MPLS Working Group A. Fulignoli, Ed. Internet Draft Ericsson Intended status: Standards Track Expires: September 2010 S. Boutros, Ed. Cisco Systems, Inc M. Vigoureux, Ed. Alcatel-Lucent March 3, 2010 Proactive Connection Verification, Continuity Check and Remote Defect indication for MPLS Transport Profile draft-asm-mpls-tp-bfd-cc-cv-02 Abstract Continuity Check (CC), Proactive Connectivity Verification (CV) and Remote Defect Indication (RDI) functionalities are MPLS-TP OAM requirements listed in [3]. Continuity Check monitors the integrity of the continuity of the path for any loss of continuity defect. Connectivity verification monitors the integrity of the routing of the path between sink and source for any connectivity issues. RDI enables an End Point to report, to its associated End Point, a fault or defect condition that it detects on a PW, LSP or Section. It is RECOMMENDED that a protocol solution, meeting one or more functional requirement(s), be the same for PWs, LSPs and Sections as per [3]. This document specifies methods for proactive CV, CC, and RDI for MPLS-TP Label Switched Path (LSP), PWs and Sections using Bidirectional Forwarding Detection (BFD). Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and 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. Fulignoli et al., Expires September 3, 2010 [Page 1] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 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. 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Table of Contents Table of Contents 1. Introduction.................................................3 1.1. Contributing Authors.......................................3 2. Conventions used in this document............................4 2.1. Terminology................................................4 3. MPLS-TP CC, proactive CV and RDI Mechanism using BFD.........4 3.1. MPLS-TP BFD CC Message format..............................6 3.2. MPLS-TP BFD proactive CV/CC Message format.................6 3.3. BFD Session in MPLS-TP terminology.........................7 3.4. BFD Profile for MPLS-TP....................................8 3.4.1. Administrative Down State...............................10 3.4.2. Timer negotiation.......................................11 3.4.3. Discriminator values....................................11 3.5. Remote Detection Indication (RDI).........................12 Fulignoli et al., Expires September 4, 2010 [Page 2] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 4. Operation on bidirectional p2p connection...................12 4.1. Bidirectional BFD.........................................12 4.2. Unidirectional BFD........................................13 5. Unidirectional p2p or p2mp transport path...................15 6. Acknowledgments.............................................15 7. IANA Considerations.........................................15 8. Security Considerations.....................................15 9. References..................................................16 9.1. Normative References......................................16 9.2. Informative References....................................16 1. Introduction In traditional transport networks, circuits are provisioned on multiple switches. Service Providers (SP) need OAM tools to detect mis-connectivity and loss of continuity of transport circuits. MPLS- TP LSPs [11]emulating traditional transport circuits need to provide the same CC and proactive CV capabilities as mentioned in [3]. This document describes the use of BFD for CC, proactive CV, and RDI of an MPLS-TP LSP between two Maintenance End Points (MEPs). As described in [9], Continuity Check (CC) and Proactive Connectivity Verification (CV) functions are used to detect loss of continuity (LOC), unintended connectivity between two MEPs (e.g. mismerging or misconnection or unexpected MEP). The Remote Defect Indication (RDI) is an indicator that is transmitted by a MEP to communicate to its peer MEPs that a signal fail condition exists. RDI is only used for bidirectional connections and is associated with proactive CC & CV packet generation. The main goal here is to specify the BFD extension and behavior to satisfy the CC, proactive CV monitoring and the RDI functionality. The mechanism specified in this document is restricted only to BFD asynchronous mode. 1.1. Contributing Authors Siva Sivabalan, George Swallow, David Ward. Fulignoli et al., Expires September 4, 2010 [Page 3] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 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 RFC-2119 [1]. 