--- 1/draft-ietf-mpls-spl-terminology-04.txt 2020-11-15 22:13:42.664664115 -0800 +++ 2/draft-ietf-mpls-spl-terminology-05.txt 2020-11-15 22:13:42.680664519 -0800 @@ -1,21 +1,21 @@ MPLS Working Group L. Andersson Internet-Draft Bronze Dragon Consulting Updates: 3032, 7274 (if approved) K. Kompella Intended status: Standards Track Juniper Networks -Expires: March 28, 2021 A. Farrel +Expires: May 19, 2021 A. Farrel Old Dog Consulting - September 24, 2020 + November 15, 2020 Special Purpose Label terminology - draft-ietf-mpls-spl-terminology-04 + draft-ietf-mpls-spl-terminology-05 Abstract This document discusses and recommends a terminology that may be used when MPLS Special Purpose Labels (SPL) are specified and documented. This document applies that terminology change to the relevant IANA registry and also clarifies the use of the Entropy Label Indicator (7) when immediately preceded by the Extension Label (15). @@ -29,21 +29,21 @@ 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 March 28, 2021. + This Internet-Draft will expire on May 19, 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 @@ -53,21 +53,21 @@ the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. Background . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. GMPLS Special Purpose Labels . . . . . . . . . . . . . . 3 3. Terminology and Abbreviations . . . . . . . . . . . . . . . . 3 - 4. Clarification on Use of Entropy Label Indicator . . . . . . . 5 + 4. Clarification on Handling of the Entropy Label Indicator . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 6 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 6 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 9.1. Normative References . . . . . . . . . . . . . . . . . . 7 9.2. Informative References . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction @@ -182,28 +182,28 @@ | MPLS Label Stack entry | +--------+--------+--------+--------+ xSPL | Extension Label (XL) | <--+ +--------+--------+--------+--------+ |--- cSPL eSPL | Extended SPL | <--+ +--------+--------+--------+--------+ | MPLS Label Stack entry (cont.) | Figure 2: Example of Label Stack -4. Clarification on Use of Entropy Label Indicator +4. Clarification on Handling of the Entropy Label Indicator Section 3.1 of [RFC7274] contains two paragraphs that describe the - use of the Entropy Label Indicator (label 7). These paragraphs have - introduced some confusion about whether the Entropy Label Indicator - can be present when immediately preceded by the Extension Label. - This document updates [RFC7274] by replacing those paragraphs as - follows. + handling of the Entropy Label Indicator (label 7). These paragraphs + have introduced some confusion about whether the Entropy Label + Indicator can be present when immediately preceded by the Extension + Label. This document updates [RFC7274] by replacing those paragraphs + as follows. OLD Values 0-15 of the "Extended Special-Purpose MPLS Label Values" registry are set aside as reserved. Furthermore, values 0-6 and 8-15 MUST NOT appear in the data plane following an XL; an LSR processing a packet with an XL at the top of the label stack followed by a label with value 0-6 or 8-15 MUST drop the packet. Label 7 (when received) retains its meaning as Entropy Label @@ -220,21 +220,21 @@ registry are set aside as reserved. Furthermore, an implementation MUST NOT place a label with value 0-15 in the label stack immediately following an XL; an LSR processing a packet with an XL at the top of the label stack immediately followed by a label with value 0-15 MUST drop the packet. When inspecting a label stack to find an Entropy Label Indicator (ELI - label 7) a pre-existing implementation may fail to inspect the previous label, and so not notice that it is an XL. Such systems can continue to process the entropy information and - forward the packet when the previous label is an XP without + forward the packet when the previous label is an XL without causing harm. However, the packet will be dropped when the XL reaches the top of the stack at another LSR. END 5. Security Considerations 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