[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-aissaoui-l2vpn-vpws-iw-oam) 00 01 02 03 04

Network Working Group                                  Mustapha Aissaoui
Internet Draft                                          Peter Busschbach
Expires: September 12, 2014                               Alcatel-Lucent

                                                              Dave Allan
                                                                Ericsson

                                                          Monique Morrow
                                                      Cisco Systems Inc.

                                                           Thomas Nadeau
                                                        Juniper Networks

                                                                 Editors


                                                          March 12, 2014

                   OAM Procedures for VPWS Interworking
                    draft-ietf-l2vpn-vpws-iw-oam-04.txt



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.

   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 September 12, 2014.






Aissaoui, et al.       Expires September 12, 2014           [Page 1]


Internet-Draft   OAM Procedures for VPWS Interworking     March 2014


 Copyright and License Notice

   Copyright (c) 2013 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 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.

Abstract

   This draft proposes OAM procedures for the Ethernet interworking, IP
   interworking and FR-ATM interworking Virtual Private
   Wire Service (VPWS).



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.

Table of Contents


   1. Contributors...................................................3
   2. Introduction...................................................3
   3. Conventions....................................................4
   4. Reference Model and Defect Locations...........................5
   5. Abstract Defect States.........................................6
   6. VPWS OAM Modes.................................................8
   7. PW Defect State Entry/Exit....................................10
   8. ATM AC Defect State Entry/Exit................................10
   9. FR AC Defect State Entry/Exit.................................11
   10. Ethernet AC Defect State Entry/Exit..........................11
   11. PPP AC Defect State Entry/Exit...............................11
   12. Security Considerations......................................11
   13. IANA Considerations..........................................12
   14. References...................................................12
      14.1. Normative References....................................12


Aissaoui, et al.       Expires September 12, 2014              [Page 2]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


      14.2. Informative References..................................12
   15. Editor's Addresses...........................................13

1. Contributors

   The following individuals contributed significant ideas or text:

   Matthew Bocci, matthew.bocci@alcatel-lucent.com
   Simon Delord, simon.delord@gmail.com
   Paul Doolan, paul.doolan@coriant.com
   Mike Loomis, mike.loomis@alcatel-lucent.com
   Hamid Ould-Brahim, ouldh@yahoo.com
   Vasile Radoaca, vasile.radoaca@alcatel-lucent.com
   Himanshu Shah, hshah@ciena.com
   David Watkinson, david.watkinson@alcatel-lucent.com
   John Z. Yu.


2. Introduction

   This draft augments OAM message mapping [RFC6310] with OAM
   procedures for scenarios when the attachment circuit does not
   correspond to the pseudo wire. When combined with procedures defined
   in [RFC6310] and [RFC7023], comprehensive OAM interworking can be
   defined for VPWS services. VPWS services are defined in the L2 VPN
   framework [RFC4664].

   The following VPWS are covered in this document:

   1. VPWS with heterogeneous ACs of ATM and FR types, and in which the
      PW type is ATM or FR. In this case, FR-ATM service interworking
      [FRF8.2] is performed at one end of the VPWS and a FR (or ATM) PW
      is extended to the remote PE. This VPWS will be referred to as
      FR-ATM Interworking VPWS.

   2. VPWS with heterogeneous ACs of ATM, FR, Ethernet, and PPP/BCP
      types, and in which the PW type is Ethernet. This VPWS will be
      referred to as Ethernet Interworking VPWS.

   3. VPWS with heterogeneous ACs of ATM, FR, Ethernet, and PPP/IPCP
      types, and in which the PW type is IP [RFC6575]. This VPWS will
      be referred to as IP Interworking VPWS.

   OAM procedures for homogeneous VPWS circuits of ATM and FR types are
   described in [RFC6310]. OAM procedures for homogeneous VPWS circuits
   of Ethernet type are defined in [RFC7023].



