One document matched: draft-takeda-l1vpn-applicability-00.txt




Network Working Group                        Tomonori Takeda (Editor)
Internet Draft                                                    NTT
Proposed Status: Informational
Expires: January 2005                                       July 2004


          Applicability of GMPLS protocols and architectures
                 to Layer 1 Virtual Private Networks
                draft-takeda-l1vpn-applicability-00.txt

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   conformance with all provisions of Section 10 of RFC 2026
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Copyright Notice 
    
   Copyright (C) The Internet Society (2004).  All Rights Reserved.

Abstract

   This document provides materials to show how existing Generalized
   Multiprotocol Label Switching (GMPLS) protocols and architectures,
   and current proposals for modifications to those protocols and
   architectures can be used to satisfy the requirements of Layer 1
   Virtual Private Networks (L1VPNs).

   In addition, this document identifies any areas where additional
   protocol extensions or procedures are necessary so that GMPLS


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   protocols can be used to satisfy the requirements of L1VPNs, and sets
   guidelines for possible solution work.

0. Summary

   (This section to be removed before publication as an RFC.)

0.1. Summary

   This document shows applicability of existing GMPLS protocols and
   architectures to L1VPNs. In addition, this document identifies several
   items where additional protocol extensions are necessary to meet the
   full set of L1VPN services.

0.2. Where does it fit in the picture of the IETF Work

   Services may be provisioned across layer 1 networks using
   GMPLS protocols. L1VPNs may be managed and operated using these
   protocols as described in this document. GMPLS protocols were
   developed within the IETF using IP addressing and based on IP and
   other Internet protocols. The IETF continues to work with GMPLS
   protocols, enhancing them and applying them to new requirements.

   VPN related work areas might also have points of interaction with the
   content of this document.

0.3. Justification

   L1VPN mailing list is setup to discuss issues related to L1VPNs. This
   document is intended to progress the work by showing applicability of
   existing documents (in 0.4), as well to identify several items where
   additional work is required.

0.4. Related Internet Documents

   The present draft discusses applicability of existing solutions drafts
   below to L1VPN service requirements mentioned in the following draft.

   o draft-takeda-l1vpn-framework-00.txt (Feb 2004)
     "Framework for Layer 1 Virtual Private Networks"
     This draft examines motivations for L1VPNs, high level (service
     level) requirements, and outlines some of the architectural models
     that might be used to build L1VPNs.
     Note this document is based heavily on the work of ITU-T Study
     Group 13 Question 11.

   This draft mainly discusses applicability of following solution
   drafts to L1VPN service requirements mentioned in the above draft.

   o draft-ouldbrahim-ppvpn-gvpn-bgpgmpls-05.txt (May 2004)
     "GVPN Services: Generalized VPN Services using BGP and GMPLS


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      Toolkit"
     This draft describes a suite of port-based Provider-provisioned VPN
     services called Generalized VPNs (GVPNs) that uses BGP as a VPN
     auto-discovery and GMPLS as a signaling mechanism.

   o draft-ietf-ccamp-gmpls-overlay-04.txt (April 2004)
     "GMPLS UNI: RSVP Support for the Overlay Model"
     This memo addresses the application of GMPLS to the overlay model.
     In one section, the memo provides a description of how the overlay
     model may be used to support VPN connections across a core GMPLS
     network.

