From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc6423.txt | 283 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 283 insertions(+) create mode 100644 doc/rfc/rfc6423.txt (limited to 'doc/rfc/rfc6423.txt') diff --git a/doc/rfc/rfc6423.txt b/doc/rfc/rfc6423.txt new file mode 100644 index 0000000..d30b217 --- /dev/null +++ b/doc/rfc/rfc6423.txt @@ -0,0 +1,283 @@ + + + + + + +Internet Engineering Task Force (IETF) H. Li +Request for Comments: 6423 China Mobile +Updates: 5586 L. Martini +Category: Standards Track Cisco System +ISSN: 2070-1721 J. He + Huawei + F. Huang + Alcatel-Lucent + November 2011 + + + Using the Generic Associated Channel Label for Pseudowire in + the MPLS Transport Profile (MPLS-TP) + +Abstract + + This document describes the requirements for using the Generic + Associated Channel Label (GAL) in pseudowires (PWs) in MPLS Transport + Profile (MPLS-TP) networks, and provides an update to the description + of GAL usage in RFC 5586 by removing the restriction that is imposed + on using GAL for PWs, especially in MPLS-TP environments. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 5741. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + http://www.rfc-editor.org/info/rfc6423. + + + + + + + + + + + + + + + + +Li, et al. Standards Track [Page 1] + +RFC 6423 Using GAL in MPLS-TP PW November 2011 + + +Copyright Notice + + Copyright (c) 2011 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 + (http://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + +Table of Contents + + 1. Introduction ....................................................2 + 2. Conventions Used in This Document ...............................2 + 2.1. Terminology ................................................3 + 3. GAL Usage for MPLS-TP PW ........................................3 + 4. Security Considerations .........................................4 + 5. Acknowledgments .................................................4 + 6. References ......................................................5 + 6.1. Normative References .......................................5 + 6.2. Informative References .....................................5 + +1. Introduction + + [RFC5586] generalizes the Associated Channel mechanism of [RFC5085] + to be used for Sections, Label Switched Paths (LSPs), and Pseudowires + (PWs) in MPLS networks. [RFC5085] defines the Associated Channel + Header (ACH), and [RFC5586] generalizes this for use as the Generic + Associated Channel (G-ACh). + + [RFC5586] defines a generalized label-based exception mechanism using + the Generic Associated Channel Label (GAL) to work together with the + ACH for use with LSPs but prohibits GAL usage with PWs. + + This document removes the restriction imposed by [RFC5586]. + +2. Conventions Used in This Document + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this + document are to be interpreted as described in [RFC2119]. + + + + + +Li, et al. Standards Track [Page 2] + +RFC 6423 Using GAL in MPLS-TP PW November 2011 + + +2.1. Terminology + + ACH Associated Channel Header + + CW Control Word + + G-ACh Generic Associated Channel + + GAL Generic Associated Channel Label + + MPLS-TP MPLS Transport Profile + + OAM Operation, Administration, and Maintenance + +3. GAL Usage for MPLS-TP PW + + According to the MPLS-TP requirements document [RFC5654], it is + necessary that MPLS-TP mechanisms and capabilities be able to + interoperate with the existing IETF MPLS [RFC3031] and IETF PWE3 + [RFC3985] architectures as appropriate. [RFC5586] differentiates + between the usage of the GAL with PWs in MPLS and MPLS-TP + environments in Section 4.2 as follows: + + In MPLS-TP, the GAL MUST be used with packets on a G-ACh on LSPs, + Concatenated Segments of LSPs, and with Sections, and MUST NOT be + used with PWs. + + This indicates that the GAL can be used for MPLS-TP LSPs and + Sections, but not for PWs in an MPLS-TP network. + + However, there is no restriction imposed on the usage of the GAL in + MPLS PWs, which is described immediately afterwards in the same + section (Section 4.2) of [RFC5586]: + + However, in other MPLS environments, this document places no + restrictions on where the GAL may appear within the label stack or + its use with PWs. + + The inconsistency between the usage of the GAL with MPLS PWs and + MPLS-TP PWs may cause unnecessary implementation differences and is + in disagreement with the MPLS-TP requirements. + + Therefore, this document specifies that the GAL can be used with + packets on a G-ACh on LSPs, Concatenated Segments of LSPs, Sections, + and PWs in both MPLS and MPLS-TP environments without discrimination. + + + + + + +Li, et al. Standards Track [Page 3] + +RFC 6423 Using GAL in MPLS-TP PW November 2011 + + + [RFC5586] is updated by removing the restrictions on using GAL for PW + as follows: + + - Section 1 (Introduction) in [RFC5586], the original text: + + The GAL mechanism is defined to work together with the ACH for + LSPs and MPLS Sections. + + is replaced by: + + The GAL mechanism is defined to work together with the ACH for + LSPs and MPLS Sections, and for PWs. + + - Section 4.2. (GAL Applicability and Usage) in [RFC5586], the + original text: + + In MPLS-TP, the GAL MUST be used with packets on a G-ACh on + LSPs, Concatenated Segments of LSPs, and with Sections, and + MUST NOT be used with PWs. It MUST always be at the bottom of + the label stack (i.e., S bit set to 1). However, in other MPLS + environments, this document places no restrictions on where the + GAL may appear within the label stack or its use with PWs. + + is replaced by: + + In MPLS-TP, the GAL MUST be used with packets on a G-ACh on + LSPs, Concatenated Segments of LSPs, and with Sections, and MAY + be used with PWs. The presence of a GAL indicates that an ACH + immediately follows the MPLS label stack. + +4. Security Considerations + + There are no further security considerations than those in [RFC5586]. + +5. Acknowledgments + + The authors would like to thank Luyuan Fang, Adrian Farrel, Haiyan + Zhang, Guanghui Sun, Italo Busi, and Matthew Bocci for their + contributions to this work. + + The authors would also like to thank the authors of [RFC5586] and + people who were involved in the development of [RFC5586]. + + + + + + + + + +Li, et al. Standards Track [Page 4] + +RFC 6423 Using GAL in MPLS-TP PW November 2011 + + +6. References + +6.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997 + + [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol + Label Switching Architecture", RFC 3031, January 2001. + + [RFC3985] Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation + Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005. + + [RFC5586] Bocci, M., Ed., Vigoureux, M., Ed., and S. Bryant, Ed., + "MPLS Generic Associated Channel", RFC 5586, June 2009. + +6.2. Informative References + + [RFC5085] Nadeau, T., Ed., and C. Pignataro, Ed., "Pseudowire Virtual + Circuit Connectivity Verification (VCCV): A Control Channel + for Pseudowires", RFC 5085, December 2007. + + [RFC5654] Niven-Jenkins, B., Ed., Brungard, D., Ed., Betts, M., Ed., + Sprecher, N.,and S. Ueno, "Requirements of an MPLS + Transport Profile", RFC 5654, September 2009. + +Authors' Addresses + + Han Li + China Mobile Communications Corporation + EMail: lihan@chinamobile.com + + + Luca Martini + Cisco Systems, Inc. + EMail: lmartini@cisco.com + + + Jia He + Huawei Technologies Co., Ltd. + EMail: hejia@huawei.com + + + Feng Huang + Alcatel-Lucent shanghai Bell + EMail: feng.f.huang@alcatel-sbell.com.cn + + + + + +Li, et al. Standards Track [Page 5] + -- cgit v1.2.3