Aissaoui, et al.       Expires August 18, 2014              [Page 3]


Internet-Draft   OAM Procedures for VPWS Interworking     March 2014


   The PPP PW encapsulation [RFC 4618] describes in Section 5.3 the
   need to generate a PW status notification to the far-end PE if a
   change to the status of the PPP AC or PW is detected. However, the
   PPP protocol does not have a standardized OAM mechanism to propagate
   to the PPP AC defects detected on the PW.


3. Conventions

   The words "defect" and "fault" are used interchangeably to mean any
   condition that obstructs forwarding of user traffic between the CE
   endpoints of the VPWS.

   The words "defect notification" and "defect indication" are used
   interchangeably to mean any OAM message generated by a PE and sent
   to other nodes in the network to convey the defect state local to
   this PE.

   An end-to-end virtual circuit in a VPWS consists of a 3 segment set:
   <AC, PW, AC> [RFC4664]. Note that the AC does not need to connect a
   CE directly to a PE. An intermediate L2 network may exist.

   A VPWS is homogeneous if AC and PW types are the same. E.g., ATM
   VPWS: <ATM AC, ATM PW, ATM AC>.

   A VPWS is heterogeneous if any two segments of the circuit are of
   different types. E.g., IP interworking circuit: <ATM AC, IP PW, ATM
   AC>, or <ATM AC, IP PW, ETH AC>.

   The PW of a VPWS can be carried over three types of Packet Switched
   Networks (PSNs). An "MPLS PSN" makes use of MPLS Label Switched
   Paths [RFC3031] as the tunneling technology to forward the PW
   packets. An "MPLS/IP PSN" makes use of MPLS-in-IP tunneling
   [RFC4023], with an MPLS shim header used as PW demultiplexer. An
   "L2TPv3/IP PSN" makes use of L2TPv3/IP [RFC3931] as the tunneling
   technology with the L2TPv3/IP Session ID as the PW demultiplexer.

   If LSP-Ping [RFC4379] is run over a PW as described in [RFC5085], it
   will be referred to as "VCCV-Ping". If BFD is run over a PW as
   described in [RFC5885], it will be referred to as "VCCV-BFD".

   While PWs are inherently bidirectional entities, defects and OAM
   messaging are related to a specific traffic direction. We use the
   terms "upstream" and "downstream" to identify PEs in relation to the
   traffic direction. A PE is upstream for the traffic it is forwarding
   and is downstream for the traffic it is receiving.



Aissaoui, et al.       Expires September 12, 2014              [Page 4]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


   We use the terms "local" and "remote" to identify native service
   networks and ACs in relation to a specific PE. The local AC is
   attached to the PE in question, while the remote AC is attached to
   the PE at the other end of the PW.

   A "transmit defect" is any defect that uniquely impacts traffic sent
   or relayed by the observing PE.  A "receive defect" is any defect
   that impacts information transfer to the observing PE.  Note that a
   receive defect also impacts traffic relayed, and thus can be
   considered to incorporate two defect states.  Thus, when a PE
   enters both receive and transmit defect states of a VPWS, the
   receive defect takes precedence over the transmit defect in terms of
   the consequent actions.

   A "forward defect indication" (FDI) is sent in the same direction as
   the user traffic impacted by the defect. A "reverse defect
   indication" (RDI) is sent in the direction opposite to that of the
   impacted traffic.

   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].

4. Reference Model and Defect Locations

   Figure 1 illustrates the VPWS network reference model with an
   indication of the possible defect locations. This model is
   introduced in [RFC6310] for homogeneous VPWS and is also valid for
   heterogeneous VPWS.


