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Versions: 00 01 02 03 04 05 draft-ietf-mpls-explicit-resource-control-bundle

   MPLS Working Group
   Internet Draft                                          Anca Zamfir,
                                                              Zafar Ali
                                                          Cisco Systems
                                                       D. Papadimitriou
                                                                Alcatel
   Document: draft-zamfir-explicit-
   resource-control-bundle-05.txt
   Expires: December 2005                                     June 2005


   Component Link Recording and Resource Control for GMPLS Link Bundles


         draft-zamfir-explicit-resource-control-bundle-05.txt


Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups. Note that other
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   Internet-Drafts are draft documents valid for a maximum of six months
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   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.

Abstract

   Record Route is a useful administrative tool that has been used
   extensively by the service providers. However, when TE links are
   bundled, identification of label resource in RRO is not enough for
   the administrative purpose. Network service providers would like to
   know the component link within a TE link that is being used by a



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   given LSP. In other words, when link bundling is used, resource
   recording requires mechanisms to specify the component link
   identifier, along with the TE link identifier and Label. As , it is
   not possible to record component link in the RRO, this draft defines
   the extensions to RSVP-TE [RFC3209] and [RFC3473] to specify
   component link identifiers for resource recording purposes.

   This draft also defines the ERO counterpart of the RRO extension. The
   ERO extensions are needed to perform explicit label/ resource control
   over bundled TE link. Hence, this draft defines the extensions to
   RSVP-TE [RFC3209] and [RFC3473] to specify component link identifiers
   for explicit resource control and recording over GMPLS link bundles.


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 [RFC2119].


Table of Contents

   1. Terminology....................................................2
   2. Resource Control and Recording.................................3
   3. LSP Resource Recording.........................................4
      3.1 Component Interface Identifier RRO subobject...............4
      3.2 Processing of Component Interface identifier RRO Subobject.5
   4. Signaling Component Interface Identifier in ERO................6
      4.1 Processing of Component Interface Identifier ERO Subobject.7
   5. Forward Compatibility Note.....................................9
   6. Security Considerations........................................9
   7. IANA Considerations...........................................10
   8. Intellectual Property Considerations..........................10
   9. References....................................................10
      9.1 Normative Reference.......................................10
      9.2 Informative Reference.....................................11
   10. Author's Addresses...........................................11
   11. Full Copyright Statement.....................................11


1. Terminology

   TE Link: Unless specified otherwise, it refers to a bundled Traffic
   Engineering link as defined in [BUNDLE]. Furthermore, the terms TE
   Link and bundled TE Link are used interchangeably in this draft.




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   Component  (interface) link: refers (locally) to a component link as
   part of a bundled TE link. A component link is numbered/ unnumbered
   in its own right. For unnumbered component links, the component link
   ID is assumed to be unique on an advertising node. For numbered
   component links, the component link ID is assumed to be unique within
   a domain.

   Component Interface Identifier: Refers to an ID used to uniquely
   identify a Component Interface. On a bundled link a combination of
   <component link identifier, label> is sufficient to unambiguously
   identify the appropriate resources used by an LSP [BUNDLE].

2. Resource Control and Recording

   In GMPLS networks that deals with unbundled  (being either PSC, L2SC,
   TDM or LSC) TE Links, one of the types of resources that an LSP
   originator can control and would like to record are the TE Link
   interfaces used by the LSP. The resource control and recording is
   done by the use of an explicit route, i.e., Explicit Route (ERO)
   Object and record Route, i.e., Record Route Object (RRO) object,
   respectively.

   Link Bundling introduced by [BUNDLE], is used to improve routing
   scalability by reducing the amount of TE related information that
   needs to be flooded and handled by IGP in a TE network. This is
   accomplished by aggregating and abstracting the TE Link resource. In
   some cases the complete resource identification is left as a local
   decision. However, as described above there are cases when it is
   desirable for a non-local (e.g., LSP head-end) node to identify
   completely or partially the LSP resources. In either case, for
   administrative reasons, it is required to know which component link
   within a bundled TE link has been used for a given LSP.

   When link bundling is used to aggregate multiple component links into
   a TE link, label is not the only resource that needs to be identified
   and recorded. In other words, the TE Link and the Label specified in
   the ERO/ RRO objects are not enough to completely identify the
   resource. For the bundled TE link case, in order to fully specify the
   resources on a link for a given LSP, the component link needs to be
   specified along with the label. In the case of bi-directional LSPs
   both upstream and downstream information may be specified. Therefore,
   explicit resource control  and recording over a bundled TE link also
   requires ability to specify a component link within the TE link.