Contents

   1.     Contributors .............................................  4
   2.     Terminology ..............................................  4
   3.     Introduction .............................................  4
   4.     General Guideline ........................................  5
   5.     Applicability to Management-based Service Models .........  5
   5.1.   Overview of the Service Models ...........................  6
   5.2.   Applicability of Existing Solutions ......................  6
   5.3.   Additional Work Area(s) ..................................  6
   6.     Applicability to Signaling-based Service Models ..........  7
   6.1.   Overlay Service Models ...................................  7
   6.1.1. Overview of the Service Models ...........................  7
   6.1.2. Applicability of Existing Solutions ......................  7
   6.1.3. Additional Work Area(s) ..................................  7
   6.2.   Overlay Extension Service Models .........................  8
   6.2.1. Overview of the Service Models ...........................  8
   6.2.2. Applicability of Existing Solutions ......................  8
   6.2.3. Additional Work Area(s) ..................................  9
   7.     Applicability to Signaling and Routing Service Models ....  9
   7.1.   Virtual Node Service Models ..............................  9
   7.1.1. Overview of the Service Models ...........................  9
   7.1.2. Applicability of Existing Solutions ......................  9
   7.1.3. Additional Work Area(s) ..................................  9
   7.2.   Virtual Link Service Models .............................. 10
   7.2.1. Overview of the Service Models ........................... 10
   7.2.2. Applicability of Existing Solutions ...................... 10
   7.2.3. Additional Work Area(s) .................................. 10
   7.3.   Per VPN Peer Service Models .............................. 10
   7.3.1. Overview of the Service Models ........................... 11
   7.3.2. Applicability of Existing Solutions ...................... 11
   7.3.3. Additional Work Area(s) .................................. 11
   8.     Management Aspect ........................................ 12
   8.1.   Fault Management ......................................... 12
   8.2.   Configuration Management ................................. 13
   9.     Discussion ............................................... 13
   10.    Security Considerations .................................. 14
   11.    IANA Considerations ...................................... 14
   12.    Acknowledgement .......................................... 14


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   13.    Normative References ..................................... 14
   14.    Informative References ................................... 14
   15.    Authors' Addresses ....................................... 16
   16.    Intellectual Property Considerations ..................... 17
   17.    Full Copyright Statement ................................. 17

1. Contributors

   The details of this document are the result of contributions from
   several authors who are listed here in alphabetic order. Contact
   details for these authors can be found in a separate section near
   the end of this document.

   Adrian Farrel (Olddog Consulting)
   Hamid Ould-Brahim (Nortel Networks)
   Dimitri Papadimitriou (Alcatel)
   Tomonori Takeda (NTT)

2. Terminology

   The reader is assumed to be familiar with the terminology in
   [RFC3031], [RFC3209], [RFC3471], [RFC3473], [GMPLS-RTG],
   [PPVPN-TERM] and [L1VPN-FW].

3. Introduction

   This document shows the applicability of existing Generalized
   Multiprotocol Label Switching (GMPLS) protocols and architectures to
   Layer 1 Virtual Private Networks (L1VPNs). In addition, this document
   identifies several items where additional protocol extensions or
   modifications are necessary to meet L1VPN services.

   In particular, this document shows section by section (from section 5
   to 7) the applicability of GMPLS protocols and architectures to each
   L1VPN service model mentioned in [L1VPN-FW], along with additional
   work areas needed to fully support the requirements for each service
   model. Note management aspects some of which are common over various
   service models will be described separately in section 8.

   Note that discussion in this document is limited to areas where GMPLS
   protocols and architectures are relevant.

   As will be described in detail in this document, support of
   management-based service models, signaling-based service models and
   virtual node service models are well covered by existing documents,
   with minor extensions. Virtual link service models and per VPN peer
   service models are not explicitly covered by existing documents, but
   would be well realized by extending current GMPLS protocols and
   architectures.

   Also, as will be described in detail, the following are possible work


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   areas where additional work would be required to fully support the
   requirements for each L1VPN service model. Some of the requirements
   are optional meaning that the additional work is also optional. The
   list of additional work areas will be updated in later versions of
   this document along with development of the additional or enhanced
   requirements and increased understanding of the issues.

   o MIB module for SPC
   o Resource management per VPN
   o Tunnel mechanisms
   o CE-PE TE link information
   o Control plane routing (routing information exchange related to
     control plane topology, per VPN control packet routing)
   o Signaling and routing for support of per VPN peer service models
   o Management aspect (fault management, configuration management)

   A MIB module for possible protocol extensions will also need to be
   studied.

4. General Guideline

   This section provides several general guidelines for L1VPN solutions.
   In other words, this section provides general requirements that any
   solution for any service model should consider. Note applicability to
   specific service models will be separately described in following
   sections.