               ACs             PSN tunnel            ACs
                      +----+                  +----+
      +----+          | PE1|==================| PE2|          +----+
      |    |---(a)---(b)..(c)......PW1..(d)..(e)..(f)---(g)---|    |
      | CE1|   (N1)   |    |                  |    |    (N2)  |CE2 |
      |    |----------|............PW2.............|----------|    |
      +----+          |    |==================|    |          +----+
           ^          +----+                  +----+          ^
           |      Provider Edge 1         Provider Edge 2     |
           |                                                  |
           |<-------------- Emulated Service ---------------->|
     Customer                                                Customer
      Edge 1                                                  Edge 2
                  Figure 1: PWE3 Network Defect Locations




Aissaoui, et al.       Expires September 12, 2014              [Page 5]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


   The procedures will be described in this document from the viewpoint
   of PE1, so that N1 is the local Native Service (NS) network and N2
   is the remote NS network. It is assumed that the AC and PW are of
   different types at PE1. PE2 will typically implement the same
   procedures. Note that PE1 is the upstream PE for traffic originating
   in the local NS network N1, while it is the downstream PE for
   traffic originating in the remote NS network N2.

   The following is a brief description of the defect locations:

     a. Defect in NS network N1. This covers any defect in network N1
        (including any CE1 defect) that impacts all or some ACs
        attached to PE1, and is thus a local AC defect. The defect is
        conveyed to PE1 and to NS network N2 using NS specific OAM
        defect indications.

     b. Defect on a PE1 AC interface (another local AC defect).

     c. Defect on a PE1 PSN interface.

     d. Defect in the PSN network. This covers any defect in the PSN
        that impacts all or some PWs between PE1 and PE2. The defect is
        conveyed to the PE using a PSN and/or a PW specific OAM defect
        indication. Note that both data plane defects and control plane
        defects must be taken into consideration. Although control
        plane packets may follow a different path than PW data plane
        packets, a control plane defect may affect the PW status.

     e. Defect on a PE2 PSN interface.

     f. Defect on a PE2 AC interface (a remote AC defect).

     g. Defect in NS network N2 (another remote AC defect). This covers
        any defect in N2 (including any CE2 defect) which impacts all
        or a subset of ACs attached to PE2. The defect is conveyed to
        PE2 and to NS network N1 using the NS OAM defect indication.


5. Abstract Defect States

   PE1 must track four defect states that reflect the observed states
   of both directions of the VPWS on both the AC and the PW sides.

   Defects may impact one or both directions of the VPWS. The observed
   state is a combination of defects directly detected by PE1 and
   defects of which it has been made aware via notifications.



Aissaoui, et al.       Expires September 12, 2014              [Page 6]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


                              +-----+
           ----AC receive---->|     |-----PW transmit---->
      CE1                     | PE1 |                       PE2/CE2
           <---AC transmit----|     |<----PW receive-----
                              +-----+

     (arrows indicate direction of user traffic impacted by a defect)
               Figure 2: Receive and Transmit Defect States

   PE1 will directly detect or be notified of AC receive or PW receive
   defects as they occur upstream of PE1 and impact traffic being sent
   to PE1. As a result, PE1 enters the AC or PW receive defect state.

   In Figure 2, PE1 may be notified of a receive defect in the AC by
   receiving a Forward Defect indication, e.g., ATM AIS, from CE1 or an
   intervening network. This defect notification indicates that user
   traffic sent by CE1 may not be received by PE1 due to a defect. PE1
   can also directly detect an AC receive defect if it resulted from a
   failure of the receive side in the local port or link over which the
   AC is configured.

   Similarly, PE1 may detect or be notified of a receive defect in the
   PW by receiving a Forward Defect indication from PE2. If PW status
   is used for fault notification, this message will indicate a Local
   PSN-facing PW (egress) Transmit Fault or a Local AC (ingress)
   Receive Fault at PE2 [RFC4446]. This defect notification indicates
   that user traffic sent by CE2 may not be received by PE1 due to a
   defect. As a result, PE1 enters the PW receive defect state.

   Note that a Forward Defect Indication is sent in the same direction
   as the user traffic impacted by the defect.

   Generally, a PE cannot detect transmit defects by itself and will
   therefore need to be notified of AC transmit or PW transmit defects
   by other devices.