   This draft defines extensions to and describes the use of RSVP-TE
   [RFC3209], [RFC3471], [RFC3473] to specify the component link
   identifier for resource recording and explicit resource control over
   GMPLS link bundles. Specifically, in this document, component


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   interface identifier RRO and ERO subobjects are defined to complement
   their Label RRO and ERO counterparts. Furthermore, procedures for
   processing component interface identifier RRO and ERO subobjects and
   how they can co-exist with the Label RRO and ERO subobjects are
   specified.

3. LSP Resource Recording

   This refers to the ability to record the resources used by an LSP.
   The procedure for unbundled numbered TE links is described in
   [RFC3209] and for unbundled unnumbered TE links in [RFC 3477]. For
   the purpose of recording LSP resources used over bundled TE Links,
   the Component Interface Identifier RRO sub-object is introduced.

3.1 Component Interface Identifier RRO subobject

   A new subobject of the Record Route Object (RRO) is used to record
   component interface identifier of a (bundled) TE Link. This subobject
   has the following format:
      Figure 2: Component Interface Identifier RRO subobject


       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |L|    Type     |     Length    |U| Reserved  (must be zero)    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      //   IPv4, IPv6 or unnumbered Component Interface Identifier   //
      |                            . . .                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       0                   1                   2                   3

           L: 1 bit

            This bit must be set to 0.


         Type

            10 (TBD) Component Interface identifier IPv4
            11 (TBD) Component Interface identifier IPv6
            12 (TBD) Component Interface identifier Unnumbered


         Length




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            The Length contains the total length of the subobject in
            bytes, including the Type and Length fields. The Length is
            8 bytes for the Component Interface identifier IPv4 and
            Component Interface identifier Unnumbered types. For
            Component Interface identifier IPv6 type of sub-object, the
            length field is 20 bytes.

         U: 1 bit

            This bit indicates the direction of the component
            interface.  It is 0 for the downstream interface.  It is
            set to 1 for the upstream interface and is only used for
            bi-directional LSPs.

3.2  Processing of Component Interface identifier RRO Subobject

      If a node desires component link recording, the "Component Link
   Recording desired" flag (value TBD) should be set in the
   LSP_ATTRIBUTES object, object that is defined in [RSVP-TE-ATTRIBUTE].
   Setting of "Component Link Recording desired" flag is independent of
   the Label Recording flag in SESSION_ATTRIBUTE object as specified in
   [RFC3209]. Nevertheless, the following combinations are valid:
      1) If both Label and Comp Link flags are clear, then neither
   Labels nor Component Links are recorded.
      2) If Label Recording flag is set and Component Link flag is
   clear, then only Label Recording is performed as defined in
   [RFC3209].
      3) If Label Recording flag is clear and Component Link flag is
   set, then Component Link Recording is performed as defined in this
   proposal.
      4) If both Label Recording and Component Link flags are set, then
   Label Recording is performed as defined in [RFC3209] and also
   Component Link recording is performed as defined in this proposal.

   In most cases, a node initiates recording for a given LSP by adding
   the RRO to the Path message. If the node desires Component Link
   recording and if the outgoing TE link is bundled, then the initial
   RRO contains the Component Link identifier (numbered or unnumbered)
   as selected by the sender. As well, the Component Link Recording
   desired flag is set in the LSP_ATTRIBUTE object. If the node also
   desires label recording, it sets the Label_Recording flag in the
   SESSION_ATTRIBUTE object.

   When a Path message with the "Component Link Recording desired" flag
   set is received by an intermediate node, if a new Path message is to
   be sent for a downstream bundled TE link, the node adds a new
   Component Link subobject to the RRO and appends the resulting RRO to
   the Path message before transmission.


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   Note also that, unlike Labels, Component Link identifiers are always
   known on receipt of the Path message.

   When the destination node of an RSVP session receives a Path message
   with an RRO and the "Component Link Recording desired" flag set, this
   indicates that the sender node needs TE route as well as component
   link recording.  The destination node initiates the RRO process by
   adding an RRO to Resv messages. The processing mirrors that of the
   Path messages

   The Component Interface Record subobject is pushed onto the
   RECORD_ROUTE object prior to pushing on the node's IP address. A node
   MUST NOT push on a Component Interface Record subobject without also
   pushing on the IP address or unnumbered Interface Id subobject that
   identifies the TE Link.

   When component interfaces are recorded for bi-directional LSPs,
   component interface RRO subobjects for both downstream and upstream
   interfaces MUST be included.