   One important general guideline is that solutions should be
   incremental. In other words, the same mechanisms should be maximally
   reused in various service models, and as service models vary and
   additional functionalities are required, delta functionalities should
   be added. For example, in signaling-based service models and
   signaling and routing service models, it is highly desirable that the
   same signaling protocols are used, and routing
   functions are added or enhanced from signaling-based service models
   to signaling and routing service models.

   In addition, the following are general guidelines.

   - Solutions should consider interoperability with non-VPN devices
     (devices that do not support any specific L1VPN extension).
   - Solutions should be scalable and manageable.
   - Solutions should be secure. (i.e., providers should be able to
     screen and protect information based on their operational policies.)

   Note that some deployments may wish to support multiple L1 connection
   types (such as VC3, VC4, etc.) at the same time. Specific
   functionalities may need to be considered for these scenarios. This is
   for further study.

5. Applicability to Management-based Service Models


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5.1. Overview of the Service Models

   The customer and the provider communicate via a management interface.
   The provider management system(s) communicate with the PE/P to set up
   a connection.

5.2. Applicability of Existing Solutions

   SNMP MIB modules are one way to realize connection
   setup/deletion/modification from the management system(s). In
   particular, GMPLS-LSR-STD-MIB [LSR MIB] can control static
   connections, while GMPLS-TE-STD-MIB [TE MIB] can control signaled
   connections.

   As indicated in [L1VPN-FW], the specification of interface(s)
   between management system(s) is out of the scope of this document.

5.3. Additional Work Area(s)

   The following additional work areas are identified to support the
   Management-based Service Models.

   o MIB module for SPC (Soft Permanent Connection)

     For static connections, there is no required extension to the MIB
     Modules.

     For signaled connections, MIB modules may need to be extended to
     inform the ingress PE which CE-PE TE link should be used.

     Note that there are several other ways to control signaled
     connections without MIB module extensions. One such way is:

     (1) Use GMPLS-LSR-STD-MIB for CE-PE TE link and PE-P/PE TE link
         cross-connect at the ingress PE
     (2) Then use GMPLS-TE-STD-MIB to request signaling with egress
         control [EGRESS-CONTROL]

     However, this increases overhead in terms of message exchange and
     required states. As an alternative, extension of MIB modules for
     SPC is highly desirable.

   o Resource management per VPN

     In this type of service model, one optional requirement is resource
     management for a dedicated Data-Plane (the provider network
     partitions link resources per VPN for exclusive use by a particular
     VPN), and resource management for sharing the Data-Plane among a
     specific set of VPNs (the provider network assigns link resources
     to a specific set of VPNs). Note in [L1VPN-FW], the term U-Plane is


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     generally used for Data-Plane.

     A simple way to meet this requirement is to implement resource
     management functionalities in the management system(s). However, if
     the PE/P need path computation locally, not relying on the
     management system(s), then support of resource management in PE/P
     (e.g., routing protocol extension) is necessary. This is especially
     beneficial in the case of dynamic restoration (restoration that does
     not reserve backup resources in advance).

     Note link coloring may be used for this purpose, but this eliminates
     the opportunity to use link coloring for other purposes (e.g., link
     coloring within VPNs).

   When path computation is done in the management system(s), it would
   be important that resource information is synchronized between the
   management system(s) and PE/P.

6. Applicability to Signaling-based Service Models

6.1. Overlay Service Models

6.1.1. Overview of the Service Models

   In this type of service model, there is no routing between the CE
   and the PE. Connections are setup by GMPLS signaling between the CE
   and the PE, and then across the provider network.

6.1.2. Applicability of Existing Solutions

   [GVPN] and [GMPLS-UNI] cover most of the requirements.

   Specifically, [GVPN] and [GMPLS-UNI] suggest signaling procedures for
   VPN connections (i.e., nesting). In addition, [GVPN] covers auto-
   discovery of VPN instances, and CE-PE pair address exchange between
   PEs by BGP. This allows PEs to perform address translation/mapping and
   connectivity restriction. [GVPN] calls the equivalent service model
   GVPW (Generalized Virtual Private Wire).

