--- 1/draft-ietf-mpls-spl-terminology-02.txt 2020-08-12 11:13:16.833678829 -0700 +++ 2/draft-ietf-mpls-spl-terminology-03.txt 2020-08-12 11:13:16.869679849 -0700 @@ -1,21 +1,21 @@ MPLS Working Group L. Andersson Internet-Draft Bronze Dragon Consulting Updates: 3032, 7274 (if approved) K. Kompella Intended status: Informational Juniper Networks -Expires: November 6, 2020 A. Farrel +Expires: February 13, 2021 A. Farrel Old Dog Consulting - May 5, 2020 + August 12, 2020 Special Purpose Label terminology - draft-ietf-mpls-spl-terminology-02 + draft-ietf-mpls-spl-terminology-03 Abstract This document discusses and recommends a terminology that may be used when MPLS Special Purpose Labels (SPL) are specified and documented. This document updates RFC 7274 and RFC 3032. Status of This Memo @@ -25,21 +25,21 @@ 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 November 6, 2020. + This Internet-Draft will expire on February 13, 2021. Copyright Notice Copyright (c) 2020 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 @@ -61,65 +61,65 @@ 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction RFC 7274 [RFC7274] made some changes to the terminology used for MPLS Special Purpose Labels, but did not define consistent terminology. - One thing that RFC 7274 did was to deprecate use use of the term + One thing that RFC 7274 did was to deprecate use of the term "reserved labels" when describing a range of labels allocated from a registry maintained by IANA. The term "Reserved" in such a registry means "set aside, not to be used", but that range of labels was - available for allocation according to the policies set out in the + available for allocation according to the policies set out in that registry. The name "Special Purpose Labels" was introduced in RFC 7274 in place of the previous term, and the abbreviation SPL was recommended. At the time of writing the first version of this document, the IETF was in the process of allocating the very first SPLs from the - Extended SPL range [RFC8595]. This document discusses and recommends - terminology and abbreviations to be used when talking about and - documenting Special Purpose Labels. + Extended SPL (eSPL) range [RFC8595]. This document discusses and + recommends terminology and abbreviations to be used when talking + about and documenting Special Purpose Labels. - This document updates RFC 3032 [RFC3032] and RFC 7274 [RFC7274] and - RFC 3032 [RFC3032] in that it changes the terminology for both Base - SPLs and Extended SPLs. + This document updates RFC 3032 [RFC3032] and RFC 7274 [RFC7274] in + that it changes the terminology for both Base SPLs and Extended SPLs. 2. Background Two sets of SPLs are defined for use in MPLS: - The range of SPLs 0-15 is specified in RFC 3032 [RFC3032]. + The range of 0-15, Base Special Purpose Labels (bSPLs), is + specified in RFC 3032 [RFC3032]. - The range of SPLs 0-1048575 is specified in RFC 7274 [RFC7274]. + The range 0-1048575 of eSPLs is specified in RFC 7274 [RFC7274]. - * the values 0-15 has been reserved never to be allocated + * the values 0-15 have been reserved never to be allocated - * the values 15-239 are available for allocation + * the values 16-239 are available for allocation * the values 240-255 are for experimental use * the values 256-1048575 are currently not available for - allocation, and a standard tracks RFC will be needed to make - the entire range or part of it available for allocation + allocation. A standard track RFC will be needed to allocate + any labels from this range. 2.1. GMPLS Special Purpose Labels Note that IANA maintains a registry called "Special Purpose Generalized Label Values". Labels in that registry have special meaning when present in certain signalling objects, are 32 bits long, and are not to be confused with MPLS forwarding plane labels. This - document does not make any changes to the registry or how labels from - that registry are described. + document does not make any changes to the GMPLS registry or to how + labels from that registry are described. 3. Terminology and Abbreviations IANA maintains a name space for 'Special-Purpose Multiprotocol Label Switching (MPLS) Label Values' code points [SPL-NAME-SPACE]. Within this name space there are two registries. One is called the 'Special-Purpose MPLS Label Values' registry [bSPL]. The other is called 'Extended Special-Purpose MPLS Label Values' registry [eSPL]. The difference in the name of the name space and the first registry @@ -133,21 +133,21 @@ o Collectively, the two ranges are known as Special Purpose Labels (SPL). o The special purpose labels from the lower range will be called Base Special Purpose Labels (bSPL). o The special purpose labels from the higher range will be called Extended Special Purpose Labels (eSPL). - o The combination of the Extension Label (XL) (value 15 which is an + o The combination of the Extension Label (XL) (value 15 which is a bSPL, but that is also called xSPL) and an eSPL is called a Composite Special Purpose Label (cSPL). This results in a label stacks such as the illustrative examples shown in Figure 1 and Figure 2. 0 31 | MPLS Label Stack entry | +--------+--------+--------+--------+ | MPLS Label Stack entry | @@ -166,40 +166,42 @@ xSPL | Extension Label (XL) | <--+ +--------+--------+--------+--------+ |--- cSPL eSPL | Extended SPL | <--+ +--------+--------+--------+--------+ | MPLS Label Stack entry (cont.) | Figure 2: Example of Label Stack 4. Security Considerations - This document is entirely about terminology for SPLs and does not - effect the forwarding in the MPLS data plane, nor does it have any - effect on how LSPs are establsihed by an MPLS control plane or by a - centralized controller. The doucment describes a terminology to be - used when describing and specifying the use of SPLs. + The document describes the terminology to be used when describing and + specifying the use of SPLs. It does not effect the forwarding in the + MPLS data plane, nor does it have any effect on how LSPs are + established by an MPLS control plane or by a centralized controller. This document does not aim to describe existing implementations of - SPLs or the potential vulnerabilities of SPLs. + SPLs or potential vulnerabilities of SPLs. 5. IANA Considerations We request that the name of the IANA registry that today is called "Special-Purpose MPLS Label Values" is changed to "Base Special- Purpose MPLS Label Values". 6. Acknowledgements The authors of this document would like to thank Stewart Bryant for careful review and constructive suggestions. + We would also like to thank the Routing Directorate reviwer Eric Gray + for a detailed, careful and insightful review. + 7. References 7.1. Normative References [bSPL] "Special-Purpose MPLS Label Values", . [eSPL] "Extended Special-Purpose MPLS Label Values",