4. Signaling Component Interface Identifier in ERO

   A new OPTIONAL subobject of the EXPLICIT_ROUTE Object (ERO) is used
   to specify component interface identifier of a bundled TE Link.


   This subobject has the following format:

      Figure 1: Component Interface Identifier ERO subobject

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |L|    Type     |     Length    |U|   Reserved (MUST be zero)   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      //  IPv4, IPv6 or unnumbered Component Interface Identifier    //
      |                            . . .                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         L: 1 bit

            This bit must be set to 0.

         Type

            10 (TBD) Component Interface identifier IPv4
            11 (TBD) Component Interface identifier IPv6


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            12 (TBD) Component Interface identifier Unnumbered


         Length

             The Length contains the total length of the subobject in
             bytes, including the Type and Length fields. The Length is
             8 bytes for the Component Interface identifier types: IPv4
             and Component Interface identifier Unnumbered. For
             Component Interface identifier IPv6 type of sub-object,
             the length field is 20 bytes.


         U: 1 bit
             This bit indicates the direction of the component
             interface.  It is 0 for the downstream interface.  It is
             set to 1 for the upstream interface and is only used for
             bi-directional LSPs.


4.1 Processing of Component Interface Identifier ERO Subobject

   The Component Interface Identifier ERO subobject follows a subobject
   containing the IP address, or the link identifier [RFC3477],
   associated with the TE link on which it is to be used. It is used to
   identify the component of a bundled TE Link.

   The following SHOULD result in "Bad EXPLICIT_ROUTE object" error
   being sent upstream by a node processing an ERO that contains the
   Component Interface ID sub-object:

      o The first component interface identifier subobject is not
      preceded by a sub-object containing an IPv4 or IPv6 address, or
      an interface identifier [RFC3477], associated with a TE link.
      o The Component Interface Identifier ERO subobject follows a
      subobject that has the L-bit set.
      o On unidirectional LSP setup, there is a Component Interface
      Identifier ERO subobject with the U-bit set.
      o Two Component Interface Identifier ERO subobjects with the same
      U-bit values exist.

   If a node implements the component interface identifier subobject, it
   must check if it represents a component interface in the bundled TE
   Link specified in the preceding subobject that contains the IPv4/IPv6
   address or interface identifier of the TE Link. If the content of the
   component interface identifier subobject does not match a component
   interface in the TE link, a "Bad EXPLICIT_ROUTE object" error SHOULD
   be reported as "Routing Problem" (error code 24).


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   If U-bit of the subobject being examined is cleared (0) and the
   upstream interface specified in this subobject is acceptable, then
   the value of the upstream component interface is translated locally
   in the TLV of the IF_ID RSVP HOP object [RFC 3471]. The local
   decision normally used to select the upstream component link is
   bypassed except for local translation into the outgoing interface
   identifier from the received incoming remote interface identifier. If
   this interface is not acceptable, a "Bad EXPLICIT_ROUTE object" error
   SHOULD be reported as "Routing Problem" (error code 24).

   If the U-bit of the subobject being examined is set (1), then the
   value represents the component interface to be used for upstream
   traffic associated with the bidirectional LSP.  Again, if this
   interface is not acceptable or if the request is not one for a
   bidirectional LSP, then a "Bad EXPLICIT_ROUTE object" error SHOULD be
   reported as "Routing Problem" (error code 24).  Otherwise, the
   component interface IP address/ identifier is copied into a TLV sub-
   object as part of the IF_ID RSVP_HOP object. The local decision
   normally used to select the upstream component link is bypassed
   except for local translation into the outgoing interface identifier
   from the received incoming remote interface identifier.

   The IF_ID RSVP_HOP object constructed as above MUST be included in
   the corresponding outgoing Path message.

   Note that, associated with a TE Link sub-object in the ERO, either
   the (remote) upstream component interface or the (remote) downstream
   component interface or both may be specified. As specified in
   [BUNDLE] there is no relationship between the TE Link type (numbered
   or unnumbered) and the Link type of any one of its components.