   In Figure 2, PE1 may be notified of a transmit defect in the AC by
   receiving a Reverse Defect indication, e.g., ATM RDI, from CE1. This
   defect relates to the traffic sent by PE1 to CE1 on the AC.

   Similarly, PE1 may be notified of a transmit defect in the PW by
   receiving a Reverse Defect indication from PE2. If PW status is used
   for fault notification, this message will indicate a Local PSN
   facing PW (ingress) Receive Fault or a Local Attachment Circuit
   (egress) Transmit Fault at PE2 [RFC4446]. This defect impacts the
   traffic sent by PE1 to CE2. As a result, PE1 enters the PW transmit
   defect state.


Aissaoui, et al.       Expires September 12, 2014              [Page 7]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


   Note that a Reverse Defect indication is sent in the reverse
   direction to the user traffic impacted by the defect.

   The procedures outlined in this document define the entry and exit
   criteria for each of the four states with respect to the set of
   heterogeneous VPWS within the document scope and the consequent
   actions that PE1 must perform.

   When a PE enters both receive and transmit defect states related to
   the same VPWS, then the receive defect takes precedence over
   transmit defect in terms of the consequent actions.

6. VPWS OAM Modes

   A heterogeneous VPWS forwards packets between an AC and a PW of
   different types. It thus implements both NS OAM and PW OAM
   mechanisms.

   PW OAM defect notification messages and NS OAM messages are
   described in [RFC6310]. Ethernet NS OAM messages are described in
   [RFC7023].

   [RFC6310] defined two different OAM modes, the distinction being the
   method of mapping between the NS and PW OAM defect notification
   messages.

   The first mode, illustrated in Figure 3, is called the "single
   emulated OAM loop" mode. Here a single end-to-end NS OAM loop is
   emulated by transparently passing NS OAM messages over the PW. Note
   that the PW OAM is shown outside the PW in Figure 3, as it is
   transported in LDP messages or in the associated channel, not inside
   the PW itself.


                       +-----+                 +-----+
        +-----+          |     |=================|     |          +-----+
        | CE1 |-=NS-OAM=>| PE1 |----=NS-OAM=>----| PE2 |-=NS-OAM=>| CE2 |
        +-----+          |     |=================|     |          +-----+
                       +-----+                 +-----+
                         \                       /
                          -------=PW-OAM=>-------
                  Figure 3: Single Emulated OAM Loop Mode

   The single emulated OAM loop mode implements the following behavior:

      a. The upstream PE (PE1) MUST transparently relay NS OAM messages
         over the PW.


Aissaoui, et al.       Expires September 12, 2014              [Page 8]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


      b. The upstream PE MUST signal local defects affecting the AC
         using a NS defect notification message sent over the PW.  In
         the case that it is not possible to generate NS OAM messages
         (e.g., because the defect interferes with NS OAM message
         generation), the PE MUST signal local defects affecting the AC
         using a PW defect notification message.

      c. The upstream PE MUST signal local defects affecting the PW
         using a PW defect notification message.

      d. The downstream PE (PE2) MUST insert NS defect notification
         messages into its local AC when it detects or is notified of a
         defect in the PW or remote AC.  This includes translating
         received PW defect notification messages into NS defect
         notification messages for defects signaled by the upstream PE.

   The second OAM mode operates three OAM loops joined at the AC/PW
   boundaries of the PEs. This is referred to as the "coupled OAM
   loops" mode and is illustrated in Figure 4. Note that in contrast to
   Figure 3, NS OAM messages are never carried over the PW.