   The other possibility is to use IGP based node capability
   advertisement for auto-discovery and CE-PE pair addresses exchange
   (e.g., based on [OSPF-TE-CAP] with extensions). This requires
   implementation of such IGP.

6.1.3. Additional Work Area(s)

   The following additional work areas are identified to support the
   Overlay Service Models.

   o Resource management per VPN



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     This is an optional requirement.

     Note there could be L1VPN solutions where path computation is
     conducted in centralized fashion (e.g., in management system(s),
     PCE). In this case, it is possible to implement resource
     management functionalities solely in those entities. However,
     implementing resource management functionality in PE/P is
     beneficial in certain scenarios, especially in restoration. See
     section 5.1.3 for related description.

   o Tunnel mechanism

     [GMPLS-UNI] and [GVPN] propose to use control plane tunnels between
     PEs. In addition, [GVPN] proposes to use BGP for auto-discovery of
     tunnel end points. However, [GMPLS-UNI] and [GVPN] do not specify a
     specific tunnel mechanism for default. Since tunnel mechanisms are
     strongly related to what information should be carried in auto-
     discovery mechanisms, a default tunnel mechanism may need to be
     specified. By doing this, required information to be exchanged by
     auto-discovery mechanisms can be identified.

   o CE-PE TE link information

     In signaling-based service models, it may be useful to consider not
     only TE link information within the provider network (PE-P, PE-PE
     TE links), but also remote CE-PE TE link information in path
     computation. This prevents connection setup failure due to lack of
     resources of remote CE-PE TE links. Therefore, CE-PE TE link
     information should be optionally propagated within the provider
     network to be used for path computation.

   Note, there could be a L1VPN solution where connectivity restriction,
   address translation/mapping etc. are performed not in PEs, but in
   other entities, such as a centralized server. In this case, the
   interface between the PE and the other entity may need to be
   specified. This could utilise existing mechanisms such as COPS or
   LDAP.

   Also note [GVPN] assumes that on a PE and a CE, control channels are
   separate for each VPN (i.e., CE-PE control channel is not shared by
   multiple VPNs).

6.2. Overlay Extension Service Models

6.2.1. Overview of the Service Models

   Requirements for this type of service models are almost the same as
   the ones for overlay service models. One additional requirement is
   membership information exchange between the CE and the PE.

6.2.2. Applicability of Existing Solutions


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   [GVPN] covers the requirement to exchange membership information
   between the CE and the PE by BGP.

6.2.3. Additional Work Area(s)

   There is no additional work area beyond those identified for the
   Overlay Service Models.

7. Applicability to Signaling and Routing Service Models

7.1. Virtual Node Service Models

7.1.1. Overview of the Service Models

   In this type of service model, there is private routing between the CE
   and the PE or to be more precise between the CE routing protocol and
   the VPN routing protocol instance running on the PE. The provider
   network is considered as one private node from the customer's
   perspective. The routing information exchanged between the CE and the
   PE includes CE-PE link information, CE sites, and may include FA-LSPs
   (connections between CEs (or Cs)), CE sites routing information
   related to control plane topology.

7.1.2. Applicability of Existing Solutions

   [GVPN] covers most of requirements.

   Specifically, [GVPN] handles VPN routing by a per VPN database called
   GVSI (Generalized Virtual Switching Instance) in PEs. GVSIs are inter-
   connected by tunnel based control channel, and routing adjacency is
   established between them. BGP is used for auto-discovery of remote
   GVSI in the same VPN. GVSIs advertise VPN routing information by
   using the same ROUTER_ID to represent the provider network as one
   node. [GVPN] calls the equivalent service model GVPXC (Generalized
   Virtual Private Cross-Connect).

7.1.3. Additional Work Area(s)

   The following additional work areas are identified to support the
   Virtual Node Service Models.

   o Tunnel mechanism

     See section 6.1.3

   o Resource management per VPN

     See section 6.1.3

   o Control plane routing


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     The provider network must carefully design whether to allow routing
     information related to control plane topology of the provider
     network to be leaked to the CE. If routing information related to
     control plane topology of the provider network is leaked to the CE,
     this routing information may need to be assigned private addresses.

