idnits 2.17.1 draft-ietf-mpls-spl-terminology-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- -- The draft header indicates that this document updates RFC3032, but the abstract doesn't seem to mention this, which it should. -- The draft header indicates that this document updates RFC7274, but the abstract doesn't seem to mention this, which it should. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year (Using the creation date from RFC3032, updated by this document, for RFC5378 checks: 1997-11-20) -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (July 7, 2019) is 1755 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- No issues found here. Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 4 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 MPLS Working Group L. Andersson 3 Internet-Draft Bronze Dragon Consulting 4 Updates: 3032, 7274 (if approved) K. Kompella 5 Intended status: Informational Juniper Networks 6 Expires: January 8, 2020 A. Farrel 7 Old Dog Consulting 8 July 7, 2019 10 Special Purpose Label terminology 11 draft-ietf-mpls-spl-terminology-00 13 Abstract 15 This document discusses and recommends a terminology that may be used 16 when MPLS Special Purpose Labels (SPL) are specified and documented. 18 Note: The rest of the text in this section is not really part of the 19 abstract even though the text is placed here. It is working notes. 21 Note: At least at the moment it is not the intention to take this 22 document to an RFC, but it might be polled to become a wg document to 23 see if the MPLS working group agree on the proposed terminology. 25 Note: The changes we propose are minor, but we might have to progress 26 the document to RFC since there is a proposed change to the "Special- 27 Purpose Multiprotocol Label Switching (MPLS) Label Values" registry. 29 Status of This Memo 31 This Internet-Draft is submitted in full conformance with the 32 provisions of BCP 78 and BCP 79. 34 Internet-Drafts are working documents of the Internet Engineering 35 Task Force (IETF). Note that other groups may also distribute 36 working documents as Internet-Drafts. The list of current Internet- 37 Drafts is at https://datatracker.ietf.org/drafts/current/. 39 Internet-Drafts are draft documents valid for a maximum of six months 40 and may be updated, replaced, or obsoleted by other documents at any 41 time. It is inappropriate to use Internet-Drafts as reference 42 material or to cite them other than as "work in progress." 44 This Internet-Draft will expire on January 8, 2020. 46 Copyright Notice 48 Copyright (c) 2019 IETF Trust and the persons identified as the 49 document authors. All rights reserved. 51 This document is subject to BCP 78 and the IETF Trust's Legal 52 Provisions Relating to IETF Documents 53 (https://trustee.ietf.org/license-info) in effect on the date of 54 publication of this document. Please review these documents 55 carefully, as they describe your rights and restrictions with respect 56 to this document. Code Components extracted from this document must 57 include Simplified BSD License text as described in Section 4.e of 58 the Trust Legal Provisions and are provided without warranty as 59 described in the Simplified BSD License. 61 Table of Contents 63 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 64 2. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3 65 2.1. GMPLS Special Purpose Labels . . . . . . . . . . . . . . 3 66 3. Terminology and Abbreviations . . . . . . . . . . . . . . . . 3 67 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 68 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 69 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 70 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 71 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 72 7.2. Informative References . . . . . . . . . . . . . . . . . 6 73 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 75 1. Introduction 77 RFC 7274 [RFC7274] made some changes to the terminology used for MPLS 78 Special Purpose Labels, but did not define consistent terminology. 80 One thing that RFC 7274 did was to deprecate use use of the term 81 "reserved labels" when describing a range of labels allocated from a 82 registry maintained by IANA. The term "Reserved" in such a registry 83 means "set aside, not to be used", but that range of labels was 84 available for allocation according to the policies set out in the 85 registry. The name "Special Purpose Labels" was introduced in RFC 86 7274 in place of the previous term, and the abbreviation SPL was 87 recommended. 89 At the time of posting this Internet-Draft, the IETF is in the 90 process of allocating the very first SPLs from the Extended SPL range 91 [I-D.ietf-mpls-sfc]. This document discusses and recommends 92 terminology and abbreviations to be used when talking about and 93 documentating Special Purpose Labels. 