2.1. Terminology ACH: Associated Channel Header BFD: Bidirectional Forwarding Detection CV: Connection Verification EOS: End of Stack GAL: Generalized Alert Label LSR: Label Switching Router MEP: Maintenance End Point MIP: Maintenance Intermediate Point MPLS-OAM: MPLS Operations, Administration and Maintenance MPLS-TP: MPLS Transport Profile MPLS-TP LSP: Bidirectional Label Switch Path representing a circuit MS-PW: Mult-Segment PseudoWire NMS: Network Management System PW: PseudoWire RDI: Remote defect indication. TTL: Time To Live TLV: Type Length Value 3. MPLS-TP CC, proactive CV and RDI Mechanism using BFD This document proposes two modes of BFD operation Fulignoli et al., Expires September 4, 2010 [Page 4] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 o CC mode: uses the existing ACH code point (0x0007) and BFD ACH packet encapsulation (BFD without IP/UDP headers ) as defined in [6]. In this mode Continuity Check and RDI functionalities are supported. o CV/CC mode: defines a new code point in the Associated Channel Header (ACH) described in [2]. Under MPLS label stack of the MPLS- TP LSP, the ACH with "MPLS-TP Proactive CV/CC" code point indicates that the message is an MPLS-TP BFD proactive CV and CC message. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 1|Version| Flags |0xHH MPLS-TP CV/CC Code Point | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: ACH Indication of MPLS-TP Connection Verification The first nibble (0001b) indicates the ACH. The version and the reserved values are both set to 0 as specified in [2]. MPLS-TP proactive CV/CC code point = 0xHH. [HH to be assigned by IANA from the PW Associated Channel Type registry.] In this mode Continuity Check, Connectivity Verifications and RDI functionalities are supported. Editor's Note: 1) CV/CC mode require extension of CV types, foreseen by [4] and yet extended by [5], in order to include the MPLS-TP OAM mechanism too for PW Fault Detection only. This is due to the fact that VCCV also includes mechanisms for negotiating the control channel and connectivity verification (i.e. OAM functions) between PEs. 2) Does also the CC mode for MPLS-TP require such extension ? 3) Shall we trace that in this document ? EndofEditorNote Both CC and CV/CC modes apply to PWs, MPLS LSPs (including tandem connection monitoring), and Sections. Fulignoli et al., Expires September 4, 2010 [Page 5] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 It's possible to run the BFD in CC mode on some transport paths and the BFD in CV/CC mode on other transport paths. In any case, only one tool for OAM instance at time, configurable by operator, can run. A MEP that is configured to support CC mode and receives CV/CC BFD packets, or vice versa, MUST consider them as an unexpected packet, i.e. detect a mis-connectivity defect. 3.1. MPLS-TP BFD CC Message format The format of an MPLS-TP CC Message format is shown below. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 1|Version| Flags |0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ BFD Control Packet ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: MPLS-TP CC Message 3.2. MPLS-TP BFD proactive CV/CC Message format The format of an MPLS-TP CV/CC Message format is shown below, ACH TLVs MUST precede the BFD control packet. Fulignoli et al., Expires September 4, 2010 [Page 6] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0 0 0 1|Version| Flags |0xHH MPLS-TP CV/CC Code Point | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ACH TLV Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ Unique MEP-ID of source of the BFD packet ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ BFD Control Packet ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: MPLS-TP CV/CC Message As shown in Figure 3, BFD Control packet as defined in [6] is transmitted as MPLS labeled packets along with ACH, ACH TLV Header defined in Section 3 of RFC 5586 and one ACH TLV object carrying the unique MEP Identifier of the source of the BFD packet defined in [12] When GAL label is used, the TTL field of the GAL MUST be set to at least 1, and the GAL will be the end of stack label. 3.3. BFD Session in MPLS-TP terminology A BFD session corresponds to a CC or a proactive CV/CC OAM instance in MPLS-TP terminology. A BFD session is enabled when the CC or proactive CV/CC functionality is enabled on a configured Maintenance Entity (ME). On a Sink MEP, an enabled bidirectional BFD session can be in DOWN, INIT or UP state as detailed in [6]. On a Sink MEP, a unidirectional BFD session can be in UP or DOWN state as reported in [10]. When on a ME the CC or proactive CV/CC functionality is disabled, the BFD session transits in the ADMIN DOWN State and the BFD session ends. Fulignoli et al., Expires September 4, 2010 [Page 7] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 A new BFD session is initiated when the operator enables or re- enables the CC or CV/CC functionality on the same ME. 3.4. BFD Profile for MPLS-TP BFD MUST run in asynchronous mode. In this mode, the BFD Control packets are periodically sent at configurable