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Network Working Group                                 J.L. Le Roux (Ed.)
Internet Draft                                            France Telecom
Category: Informational
Expires: May 2008                                D.  Papadimitriou (Ed.)
                                                          Alcatel-Lucent





                                                           November 2007


        Evaluation of existing GMPLS Protocols against Multi Layer
                    and Multi Region Networks (MLN/MRN)

               draft-ietf-ccamp-gmpls-mln-eval-04.txt



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Abstract

   This document provides an evaluation of Generalized Multi-Protocol
   Label Switching (GMPLS) protocols and mechanisms against the
   requirements for Multi-Layer Networks (MLN) and Multi-Region Networks
   (MRN). In addition, this document identifies areas where additional
   protocol extensions or procedures are needed to satisfy these
   requirements, and provides guidelines for potential extensions.

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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.      Introduction................................................3
   2.      MLN/MRN Requirements Overview...............................4
   3.      Analysis....................................................4
   3.1.    Multi Layer Network Aspects.................................4
   3.1.1.  Support for Virtual Network Topology Reconfiguration........4
   3.1.1.1.  Control of FA-LSPs Setup/Release..........................5
   3.1.1.2.  Virtual TE-Links..........................................6
   3.1.1.3.  Traffic Disruption Minimization During FA Release.........7
   3.1.1.4.  Stability.................................................7
   3.1.2.  Support for FA-LSP Attributes Inheritance...................8
   3.1.3.  FA-LSP Connectivity Verification............................8
   3.2.    Specific Aspects for Multi-Region Networks..................8
   3.2.1.  Support for Multi-Region Signaling..........................8
   3.2.2.  Advertisement of Adjustment Capacities......................9
   4.      Evaluation Conclusion......................................12
   5.      Security Considerations....................................12
   6.      Acknowledgments............................................13
   7.      References.................................................13
   7.1.    Normative..................................................13
   7.2.    Informative................................................13
   8.      Editors' Addresses:........................................14
   9.      Contributors' Addresses:...................................14
   10.     Intellectual Property Statement............................15



















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1. Introduction

   Generalized MPLS (GMPLS) extends MPLS to handle multiple switching
   technologies: packet switching, layer-2 switching, TDM switching,
   wavelength switching, and fiber switching (see [RFC3945]). The
   Interface Switching Capability (ISC) concept is introduced for
   these switching technologies and is designated as follows: PSC
   (Packet Switch Capable), L2SC (Layer-2 Switch Capable), TDM (Time
   Division Multiplex capable), LSC (Lambda Switch Capable), and FSC
   (Fiber Switch Capable). The representation, in a GMPLS control
   plane, of a switching technology domain is referred to as a region
   [RFC4206]. A switching type describes the ability of a node to
   forward data of a particular data plane technology, and uniquely
   identifies a network region.

   A data plane switching layer describes a data plane switching
   granularity level. For example, LSC, TDM VC-11 and TDM VC-4-64c are
   three different layers.  [MLN-REQ] defines a Multi Layer Network (MLN)
   to be a TE domain comprising multiple data plane switching layers
   either of the same ISC (e.g. TDM) or different ISC (e.g. TDM and
   PSC) and controlled by a single GMPLS control plane instance.
   [MLN-REQ] further define a particular case of MLNs. A Multi Region
   Network (MRN) is defined as a TE domain supporting at least two
   different switching types (e.g., PSC and TDM), either hosted on the
   same device or on different ones, and under the control of a single
   GMPLS control plane instance.

   The objectives of this document are to evaluate existing GMPLS
   mechanisms and protocols ([RFC 3945], [RFC4202], [RFC3471,
   [RFC3473]]) against the requirements for MLN and MRN, defined in
   [MLN-REQ]. From this evaluation, we identify several areas where
   additional protocol extensions and modifications are required to meet
   these requirements, and provide guidelines for potential extensions.