     When the provider network supports routing information related to
     control plane topology of CE sites to be exchanged between the CE
     and the PE, and allows control packet transferring between CE sites
     (e.g., BGP packets), the provider network must carefully design how
     to route per VPN control packets received from the CE.

7.2. Virtual Link Service Models

7.2.1. Overview of the Service Models

   In this type of service model, virtual links are established between
   PEs. The routing information exchanged between the CE and the PE
   includes CE-PE TE link, CE sites, virtual links, and may include
   FA-LSP and CE sites routing information related to control plane
   topology.

7.2.2. Applicability of Existing Solutions

   Currently, there is no solution document for this type of service
   model. However, simple modifications of [GVPN], in addition to
   enhancements mentioned in section 7.1.3, may realize this type of
   service model. Modifications could be:

    - Do NOT modify ROUTE_ID of TE link information when advertising TE
      link to the CE (in OSPF packet header as well as in LSA header)

    - Setup FA-LSPs (GVSI-LSPs in [GVPN] term) between PEs to construct
      virtual links, and advertise these FA-LSPs in VPN routing.
      Note these FA-LSPs (virtual links) may be assigned private
      addresses, which means customer assigned addresses (or customers
      are allowed to configure addresses). This may require extension
      from current IGP behavior.

   Note there could be other ways to construct virtual links (e.g.,
   virtual link without actually setting up a FA-LSP).

7.2.3. Additional Work Area(s)

   There is no additional work area from virtual node service models
   mentioned in section 7.1.3. Note resource management for dedicated
   Data-Plane is a mandatory requirement for virtual link service models.

7.3. Per VPN Peer Service Models



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7.3.1. Overview of the Service Models

   In this type of service model, the provider partitions TE links
   within the provider network per VPN. The routing information
   exchanged between the CE and the PE includes CE-PE TE links, CE
   sites, as well as partitioned portions of the provider network, and
   may include FA-LSPs and CE sites routing information related to
   control plane topology. Note that PEs may advertise abstracted routing
   information of the provider network to CEs.

   Note scalability must be carefully considered for advertising
   provider network routing information to the CE [INTER-DOMAIN FW].

7.3.2. Applicability of Existing Solutions

   Currently, there is no solution document for this type of service
   model. However, [GVPN] provides several functionalities to meet
   this type of service model, as described in section 7.1.2. The
   other possibility is to use virtual router based approach (virtual
   routers (VPN instances) on every node which is the end point of at
   least one virtual link) [VR].

7.3.3. Additional Work Area(s)

   As described in section 7.3.2, it could be possible to realize this
   service model by extending [GVPN] including following aspects, in
   addition to aspects mentioned in section 7.1.3.

   o Topology filtering

     The PE must choose TE links that are assigned to a specific VPN,
     and then advertise these TE links to a specific set of CEs
     corresponding to that VPN.

   o Topology abstraction

     The PE may abstract routing information of the provider network,
     and then advertise abstracted topology information to the CE. It
     means that the PE may construct a TE link where a direct physical
     link does not exit, or the PE may construct a single node to
     represent multiple nodes and TE links.

     Note scalability must be carefully considered [INTER-DOMAIN FW].

   o ERO/RRO expansion/modification

     The CE may specify ERO with abstracted topology. The provider
     network must expand this ERO to match the provider network
     topology. Note this must be done even if strict route is
     specified in ERO passed from the CE.



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     At the same time, when RRO is requested, RRO passed to the CE must
     be either edited to match the abstracted topology, or removed.

   o Private address

     The provider network may support private address for routing
     information provided to the customer. This means that the customer
     is able to assign private addresses to partitioned portion of TE
     links within the provider network.

   It would be also possible to realize this type of service models by
   using virtual router based approach (i.e., every PE/P (or PE/P that
   contains the end point of virtual links in abstracted topology)
   containing virtual router (VPN instance) for each VPN).

   Details for additional work areas for this type of service model are
   for further study.

8. Management Aspect

8.1. Fault Management

   The provider network may support various recovery techniques
   mentioned in [P&R TERM]. The customer may be able to specify the
   desired level of recovery in connection setup requests. The provider
   network may constitute a recovery domain (PE-PE recovery).