                       +-----+                 +-----+
        +-----+          |     |=================|     |          +-----+
        | CE1 |-=NS-OAM=>| PE1 |                 | PE2 |-=NS-OAM=>| CE2 |
        +-----+          |     |=================|     |          +-----+
                       +-----+                 +-----+
                         \                       /
                          -------=PW-OAM=>-------
                      Figure 4: Coupled OAM Loops Mode

   The coupled OAM loops mode implements the following behavior:

     a. The upstream PE (PE1) MUST terminate and translate a received
        NS defect notification message into a PW defect notification
        message.

     b. The upstream PE MUST signal local failures affecting its local
        AC using PW defect notification messages to the downstream PE.

     c. The upstream PE MUST signal local failures affecting the PW
        using PW defect notification messages.

     d. The downstream PE (PE2) MUST insert NS defect notification
        messages into the AC (unless the AC is PPP) when it detects or
        is notified of defects in the PW or remote AC. This includes



Aissaoui, et al.       Expires September 12, 2014              [Page 9]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


        translating received PW defect notification messages into NS
        defect notification messages.

   Table 1 summarizes the OAM mode used with each VPWS covered in this
   document.

   -----------------------------------------------------------------
   |VPWS                   | Single Emulated     | Coupled OAM      |
   |                       | OAM Loop Mode       | Loops Mode       |
   ------------------------------------------------------------------
   |FR-ATM Interworking    |                     |                  |
   |- ATM cell mode PW     |          X          |                  |
   ------------------------------------------------------------------
   |FR-ATM Interworking    |                     |                  |
   |- FR or AAL5 PDU/SDU PW|                     |        X         |
   ------------------------------------------------------------------
   |Ethernet Interworking  |                     |        X         |
   ------------------------------------------------------------------
   |IP Interworking        |                     |        X         |
   -----------------------------------------------------------------
             Table 1: Summary of Heterogeneous VPWS OAM Modes

7. PW Defect State Entry/Exit

   The details of the PW transmit and receive defect state entry/exit
   criteria are described in Section 6.2 of [RFC6310].

   The consequent actions for an ATM AC are described in sections 7.3.1
   and 7.3.2 of [RFC6310].

   The consequent actions for a FR AC are described in sections 8.3.1
   and 8.3.2 of [RFC6310].

   The consequent actions for an Ethernet AC are described in sections
   6.1 through 6.4 of [RFC7023].

8. ATM AC Defect State Entry/Exit

   The details of the ATM AC receive and transmit defect state
   entry/exit criteria are described in sections 7.1 and 7.2
   respectively of [RFC6310].

   The consequent actions are described in sections 7.3.4 and 7.3.5 of
   [RFC6310].





Aissaoui, et al.       Expires September 12, 2014             [Page 10]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


   Note that all interworking VPWS covered in this document make use of
   ATM VC as the AC. ATM VP cannot be used as a AC in an interworking
   VPWS. Therefore only ATM F5 OAM messages are relevant.

9. FR AC Defect State Entry/Exit

   The details of the FR AC receive and transmit defect state
   entry/exit criteria are described in sections 8.1 and 8.2
   respectively of [RFC6310].

   The consequent actions are described in sections 8.3.4 and 8.3.5 of
   [RFC6310]. Note however that if the FR AC is part of a FR-ATM
   interworking VPWS operating in the single emulated OAM loop mode,
   then the consequent actions are described sections 7.3.4 and 7.3.5
   of [RFC6310].

10. Ethernet AC Defect State Entry/Exit

   The details of the Ethernet AC receive and transmit defect state
   entry/exit criteria are described in sections 5.1 and 5.2
   respectively of [RFC7023].

   The consequent actions are described in sections 6.5 through 6.8 of
   [RFC7023].

11. PPP AC Defect State Entry/Exit

   The PPP PW encapsulation [RFC 4618] describes in Section 5.3 the
   need to generate a PW status notification to the far-end PE if a
   change to the status of the PPP AC or PW is detected. However, the
   PPP protocol does not have a standardized OAM mechanism to propagate
   to the PPP AC defects detected on the PW.

   This document does not define additional procedures for a PPP AC
   used in an Ethernet or IP interworking VPWS.