   A summary of MLN/MRN requirements is provided in section 2. Then
   section 3 evaluates for each of these requirements, whether current
   GMPLS protocols and mechanisms meet the requirements. When the
   requirements are not met by existing protocols, the document
   identifies whether the required mechanisms could rely on GMPLS
   protocols and procedure extensions or whether it is entirely out of
   the scope of GMPLS protocols.

   Note that this document specifically addresses GMPLS control plane
   functionality for MLN/MRN in the context of a single administrative
   control plane partition. Partitions of the control plane where
   separate layers are under distinct administrative control are for
   future study.

   This document uses terminologies defined in [RFC3945], [RFC4206], and
   [MLN-REQ].


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2. MLN/MRN Requirements Overview

   Section 5 of [MLN-REQ] lists a set of functional requirements for
   Multi Layer/Region Networks (MLN/MRN). These requirements are
   summarized below, and a mapping with sub-sections of [MLN-REQ] is
   provided.

   Here is the list of requirements that apply to MLN (and thus to MRN):

        - Support for robust Virtual Network Topology (VNT)
          reconfiguration. This implies the following requirements:
                - Optimal control of Forwarding Adjacency LSP (FA-LSP)
                  setup and release (section  5.8.1 of [MLN-REQ]);
                - Support for virtual TE-links (section 5.8.2 of [MLN-
                  REQ]);
                - Traffic Disruption minimization during FA-LSP release
                  (section 5.5 of [MLN-REQ]);
                - Stability (section 5.4 of [MLN-REQ]);

        - Support for FA-LSP attributes inheritance (section 5.6 of
          [MLN-REQ]);

        - Support for FA-LSP data plane connectivity verification
          (section 5.9 of [MLN-REQ]);

   Here is the list of requirements that apply to MRN only:

        - Support for Multi-Region signaling (section 5.7 of [MLN-REQ]);

        - Advertisement of the adjustment capacity (section 5.2 of
           [MLN-REQ]);

3. Analysis

3.1. Multi Layer Network Aspects

3.1.1. Support for Virtual Network Topology Reconfiguration

   A set of lower-layer FA-LSPs provides a Virtual Network Topology
   (VNT) to the upper-layer [MLN-REQ]. By reconfiguring the VNT (FA-LSP
   setup/release) according to traffic demands between source and
   destination node pairs within a layer, network performance factors
   such as maximum link utilization and residual capacity of the network
   can be optimized. Such optimal VNT reconfiguration implies several
   mechanisms that are analyzed in the following sections.

   Note that the VNT approach is just one possible approach to perform
   inter-layer Traffic Engineering.




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3.1.1.1. Control of FA-LSPs Setup/Release

   In a Multi-Layer Network, FA-LSPs are created, modified, released
   periodically according to the change of incoming traffic demands from
   the upper layer.

   This implies a TE mechanism that takes into account the demands
   matrix, the TE topology and potentially the current VNT, in order to
   compute and setup a new VNT.

   Several functional building blocks are required to support such TE
   mechanism:

        - Discovery of TE topology and available resources.

        - Collection of upper layer traffic demands.

        - Policing and scheduling of VNT resources with regard to
          traffic demands and usage (that is, decision to setup/release
          FA-LSPs); The functional component in charge of this function
          is called a VNT Manager (VNTM).

        - VNT Paths Computation according to TE topology, and
          potentially taking into account the old (existing) VNT to
          minimize changes. The Functional component in charge of VNT
          computation may be distributed on network elements or may be
          performed on an external tool (such as a Path Computation
          Element (PCE), [RFC4655]).

        - FA-LSP setup/release.

   GMPLS routing protocols provide TE topology discovery.
   GMPLS signaling protocols allow setting up/releasing FA-LSPs.

   VNTM functions (resources policing/scheduling, decision to
   setup/release FA-LSPs, FA-LSP configuration) are out of the scope of
   GMPLS protocols. Such functionalities can be achieved directly on
   layer border LSRs, or through one or more external tools. When an
   external tool is used, an interface is required between the VNTM and
   the network elements so as to setup/release FA-LSPs. This could use
   standard management interfaces such as [RFC4802].