   Following aspects must be considered particularly for L1VPNs.

   o Shared recovery

     When the provider network supports shared recovery (e.g., shared
     mesh restoration), the provider network may be able to support
     shared recovery only within the same VPN and/or shared recovery
     among multiple VPNs. The default mode is to be specified.

     If the provider network supports both, the provider network must
     provide configuration tools for operators.

   o Extra traffic

     GMPLS supports functionalities called extra traffic. Extra traffic
     is user traffic carried over recovery resources when these resources
     are not being used for the recovery of normal traffic [P&R TERM].

     When the provider network supports extra traffic, the provider
     network may be able to support extra traffic only within the same
     VPN and/or extra traffic among multiple VPNs. The default mode is
     to be specified.

     If the provider network supports both, the provider network must


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     provide configuration tools for operators.

8.2. Configuration Management

   Some VPN specific configuration aspects must be considered, such as:

   o Configuration of resource management per VPN

     Physical link resources may be dedicated, share by a specific set of
     VPNs, or shared by any VPNs. The provider network must provide
     configuration tools for resource management per VPN.

   o Configuration of virtual links

     For virtual link service models and per VPN peer service models,
     the provider network must provide configuration tools for
     operators.

   o Configuration of service model for each VPN

     When the provider network supports multiple service models, the
     provider network must provide configuration tools for operators.

9. Discussion

   This section summarizes items that existing solutions may need to be
   extended to fulfill full set of functionalities to realize various
   L1VPN service models mentioned in sections 5 to 7.

   Note that several items that existing solutions are missing are
   optional features. For management-based service model, signaling-
   based service models and virtual node service models, existing
   solutions can be applied with few extensions for optional
   requirements.

   As described in section 7.2.2 and 7.2.3, there are no existing
   solutions to support virtual link service models and per VPN peer
   service models. For virtual link service models, however, minor
   extensions from existing solutions are expected to meet the
   requirements.

   Note the list of additional work areas will be updated in later
   versions of this document with development of additional or enhanced
   requirements and understanding of the issues.

   o MIB module for SPC
     - Optional, but highly required for management-based service models
     - Impact: MIB module

   o Resource management per VPN
     - Optional requirement for management-based, signaling-based and


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       virtual node service models
     - Mandatory requirement for virtual link and per VPN peer service
       models (support of resource management for dedicated Data-Plane)
     - Impact: Routing

   o Tunnel mechanisms
     - Optional requirement for signaling-based service models and
       signaling and routing service models.
     - Impact: Auto-discovery

   o CE-PE TE link information
     - Optional requirement for signaling-based service models
     - Impact: Routing

   o Control plane routing
     - Optional requirement for signaling and routing service models
     - Impact: Routing

   o Signaling and routing for support of per VPN peer service models
     - Impact: Routing, signaling (details to be studied)

   o Management aspects
     - Default mode to be specified for shared recovery and extra traffic
     - Support of configuration tools mandatory for fault management and
       configuration management
     - Impact: mostly on operational tools (impacts on protocols to be
       studied)

10. Security Considerations

   TBD

11. IANA Considerations

   TBD

12. Acknowledgement

   We would like to thank Marco Carugi, Ichiro Inoue and Takumi Ohba for
   their useful comments and suggestions.

13. Normative References

   [RFC2026]          Bradner, S., "The Internet Standards Process
                      -- Revision 3", RFC 2026, October 1996.

   [L1VPN-FW]         Takeda, T., Editor "Framework for Layer 1 Virtual
                      Private Networks", draft-takeda-l1vpn-framework,
                      work in progress.

14. Informative References


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   [Y.1312]           Y.1312 - Layer 1 Virtual Private Network Generic
                      requirements and architecture elements, ITU-T
                      Recommendation, September 2003.

   [Y.1313]           Y.l1vpnarch - Layer 1 Virtual Private Network
                      service and network architectures, ITU-T draft
                      Recommendation.