time rate. When on bidirectional path, associated or co-routed, it is required the BFD state be independent from the peer MEP BFD state, two unidirectional BFD sessions MUST be configured, one for each direction of the bidirectional path to be monitored; each MEP is aware of the relationship among the MEP source function and MEP sink function of the two unidirectional BFD sessions. This applies, for instance, when it is required to transmit the BFD control packet at a regular, operator configured rate and to maintain this rate at any BFD state in order to manage the 1+1 unidirectional protection. When it is required that both sessions on peer MEPs go in DOWN state if one goes in DOWN state, the bidirectional BFD session MUST be configured on the bidirectional using the three state machine and following the behavior detailed in [6]. The unidirectional BFD on the sink MEP uses the two state machine defined in [10]. When running the unidirectional state machine the M bit MUST be always set to 1. On a Sink MEP, a BFD session is declared Down if one of the following defects identified by the proactive CC-CV functions occurs: - an unexpected globally unique Source MEP identifier is received (Mis-connectivity defect), - timer negotiation is disabled and the value of the received "Desired min TX Interval field" is different from the locally configured reception period, or the received value of the "DetectMult field" is different from the locally configured one (Period Mis-configuration defect); - BFD session times out (Loss of Continuity defect). - a Mis-connectivity defect SHOULD be also detected if an unexpected M bit value is received. Fulignoli et al., Expires September 4, 2010 [Page 8] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 The raising and clearing conditions of defects identified by the Continuity Check, proactive Connectivity Verification functionality and RDI MUST be as per [9] where a protocol constant set to 3,5 is used. This protocol constant corresponds to the BFD Detection Time multiplier that is RECOMMENDED to be set to value 3. Traffic MUST NOT be affected when proactive CV/CC or CC monitoring is enabled/disabled by an operator on a configured MEP or when a BFD session transits from one state to another; the blocking of traffic as consequent action MUST be driven only by a defect's consequent action as specified in [9] section 5.1.2 The diagram in Figure 4 provides an overview of the three state machine as defined in [6]. +--+ | | UP, ADMIN DOWN, Defects, | V DOWN +------+ INIT +------------| |------------+ | | DOWN | | | +-------->| |<--------+ | | | +------+ | | | | | | | | ADMIN DOWN,| | | |ADMIN DOWN, DOWN,| | | |Defects Defects | | V | | V +------+ +------+ +----| | | |----+ DOWN| | INIT |--------------------->| UP | |INIT, UP +--->| | INIT, UP | |<---+ +------+ +------+ Figure 4: State Machine for bidirectional BFD Fulignoli et al., Expires September 4, 2010 [Page 9] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 The diagram in Figure 5 provides an overview of the two state machine of unidirectional BFD on Sink MEP ADMIN DOWN, +------+ Defects +------+ +----| |<---------------------| |----+ Defects,| | DOWN | | UP | |UP ADMIN DOWN,+--->| |--------------------->| |<---+ +------+ No defects +------+ && UP Figure 5: MEP Sink State Machine for unidirectional BFD State transitions on MEP Source of unidirectional BFD are administratively driven. On a Source MEP, when the CC, CV/CC functionality is enabled, the state machine transits from the ADMIN- DOWN State to UP State; vice-versa when the functionality is disabled. In both diagram, each arc represents the state of the remote system (as received in the State field in the BFD Control packet) or the occurrence of one or more of the following defect: Mis-connectivity, Period Misconfiguration, Loss of Continuity as previously detailed. As reported in [6], another state (AdminDown) exists so that the BFD session can be administratively put down indefinitely. In the above diagram transitions involving AdminDown state are deleted for clarity; further considerations are reported in section 3.4.1. 3.4.1. Administrative Down State The AdminDown state semantic is equivalent to disabling on a MEP the CC-CV proactive function. When the MEP source function is disabled, BFD Control packets SHOULD be sent in AdminDown state for a period equal to(bfd.DesiredMinTxInterval * bfd.DetectMult) in order to ensure that the remote system is aware of the state change. Fulignoli et al., Expires September 4, 2010 [Page 10] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 A MEP Sink receiving a BFD packet with AdminDown State MUST transit to the DOWN State and report the event to the operator. The MEP Sink receiving the BFD packet with AdminDown State SHOULD continue to monitor the path until the operator disables the CC or proactive CV monitoring on it. On bidirectional path, the MEP source function of the MEP receiving BFD packets in AdminDown state SHOULD continue to transmit BFD control packet until the operator disables the CC or proactive CV monitoring on it. Editor's Note: The behavior of the sink MEP needs further review and will be updated in the next version of this document. 