   The set of traffic demands of the upper layer is required for the
   VNT Manager to take decisions to setup/release FA-LSPs. Such
   traffic demands include satisfied demands, for which one or more
   upper layer LSP have been successfully setup, as well as unsatisfied
   demands and future demands, for which no upper layer LSP has been
   setup yet. The collection of such information is beyond the scope of
   GMPLS protocols. Note that it may be partially inferred from
   parameters carried in GMPLS signalling or advertised in GMPLS routing.



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   Finally, the computation of FA-LSPs that form the VNT can be
   performed directly on layer border LSRs or on an external tool (such
   as a Path Computation Element (PCE), [RFC4655]), and this is
   independent of the location of the VNTM.

   Hence, to summarize, no GMPLS protocol extensions are required to
   control FA-LSP setup/release.

3.1.1.2. Virtual TE-Links

   A Virtual TE-link is a TE-link between two upper layer nodes that is
   not actually associated with a fully provisioned FA-LSP in a lower
   layer. A Virtual TE-link represents the potentiality to setup an FA-
   LSP in the lower layer to support the TE-link that has been
   advertised. A Virtual TE-link is advertised as any TE-link, following
   the rules in [RFC4206] defined for fully provisioned TE-links. In
   particular, the flooding scope of a Virtual TE-link is within an IGP
   area, as is the case for any TE-link.

   If an upper-layer LSP attempts (through a signalling message) to make
   use of a Virtual TE-link, the underlying FA-LSP is immediately
   signalled and provisioned (provided there are available resources in
   the lower layer) in the process known as triggered signaling.

   The use of Virtual TE-links has two main advantages:

     - Flexibility: allows the computation of an LSP path using TE-links
       without needing to take into account the actual provisioning
       status of the corresponding FA-LSP in the lower layer;

     - Stability: allows stability of TE-links in the upper layer, while
       avoiding wastage of bandwidth in the lower layer, as data plane
       connections are not established until they are actually needed.

   Virtual TE-links are setup/deleted/modified dynamically, according to
   the change of the (forecast) traffic demand, operator's policies for
   capacity utilization, and the available resources in the lower layer.

   The support of Virtual TE-links requires two main building blocks:

   - A TE mechanism for dynamic modification of Virtual TE-link
     Topology;

   - A signaling mechanism for the dynamic setup and deletion of
     virtual TE-links. Setting up a virtual TE-link requires a
     signaling mechanism allowing an end-to-end association
     between Virtual TE-link end points so as to exchange link
     identifiers as well as some TE parameters.

   The TE mechanism responsible for triggering/policing dynamic
   modification of Virtual TE-links is out of the scope of GMPLS
   protocols.

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   Current GMPLS signalling does not allow setting up and releasing
   Virtual TE-links. Hence GMPLS signalling must be extended to support
   Virtual TE-links.

   We can distinguish two options for setting up Virtual TE-links:

   - The Soft FA approach that consists of setting up the FA-LSP in the
     control plane without actually activating cross connections in the
     data plane. On the one hand, this requires state maintenance on all
     transit LSRs (N square issue), but on the other hand this may allow
     for some admission control. Indeed, when a soft-FA is activated,
     the resources may be no longer available for use by other soft-FAs
     that have common links. These soft-FA will be dynamically released
     and corresponding virtual TE-links are deleted. The soft-FA LSPs
     may be setup using procedures similar to those described in
     [RFC4872] for setting up secondary LSPs.

   - The remote association approach that simply consists of exchanging
      virtual TE-links IDs and parameters directly between TE-link end
      points. This does not require state maintenance on transit LSRs,
      but reduces admission control capabilities. Such an association
      between Virtual TE-link end-points may rely on extensions to the
      RSVP-TE ASON Call procedure ([RSVP-CALL]).

   Note that the support of Virtual TE-links does not require any GMPLS
   routing extension.

