Network Working Group Matthew Bocci Internet Draft Marc Lasserre Intended status: Informational Alcatel-Lucent Expires: January 2009 Stewart Bryant Cisco Systems, Inc. July 7, 2008 A Framework for MPLS in Transport Networks draft-blb-mpls-tp-framework-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 January 7, 2009. Copyright Notice Copyright (C) The IETF Trust (2008). Expires January 7, 2009 [Page 1] Internet-Draft MPLS TP Framework July 2008 Abstract There is a requirement to use MPLS to provide a network layer to support packet transport services. It is desirable that the operation and maintenance of such an MPLS based packet transport network follow operational models typical in optical transport networks, while providing additional OAM, survivability and other maintenance functions not currently supported by MPLS. This draft presents a framework for an architectural and functional profile of MPLS in order to support packet transport services. 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 RFC-2119 [1]. Table of Contents 1. Introduction...................................................3 1.1. Motivation................................................3 1.2. Scope.....................................................3 1.3. Terminology...............................................3 2. Summary of Requirements........................................3 3. Transport Profile Overview.....................................4 3.1. Architecture..............................................4 3.2. Generic-ACH Label (GAL)...................................4 3.3. Generic Associated Channel Header(GE-ACH).................5 3.4. Forwarding................................................7 3.5. Operations and Management (OAM)...........................8 3.6. Control Plane.............................................9 3.6.1. PW Control Plane....................................10 3.6.2. LSP Control Plane...................................10 3.7. Survivability............................................11 3.8. Network Management.......................................12 4. Security Considerations.......................................13 5. IANA Considerations...........................................13 6. Acknowledgments...............................................13 7. References....................................................14 7.1. Normative References.....................................14 7.2. Informative References...................................15 Authors' Addresses...............................................16 Contributing Authors' Addresses..................................16 Intellectual Property Statement..................................17 Disclaimer of Validity...........................................17 Expires January 7, 2009 [Page 2] Internet-Draft MPLS TP Framework July 2008 1. Introduction 1.1. Motivation Transport technologies (e.g. SDH, ATM, OTN) have been designed with specific characteristics: o Strictly connection oriented Long-lived connections Manually provisioned connections o High level of protection and availability o Quality of service o Extended OAM capabilities The development of MPLS-TP has been driven by carriers needing to evolve SONET/SDH networks to support packet based services and networks. MPLS-TP defines a profile of MPLS targeted at transport applications. This profile specifies the specific MPLS characteristics and extensions required to meet transport requirements. 1.2. Scope This document specifies the high-level functionality of MPLS-TP required for adding transport-oriented capabilities to MPLS. 1.3. Terminology 2. Summary of Requirements This section summarizes the requirements for the MPLS transport profile. Such requirements are specified in more detail in [21], . [22] and [23]. Solutions MUST NOT modify the MPLS forwarding architecture, and MUST be based on existing pseudowire and LSP constructs. Point to point LSPs MAY be unidirectional or bi-directional. Bi-directional LSPs MUST be congruent. Point to multipoint LSPs MUST be unidirectional. There MUST NOT be any LSP merging. Expires January 7, 2009 [Page 3] Internet-Draft MPLS TP Framework July 2008 OAM, protection and forwarding of data packets MUST be able to operate without IP forwarding support i.e. it MUST be possible to forward packets solely based on switching the MPLS or PW label. It must also be possible to establish and maintain LSPs and pseudowires both in the absence or presence of a dynamic control plane. When static provisioning is used, there MUST be no dependency on dynamic routing or signaling. LSP and pseudowire monitoring is only achieved through the use of OAM and MUST NOT rely on control plane or routing functions to determine the health of a path. Information from OAM functions is solely responsible for initiating path recovery actions. Mechanisms and capabilities must be able to interoperate with existing MPLS and pseudowire control and forwarding planes. 