   [GMPLS-UNI]        Swallow, G., et al., "GMPLS UNI: RSVP Support for
                      the Overlay Model", draft-ietf-ccamp-gmpls-overlay
                      work in progress.

   [GVPN]             Ould-Brahim, H., and Rekhter, Y. (editors), "GVPN
                      Services: Generalized VPN Services using BGP and
                      GMPLS Toolkit", draft-ouldbrahim-ppvpn-gvpn-
                      bgpgmpls, work in progress.

   [INTER-DOMAIN FW]  Farrel, A., et al., "A Framework for Inter-Domain
                      MPLS Traffic Engineering", draft-farrel-ccamp-
                      inter-domain-framework, work in progress.

   [P&R TERM]         Mannie, E., and Papadimitriou, D. (editors),
                      "Recovery (Protection and Restoration) Terminology
                      for Generalized Multi-Protocol Label Switching
                      (GMPLS)", draft-ietf-ccamp-gmpls-recovery-
                      terminology, work in progress.

   [LSR MIB]          Nadeau, T., et al., "Generalized Multiprotocol
                      Label Switching (GMPLS) Label Switching Router
                      (LSR) Management Information Base", draft-ietf-
                      ccamp-gmpls-lsr-mib, work in progress.

   [TE MIB]           Nadeau, T., et al., "Generalized Multiprotocol
                      Label Switching (GMPLS) Traffic Engineering
                      Management Information Base", draft-ietf-ccamp-
                      gmpls-te-mib, work in progress.

   [RFC3031]          Rosen, E., Viswanathan, A. and R. Callon,
                      "Multiprotocol label switching Architecture", RFC
                      3031, 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.

   [RFC3471]          Berger, L., Editor, "Generalized Multi-Protocol
                      Label Switching (GMPLS) Signaling Functional
                      Description", RFC 3471, January 2003.



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   [RFC3473]          Berger, L., Editor "Generalized Multi-Protocol
                      Label Switching (GMPLS) Signaling - Resource
                      ReserVation Protocol-Traffic Engineering (RSVP-TE)
                      Extensions", RFC 3473, January 2003.

   [GMPLS-RTG]        Kompella, K., et al., "Routing Extensions in
                      Support of Generalized MPLS", draft-ietf-ccamp-
                      gmpls-routing, work in progress.

   [EGRESS CONTROL]   Berger, L., "GMPLS Signaling Procedure For Egress
                      Control", draft-ietf-ccamp-gmpls-egress-control,
                      work in progress.

   [OSPF-TE-CAP]      Vesseur, J.P., et al., "OSPF MPLS Traffic
                      Engineering capabilities", draft-vasseur-ccamp-
                      ospf-te-caps, work in progress.

   [PPVPN-TERM]       Andersson, L., and Madsen, T., "PPVPN terminology",
                      draft-andersson-ppvpn-terminology, work in
                      progress.

   [VR]               Knight, P., Editor, ügNetwork based IP VPN
                      Architecture using Virtual Routersüh, draft-ietf-
                      l3vpn-vpn-vr, work in progress.

15. Authors' Addresses

   Adrian Farrel
   Old Dog Consulting
   Phone:  +44 (0) 1978 860944
   Email:  adrian@olddog.co.uk

   Hamid Ould-Brahim
   Nortel Networks
   P O Box 3511 Station C
   Ottawa, ON K1Y 4H7 Canada
   Phone: +1 (613) 765 3418
   Email: hbrahim@nortelnetworks.com

   Dimitri Papadimitriou (Alcatel)
   Francis Wellensplein 1,
   B-2018 Antwerpen, Belgium
   Phone: +32 3 2408491
   Email: dimitri.papadimitriou@alcatel.be

   Tomonori Takeda
   NTT Network Service Systems Laboratories, NTT Corporation
   3-9-11, Midori-Cho
   Musashino-Shi, Tokyo 180-8585 Japan
   Phone: +81 422 59 7434
   Email : takeda.tomonori@lab.ntt.co.jp


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16. Intellectual Property Considerations

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17. Full Copyright Statement

   Copyright (C) The Internet Society (2004). This document is subject
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