3.1.1.3. Traffic Disruption Minimization During FA Release

   Before deleting a given FA-LSP, all nested LSPs have to be rerouted
   and removed from the FA-LSP to avoid traffic disruption.
   The mechanisms required here are similar to those required for
   graceful deletion of a TE-Link. A Graceful TE-link deletion mechanism
   allows for the deletion of a TE-link without disrupting traffic of
   TE-LSPs that were using the TE-link.

   Hence, GMPLS routing and/or signaling extensions are required
   to support graceful deletion of TE-links. This may utilize the
   procedures described in [GR-SHUT]: A transit LSR notifies a head-end
   LSR that a TE-link along the path of a LSP is going to be torn down,
   and also withdraws the bandwidth on the TE-link so that it is not
   used for new LSPs.

3.1.1.4. Stability

   The stability of upper-layer LSP may be impaired if the VNT undergoes
   frequent changes. In this context robustness of the VNT is defined as
   the capability to smooth the impact of these changes and avoid their
   subsequent propagation.



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   Guaranteeing VNT stability is out of the scope of GMPLS protocols and
   relies entirely on the capability of the TE and VNT management
   algorithms to minimize routing perturbations. This requires that the
   algorithms takes into account the old VNT when computing a new VNT,
   and try to minimize the perturbation.

   Note that a full mesh of lower-layer LSPs may be created between
   every pair of border nodes between the upper and lower layers. The
   merit of a full mesh of lower-layer LSPs is that it provides
   stability to the upper layer routing. That is, forwarding table used
   in the upper layer is not impacted if the VNT undergoes changes.
   Further, there is always full reachability and immediate access to
   bandwidth to support LSPs in the upper layer. But it also has
   significant drawbacks, since it requires the maintenance of n^2 RSVP-
   TE sessions, which may be quite CPU and memory consuming (scalability
   impact). Also this may lead to significant bandwidth wastage. Note
   that the use of virtual TE-links solves the bandwidth wastage issue,
   and may reduce the control plane overload.


3.1.2. Support for FA-LSP Attributes Inheritance

   When a FA TE Link is advertised, its parameters are inherited from
   the parameters of the FA-LSP, and specific inheritance rules are
   applied.

   This relies on local procedures and policies and is out of the scope
   of GMPLS protocols. Note that this requires that both head-end and
   tail-end of the FA-LSP are driven by same policies.

3.1.3. FA-LSP Connectivity Verification

   Once fully provisioned, FA-LSP liveliness may be achieved by
   verifying its data plane connectivity.

   FA-LSP connectivity verification relies on technology specific
   mechanisms (e.g., for SDH using G.707 and G.783; for MPLS using BFD;
   etc.) as for any other LSP. Hence this requirement is out of the
   scope of GMPLS protocols.


3.2. Specific Aspects for Multi-Region Networks

3.2.1. Support for Multi-Region Signaling

   There are actually several cases where a transit node could choose
   between multiple SCs to be used for a lower region FA-LSP:

   - ERO expansion with loose hops: The transit node has to expand the
     path, and may have to select among a set of lower region SCs.

   - Multi-SC TE link: When the ERO of a FA LSP, included in the ERO of

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     an upper region LSP, comprises a multi-SC TE-link, the region
     border node has to select among these SCs.

   Existing GMPLS signalling procedures do not allow solving this
   ambiguous choice of SC that may be used along a given path.

   Hence an extension to GMPLS signalling has to be defined to indicate
   the SC(s) that can be used and the SC(s) that cannot be used along
   the path.

3.2.2. Advertisement of Adjustment Capacities

   In the MRN context, nodes supporting more than one switching
   capability on at least one interface are called Hybrid nodes ([MLN-
   REQ]). Conceptually, hybrid nodes can be viewed as containing at
   least two distinct switching elements interconnected by internal
   links which provide adjustment between the supported switching
   capabilities. These internal links have finite capacities and must be
   taken into account when computing the path of a multi-region TE-LSP.
   The advertisement of the adjustment capacities is required as it
   provides critical information when performing multi-region path
   computation.