3. Transport Profile Overview 3.1. Architecture The architecture for a transport profile of MPLS (MPLS-TP) is based on the MPLS-TE and (MS-)PW architectures defined in RFC 3031 [2], RFC 3985 [5] and [16]. The MPLS-TP forwarding plane is a profile of the MPLS LSP and (MS-)PW forwarding paradigm as detailed in section .3.4. MPLS-TP supports a comprehensive set of OAM and protection-switching capabilities for packet transport applications, similar to existing SONET/SDH OAM and protection, as described in sections .3.5. and . 3.7. MPLS-TP is operated with centralized Network Management Systems with or without the support of a distributed control plane as described in sections .3.6. and .3.8. MPLS-TP defines mechanisms to differentiate specific packets (e.g. OAM, APS, MCC or SCC) from those carrying user data packets. These mechanisms are described in sections .3.2. and .3.3. 3.2. Generic-ACH Label (GAL) MPLS-TP requires a mechanism to differentiate specific packets (e.g. OAM) from others, such as normal user-plane ones. This special label is referred to as the 'Generic-ACH Label (GAL)', as defined in [17]. The 'Generic-ACH Label (GAL)' is a generic exception mechanism used firstly to differentiate specific packets (e.g. OAM) from others, Expires January 7, 2009 [Page 4] Internet-Draft MPLS TP Framework July 2008 such as normal user-plane ones, and secondly, to indicate that the Generic Associated Channel Header (GE-ACH) appears immediately after the bottom of the label stack. Note that MPLS-TP OAM packets will not reside immediately after the 'Generic-ACH Label (GAL)' but behind the Generic Associated Channel Header (GE-ACH). In MPLS-TP, the 'Generic-ACH Label (GAL)' always appears at the bottom of the label stack (i.e. S bit set to 1). 3.3. Generic Associated Channel Header(GE-ACH) The MPLS transport profile makes use of a generic associated channel (GE-ACH) to support Fault, Configuration, Accounting, Performance and Security (FCAPS) functions by carrying packets related to OAM, APS, SCC and MCC, over LSPs or PWs, carried in band. The GE-ACH is defined in [18] and it is similar to the PWE3 Associated Channel, which is used to carry OAM packets across pseudowires. The GE-ACH is indicated by a generic associated channel header, similar to the PWE3 VCCV control word, and this is present for all LSPs and PWs making use of FCAPS functions supported by the GE-ACH. The GE-ACH functionality for LSPs SHOULD be limited to only OAM, APS, MCC and SCC channel data. Figure 1 shows the reference model depicting how the control channel is associated with the pseudowire protocol stack, as per RFC 5085 . [15]. Expires January 7, 2009 [Page 5] Internet-Draft MPLS TP Framework July 2008 +-------------+ +-------------+ | Layer2 | | Layer2 | | Emulated | < Emulated Service > | Emulated | | Services | | Services | +-------------+ +-------------+ | | VCCV/PW | | |Demultiplexer| < Associated Channel > |Demultiplexer| +-------------+ +-------------+ | PSN | < PSN Tunnel > | PSN | +-------------+ +-------------+ | Physical | | Physical | +-----+-------+ +-----+-------+ | | | ____ ___ ____ | | _/ \___/ \ _/ \__ | | / \__/ \_ | | / \ | +--------| MPLS/MPLS-TP Network |---+ \ / \ ___ ___ __ _/ \_/ \____/ \___/ \____/ Figure 1 : PWE3 Protocol Stack Reference Model including the PW Associated Control Channel PW associated channel messages are encapsulated using the PWE3 encapsulation, so that they are handled and processed in the same manner (or in some cases, an analogous manner) as the PW PDUs for which they provide a control channel. Figure 2 shows the reference model depicting how the control channel is associated with the LSP protocol stack. Expires January 7, 2009 [Page 6] Internet-Draft MPLS TP Framework July 2008 +-------------+ +-------------+ | | | | | Payload | < Service > | Payload | | Services | | | +-------------+ +-------------+ | | LSP | | |Demultiplexer| < Associated Channel > |Demultiplexer| +-------------+ +-------------+ | PSN | < LSP > | PSN | +-------------+ +-------------+ | Physical | | Physical | +-----+-------+ +-----+-------+ | | | ____ ___ ____ | | _/ \___/ \ _/ \__ | | / \__/ \_ | | / \ | +--------| MPLS/MPLS-TP Network |---+ \ / \ ___ ___ __ _/ \_/ \____/ \___/ \____/ Figure 2 : MPLS Protocol Stack Reference Model including the LSP Associated Control Channel LSP associated channel messages are encapsulated using a generic associated control channel header (GE-ACH). The presence of the GE- ACH is indicated by the inclusion of an additional 'Generic-ACH Label (GAL)'. This arrangement means that both normal data packets and packets carrying an ACH are carried over LSPs in a similar manner. Note that where a traffic engineered LSP is used the paths will be identical. 3.4. Forwarding MPLS-TP LSPs use the MPLS label switching operations defined in RFC 3031 [2]. The MPLS encapsulation format is as defined in RFC 3032 . [3]. Per-platform or the per-interface label space can be selected. MPLS-TP (MS-)PWs support the PW forwarding operations defined in . [5]. Standard PW encapsulation mechanisms are applicable for different client layers as defined by the IETF PWE3 WG. MPLS-TP LSPs can be unidirectional or bidirectional point-to-point. As for MPLS, point-to-multipoint MPLS-TP LSPs are unidirectional. Expires January 7, 2009 [Page 7] Internet-Draft MPLS TP Framework July 2008 The forward and backward directions of bidirectional MPLS-TP LSPs are congruent: they follow the same path and the pairing relationship between the forward and the backward directions is known in each node traversed by bidirectional LSPs. Equal cost multi-path (ECMP) load balancing is not applicable to MPLS-TP LSPs. MPLS-TP LSP merging is prohibited. Penultimate hop popping (PHP) is disabled on MPLS-TP LSPs by default. Both E-LSP and L-LSP are supported in MPLS-TP, as defined in RFC 3270 [4]. The Class of Service (CoS) field (former MPLS EXP field) follows the definition and processing rules of [19] and RFC 3270 [4], only the pipe and short-pipe models are supported in MPLS-TP. 3.5. Operations and Management (OAM) MPLS-TP requires that a set of OAM capabilities is available to perform fault management (e.g. fault detection and localization) and performance monitoring (e.g. signal quality measurement) of the MPLS- TP network and the services. The following OAM functions are intended to be supported by MPLS-TP and are intended to be applicable to any layer defined within MPLS- TP, i.e. MPLS Section, LSP and PW: o Continuity Check o Connectivity verification o Performance monitoring o Alarm suppression o Remote Integrity For all of the above listed functions, (except alarm suppression) both "continuous" and "on-demand" operations are envisaged. Performance monitoring includes means for both "packet loss measurement" and "delay measurement". A requirement has been expressed for MPLS-TP OAM packets share the same fate as of data packets and that a means exists to identify OAM packets. The documents [17] and [18] propose specific mechanisms Expires January 7, 2009 [Page 8] Internet-Draft MPLS TP Framework July 2008 relying on the combination of the 'Generic-ACH Label (GAL)' and Generic Associated Channel Header for MPLS Sections and LSPs and using the Generic Associated Channel Header only for MPLS PWs. MPLS-TP OAM toolset is able to operate without IP functionality and without relying on control and/or management planes. In the case of MPLS-TP deployment with IP functionality, all existing IP-MPLS OAM functions, e.g. LSP-Ping, BFD and VCCV, can be used. OAM mechanisms are able to detect link and node failures and performance degradations and trigger recovery actions, according to the requirements of the service. 