MPLS Working Group D. Frost, Ed. Internet-Draft Cisco Systems Intended status: Informational M. Bocci, Ed. Expires: July 8, 2011 Alcatel-Lucent L. Berger, Ed. LabN Consulting January 4, 2011 A Framework for Point-to-Multipoint MPLS in Transport Networks draft-fbb-mpls-tp-p2mp-framework-02 Abstract The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP) is the common set of MPLS protocol functions defined to enable the construction and operation of packet transport networks. The MPLS-TP supports both point-to-point and point-to-multipoint transport paths. This document defines the elements and functions of the MPLS-TP architecture applicable specifically to supporting point-to- multipoint transport paths. This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunication Union Telecommunication Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and PWE3 architectures to support the capabilities and functionalities of a packet transport network. 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 July 8, 2011. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the Frost, et al. Expires July 8, 2011 [Page 1] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4 1.2.1. Additional Definitions and Terminology . . . . . . . . 4 1.3. Applicability . . . . . . . . . . . . . . . . . . . . . . . 4 2. MPLS Transport Profile Point-to-Multipoint Requirements . . . . 4 3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. MPLS-TP Encapsulation and Forwarding . . . . . . . . . . . 6 4. Operations, Administration and Maintenance (OAM) . . . . . . . 6 5. Control Plane . . . . . . . . . . . . . . . . . . . . . . . . . 6 5.1. Point-to-Multipoint LSP Control Plane . . . . . . . . . . . 6 5.2. Point-to-Multipoint PW Control Plane . . . . . . . . . . . 6 6. Survivability . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. Network Management . . . . . . . . . . . . . . . . . . . . . . 7 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 10.1. Normative References . . . . . . . . . . . . . . . . . . . 7 10.2. Informative References . . . . . . . . . . . . . . . . . . 8 Frost, et al. Expires July 8, 2011 [Page 2] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 1. Introduction The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP) is the common set of MPLS protocol functions defined to meet the requirements specified in [RFC5654]. The MPLS-TP Framework [I-D.ietf-mpls-tp-framework] provides an overall introduction to the MPLS-TP and defines the general architecture of the Transport Profile, as well as those aspects specific to point-to-point transport paths. The purpose of this document is to define the elements and functions of the MPLS-TP architecture applicable specifically to supporting point-to-multipoint transport paths. This document is a product of a joint Internet Engineering Task Force (IETF) / International Telecommunication Union Telecommunication Standardization Sector (ITU-T) effort to include an MPLS Transport Profile within the IETF MPLS and PWE3 architectures to support the capabilities and functionalities of a packet transport network. 1.1. Scope This document defines the elements and functions of the MPLS-TP architecture related to supporting point-to-multipoint transport paths. The reader is referred to [I-D.ietf-mpls-tp-framework] for those aspects of the MPLS-TP architecture that are generic, or concerned specifically with point-to-point transport paths. Frost, et al. Expires July 8, 2011 [Page 3] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 1.2. Terminology Term Definition ------- ------------------------------------------ LSP Label Switched Path MPLS-TP MPLS Transport Profile SDH Synchronous Digital Hierarchy ATM Asynchronous Transfer Mode OTN Optical Transport Network OAM Operations, Administration and Maintenance G-ACh Generic Associated Channel GAL G-ACh Label MEP Maintenance End Point MIP Maintenance Intermediate Point APS Automatic Protection Switching SCC Signaling Communication Channel MCC Management Communication Channel EMF Equipment Management Function FM Fault Management CM Configuration Management PM Performance Management LSR Label Switching Router MPLS-TE MPLS Traffic Engineering P2MP Point-to-multipoint PW Pseudowire 1.2.1. Additional Definitions and Terminology Detailed definitions and additional terminology may be found in [I-D.ietf-mpls-tp-framework] and [RFC5654]. 1.3. Applicability The point-to-multipoint connectivity provided by an MPLS-TP network is based on the point-to-multipoint connectivity provided by MPLS networks. MPLS TE-LSP support is discussed in [RFC4875] and [RFC5332], and PW support is being developed based on [I-D.ietf-pwe3-p2mp-pw-requirements] and [I-D.ietf-l2vpn-vpms-frmwk-requirements]. MPLS-TP point-to- multipoint connectivity is analogous to that provided by traditional transport technologies such as Optical Transport Network (OTN) point- to-multipoint [ref?] and optical drop-and-continue [ref?], and thus supports the same class of traditional applications. 