95 2. Background 97 Two sets of SPLs are defined for use in MPLS: 99 The range of SPLs 0-15 is specified in RFC 3032 [RFC3032]. 101 The range of SPLs 0-1048575 is specified in RFC 7274 [RFC7274]. 103 * the values 0-15 has been reserved never to be allocated 105 * the values 15-239 are available for allocation 107 * the values 240-255 are for experimental use 109 * the values 256-1048575 are currently not available for 110 allocation, and a standard tracks RFC will be needed to make 111 the entire range or part of it available for allocation 113 2.1. GMPLS Special Purpose Labels 115 Note that IANA maintains a registry called "Special Purpose 116 Generalized Label Values". Labels in that registry have special 117 meaning when present in certain signalling objects, are 32 bits long, 118 and are not to be confused with MPLS forwarding plane labels. This 119 document does not make any changes to the registry or how labels from 120 that registry are described. 122 3. Terminology and Abbreviations 124 IANA maintains a name space for 'Special-Purpose Multiprotocol Label 125 Switching (MPLS) Label Values' code points [SPL-NAME-SPACE]. Within 126 this name space there are two registries. One is called the 127 'Special-Purpose MPLS Label Values' registry [bSPL]. The other is 128 called 'Extended Special-Purpose MPLS Label Values' registry [eSPL]. 130 The difference in the name of the name space and the first registry 131 is only that the MPLS abbreviation is expanded. This document 132 changes the name of the first registry to 'Base Special-Purpose MPLS 133 Label Values', but leaves the name of the latter registry unchanged 134 as 'Extended Special-Purpose MPLS Label Values'. 136 The following conventions will be used in specifications and when 137 talking about SPLs 139 o Collectively, the two ranges are known as Special Purpose Labels 140 (SPL). 142 o The special purpose labels from the lower range will be called 143 Base Special Purpose Labels (bSPL). 145 o The special purpose labels from the higher range will be called 146 Extended Special Purpose Labels (eSPL). 148 o The combination of the Extension Label (XL) (value 15 which is an 149 bSPL, but that is also called xSPL) and an eSPL is called a 150 Composite Special Purpose Label (cSPL). 152 This results in a label stacks such as the illustrative examples 153 shown in Figure 1 and Figure 2. 155 0 31 156 | MPLS Label Stack entry | 157 +--------+--------+--------+--------+ 158 | MPLS Label Stack entry | 159 +--------+--------+--------+--------+ 160 bSPL | Base SPL | 161 +--------+--------+--------+--------+ 162 | MPLS Label Stack entry (cont.) | 164 Figure 1: Example of Label Stack 166 0 31 167 | MPLS Label Stack entry | 168 +--------+--------+--------+--------+ 169 | MPLS Label Stack entry | 170 +--------+--------+--------+--------+ 171 xSPL | Extension Label (XL) | <--+ 172 +--------+--------+--------+--------+ |--- cSPL 173 eSPL | Extended SPL | <--+ 174 +--------+--------+--------+--------+ 175 | MPLS Label Stack entry (cont.) | 177 Figure 2: Example of Label Stack 179 4. Security Considerations 181 This document is entirely about terminology for SPLs and does not 182 effect the forwarding in the MPLS data plane, nor does it have any 183 effect on how LSPs are establsihed by an MPLS control plane or by a 184 centralized controller. The doucment describes a terminology to be 185 used when describing and specifying the use of SPLs. 187 This document does not aim to describe existing implementations of 188 SPLs or the potential vulnerabilities of SPLs. 190 5. IANA Considerations 192 We request that the name of the IANA registry that today is called 193 "Special-Purpose MPLS Label Values" is changed to "Base Special- 194 Purpose MPLS Label Values". 196 6. Acknowledgements 198 The authors of this document would like to thank Stewart Bryant for 199 careful review and constructive suggestions. 201 7. References 203 7.1. Normative References 205 [bSPL] "Special-Purpose MPLS Label Values", 206 . 209 [eSPL] "Extended Special-Purpose MPLS Label Values", 210 . 213 [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., 214 Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack 215 Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001, 216 . 218 [RFC7274] Kompella, K., Andersson, L., and A. Farrel, "Allocating 219 and Retiring Special-Purpose MPLS Labels", RFC 7274, 220 DOI 10.17487/RFC7274, June 2014, 221 . 223 [SPL-NAME-SPACE] 224 "Special-Purpose Multiprotocol Label Switching (MPLS) 225 Label Values", . 228 7.2. Informative References 230 [I-D.ietf-mpls-sfc] 231 Farrel, A., Bryant, S., and J. Drake, "An MPLS-Based 232 Forwarding Plane for Service Function Chaining", draft- 233 ietf-mpls-sfc-07 (work in progress), March 2019. 235 Authors' Addresses 237 Loa Andersson 238 Bronze Dragon Consulting 240 Email: loa@pi.nu 242 Kireeti Kompella 243 Juniper Networks 245 Email: kireeti@juniper.net 247 Adrian Farrel 248 Old Dog Consulting 250 Email: adrian@olddog.co.uk