Network Working Group S Bryant. Bryant, Ed. Internet-Draft M Morrow. Intended status: Informational T Nadeau. Expires: November 22, 2007 G Swallow. Cisco Systems R Cherukuri. Juniper Networks, N Harrison. BT Global Services May 21, 2007 Application of PWE3 to MPLS Transport Networks draft-ietf-pwe3-mpls-transport-00 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on November 22, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract A key requirement has been identified by the operator community for the transparent carriage of the MPLS network of one party over the Bryant, et al. Expires November 22, 2007 [Page 1] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 MPLS network of another party. This document describes one IETF- recommended profile to satisfy this requirement using the existing RFC4448 PWE3 Ethernet pseudowire standard. This solution does not preclude other solutions being developed in the future. Requirements Language 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 [RFC2119]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. PWE3 Configuration . . . . . . . . . . . . . . . . . . . . . . 4 3. OAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. VCCV profile 1: BFD without IP/UDP Headers . . . . . . . . 5 3.2. VCCV profile 2: BFD with IP/UDP Headers . . . . . . . . . 5 4. MPLS Layer . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1. External Configuration . . . . . . . . . . . . . . . . . . 6 4.2. Control Plane Configuration . . . . . . . . . . . . . . . 6 5. Congestion Considerations . . . . . . . . . . . . . . . . . . 7 6. Security Considerations . . . . . . . . . . . . . . . . . . . 7 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 8.1. Normative References . . . . . . . . . . . . . . . . . . . 7 8.2. Informative References . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 Intellectual Property and Copyright Statements . . . . . . . . . . 11 Bryant, et al. Expires November 22, 2007 [Page 2] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 1. Introduction MPLS [RFC3031] is based on the ability to arbitrarily stack label switched paths (LSPs). Such stacked LSPs all belong to the same MPLS layer network. The limited isolation provided by this mechanism means that it is not possible to directly carry an LSP belonging to the MPLS network of party A over an LSP belonging to the MPLS network of party B in a truly transparent, functionally decoupled manner. In other words, stacked LSPs do not intrinsically provide a client- server layer network relationship. Several operators have identified this as a problem that requires urgent attention. One solution to the problem is to use existing pseudo-wire (PW) techniques to insert a 'functional other technology breakwater' between the two MPLS networks (of say party A and party B as noted above). This could in principle use any PW technology. However, in this document we restrict our solution to using an Ethernet PW as defined in RFC4448 [RFC4448] . The design described here fulfills the requirements liaised to the IETF PWE3 working group by the ITU - [1]- [2] Note that this does not preclude other solutions emerging in the future. The key purpose of this document is to show that there exists a solution to the problem posed by the operator community using already defined IETF standards. This document is focused on providing a client/server relationship between two MPLS networks owned/operated by different parties, as this is the essential requirement that operators have indicated must be met from the larger set of "transport network" requirements generated in the liaison to the IETF PWE3 WG from ITU SG15ITU2 [2]. The architecture required for this configuration is illustrated in Figure 1 below. Bryant, et al. Expires November 22, 2007 [Page 3] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 +----------------------------------------------------------------+ | | | IP/MPLS PSN (PHP may be enabled) | | | | +---------------------------+ | | | | | | | MPLS PSN (No PHP) | | | | | | | CE1 |PE1 PE2| CE2 | | +-----+ +-----+ +-----+ +-----+ | | | | | | | | | | | | | | | | | | | | | | | +------+ | | | | | | +------+ | | | | | | | | | 802.3| | | | | | | | 802.3| | | | | | +-----+ +-----+ +-----+ +-----+ | | | | | | | | | | | | | | +-- ---------------------- -+ | | | +----- --- -------- -- ---------------------- - -------- --- ----+ | | | |<--MPLS PSN (no PHP)->| | | | | | | | | | | | |<------------PW----------->| | | | | | | | |<-------------802.3 (Ethernet)-------------->| | | | |<---------IP/MPLS LSP (PHP may be supported)-------->| Figure 1: Application PWE3 to MPLS Transport Networks An IP or an MPLS Label Switched Path (LSP) must be established between CE1 and CE2. This MPLS PSN may utilize Penultimate-Hop Popping (PHP). This LSP is to be carried over Ethernet. An Ethernet PW is provisioned between PE1 and PE2 and used to carry the Ethernet from PE1 to PE2. The Ethernet PW is carried over an MPLS PSN, but this PSN MUST NOT be configured with PHP. 2. PWE3 Configuration The only PWE3 encapsulation that is supported in this version of the profile is Ethernet RFC4448 [RFC4448]. This is used in "raw" mode. The Control Word MUST be used. The Sequence number MUST be zero. The use of the Pseudowire Setup and Maintenance Label Distribution Protocol RFC4447 [RFC4447] is not supported in this version of the profile. The Pseudowire Label is statically provisioned. Bryant, et al. Expires November 22, 2007 [Page 4] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 3. OAM The OAM mechanism is VCCV [I-D.ietf-pwe3-vccv]. One of the VCCV profiles described in Section 3.1 or Section 3.2 MUST be used. Once a VCCV profile is provisioned, and the operational status of the PW is UP, no other profile SHOULD be used until such time as the PW's operational status is set to DOWN. 3.1. VCCV profile 1: BFD without IP/UDP Headers As specified in VCCV [I-D.ietf-pwe3-vccv], the first nibble is set to 0001b to indicate a channel associated with a pseudowire RFC4385 [RFC4385]. The Version and the Reserved fields are set to 0, and the Channel Type is set to 0x07 to indicate that the payload carried is BFD without IP/UDP headers, as is defined in section 4.1.1 of VCCV [I-D.ietf-pwe3-vccv]. The connection verification method used by VCCV is BFD with diagnostics as defined in 4.1 of VCCV [I-D.ietf-pwe3-vccv]. 