   The component interface identifier ERO subobject is optional.
   Similarly, presence of the Label ERO sub-objects is not mandatory
   [RFC 3471], [RFC 3473]. Furthermore, component interface identifier
   ERO subobject and Label ERO subobject may be included in the ERO
   independently of each other. One of the following alternatives
   applies:
   o When both sub-objects are absent, a node may select any appropriate
   component link within the TE link and any label on the selected
   component link.
   o When the Label subobject is only present for a bundled link, then
   the selection of the component link within the bundle is a local
   decision and the node may select any appropriate component link,
   which can assume the label specified in the Label ERO.
   o When only the component interface identifier ERO subobject is
   present, a node MUST select the component interface specified in the



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   ERO and may select any appropriate label value at the specified
   component link.
   o When both component interface identifier ERO subobject and Label
   ERO subobject are present, the node MUST select the locally
   corresponding component link and the specified label value on that
   component link. When present, both subobjects  may appear in any
   relative order to each other but they MUST appear after the TE Link
   sub-object that they refer to.

   After processing, the component interface identifier subobjects are
   removed from the ERO.

   Inferred from above, the interface subobject should never be the
   first subobject in a newly received message.  If the component
   interface subobject is the first subobject in a received ERO, then it
   SHOULD be treated as a "Bad strict node" error.

   Note: Information to construct the Component Interface ERO subobject
   may come from the same mean used to populate the label ERO subobject.
   Procedures by which an LSR at the head-end of an LSP obtains the
   information needed to construct the Component Interface subobject are
   outside the scope of this document.

5.  Forward Compatibility Note

   The extensions specified in this draft do not affect the processing
   of the RRO, ERO at nodes that do not support them. A node that does
   not support the Component Interface RRO subobject but that does
   support Label subobject SHOULD only insert the Label subobject in the
   RRO as per [RFC3471] and [RFC3473].

   A node that receives an ERO that contains a Component Link ID
   subobject SHOULD send "Bad EXPLICIT_ROUTE object" if it does not
   implement this subobject.

   As per [RFC3209], Section 4.4.5, a non-compliant node that receives
   an RRO that contains Component Interface Identifier sub-objects
   should ignore and pass them on. This limits the full applicability of
   if nodes traversed by the LSP are compliant with the proposed
   extensions.

6.  Security Considerations

     This document does not introduce new security issues. The security
   considerations pertaining to the original RSVP protocol [RFC2205]
   remain relevant.




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7.  IANA Considerations

   Type of Component Interface Identifier ERO subobject needs to be
   assigned.

8.  Intellectual Property Considerations

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights. Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard. Please address the information to the IETF at ietf-
   ipr@ietf.org.

9.  References


9.1 Normative Reference

   [RFC2205] "Resource ReSerVation Protocol (RSVP) - Version 1,
      Functional Specification", RFC 2205, Braden, et al, September
      1997.
   [RFC3209] "Extensions to RSVP for LSP Tunnels", D. Awduche, et al,
   RFC 3209, December 2001.
   [BUNDLE] "Link Bundling in MPLS Traffic Engineering", draft-ietf-
      mpls-bundle-05.txt, K. Kompella, et al, January 2003.
   [RFC3471] Generalized Multi-Protocol Label Switching (GMPLS)
      Signaling Functional Description, RFC 3471, L. Berger, et al,
      January 2003.
   [RFC3473] "Generalized Multi-Protocol Label Switching (GMPLS)
      Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-
      TE) Extensions", RFC 3473, L. Berger, et al, January 2003.



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   [RFC3477] "Signaling Unnumbered Links in Resource ReSerVation
      Protocol - Traffic Engineering (RSVP-TE) ", RFC 3477, K. Kompella,
      Y. Rekhter, January 2003.
   [RFC2119] "Key words for use in RFCs to Indicate Requirement Levels",
      RFC 2119, S. Bradner, March 1997.

9.2 Informative Reference

   [RSVP-TE-ATTRIBUTE] "Encoding of Attributes for  Multiprotocol Label
      Switching (MPLS) Label Switched Path (LSP) Establishment Using
      RSVP-TE", draft-farrel-rsvpte-attributes-00.txt., A. Farrel.
      et al, April 2004


10.  Author's Addresses

   Anca Zamfir
   Cisco Systems Inc.
   2000 Innovation Dr.,
   Kanata, Ontario, K2K 3E8
   Canada.
   Phone: (613)-254-3484
   Email: ancaz@cisco.com

   Zafar Ali
   Cisco Systems Inc.
   2000 Innovation Dr.,
   Kanata, Ontario, K2K 3E8
   Canada.
   Phone: (613) 889-6158
   Email: zali@cisco.com

   Dimitri Papadimitriou (Alcatel)
   Fr. Wellesplein 1,
   B-2018 Antwerpen, Belgium
   Phone: +32 3 240-8491
   Email: dimitri.papadimitriou@alcatel.be

11.  Full Copyright Statement

   Copyright (C) The Internet Society (2005).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET


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   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.














































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