   The term adjustment capacity refers to the property of a hybrid node
   to interconnect different switching capabilities it provides though
   its external interfaces [MLN-REQ]. This information allows path
   computation to select an end-to-end multi-region path that includes
   links of different switching capabilities that are joined by LSRs
   that can adapt the signal between the links.


   Figure 1a below shows an example of hybrid node. The hybrid node has
   two switching elements (matrices), which support here TDM and PSC
   switching respectively. The node has two PSC and TDM ports (port1 and
   port2 respectively). It also has internal link connecting the two
   switching elements.

   The two switching elements are internally interconnected in such a
   way that it is possible to terminate some of the resources of the TDM
   port 2 and provide through them adjustment for PSC traffic,
   received/sent over the internal PSC interface (#b). Two ways are
   possible to set up PSC LSPs (port 1 or port 2). Available resources
   advertisement e.g. Unreserved and Min/Max LSP Bandwidth should cover
   both ways.









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                             Network element
                        .............................
                        :            --------       :
              PSC       :           |  PSC   |      :
            Port1-------------<->---|#a      |      :
                        :  +--<->---|#b      |      :
                        :  |         --------       :
                        :  |        ----------      :
              TDM       :  +--<->--|#c  TDM   |     :
            Port2 ------------<->--|#d        |     :
                        :           ----------      :
                        :............................

                             Figure 1a. Hybrid node.



   Port 1 and Port 2 can be grouped together thanks to internal DWDM, to
   result in a single interface: Link 1. This is illustrated in figure
   1b below.

                             Network element
                        .............................
                        :            --------       :
                        :           |  PSC   |      :
                        :           |        |      :
                        :         --|#a      |      :
                        :        |  |   #b   |      :
                        :        |   --------       :
                        :        |       |          :
                        :        |  ----------      :
                        :    /|  | |    #c    |     :
                        :   | |--  |          |     :
              Link1 ========| |    |    TDM   |     :
                        :   | |----|#d        |     :
                        :    \|     ----------      :
                        :............................

                        Figure 1b. Hybrid node.


   Let's assume that all interfaces are STM16 (with VC4-16c capable
   as Max LSP bandwidth). After, setting up several PSC LSPs via port #a
   and setting up and terminating several TDM LSPs via port #d and port
   #b, there is only 155 Mb capacities still available on port #b.
   However a 622 Mb capacity remains on port #a and VC4-5c capacity on
   port #d.

   When computing the path for a new VC4-4c TDM LSP, one must know, that
   this node cannot terminate this LSP, as there is only 155Mb still
   available for TDM-PSC adjustment. Hence the TDM-PSC adjustment
   capacity must be advertised.

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   With current GMPLS routing [RFC4202] this advertisement is possible
   if link bundling is not used and if two TE-links are advertised for
   link1:

   We would have the following TE-link advertisements:

   TE-link 1 (port 1):
        - ISCD sub-TLV: PSC with Max LSP bandwidth = 622Mb
        - Unreserved bandwidth = 622Mb.

   TE-Link 2 (port 2):
        - ISCD #1 sub-TLV: TDM with Max LSP bandwidth = VC4-4c,
        - ISCD #2 sub-TLV: PSC with Max LSP bandwidth = 155 Mb,
        - Unreserved bandwidth (equivalent): 777 Mb.

   The ISCD 2 in TE-link 2 represents actually the TDM-PSC adjustment
   capacity.

   However if for obvious scalability reasons link bundling is done then
   the adjustment capacity information is lost with current GMPLS
   routing, as we have the following TE-link advertisement:

   TE-link 1 (port 1 + port 2):
        - ISCD #1 sub-TLV: TDM with Max LSP bandwidth = VC4-4c,
        - ISCD #2 sub-TLV: PSC with Max LSP bandwidth = 622 Mb,
        - Unreserved bandwidth (equivalent): 1399 Mb.

   With such TE-link advertisement an element computing the path of a
   VC4-4c LSP cannot know that this LSP cannot be terminated on the
   node.