3.2. VCCV profile 2: BFD with IP/UDP Headers When PE1 and PE1 are IP capable and have been configured with IP addresses, the following VCCV mechanism MAY be used. As specified in VCCV [I-D.ietf-pwe3-vccv], the first nibble is set to 0001b to indicate a channel associated with a pseudowire RFC4385 [RFC4385]. The Version and the Reserved fields are set to 0, and the Channel Type is set to 0x21 for IPv4 and 0x56 for IPv6 payloads RFC4446 [RFC4446]. The connection verification method used by VCCV is BFD with diagnostics as defined in 4.1 of VCCV [I-D.ietf-pwe3-vccv]. 4. MPLS Layer This section describes the profile of the MPLS RFC3031 [RFC3031] PSN . The profile considers two cases: 1. The case where external configuration is used 2. The case where a control plane is available Bryant, et al. Expires November 22, 2007 [Page 5] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 4.1. External Configuration All MPLS labels RFC3032 [RFC3032] used by the transport LSPs supporting (i.e. acting as a server to) the PWs described in section 2 MUST be statically provisioned. Labels may be selected from the per-platform or the per-interface label space. All LSPs for the transport LSPs utilized by the PWs described in section 2 MUST support both unidirectional and bi-directional point- to-point connections. The transport LSPs SHOULD support unidirectional point-to-multipoint connections. The forward and backward directions of a bi-directional connection should follow a symmetrically routed (reciprocal) LSP in the server network. Equal cost multi-path (ECMP) load balancing MUST NOT be configured on the transport LSPs utilized by the PWs described in sections 2. The merging of label switched paths is prohibited and MUST NOT be configured for the transport LSPs utilized by the PWs described in section 2. Penultimate hop popping by the LSRs MUST be disabled on LSPs providing PWE3 transport network functionality. Both E-LSP and L-LSP MUST be supported as defined in RFC3270 [RFC3270]. The MPLS EXP field is supported according to RFC3270 for only when the pipe and short-pipe models are utilized. 4.2. Control Plane Configuration In this section we describe the profile when RSVP-TE RFC3209 [RFC3209] or the bi-directional support in GMPLS RFC3471 [RFC3471] RFC3473 [RFC3473] are used to configure the MPLS PSN used to provide the transport LSPs. When these protocols are used to provide the control plane the following are automatically provided: 1. There is no label merging unless it is deliberately enabled to support Fast Re-route (FRR) RFC3209 [RFC3209]. 2. A single path is provided end-to-end (There is no ECMP). Bryant, et al. Expires November 22, 2007 [Page 6] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 3. Paths may be unidirectional or bidirectional as required. Additionally the following configurations restrictions required to support external configuration MUST be applied: o Penultimate hop popping by the LSRs MUST be disabled on LSPs providing PWE3 transport network functionality. o Both E-LSP and L-LSP MUST be supported as defined in RFC3270 [RFC3270]. o The MPLS EXP field is supported according to RFC3270 for only when the pipe and short-pipe models are utilized. 5. Congestion Considerations This draft is a profile of an RFC4448 [RFC4448] PWE3 Ethernet pseudowire. The congestion considerations associated with that pseudowire and all subsequent work on congestion considerations regarding Ethernet pseudowires is applicable to this draft. 6. Security Considerations PWE3 security considerations are described in RFC3985 [RFC3985]. This draft is a profile of existing IETF proposed standards and raises no new security issues. 7. IANA Considerations There are no IANA actions required by this draft. 8. References 8.1. Normative References [I-D.ietf-pwe3-vccv] Nadeau, T., "Pseudo Wire Virtual Circuit Connectivity Verification (VCCV)", draft-ietf-pwe3-vccv-13 (work in progress), March 2007. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. Bryant, et al. Expires November 22, 2007 [Page 7] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001. [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Encoding", RFC 3032, January 2001. [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC 3209, December 2001. [RFC3270] Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen, P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi- Protocol Label Switching (MPLS) Support of Differentiated Services", RFC 3270, May 2002. [RFC3471] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003. [RFC3473] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", RFC 3473, January 2003. [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. [RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)", BCP 116, RFC 4446, April 2006. [RFC4447] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G. Heron, "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", RFC 4447, April 2006. [RFC4448] Martini, L., Rosen, E., El-Aawar, N., and G. Heron, "Encapsulation Methods for Transport of Ethernet over MPLS Networks", RFC 4448, April 2006. 8.2. Informative References [RFC3985] Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to- Edge (PWE3) Architecture", RFC 3985, March 2005. URIs [1] Bryant, et al. Expires November 22, 2007 [Page 8] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 [2] Authors' Addresses Stewart Bryant (editor) Cisco Systems 250, Longwater, Green Park, Reading RG2 6GB, UK UK Email: stbryant@cisco.com Monique Morrow Cisco Systems Glatt-com CH-8301 Glattzentrum Switzerland Email: mmorrow@cisco.com Thomas D. Nadeau Cisco Systems 300 Beaver Brook Drive Boxborough, MA USA Email: tnadeau@cisco.com George Swallow Cisco Systems 1414 Massachusetts Ave Boxborough, MA 01719 Email: swallow@cisco.com Rao Cherukuri Juniper Networks, 1194 N. Mathilda Ave Sunnyvale CA 94089 Bryant, et al. Expires November 22, 2007 [Page 9] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 Neil Harrison BT Global Services CTO, Network Architecture Email: neil.2.harrison@bt.com Bryant, et al. Expires November 22, 2007 [Page 10] Internet-Draft App'n of PWE3 to MPLS Transport Networks May 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Bryant, et al. Expires November 22, 2007 [Page 11]