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Versions: 00 01 02 03 04 05 RFC 4860

                 Generic Aggregate RSVP Reservations   September 2006



   Internet Draft                                  Francois Le Faucheur
                                                            Bruce Davie
                                                    Cisco Systems, Inc.

                                                            Pratik Bose
                                                        Lockheed Martin

                                                         Chris Christou
                                                      Michael Davenport
                                                    Booz Allen Hamilton
   draft-ietf-tsvwg-rsvp-ipsec-03.txt
   Expires: March 2007                                   September 2006


                    Generic Aggregate RSVP Reservations
                    draft-ietf-tsvwg-rsvp-ipsec-03.txt



Status of this Memo

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   applicable patent or other IPR claims of which he or she is aware
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       http://www.ietf.org/ietf/1id-abstracts.txt.

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Abstract

   [RSVP-AGG] defines aggregate RSVP reservations allowing resources to
   be reserved in a Diffserv network for a given DSCP from a given
   source to a given destination. [RSVP-AGG] also defines how end-to-end
   RSVP reservations can be aggregated onto such aggregate reservations


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   when transiting through a Diffserv cloud. There are situations where
   multiple such aggregate reservations are needed for the same source
   IP address, destination IP address and DSCP. However, this is not
   supported by the aggregate reservations defined in [RSVP-AGG]. In
   order to support this, the present document defines a more flexible
   type of aggregate RSVP reservations, referred to as generic aggregate
   reservation. Multiple such generic aggregate reservations can be
   established for a given DSCP from a given source IP address to a
   given destination IP address. The generic aggregate reservations may
   be used to aggregate end-to-end RSVP reservations. This document also
   defines the procedures for such aggregation. The generic aggregate
   reservations may also be used end-to-end directly by end-systems
   attached to a Diffserv network.


Copyright Notice
   Copyright (C) The Internet Society (2006).


Table Of Content

   1. Introduction...................................................3
      1.1. Related RFCs and Internet-Drafts..........................5
      1.2. Organization Of This Document.............................6
   2. Object Definition..............................................6
      2.1. SESSION Class.............................................7
      2.2. SESSION-OF-INTEREST (SOI) Class..........................10
   3. Processing Rules For Handling Generic Aggregate RSVP Reservations
   .................................................................12
      3.1. Required Changes to Path and Resv Processing.............12
   4. Procedures for Aggregation over Generic Aggregate RSVP
   Reservations.....................................................13
   5. Example Usage Of Multiple Generic Aggregate Reservations Per DSCP
   From a Given Aggregator to a Given Deaggregator..................17
   6. Security Considerations.......................................20
   7. IANA Considerations...........................................20
   8. Acknowledgments...............................................21
   9. Normative References..........................................21
   10. Informative References.......................................22
   11. Authors' Addresses...........................................22
   Appendix A: Example Signaling Flow...............................24



Specification of Requirements

   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 [KEYWORDS].


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1.  Introduction

   [RSVP-AGG] defines RSVP aggregate reservations allowing resources to
   be reserved in a Diffserv network for a flow characterized by its 3-
   tuple <source IP address, destination IP address, DSCP>.

   [RSVP-AGG] also defines the procedures for aggregation of end-to-end
   RSVP reservations onto such aggregate reservations when transiting
   through a Diffserv cloud. Such aggregation is illustrated in Figure 1.
   This document reuses the terminology defined in [RSVP-AGG].


