specific 163 slice, packets are further classified into children DiffServ queues 164 which hang from the virtual port. The DSCP value in the IPv6 header 165 SHOULD be used for queue selection. 167 7. Backward Compatibility 169 The Flow Label usage described in this document is consistent with 170 [RFC6437] and [RFC6438]. 172 PE routers that do not set the SPI do not enable the SLID semantic of 173 the Flow Label bits. Hence, SLID-aware routers would not attempt to 174 classify these packets into a slice. 176 Any router that does not process the SPI nor the SLID forwards 177 packets as usual. 179 8. Acknowledgements 181 The authors would like to thank Darren Dukes, Ketan Talaulikar, Jisu 182 Bhattacharya, John Bettink, Aman Manot, and David Melman for their 183 insightful feedback on this document. 185 9. References 187 9.1. Normative References 189 [RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L., 190 Decraene, B., Litkowski, S., and R. Shakir, "Segment 191 Routing Architecture", RFC 8402, DOI 10.17487/RFC8402, 192 July 2018, . 194 [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J., 195 Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header 196 (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020, 197 . 199 [RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer, 200 D., Matsushima, S., and Z. Li, "Segment Routing over IPv6 201 (SRv6) Network Programming", RFC 8986, 202 DOI 10.17487/RFC8986, February 2021, 203 . 205 9.2. Informative References 207 [I-D.bestbar-teas-ns-packet] 208 Saad, T., Beeram, V. P., Wen, B., Ceccarelli, D., Halpern, 209 J., Peng, S., Chen, R., Liu, X., Contreras, L. M., and R. 210 Rokui, "Realizing Network Slices in IP/MPLS Networks", 211 Work in Progress, Internet-Draft, draft-bestbar-teas-ns- 212 packet-03, 11 July 2021, . 215 [I-D.ietf-teas-ietf-network-slices] 216 Farrel, A., Gray, E., Drake, J., Rokui, R., Homma, S., 217 Makhijani, K., Contreras, L. M., and J. Tantsura, 218 "Framework for IETF Network Slices", Work in Progress, 219 Internet-Draft, draft-ietf-teas-ietf-network-slices-03, 23 220 May 2021, . 223 [RFC6437] Amante, S., Carpenter, B., Jiang, S., and J. Rajahalme, 224 "IPv6 Flow Label Specification", RFC 6437, 225 DOI 10.17487/RFC6437, November 2011, 226 . 228 [RFC6438] Carpenter, B. and S. Amante, "Using the IPv6 Flow Label 229 for Equal Cost Multipath Routing and Link Aggregation in 230 Tunnels", RFC 6438, DOI 10.17487/RFC6438, November 2011, 231 . 233 Authors' Addresses 235 Clarence Filsfils (editor) 236 Cisco Systems, Inc. 237 Belgium 239 Email: cf@cisco.com 241 Francois Clad (editor) 242 Cisco Systems, Inc. 243 France 245 Email: fclad@cisco.com 247 Pablo Camarillo 248 Cisco Systems, Inc. 249 Spain 251 Email: pcamaril@cisco.com 253 Kamran Raza 254 Cisco Systems, Inc. 255 Canada 257 Email: skraza@cisco.com 259 Daniel Voyer 260 Bell Canada 261 Canada 263 Email: daniel.voyer@bell.ca 265 Reza Rokui 266 Nokia 267 Canada 269 Email: reza.rokui@nokia.com