2. MPLS Transport Profile Point-to-Multipoint Requirements The requirements for MPLS-TP are specified in [RFC5654], [I-D.ietf-mpls-tp-oam-requirements], and [I-D.ietf-mpls-tp-nm-req]. Frost, et al. Expires July 8, 2011 [Page 4] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 This section provides a brief summary of point-to-multipoint transport requirements as set out in those documents; the reader is referred to the documents themselves for the definitive and complete list of requirements. o MPLS-TP must support unidirectional point-to-multipoint (P2MP) transport paths. o MPLS-TP must support traffic-engineered point-to-multipoint transport paths. o MPLS-TP must be capable of using P2MP server (sub)layer capabilities as well as P2P server (sub)layer capabilities when supporting P2MP MPLS-TP transport paths. o The MPLS-TP control plane must support establishing all the connectivity patterns defined for the MPLS-TP data plane (i.e., unidirectional P2P, associated bidirectional P2P, co-routed bidirectional P2P, unidirectional P2MP) including configuration of protection functions and any associated maintenance functions. o Recovery techniques used for P2P and P2MP should be identical to simplify implementation and operation. o Unidirectional 1+1 and 1:n protection for P2MP connectivity must be supported. o MPLS-TP recovery in a ring must protect unidirectional P2MP transport paths. 3. Architecture The overall architecture of the MPLS Transport Profile is defined in [I-D.ietf-mpls-tp-framework]. The architecture for point-to- multipoint MPLS-TP comprises the following additional elements and functions: o Unidirectional point-to-multipoint Label Switched Paths (LSPs) o Unidirectional point-to-multipoint pseudowires (PWs) o Optional point-to-multipoint LSP and PW control planes o Survivability, network management, and Operations, Administration and Maintenance (OAM) functions for point-to-multipoint PWs and LSPs The following subsections summarise the encapsulation and forwarding Frost, et al. Expires July 8, 2011 [Page 5] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 of point-to-multipoint traffic within an MPLS-TP network, and the encapsulation options for delivery of traffic to and from MPLS-TP Customer Edge devices when the network is providing a packet transport service. 3.1. MPLS-TP Encapsulation and Forwarding Packet encapsulation and forwarding for MPLS-TP point-to-multipoint LSPs is identical to that for MPLS-TE point-to-multipoint LSPs. MPLS-TE point-to-multipoint LSPs were introduced in [RFC4875] and the related data-plane behaviour was further clarified in [RFC5332]. MPLS-TP allows for both upstream-assigned and downstream-assigned labels for use with point-to-multipoint LSPs. Packet encapsulation and forwarding for point-to-multipoint PWs is currently being defined by the PWE3 Working Group [I-D.raggarwa-pwe3-p2mp-pw-encaps]. 4. Operations, Administration and Maintenance (OAM) The overall OAM architecture for MPLS-TP is defined in [I-D.ietf-mpls-tp-oam-framework]. [Editor's note: This section will contain a summary of point-to- multipoint OAM as described in the OAM Framework.] 5. Control Plane The overall control plane architecture for MPLS-TP is defined in [I-D.abfb-mpls-tp-control-plane-framework]. [Editor's note: This section will contain a summary of the point-to- multipoint control plane as described in the Control Plane Framework.] 5.1. Point-to-Multipoint LSP Control Plane The MPLS-TP control plane for point-to-multipoint LSPs uses Generalized MPLS (GMPLS) and is based on Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for point-to-multipoint LSPs as defined in [RFC4875]. 5.2. Point-to-Multipoint PW Control Plane The MPLS-TP control plane for point-to-multipoint pseudowires is based on the LDP P2MP signaling extensions for PWs defined in [I-D.martini-pwe3-p2mp-pw]. Frost, et al. Expires July 8, 2011 [Page 6] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 6. Survivability The overall survivability architecture for MPLS-TP is defined in [I-D.ietf-mpls-tp-survive-fwk]. [Editor's note: This section will contain a summary of point-to- multipoint survivability as described in the Survivability Framework.] 7. Network Management The network management architecture and requirements for MPLS-TP are specified in [I-D.ietf-mpls-tp-nm-req]. They derive from the generic specifications described in ITU-T G.7710/Y.1701 [G.7710] for transport technologies. They also incorporate the OAM requirements for MPLS Networks [RFC4377] and MPLS-TP Networks [I-D.ietf-mpls-tp-oam-requirements] and expand on those requirements to cover the modifications necessary for fault, configuration, performance, and security in a transport network. [Editor's note: Decide what if anything needs to be said about P2MP- specific network management considerations.] 