                    --------------------------
                   /       Aggregation        \
      |----|      |          Region            |      |----|
   H--| R  |\ |-----|                       |------| /| R  |-->H
   H--|    |\\|     |   |---|     |---|     |      |//|    |-->H
      |----| \|     |   | I |     | I |     |      |/ |----|
              | Agg |======================>| Deag |
             /|     |   |   |     |   |     |      |\
   H--------//|     |   |---|     |---|     |      |\\-------->H
   H--------/ |-----|                       |------| \-------->H
                  |                            |
                   \                          /
                    --------------------------

   H       = Host requesting end-to-end RSVP reservations
   R       = RSVP router
   Agg     = Aggregator
   Deag    = Deaggregator
   I       = Interior Router

   -->   = E2E RSVP reservation
   ==>   = Aggregate RSVP reservation


                Figure 1 : Aggregation of E2E Reservations
                     over aggregate RSVP Reservations


   These aggregate reservations use a SESSION type specified in [RSVP-
   AGG] that contains the receiver (or Deaggregator) IP address and the
   DSCP of the PHB from which Diffserv resources are to be reserved. For
   example, in the case of IPv4, the SESSION object is specified as:

      o  Class = SESSION,
         C-Type = RSVP-AGGREGATE-IP4


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           +-------------+-------------+-------------+-------------+
           |              IPv4 Session Address (4 bytes)           |
           +-------------+-------------+-------------+-------------+
           | /////////// |    Flags    |  /////////  |     DSCP    |
           +-------------+-------------+-------------+-------------+


   These aggregate reservations use a SENDER_TEMPLATE and FILTER_SPEC
   types specified in [RSVP-AGG] and which contains only the sender (or
   Aggregator) IP address. For example, in the case of IPv4, the
   SENDER_TEMPLATE object is specified as:

      o  Class = SENDER_TEMPLATE,
         C-Type = RSVP-AGGREGATE-IP4

           +-------------+-------------+-------------+-------------+
           |                IPv4 Aggregator Address (4 bytes)      |
           +-------------+-------------+-------------+-------------+


   Thus, it is possible to establish, from a given source IP address to
   a given destination IP address, separate such aggregate reservations
   for different DSCPs. However, from a given source IP address to a
   given IP destination address, only a single [RSVP-AGG] aggregate
   reservation can be established for a given DSCP.

   Situations have since been identified where multiple such aggregate
   reservations are needed for the same source IP address, destination
   IP address and DSCP. One example is where E2E reservations using
   different preemption priorities (as per [RSVP-PREEMP]) need to be
   aggregated through a Diffserv cloud using the same DSCP. Using
   multiple aggregate reservations for the same DSCP allows enforcement
   of the different preemption priorities within the aggregation region.
   In turn this allows much more efficient management of the Diffserv
   resources and in period of resource shortage allows to sustain a
   larger number of E2E reservations with higher preemption priorities.

   For example, [SIG-NESTED] discusses in details how end-to-end RSVP
   reservations can be established in a nested VPN environment through
   RSVP aggregation. In particular, [SIG-NESTED] describes how multiple
   parallel generic aggregate reservations (for the same DSCP), each
   with different preemption priorities, can be used to efficiently
   support the preemption priorities of end-to-end reservations.

   This document addresses this requirement for multiple aggregate
   reservations for the same DSCP, by defining a more flexible type of
   aggregate RSVP reservations, referred to as generic aggregate
   reservations. This is achieved primarily by adding the notions of a


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   Virtual Destination Port and of an Extended Virtual Destination Port
   in the RSVP Session object.

   The notion of Virtual Destination Port was introduced in [RSVP-IPSEC]
   to address a similar requirement (albeit in a different context) for
   identification and demultiplexing of sessions beyond the IP
   destination address. This document reuses this notion from [RSVP-
   IPSEC] for identification and demultiplexing of generic aggregate
   sessions beyond the IP destination address and DSCP. This allows
   multiple generic aggregate reservations to be established for a given
   DSCP, from a given source IP address to a given destination IP
   address.

   [RSVP-TE] introduced the concept of an Extended Tunnel ID (in
   addition to the tunnel egress address and the Tunnel ID) in the
   Session object used to establish MPLS Traffic Engineering tunnels
   with RSVP. The Extended Tunnel ID provides a very convenient
   mechanism for the tunnel ingress node to narrow the scope of the
   session to the ingress-egress pair. The ingress node can achieve this
   by using one of its own IP addresses as a globally unique identifier
   and including it in the Extended Tunnel ID and therefore within the
   Session object. This document reuses this notion of Extended Tunnel
   ID from [RSVP-TE], simply renaming it Extended Virtual Destination
   Port. This provides a convenient mechanism to narrow the scope of a
   generic aggregate session to an Aggregator-Deaggregator pair.