3.6. Control Plane The MPLS Transport Profile utilizes a distributed control plane to enable fast, dynamic and reliable service provisioning in multi- vendor and multi-domain environments using standardized protocols that guarantee interoperability. The MPLS-TP control plane is based on the MPLS control plane for pseudowires and the GMPLS control plane for MPLS-TP LSPs, respectively. More specifically, LDP is used for PW signaling and RSVP-TE for LSP signaling. The distributed MPLS-TP control plane provides the following basic functions: o Signaling o Routing o Traffic engineering and constraint-based path computation In a multi-domain environment, the MPLS-TP control plane provides different types of interfaces at domain boundaries or within the domains such as UNI, I-NNI, and E-NNI where different policies are in place that control what kind of information is exchanged across these different types of interfaces. The MPLS-TP control plane is capable to activate MPLS-TP OAM functions as described in the OAM section of this document (.3.5. ) e.g. for fault detection and localization in the event of a failure in order to efficiently restore failed transport paths. The MPLS-TP control plane supports all MPLS-TP data plane connectivity patterns that are needed for establishing multiple types of transport paths including protected paths as described in the survivability section (.3.7. ) of this document. Examples of the MPLS-TP data plane connectivity patterns are LSPs utilizing the fast Expires January 7, 2009 [Page 9] Internet-Draft MPLS TP Framework July 2008 reroute backup methods as defined in [6] and ingress-to-egress 1+1 or 1:1 protected LSPs. Moreover, the MPLS-TP control plane is capable of performing fast restoration in the event of network failures. The MPLS-TP control plane provides its own survivability features and recovers from control plane failures and degradations using graceful operations. The MPLS-TP control plane is largely decoupled from the MPLS-TP data plane such that failures in the control plane do not impact the control plane and vice versa. 3.6.1. PW Control Plane An MPLS-TP packet transport network provides many of its transport services in the form of single-segment or multi-segment pseudowires following the PWE3 architecture as defined in [5] and [16] . In this context, the setup and maintenance of single-segment or multi- segment pseudowires is based on the Label Distribution Protocol (LDP) as per [9]. It shall be noted that multi-segment pseudowire signaling is still work in progress. The control plane supporting multi-segment pseudowires is based on [13]. 3.6.2. LSP Control Plane MPLS-TP provider edge nodes aggregate multiple pseudowires and carry them across the MPLS-TP network through MPLS-TP tunnels (MPLS-TP LSPs). The generalized MPLS (GMPLS) protocol suite already supports packet-switched capable (PSC) technologies and is therefore used as control plane for MPLS-TP transport paths (LSPs). The LSP control plane includes: o RSVP-TE for signalling o OSPF-TE for routing RSVP-TE signaling in support of GMPLS as defined in [11] is used for the setup, modification, and release of MPLS-TP transport paths and protection paths. It supports unidirectional, bi-directional and multicast types of LSPs. The route of a transport path is typically calculated in the ingress node of a domain and the RSVP explicit route object (ERO) is utilized for the setup of the transport path exactly following the given route. Expires January 7, 2009 [Page 10] Internet-Draft MPLS TP Framework July 2008 OSPF-TE routing in support of GMPLS as defined in [8] is used for carrying link state information in a MPLS-TP network. For routing scalability reasons, parallel physical links in an MPLS- TP network are typically bundled into TE-links as defined in [7] and the OSPF-TE routing protocol disseminates link state information on a TE-link basis. 3.7. Survivability A wide variety of resiliency schemes have been developed to meet the various network and service survivability objectives. As part of the MPLS/PW paradigms, MPLS FRR [6] provides two methods for local repair using back-up LSP tunnels, while PWE redundancy [14] supports scenarios where the protection for the PW can not be fully provided by the PSN layer (i.e. where the backup PW terminates on a different target PE node than the working PW). Additionally, GMPLS provides a set of control plane driven well known protection and restoration mechanisms [11]. Finally, as part of the transport networks and applications paradigms, APS-based linear and ring protection mechanisms are defined in [10] and [24]. These schemes have different scopes. They are protecting against link and/or node failures and can be applied end-to-end or on a segment of the considered connection. These protection schemes propose different levels of resiliency (e.g. 1+1, 1:1, shared). The applicability of any given scheme to meet specific