8. Security Considerations General security considerations for MPLS-TP are noted in [I-D.ietf-mpls-tp-framework], and security considerations for point- to-multipoint PWs and LSPs in the documents that define them. This document introduces no new security considerations in itself. 9. IANA Considerations IANA considerations resulting from specific elements of MPLS-TP functionality are detailed in the documents specifying that functionality. This document introduces no additional IANA considerations in itself. 10. References 10.1. Normative References [I-D.ietf-mpls-tp-framework] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Berger, "A Framework for MPLS in Transport Networks", draf t-ietf-mpls-tp-framework- 12 (work in progress), Frost, et al. Expires July 8, 2011 [Page 7] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 May 2010. [RFC4875] Aggarwal, R., Papadimitriou, D., and S. Yasukawa, "Extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for Point-to-Multipoint TE Label Switched Paths (LSPs)", RFC 4875, May 2007. [RFC5332] Eckert, T., Rosen, E., Aggarwal, R., and Y. Rekhter, "MPLS Multicast Encapsulations", RFC 5332, August 2008. [RFC5654] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S. Ueno, "Requirements of an MPLS Transport Profile", RFC 5654, September 2009. 10.2. Informative References [G.7710] "ITU-T Recommendation G.7710/Y.1701 (07/07), "Common equipment management function requirements"", 2005. [I-D.abfb-mpls-tp-control-plane-framework] Andersson, L., Berger, L., Fang, L., Bitar, N., Takacs, A., Vigoureux, M., and E. Bellagamba, "MPLS-TP Control Plane Framework", draft-abfb- mpls-tp-control-plane- framework-02 (work in progress), February 2010. [I-D.ietf-l2vpn-vpms-frmwk-requirements] Kamite, Y., JOUNAY, F., Niven-Jenkins, B., Brungard, D., and L. Jin, "Framework and Frost, et al. Expires July 8, 2011 [Page 8] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 Requirements for Virtual Private Multicast Service (VPMS)", draft-ietf- l2vpn-vpms-frmwk- requirements-03 (work in progress), July 2010. [I-D.ietf-mpls-tp-nm-req] Mansfield, S. and K. Lam, "MPLS TP Network Management Requirements", draft-ietf-mpls-tp-nm- req-06 (work in progress), October 2009. [I-D.ietf-mpls-tp-oam-framework] Allan, D., Busi, I., Niven-Jenkins, B., Fulignoli, A., Hernandez- Valencia, E., Levrau, L., Sestito, V., Sprecher, N., Helvoort, H., Vigoureux, M., Weingarten, Y., and R. Winter, "Operations, Administration and Maintenance Framework for MPLS- based Transport Networks", draft-ietf- mpls-tp-oam-framework-10 (work in progress), December 2010. [I-D.ietf-mpls-tp-oam-requirements] Vigoureux, M. and D. Ward, "Requirements for OAM in MPLS Transport Networks", draft-ietf- mpls-tp-oam-requirements- 06 (work in progress), March 2010. [I-D.ietf-mpls-tp-survive-fwk] Sprecher, N. and A. Farrel, "Multiprotocol Label Switching Transport Profile Survivability Framework", draft-ietf- mpls-tp-survive-fwk-06 (work in progress), June 2010. Frost, et al. Expires July 8, 2011 [Page 9] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 [I-D.ietf-pwe3-p2mp-pw-requirements] Heron, G., Wang, L., Aggarwal, R., Vigoureux, M., Bocci, M., Jin, L., JOUNAY, F., Niger, P., Kamite, Y., DeLord, S., and L. Martini, "Requirements for Point- to-Multipoint Pseudowire", draft-ietf- pwe3-p2mp-pw- requirements-03 (work in progress), August 2010. [I-D.martini-pwe3-p2mp-pw] Martini, L., Boutros, S., Sivabalan, S., Konstantynowicz, M., Vecchio, G., Nadeau, T., JOUNAY, F., Niger, P., Kamite, Y., Jin, L., Vigoureux, M., Ciavaglia, L., and S. Delord, "Signaling Root-Initiated Point-to-Multipoint Pseudowires using LDP", d raft-martini-pwe3-p2mp- pw-01 (work in progress), October 2009. [I-D.raggarwa-pwe3-p2mp-pw-encaps] Aggarwal, R. and F. JOUNAY, "Point-to- Multipoint Pseudo-Wire Encapsulation", draft- raggarwa-pwe3-p2mp-pw- encaps-01 (work in progress), March 2010. [RFC4377] Nadeau, T., Morrow, M., Swallow, G., Allan, D., and S. Matsushima, "Operations and Management (OAM) Requirements for Multi- Protocol Label Switched (MPLS) Networks", RFC 4377, February 2006. Frost, et al. Expires July 8, 2011 [Page 10] Internet-Draft MPLS Transport Profile P2MP Framework January 2011 Authors' Addresses Dan Frost (editor) Cisco Systems EMail: danfrost@cisco.com Matthew Bocci (editor) Alcatel-Lucent Voyager Place, Shoppenhangers Road Maidenhead, Berks SL6 2PJ United Kingdom EMail: matthew.bocci@alcatel-lucent.com Lou Berger (editor) LabN Consulting Phone: +1-301-468-9228 EMail: lberger@labn.net Frost, et al. Expires July 8, 2011 [Page 11]