   Thus current GMPLS routing can support the advertisement of the
   adjustment capacities but this precludes performing link bundling and
   thus faces significant scalability limitations.

   Hence, GMPLS routing must be extended to meet this requirement. This
   could rely on the advertisement of the adjustment capacities as a new
   TE link attribute (that would complement the Interface Switching
   Capability Descriptor TE-link attribute).

   Note: Multiple ISCDs MAY be associated to a single switching
   capability. This can be performed to provide e.g. for TDM interfaces
   the Min/Max LSP Bandwidth associated to each (set of) layer for that
   switching capability. As an example, an interface associated to TDM
   switching capability and supporting VC-12 and VC-4 switching, can be
   associated one ISCD sub-TLV or two ISCD sub-TLVs. In the first case,
   the Min LSP Bandwidth is set to VC-12 and the Max LSP Bandwidth to
   VC-4. In the second case, the Min LSP Bandwidth is set to VC-12 and
   the Max LSP Bandwidth to VC-12, in the first ISCD sub-TLV; and the
   Min LSP Bandwidth is set to VC-4 and the Max LSP Bandwidth to VC-4,
   in the second ISCD sub-TLV. Hence, in the first case, as long as the

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   Min LSP Bandwidth is set to VC-12 (and not VC-4) and in the second
   case, as long as the first ISCD sub-TLV is advertised there is
   sufficient capacity across that interface to setup a VC-12 LSP.


4. Evaluation Conclusion

   Most of the required MLN/MRN functions will rely on mechanisms and
   procedures that are out of the scope of the GMPLS protocols, and thus
   do not require any GMPLS protocol extensions. They will rely on local
   procedures and policies, and on specific TE mechanisms and
   algorithms.

   As regards Virtual Network Topology (VNT) computation and
   reconfiguration, specific TE mechanisms need to be defined, but these
   mechanisms are out of the scope of GMPLS protocols.

   Four areas for extensions of GMPLS protocols and procedures have been
   identified:

        - GMPLS signaling extension for the setup/deletion of
          the virtual TE-links;

        - GMPLS routing and signaling extension for graceful TE-link
          deletion;

        - GMPLS signaling extension for constrained multi-region
          signalling (SC inclusion/exclusion);

        - GMPLS routing extension for the advertisement of the
          adjustment capacities of hybrid nodes.

5. Security Considerations

   [MLN-REQ] sets out the security requirements for operating a MLN or
   MRN. These requirements are, in general, no different from the
   security requirements for operating any GMPLS network. As such, the
   GMPLS protocols already provide adequate security features. An
   evaluation of the security features for GMPLS networks may be found
   in [MPLS-SEC], and where issues or further work is identified by that
   document, new security features or procedures for the GMPLS protocols
   will need to be developed.

   [MLN-REQ] also identifies that where the separate layers of a MLN/MRN
   network are operated as different administrative domains, additional
   security considerations may be given to the mechanisms for allowing
   inter-layer LSP setup. However, this document is explicitly limited
   to the case where all layers under GMPLS control are part of the same
   administrative domain.




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   Lastly, as noted in [MLN-REQ], it is expected that solution documents
   will include a full analysis of the security issues that any protocol
   extensions introduce.


6. Acknowledgments

   We would like to thank Julien Meuric, Igor Bryskin and Adrian Farrel
   for their useful comments.

   Thanks also to Question 14 of Study Group 15 of the ITU-T for their
   thoughtful review.


7. References

7.1. Normative

   [RFC3979]    Bradner, S., "Intellectual Property Rights in IETF
                Technology", BCP 79, RFC 3979, March 2005.

   [RFC3945]    Mannie, E., et. al. "Generalized Multi-Protocol Label
                Switching Architecture", RFC 3945, October 2004

   [RFC4202]    Kompella, K., Ed. and Y. Rekhter, Ed., "Routing
                Extensions in Support of Generalized Multi-Protocol
                Label Switching", draft-ietf-ccamp-gmpls-routing,
                RFC4202, October 2005.