   The generic aggregate reservations may be used to aggregate end-to-
   end RSVP reservations. This document also defines the procedures for
   such aggregation. These procedures are based on those of [RSVP-AGG]
   and this document only specifies the differences with those.

   The generic aggregate reservations may also be used end-to-end
   directly by end-systems attached to a Diffserv network.

1.1.  Related RFCs and Internet-Drafts

   This document is heavily based on [RSVP-AGG]. It reuses [RSVP-AGG]
   wherever applicable and only specifies the necessary extensions
   beyond [RSVP-AGG].

   The mechanisms defined in [BW-REDUC] allow an existing reservation to
   be reduced in allocated bandwidth by RSVP routers in lieu of tearing
   that reservation down. These mechanisms are applicable to the generic
   aggregate reservations defined in the present document.

   [RSVP-TUNNEL] describes a general approach to running RSVP over
   various types of tunnels. One of these types of tunnel, referred to
   as a "type 2 tunnel", has some similarity with the generic aggregate
   reservations described in this document. The similarity stems from


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   the fact that a single, aggregate reservation is made for the tunnel
   while many individual flows are carried over that tunnel. However,
   [RSVP-TUNNEL] does not address the use of Diffserv-based
   classification and scheduling in the core of a network (between
   tunnel endpoints), but rather relies on a UDP/IP tunnel header for
   classification. This is why [RSVP-AGG] required additional objects
   and procedures beyond those of [RSVP-TUNNEL]. Like [RSVP-AGG], this
   document also assumes the use of Diffserv-based classification and
   scheduling in the aggregation region and, thus, requires additional
   objects and procedures beyond those of [RSVP-TUNNEL].

   As explained earlier, this document reuses the notion of Virtual
   Destination Port from [RSVP-IPSEC] and the notion of Extended Tunnel
   ID from [RSVP-TE].

1.2.  Organization Of This Document

   Section 2 defines the new RSVP objects related to generic aggregate
   reservations and to aggregation of E2E reservations onto those.
   Section 3 describes the processing rules for handling of generic
   aggregate reservations. Section 4 specifies the procedures for
   aggregation of end to end RSVP reservations over generic aggregate
   RSVP reservations. Section 5 provides example usage of how the
   generic aggregate reservations may be used.

   The Security Considerations and the IANA Considerations  are
   discussed in Section 6 and 7, respectively.

   Finally, Appendix 1 provides an example signaling flow is
   illustrating aggregation of E2E RSVP reservations onto generic
   aggregate RSVP reservations.


2.  Object Definition

   This document reuses the RSVP-AGGREGATE-IP4 FILTER_SPEC, RSVP-
   AGGREGATE-IP6 FILTER_SPEC, RSVP-AGGREGATE-IP4 SENDER_TEMPLATE and
   RSVP-AGGREGATE-IP6 SENDER_TEMPLATE objects defined in [RSVP-AGG].

   This document defines:
      - two new objects (GENERIC-AGGREGATE-IP4 SESSION and GENERIC-
        AGGREGATE-IP6 SESSION) under the existing SESSION Class, and
      - two new objects (GENERIC-AGG-IP4-SOI and GENERIC-AGG-IP6-SOI)
        under a new SESSION-OF-INTEREST Class.

   Detailed description of these objects is provided below in this
   section.




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   The GENERIC-AGGREGATE-IP4 SESSION and GENERIC-AGGREGATE-IP6 SESSION
   objects are applicable to all types of RSVP messages.

