PWE3 T. Nadeau Internet-Draft Juniper Networks Intended status: Standards Track C. Pignataro Expires: January 5, 2013 Cisco Systems, Inc. YJ. Stein RAD Data Communications July 4, 2012 Virtual Circuit Connectivity Verification version 2 (VCCV2) draft-nadeau-pwe3-vccv2-00.txt Abstract This document describes VCCV2, a new version of Virtual Circuit Connectivity Verification (VCCV), the pseudowire OAM mechanism. This new version is backwards compatible with VCCV for MPLS PWs for modes that the versions share, although the Router Alert (RA) CV type is not supported by VCCV2. Furthermore, this document collects the complete description of VCCV2 into a single specification. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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 http://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 January 5, 2013. Copyright Notice Copyright (c) 2012 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 Nadeau, et al. Expires January 5, 2013 [Page 1] Internet-Draft VCCV2 July 2012 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overview of the PW OAM Channel . . . . . . . . . . . . . . . . 3 3. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. The Protocol and its Options . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Nadeau, et al. Expires January 5, 2013 [Page 2] Internet-Draft VCCV2 July 2012 1. Introduction Virtual Circuit Connectivity Verification (VCCV), the pseudowire OAM mechanism is described in [RFC5085], [RFC5885], and [I-D.ietf-pwe3-vccv-for-gal]. This mechanism has been widely implemented and deployed, but it has been reported [I-D.ietf-pwe3-vccv-impl-survey-results] that the large number of VCCV options has led to interoperability issues. [RFC5085] together with [I-D.ietf-pwe3-vccv-for-gal] define four Control Channel (CC) types for MPLS PWs: Type 1 using the control word (CW), Type 2 using the Router Alert label (label=1) above the PW label, Type 3 using TTL expiry, Type 4 using G-ACh Label (label=13) [RFC5586] below the PW label. In order to simplify implementations and operations, we herein obsolete Type 2, and provide guidance as to when to use the remaining three types. [RFC5085] together with [RFC5885] define four Connectivity Verification (CV) types for MPLS PWs: ICMP ping, LSP ping, BFD with UDP/IP encapsulation, raw BFD (without IP encapsulation), and BFD has several options of its own (see [RFC5880]). The description of what and how to implement these is spread over several documents, and we herein attempt to summarize the entire functionality set in one place. This document only describes OAM for PWs over MPLS. Functionality for L2TPv2-based PWs remains as presently specified. The present version of this document is a skeleton only, intended to initiate discussion. Once the principles are agreed upon, the authors will flesh out the rest. 2. Overview of the PW OAM Channel 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]. VCCV and VCCV2 are fault OAM mechanisms to verify liveliness and to further diagnose the pseudowire forwarding path. This section will provide an overview of the requirements and architecture of PW OAM. Nadeau, et al. Expires January 5, 2013 [Page 3] Internet-Draft VCCV2 July 2012 3. Abbreviations AC Attachment Circuit [RFC3985] CC Control Channel (used as CC Type) CE Customer Edge CV Connectivity Verification (used as CV Type) CW Control Word [RFC3985] GACh Generic Associated Channel [RFC5586] GAL GACh Channel Label [RFC5586] MPLS-TP MPLS-Transport Profile OAM Operations, Administration and Maintenance PE Provider Edge PSN Packet Switched Network [RFC3985] PW Pseudowire [RFC3985] PW-ACH PW Associated Channel Header [RFC4385] VCCV Virtual Circuit Connectivity Verification 4. The Protocol and its Options This section will detail all the CC and CV options, the signaling needed to choose each of them, the bit-masks and codings. The description will be concise, yet readable. In particular, CC Type 2 is obsoleted. Subsections will discuss Types 1, 3, and 4. In addition, the text will provide guidance for selection of CC types, as follows: When the PW employs a CW then CC Type 1 SHOULD be used. TDM PWs always use the CW, and thus SHOULD always use Type 1. Legacy (ATM, port mode frame relay, and HDLC PWs) without CWs SHOULD use Type 3. [RFC5994] states that Ethernet PWs over MPLS-TP MUST use the CW, and thus they SHOULD use Type 1, but MAY use Type 4. Discussion is needed as to whether all CV types are required. Subsections will detail the use of the different CV types. 5. Security Considerations Are there significant threats on PWs based on VCCV? 6. IANA Considerations It is not clear what needs to be put here. Will CC Type 2 be removed? Nadeau, et al. Expires January 5, 2013 [Page 4] Internet-Draft VCCV2 July 2012 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3985] Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to- Edge (PWE3) Architecture", RFC 3985, March 2005. [RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson, "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN", RFC 4385, February 2006. [RFC5085] Nadeau, T. and C. Pignataro, "Pseudowire Virtual Circuit Connectivity Verification (VCCV): A Control Channel for Pseudowires", RFC 5085, December 2007. [RFC5586] Bocci, M., Vigoureux, M., and S. Bryant, "MPLS Generic Associated Channel", RFC 5586, June 2009. [RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, June 2010. [RFC5885] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)", RFC 5885, June 2010. [RFC5994] Bryant, S., Morrow, M., Swallow, G., Cherukuri, R., Nadeau, T., Harrison, N., and B. Niven-Jenkins, "Application of Ethernet Pseudowires to MPLS Transport Networks", RFC 5994, October 2010. [I-D.ietf-pwe3-vccv-for-gal] Nadeau, T. and L. Martini, "A Unified Control Channel for Pseudowires", draft-ietf-pwe3-vccv-for-gal-01 (work in progress), May 2012. 7.2. Informative References [I-D.ietf-pwe3-vccv-impl-survey-results] Regno, N., "The Pseudowire (PW) & Virtual Circuit Connectivity Verification (VCCV) Implementation Survey Results", draft-ietf-pwe3-vccv-impl-survey-results-00 (work in progress), April 2012. Nadeau, et al. Expires January 5, 2013 [Page 5] Internet-Draft VCCV2 July 2012 Authors' Addresses Thomas D. Nadeau Juniper Networks Email: tnadeau@juniper.net Carlos Pignataro Cisco Systems, Inc. 7200-12 Kit Creek Road PO Box 14987 Research Triangle Park, NC 27709 USA Email: cpignata@cisco.com Yaakov (Jonathan) Stein RAD Data Communications 24 Raoul Wallenberg St., Bldg C Tel Aviv 69719 ISRAEL Email: yaakov_s@rad.com Nadeau, et al. Expires January 5, 2013 [Page 6]