requirements is outside the current scope of this document. MPLS-TP resiliency mechanisms characteristics are listed below o Linear, ring and meshed protection schemes are supported. o MPLS-TP recovery mechanisms (protection and restoration), rely on OAM mechanisms to detect and localize network faults or service degenerations. o APS-based protection mechanisms (linear and ring) rely on MPLS-TP APS mechanisms to coordinate and trigger protection switching actions. o MPLS-TP recovery schemes are designed to be applicable at various levels (MPLS section, LSP and PW), providing segment and end-to- end recovery. Expires January 7, 2009 [Page 11] Internet-Draft MPLS TP Framework July 2008 o MPLS-TP recovery mechanisms support means for avoiding race conditions in switching activity triggered by a fault condition detected both at server layer and at MPLS-TP layer. o MPLS-TP recovery mechanisms can be data plane, control plane or management plane based. o MPLS-TP allows for revertive and non-revertive behavior o Multiple resiliency mechanisms can be applied to any connection. 3.8. Network Management The network management architecture and requirements for MPLS-TP are specified in [23]. It derives from the generic specifications described in ITU-T G.7710/Y.1701 [12] for transport technologies. It also leverages on the OAM requirements for MPLS Networks [20] and MPLS-TP Networks [22] and expands on the requirements to cover the modifications necessary for fault, configuration, performance, and security. The Equipment Management Function (EMF) of a MPLS-TP NE provides the means through which a management system manages the NE. The Management Communication Channel (MCC), realized by the GE-ACH, provides a logical operations channel between NEs for transferring Management information. For the management interface from a management system to a MPLS-TP NE, there is no restriction on which management protocol should be used. It is allowed to provision and manage an end-to-end connection across a network where some segments are create/managed, for examples by Netconf or SNMP and other segments by XML or CORBA interfaces. It is allowed to run maintenance operations on a connection which is independent of the provisioning mechanism. An MPLS-TP NE is not required to offer more than one standard management interface. The Fault Management (FM) functions within the EMF of an MPLS-TP NE enable the supervision, detection, validation, isolation, correction, and alarm handling of abnormal operation of the MPLS-TP network and its environment. Supervision for transmission (such as continuity, connectivity, etc.), software processing, hardware, and environment are essential for FM. Alarm handling includes alarm severity assignment, alarm suppression/aggregation/correlation, alarm reporting control, and alarm reporting. Configuration Management (CM) provides functions to exercise control over, identify, collect data from, and provide data to MPLS-TP NEs. In addition to general configuration for hardware, software, Expires January 7, 2009 [Page 12] Internet-Draft MPLS TP Framework July 2008 protection switching, alarm reporting control, and date/time setting, the EMF of the MPLS-TP NE also supports the configuration of maintenance entity identifiers (such as MEP ID and MIP ID). The EMF also supports configuration of the OAM parameters as part of connectivity management to meet specific operational requirements, such as whether one-time on-demand or periodically based on a specified frequency. The Performance Management (PM) functions within the EMF of an MPLS- TP NE supports the evaluation and reporting upon the behaviour of the equipment, NE, and network with the objective of providing coherent and consistent interpretation of the network behaviour, in particular for hybrid network which consists of multiple transport technologies. Packet loss measurement and delay measurement are collected so that they can be used to detect performance degradation. Performance degradation is reported via fault management for corrective actions (e.g. protection switch) and via performance monitoring for Service Level Agreement (SLA) verification and billing. The performance data collection mechanisms should be flexible to be configured to operate on-demand or proactively. 4. Security Considerations To be covered in a future revision of this document. 