   This specification only defines the use of the GENERIC-AGG-IP4-SOI
   and GENERIC-AGG-IP6-SOI objects in two circumstances:
      - inside an E2E PathErr message which contains an error code of
        NEW-AGGREGATE-NEEDED in order to convey the session of a new
        generic aggregate reservation which needs to be established
      - inside an E2E Resv message in order to convey the session of
        the generic aggregate reservation onto which this E2E
        reservation needs to be mapped.
   Details of the corresponding procedures can be found in section 4.

   However, it is envisioned that the ability to signal, inside RSVP
   messages, the Session of another reservation (which has some
   relationship with the current RSVP reservation) might have some other
   applicability in the future. Thus, those objects have been specified
   in a more generic manner under a flexible SESSION-OF-INTEREST class.

   All the new objects defined in this document are optional with
   respect to RSVP so that general RSVP implementations not concerned
   with generic aggregate reservations do not have to support these
   objects. RSVP routers supporting generic aggregate IPv4 (respectively
   IPv6) reservations MUST support the GENERIC-AGGREGATE-IP4 SESSION
   object (respectively GENERIC-AGGREGATE-IP6 SESSION). RSVP routers
   supporting RSVP aggregation over generic aggregate IPv4 (respectively
   IPv6) reservations MUST support the GENERIC-AGG-IP4-SOI object
   (respectively GENERIC-AGG-IP6-SOI).


2.1.  SESSION Class

      o GENERIC-AGGREGATE-IP4 SESSION object:
                     Class = 1 (SESSION)
                     C-Type = To be allocated by IANA

               0           7 8          15 16         23 24          31
              +-------------+-------------+-------------+-------------+
              |               IPv4 DestAddress (4 bytes)              |
              +-------------+-------------+-------------+--+----------+
              | Reserved    |     Flags   |  vDstPort   |Rd|  DSCP    |
              +-------------+-------------+-------------+--+----------+
              |                    Extended vDstPort                  |
              +-------------+-------------+-------------+-------------+
               0           7 8          15 16         23 24          31

   IPv4 DestAddress (IPv4 Destination Address)

       IPv4 address of the receiver (or Deaggregator)


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   Reserved

      A 8-bit field. All bits MUST be set to 0 on transmit. This field
   MUST be ignored on receipt.


   Flags

       A 8-bit field. The content and processing of this field are the
       same as for the Flags field of the IPv4/UDP SESSION object (see
       [RSVP])


   VDstPort (Virtual Destination Port)

       An 8-bit identifier used in the SESSION that remains constant
       over the life of the generic aggregate reservation.


   Rd (Reserved)

       A 2-bit field. All bits MUST be set to 0 on transmit. This field
       MUST be ignored on receipt.


   DSCP (Diffserv Code Point)

       A 6-bit field containing the DSCP of the PHB from which Diffserv
       resources are to be reserved.


   Extended vDstPort (Extended Virtual Destination Port)

       A 32-bit identifier used in the SESSION that remains constant
       over the life of the generic aggregate reservation.
       A sender (or Aggregator) that wishes to narrow the scope of a
       SESSION to the sender-receiver pair (or Aggregator-Deaggregator
       pair) SHOULD place its IPv4 address here as a network unique
       identifier. A sender (or Aggregator) that wishes to use a common
       session with other senders (or Aggregators) in order to use a
       shared reservation across senders (or Aggregators) MUST set this
       field to all zeros.


      o GENERIC-AGGREGATE-IP6 SESSION object:
                     Class = 1 (SESSION)
                     C-Type = To be allocated by IANA


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               0           7 8          15 16         23 24          31
              +-------------+-------------+-------------+-------------+
              |                                                       |
              +                                                       +
              |                                                       |
              +               IPv6 DestAddress (16 bytes)             +
              |                                                       |
              +                                                       +
              |                                                       |
              +-------------+-------------+-------------+--+----------+
              | Reserved    |     Flags   |  vDstPort   |Rd|   DSCP   |
              +-------------+-------------+-------------+--+----------+
              |                                                       |
              +                                                       +
              |                       Extended vDstPort               |
              +                                                       +
              |                            (16 bytes)                 |
              +                                                       +
              |                                                       |
              +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
               0           7 8          15 16            25 26       31

   IPv6 DestAddress (IPv6 Destination Address)

       IPv6 address of the receiver (or Deaggregator)


   Reserved

       A 8-bit field. All bits MUST be set to 0 on transmit. This field
       MUST be ignored on receipt.