12. Security Considerations

   The mapping messages described in this document do not change the
   security functions inherent in the actual messages. All generic
   security considerations applicable to PW traffic specified in
   Section 10 of [RFC3985] are applicable to NS OAM messages
   transferred inside the PW.

   Security considerations in Section 10 of [RFC5085] for VCCV apply to
   the OAM messages thus transferred. Security considerations



Aissaoui, et al.       Expires September 12, 2014             [Page 11]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


   applicable to the PWE3 control protocol of [RFC4447] Section 8.2
   apply to OAM indications transferred using the LDP status message.

13. IANA Considerations

   This document requires no IANA actions.

14. References

14.1. Normative References

  [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
       Requirement Levels", BCP 14, RFC 2119, March 1997.

  [RFC6310] Nadeau, T., et al., ''Pseudo Wire (PW) OAM Message Mapping'',
       RFC 6310, April 2011.

  [RFC7023] Qiu, R., Mohan, D., Bitar, N., DeLord, S., Niger, P., and
       A. Sajassi, "MPLS and Ethernet Operations, Administration, and
       Maintenance (OAM) Interworking ", RFC 7023, October 2013.

14.2. Informative References

  [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
       Label Switching Architecture", RFC 3031, January 2001.

   [RFC3931] Lau, J., Townsley, M., and I. Goyret, "Layer Two Tunneling
       Protocol - Version 3 (L2TPv3)", RFC 3931, March 2005.

  [RFC3985] Bryant, S. and P. Pate, "Pseudo Wire Emulation Edge-to-
       Edge (PWE3) Architecture", RFC 3985, March 2005.

  [RFC4023] Worster, T., Rekhter, Y., and E. Rosen, "Encapsulating
       MPLS in IP or Generic Routing Encapsulation (GRE)",
       RFC 4023, March 2005.

   [RFC4379] Kompella, K. and G. Swallow, "Detecting Multi-Protocol
       Label Switched (MPLS) Data Plane Failures", RFC 4379,
       February 2006.

   [RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge
        Emulation (PWE3)", BCP 116, RFC 4446, April 2006.

  [RFC4618] Martini, L., "Encapsulation Methods for Transport of
       PPP/High-Level Data Link Control (HDLC) over MPLS Networks", RFC
       4618, September 2006.



Aissaoui, et al.       Expires September 12, 2014             [Page 12]


Internet-Draft   OAM Procedures for VPWS Interworking        March 2014


  [RFC4664] Andersson, L. et. al., "L2VPN Framework", RFC 4664,
       September 2006.

   [RFC5085] Nadeau, T. and C. Pignataro, "Pseudowire Virtual Circuit
        Connectivity Verification (VCCV): A Control Channel for
        Pseudowires", RFC 5085, December 2007.

   [RFC5885] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding
       Detection (BFD) for the Pseudowire Virtual Circuit
       Connectivity Verification (VCCV)", RFC 5885, June 2010.

  [RFC6575] Shah, H., et al., ''Address Resolution Protocol (ARP)
       Mediation for IP Interworking of Layer 2 VPNs'', RFC 6575, June
       2012.

  [FRF8.2] Frame Relay Forum, ''FRF 8.2 - Frame Relay / ATM PVC Service
       Interworking Implementation Agreement'', February 2004.


15. Editor's Addresses

   Mustapha Aissaoui
   Alcatel-lucent
   Email: mustapha.aissaoui@alcatel-lucent.com

   Dave Allan
   Ericsson
   david.i.allan@ericsson.com

   Peter B. Busschbach
   Alcatel-Lucent
   Email: peter.busschbach@alcatel-lucent.com

   Thomas Nadeau
   Juniper Networks
   tnadeau@lucidvision.com

   Monique Morrow
   Cisco Systems, Inc.
   EMail: mmorrow@cisco.com









Aissaoui, et al.       Expires September 12, 2014             [Page 13]


Html markup produced by rfcmarkup 1.129d, available from https://tools.ietf.org/tools/rfcmarkup/