3.4.2. Timer negotiation When running unidirectional BFD, on unidirectional or bidirectional connection path, the timer negotiation does not apply. The configured BFD packet transmission period is carried into the ''Desired Min TX Interval field''. In a typical transport application today the period is the same in both directions; in this case, for Bidirectional BFD on p2p transport path the "Required Min RX Interval field" value is the same as "Desired Min TX Interval field" value. The source MEP of unidirectional BFD MUST set the "Required Min RX Interval field " to 0. The default timer values to be used based on what's recommended in [9]. 3.4.3. Discriminator values MPLS labels at peer MEPs are used to provide context for the received BFD packets. In the BFD control packet the discriminator values have either local or no significance. My Discriminator field MUST be set to a nonzero value (it can be a fixed value), the transmitted your discriminator value MUST reflect back the received value of My discriminator field or be set to 0 if that value is not known. Your discriminator field is always set to 0 on Unidirectional BFD control packets. Fulignoli et al., Expires September 4, 2010 [Page 11] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 3.5. Remote Detection Indication (RDI) Remote Defect Indication (RDI) is an indicator that is transmitted by a MEP to communicate to its peer MEP that a signal fail condition exists. The BFD Diagnostic (Diag) field defined in [6] is used for this functionality. When a MEP detects mis-connectivity, or loss of continuity, or period misconfiguration defect, sends to its peer MEP the proactive CC, CV/CC BFD packet with the Diagnostic (Diag) field value set to 1. When a MEP receives the proactive CC, CV/CC BFD packet with the Diagnostic (Diag) field value set to 1, enters in the RDI defect conditions. A MEP exits from the RDI defect condition when it receives a proactive CC, CV/CC BFD packet with the RDI field clear, corresponding to receive Diagnostic(Diag) field with values different from 1. 4. Operation on bidirectional p2p connection For p2p bidirectional LSPs, both endpoints of the bidirectional MPLS- TP LSP MUST send BFD messages in-band in the MPLS-TP LSP using the defined code point. When on a configured bidirectional transport path the proactive CV/CC or CC monitoring is enabled, each MEP sends the BFD Control Packets at the rate of the configured transmission period and each MEP expects to receive the BFD packets from its peer MEP at the same rate as per [9]. 4.1. Bidirectional BFD When on bidirectional path the bidirectional BFD is enabled, the behaviour SHOULD be as detailed in [6] for asynchronous BFD. Active role is the default behavior, passive role is optional. In Active role both MEPs start sending initial BFD Control Packets with the State field set to "Down" value and with "Your discriminator" field set to zero. Fulignoli et al., Expires September 4, 2010 [Page 12] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 4.2. Unidirectional BFD When on bidirectional path it is required the BFD state be independent from the peer MEP BFD state, two unidirectional BFD sessions MUST be configured. Considering figure 6 below, an unidirectional BFD session is configured to monitor the direction from A to B and an unidirectional BFD session is configured to monitor the direction from B to A. +-----+ +-----+ | |------------------->| | | A | | B | | |< ------------------| | +-----+ +-----+ Figure 6 On the unidirectional BFD session monitoring the A to B direction, the MEP source function is located on node A while the MEP sink function is located on node B. On the unidirectional BFD session monitoring the B to A direction, the MEP source function is located on node B while the MEP sink function is located on node A. o When the source function of an unidirectional BFD is enabled, the source MEP state machine transits from AdminDown State to UP state and starts sending BFD unidirectional control packets at the configured transmission rate with the M bit always set to 1, the State field set to "UP" and Diagnostic code set to zero (0). Fulignoli et al., Expires September 4, 2010 [Page 13] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 +--------+ M =1;Tx=10ms;Rx=0;MyDis=10;YourDis=0; +--------+ | | St=UP;Diag=0 | | | |-------------------------------------->| | | A | | B | | |<--------------------------------------| | | | M =1;Tx=10ms;Rx=0;MyDis=20;YourDis=0; | | | | St=UP;Diag=0 | | +--------+ +--------+ Figure 7 Editor's note: The slow rate startup requires further analysis and is under study. o When enabled, the MEP Sink is allowed to detect continuity and connectivity defects. +-----+ +-----+ | | ------- X -------->| | | A | <----------------- | B | +-----+ +-----+ Figure 8 o If the MEP sink monitoring function, as the one on MEP-B in Figure 8, detects one of the following faults: mis-connectivity, period misconfiguration, or loss of continuity defect it declares that the transport path in its receive direction is down and signals it to its peer MEP (MEP-A) sending the BFD control packet running on the unidirectional BFD from B to A with Diagnostic code set to 1 (RDI); see figure 9 below. Besides, the MEP Sink SHOULD notify the equipment fault management process of the detected defect. Fulignoli et al., Expires September 4, 2010 [Page 14] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 +--------+ M =1;Tx=10ms;Rx=0;MyDis=10;YourDis=0; +--------+ | | St=UP;Diag=0 | | | |-----------------X-------------------> | | | A | | B | | | <-------------------------------------| | | | M =1;Tx=10ms;Rx=0;MyDis=20;YourDis=0;| | | | St=UP;Diag=1 | | +--------+ +--------+ Figure 9 Timer parameters are configured by the operator and statically provisioned or signaled by the control plane; the timer configured value are carried inside the BFD packets and this value never change unless modified by operator; the new timer configuration must be statically provisioned or signaled by the control plane. 5. Unidirectional p2p or p2mp transport path. Unidirectional (point-to-point or point-to-multipoint) transport path are monitored through one unidirectional BFD session. The behavior and MPLS-TP profile is the same as described in previous section for unidirectional BFD except for RDI generation that is not required to be sent on unidirectional transport path. 6. Acknowledgments To be added in a later version of this document 7. IANA Considerations To be added in a later version of this document 8. Security Considerations The security considerations for the authentication TLV need further study. Base BFD foresees an optional authentication section (see [6] section 6.7); that can be extended also to the tool proposed in this document. Fulignoli et al., Expires September 4, 2010 [Page 15] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 Authentication methods that require checksum calculation on the outgoing packet must extend the checksum also on the ME Identifier Section. This is possible but seems uncorrelated with the solution proposed in this document: it could be better to use the simple password authentication method. 9. References 9.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Bocci, M. et al., " MPLS Generic Associated Channel ", RFC 5586 , June 2009 [3] Vigoureux, M., Betts, M. and D. Ward, "Requirements for OAM in MPLS Transport Networks", draft-ietf-mpls-tp-oam- requirements-05 (work in progress), February 2010 [4] Nadeau, T. and C. Pignataro, "Pseudowire Virtual Circuit Connectivity Verification (VCCV): A Control Channel for Pseudowires", RFC 5085, December 2007 [5] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)", draft-ietf-pwe3-vccv- bfd-07 (work in progress), July 2009 [6] Katz, D. and D. Ward, "Bidirectional Forwarding Detection", draft-ietf-bfd-base-11 (work in progress), January 2010 [7] Boutros, S. et al., "Definition of ACH TLV Structure", draft-ietf-mpls-tp-ach-tlv-01 (work in progress), June 2009 [8] Aggarwal, R., Kompella, K., Nadeau, T. and G. Swallow, "BFD For MPLS LSPs", draft-ietf-bfd-mpls-07 (work in progress), June 2008 9.2. Informative References [9] Busi, I. and B. Niven-Jenkins, "MPLS-TP OAM Framework and Overview", draft-ietf-mpls-tp-oam-framework-04 (work in progress), July 2009 Fulignoli et al., Expires September 4, 2010 [Page 16] Internet-Draft draft-asm-mpls-tp-bfd-cc-cv-02 March 2010 [10] Katz, D. and D. Ward, "BFD for Multipoint Networks", draft- katz-ward-bfd-multipoint-02 (work in progress), December 2009 [11] Bocci, M., et al., "A Framework for MPLS in Transport Networks", draft-ietf-mpls-tp-framework-10, (work in progress), February 2010 [12] Bocci, M. and G. Swallow, "MPLS-TP Identifiers", draft-ietf- mpls-tp-identifiers-00 (work in progress), July 2009 Authors' Addresses Annamaria Fulignoli (Editor) Ericsson Email: annamaria.fulignoli@ericsson.com Sami Boutros (Editor) Cisco Systems, Inc. Email: sboutros@cisco.com Martin Vigoureux (Editor) Alcatel-Lucent Email: martin.vigoureux@alcatel-lucent.com Contributing Authors' Addresses Siva Sivabalan Cisco Systems, Inc. Email: msiva@cisco.com George Swallow Cisco Systems, Inc. Email: swallow@cisco.com David Ward Cisco Systems, Inc. Email: wardd@cisco.com Fulignoli et al., Expires September 4, 2010 [Page 17]