   Flags

       A 8-bit field. The content and processing of this field are the
       same as for the Flags field of the IPv6/UDP SESSION object (see
       [RSVP])


   VDstPort (Virtual Destination Port)

       A 8-bit identifier used in the SESSION that remains constant
       over the life of the generic aggregate reservation.


   Rd (Reserved)



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       A 2-bit field. All bits MUST be set to 0 on transmit. This field
       MUST be ignored on receipt.


   DSCP (Diffserv Code Point)

       A 6-bit field containing the DSCP of the PHB from which Diffserv
       resources are to be reserved


   Extended vDstPort (Extended Virtual Destination Port)

       A 128-bit identifier used in the SESSION that remains constant
       over the life of the generic aggregate reservation.
       A sender (or Aggregator) that wishes to narrow the scope of a
       SESSION to the sender-receiver pair (or Aggregator-Deaggregator
       pair) SHOULD place its IPv6 address here as a network unique
       identifier. A sender (or Aggregator) that wishes to use a common
       session with other senders (or Aggregators) in order to use a
       shared reservation across senders (or Aggregators) MUST set this
       field to all zeros.


2.2.  SESSION-OF-INTEREST (SOI) Class

      o GENERIC-AGG-IP4-SOI object:
                     Class = To be allocated by IANA
                     C-Type = To be allocated by IANA

                0           7 8          15 16         23 24          31
               +-------------+-------------+-------------+-------------+
               |                           | SOI         |GEN-AGG-IP4- |
               |       Length (bytes)      | Class-Num   |SOI C-Type   |
               +-------------+-------------+-------------+-------------+
               |                                                       |
               //  Content of a GENERIC-AGGREGATE-IP4 SESSION Object  //
               |                                                       |
               +-------------+-------------+-------------+-------------+

   Content of a GENERIC-AGGREGATE-IP4 SESSION Object:

       This field contains a copy of the Session object of the session
       which is of interest for the reservation. In the case of a
       GENERIC-AGG-IP4-SOI, the session of interest conveyed in this
       field is a GENERIC-AGGREGATE-IP4 SESSION.



      o GENERIC-AGG-IP6-SOI object:


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                     Class = To be allocated by IANA
                             (same as for GENERIC-AGG-IP4-SOI)
                     C-Type = To be allocated by IANA

                0           7 8          15 16         23 24          31
               +-------------+-------------+-------------+-------------+
               |                           | SOI         |GEN-AGG-IP6- |
               |       Length (bytes)      | Class-Num   |SOI C-Type   |
               +-------------+-------------+-------------+-------------+
               |                                                       |
               //  Content of a GENERIC-AGGREGATE-IP6 SESSION Object  //
               |                                                       |
               +-------------+-------------+-------------+-------------+

   Content of a GENERIC-AGGREGATE-IP6 SESSION Object:

       This field contains a copy of the Session object of the session
       which is of interest for the reservation. In the case of a
       GENERIC-AGG-IP6-SOI, the session of interest conveyed in this
       field is a GENERIC-AGGREGATE-IP6 SESSION.