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


7.2. Informative

   [RSVP-CALL]  Papadimitriou, D., Farrel, A., et. al., "Generalized
                MPLS (GMPLS) RSVP-TE Signaling Extensions in support of
                Calls", draft-ietf-ccamp-gmpls-rsvp-te-call, work in
                progress.

   [MLN-REQ]    Shiomoto, K., Papadimitriou, D., Le Roux, J.L.,
                Vigoureux, M., Brungard, D., "Requirements for GMPLS-
                based multi-region and multi-layer networks", draft-
                ietf-ccamp-gmpls-mrn-reqs, work in progess.

   [RFC4206]    K. Kompella and Y. Rekhter, "LSP hierarchy with
                generalized MPLS TE", draft-ietf-mpls-lsp-hierarchy,
                RFC4206, October 2005.




Le Roux, et al.   Evaluation of GMPLS against MLN/MRN Reqs   [Page 13]


Internet Draft    draft-ietf-ccamp-gmpls-mln-eval-04.txt   November 2007


   [GR-SHUT]    Ali, Z., Zamfir, A., "Graceful Shutdown in MPLS Traffic
                Engineering Network", draft-ietf-ccamp-mpls-graceful-
                shutdown, work in progress.

   [RFC4872]    Lang, Rekhter, Papadimitriou, "RSVP-TE Extensions in
                 support of End-to-End Generalized Multi-Protocol Label
                Switching (GMPLS)-based Recovery", RFC4872, May 2007.

   [VNTM]       Oki, Le Roux, Farrel, "Definition of Virtual Network
                 Topology Manager (VNTM) for PCE-based Inter-Layer MPLS
                and GMPLS Traffic Engineering", draft-oki-pce-vntm-def,
                work in progress.

   [IW-MIG-FMWK]Shiomoto, K et al., "Framework for IP/MPLS-GMPLS
                 interworking in support of IP/MPLS to GMPLS migration",
                draft-ietf-ccamp-mpls-gmpls-interwork-fmwk, work in
                progress.

   [RFC3473]   Berger, L., et al. "GMPLS Singlaling RSVP-TE extensions",
                RFC3473, January 2003.

   [RFC4655]   Farrel, A., Vasseur, J.-P., Ash,J., "A PCE based
                Architecture", RFC4655, August 2006.

   [RFC4802]   Nadeau, T., Farrel, A., "GMPLS TE MIB", RFC4802,
                February 2007.

   [MPLS-SEC]   Fang, et al. "Security Framework for MPLS and GMPLS
                Networks draft-fang-mpls-gmpls-security-framework, work
                in progress.

8. Editors' Addresses:

   Jean-Louis Le Roux
   France Telecom
   2, avenue Pierre-Marzin
   22307 Lannion Cedex, France
   Email: jeanlouis.leroux@orange-ftgroup.com

   Dimitri Papadimitriou
   Alcatel-Lucent
   Francis Wellensplein 1,
   B-2018 Antwerpen, Belgium
   Email: dimitri.papadimitriou@alcatel-lucent.be

9. Contributors' Addresses:

   Deborah Brungard
   AT&T
   Rm. D1-3C22 - 200 S. Laurel Ave.
   Middletown, NJ, 07748 USA
   E-mail: dbrungard@att.com

Le Roux, et al.   Evaluation of GMPLS against MLN/MRN Reqs   [Page 14]


Internet Draft    draft-ietf-ccamp-gmpls-mln-eval-04.txt   November 2007



   Eiji Oki
   NTT
   3-9-11 Midori-Cho
   Musashino, Tokyo 180-8585, Japan
   Email: oki.eiji@lab.ntt.co.jp

   Kohei Shiomoto
   NTT
   3-9-11 Midori-Cho
   Musashino, Tokyo 180-8585, Japan
   Email: shiomoto.kohei@lab.ntt.co.jp

   M. Vigoureux
   Alcatel-Lucent France
   Route de Villejust
   91620 Nozay
   FRANCE
   Email: martin.vigoureux@alcatel-lucent.fr


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