5. IANA Considerations To be covered in a future revision of this document. 6. Acknowledgments To be covered in a future revision of this document. Expires January 7, 2009 [Page 13] Internet-Draft MPLS TP Framework July 2008 7. References 7.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Rosen, E., Viswanathan, A., Callon, R., "Multiprotocol Label Switching Architecture", RFC 3031, January 2001 [3] Rosen, E., et al., "MPLS Label Stack Encoding", RFC 3032, January 2001 [4] Le Faucheur, F., et al., "Multi-Protocol Label Switching (MPLS) Support of Differentiated Services", RFC 3270 May 2002 [5] Bryant, S., Pate, P. "Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005 [6] Pan, P., Swallow, G., Atlas, A., "Fast Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090, May 2005 [7] Kompella, K. Rekhter, Y., Berger, L., " Link Bundling in MPLS Traffic Engineering (TE)", RFC 4201 October, 2005 [8] Kompella, K. Rekhter, Y., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203 October 2005 [9] Martini, L. et al., "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", RFC 4447, April 2006 [10] ITU-T Recommendation G.8131/Y.1382 (02/07) " Linear protection switching for Transport MPLS (T-MPLS) networks" [11] Lang, J.P., Rekhter, Y., Papadimitriou, D. (Editors), "RSVP-TE Extensions in Support of End-to-End Generalized Multi-Protocol Label Switching (GMPLS) Recovery", RFC 4872, May 2007 [12] ITU-T Recommendation G.7710/Y.1701 (07/07), "Common equipment management function requirements" [13] Martini, L., Bocci, M., Balus, F., "Dynamic Placement of Multi Segment Pseudo Wires", draft-ietf-pwe3-dynamic-ms-pw-06, November 2007 Expires January 7, 2009 [Page 14] Internet-Draft MPLS TP Framework July 2008 [14] Muley, P., et al., "Pseudowire (PW) Redundancy", draft-muley- pwe3-redundancy-02, November 2007 [15] Nadeau, T., Pignataro, S., "Pseudowire Virtual Circuit Connectivity Verification (VCCV): A Control Channel for Pseudowires", RFC 5085, December 2007 [16] Bocci, M., Bryant, S., "An Architecture for Multi-Segment Pseudowire Emulation Edge-to-Edge", draft-ietf-pwe3-ms-pw-arch- 04, June 2008 [17] Vigoureux, M., Swallow, G., Aggarwal, R., "Assignment of the Generic Associated Channel Header Label (GAL)", draft- vigoureux-mpls-tp-gal-00, June 2008 [18] Bocci, M., Ward, D., "MPLS Generic Associated Channel", draft- bocci-pwe3-mpls-tp-ge-ach-00, June 2008 [19] Andersson, L., ""EXP field" renamed to "CoS Field"", draft- ietf-mpls-cosfield-def-03, July 2008 7.2. Informative References [20] Nadeau, T., et al., "Operations and Management (OAM) Requirements for Multi-Protocol Label Switched (MPLS) Networks", RFC 4377, February 2006 [21] Niven-Jenkins, B., Brungard, D., Betts, M., "MPLS-TP Requirements", draft-jenkins-mpls-mpls-tp-requirements-00, July 2008 [22] Vigoureux, M., Betts, M., Ward, D., "Requirements for OAM in MPLS Transport Networks", draft-vigoureux-mpls-tp-oam- requirements-00, July 2008 [23] Lam, H.-K., Mansfield, S., Gray, E., "MPLS TP Network Management Requirements", draft-gray-mpls-tp-nm-req-00, July 2008 [24] Draft ITU-T Recommendation G.8132/Y.1382, "T-MPLS shared protection ring", http://www.itu.int/md/T05-SG15-080211-TD- PLEN-0501/en Expires January 7, 2009 [Page 15] Internet-Draft MPLS TP Framework July 2008 Authors' Addresses Matthew Bocci Alcatel-Lucent Email: matthew.bocci@alcatel-lucent.co.uk Marc Lasserre Alcatel-Lucent Email: mlasserre@alcatel-lucent.com Stewart Bryant Cisco Systems, Inc. Email :stbryant@cisco.com Contributing Authors' Addresses Dieter Beller Alcatel-Lucent Email: d.beller@alcatel-lucent.de Italo Busi Alcatel-Lucent Email: italo.busi@alcatel-lucent.it Hing-Kam Lam Alcatel-Lucent Email: hklam@alcatel-lucent.com Lieven Levrau Alcatel-Lucent Email: llevrau@alcatel-lucent.com Expires January 7, 2009 [Page 16] Internet-Draft MPLS TP Framework July 2008 Vincenzo Sestito Alcatel-Lucent Email: vincenzo.sestito@alcatel-lucent.it Martin Vigoureux Alcatel-Lucent Email: martin.vigoureux@alcatel-lucent.com Intellectual Property Statement 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. Disclaimer of Validity 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. Expires January 7, 2009 [Page 17] Internet-Draft MPLS TP Framework July 2008 Copyright Statement Copyright (C) The IETF Trust (2008). 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. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Expires January 7, 2009 [Page 18]