   For example, if a SESSION-OF-INTEREST object is used inside an E2E
   Resv message (as per the procedures defined in section 4) to indicate
   which generic aggregate IPv4 session the E2E reservation is to be
   mapped onto, then the GENERIC-AGG-IP4-SOI object will be used and it
   will be encoded like this:

                0           7 8          15 16         23 24          31
               +-------------+-------------+-------------+-------------+
               |                           | SOI         |GEN-AGG-IP4- |
               |       Length (bytes)      | Class-Num   |SOI C-Type   |
               +-------------+-------------+-------------+-------------+
               |               IPv4 DestAddress (4 bytes)              |
               +-------------+-------------+-------------+--+----------+
               | Reserved    |     Flags   |  vDstPort   |Rd|   DSCP   |
               +-------------+-------------+-------------+--+----------+
               |                    Extended vDstPort                  |
               +-------------+-------------+-------------+-------------+
                0           7 8          15 16         23 24          31


   Note that a SESSION-OF-INTEREST object is not a SESSION object in
   itself. It does not replace the SESSION object in RSVP messages. It
   does not modify the usage of the SESSION object in RSVP messages. It
   simply allows conveying the Session of another RSVP reservation
   inside RSVP signaling messages, for some particular purposes. In the
   context of this document, it is used to convey, inside an E2E RSVP
   message pertaining to an end-to-end reservation, the Session of a


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   generic aggregate reservation associated with the E2E reservation.
   Details for the corresponding procedures are specified in section 4.


3.  Processing Rules For Handling Generic Aggregate RSVP Reservations

   This section presents additions to the Processing Rules presented in
   [RSVP-PROCESS]. These additions are required in order to properly
   process the GENERIC-AGGREGATE-IP4 (resp. GENERIC-AGGREGATE-IP6)
   SESSION object and the RSVP-AGGREGATE-IP4 (resp. RSVP-AGGREGATE-IP6)
   FILTER_SPEC object. Values for referenced error codes can be found in
   [RSVP]. As with the other RSVP documents, values for internally
   reported (API) errors are not defined.

   When referring to the new GENERIC-AGGREGATE-IP4 and GENERIC-
   AGGREGATE-IP6 SESSION objects, IP version will not be included and
   they will be referred to simply as GENERIC-AGGREGATE SESSION, unless
   a specific distinction between IPv4 and IPv6 is being made.

   When referring to the [RSVP-AGG] RSVP-AGGREGATE-IP4 and
   RSVP-AGGREGATE-IP6 SESSION, FILTER_SPEC and SENDER_TEMPLATE objects,
   IP version will not be included and they will be referred to simply
   as RSVP-AGGREGATE, unless a specific distinction between IPv4 and
   IPv6 is being made.

3.1.  Required Changes to Path and Resv Processing

   Both RESV and PATH processing will need to be changed to support the
   new objects.

   The following PATH message processing changes are required:

       o When a session is defined using the GENERIC-AGGREGATE SESSION
          object, only the [RSVP-AGG] RSVP-AGGREGATE SENDER_TEMPLATE may
          be used. When this condition is violated in a PATH message
          received by an RSVP end-station, the RSVP end-station SHOULD
          report a "Conflicting C-Type" API error to the application.
          When this condition is violated in a PATH message received by
          an RSVP router, the RSVP router MUST consider this as a
          message formatting error.

       o For PATH messages that contain the GENERIC-AGGREGATE SESSION
          object, the VDstPort value, the Extended VDstPort value and
          the DSCP value should be recorded (in addition to the
          destination/Deaggregator address and source/aggregator
          address). These values form part of the recorded state of the
          session. The DSCP may need to be passed to traffic control;
          however the vDstPort and Extended VDstPort are not passed to



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          traffic control since they do not appear inside the data
          packets of the corresponding reservation.

   The changes to RESV message processing are:

       o When a RESV message contains a [RSVP-AGG] RSVP-AGGREGATE
          FILTER_SPEC, the session MUST be defined using either the
          RSVP-AGGREGATE SESSION object (as per [RSVP-AGG]) or the
          GENERIC-AGGREGATE SESSION object (as per this document). If
          this condition is not met, an RSVP router or end-station MUST
          consider that there is a message formatting error.

       o When the RSVP-AGGREGATE FILTER_SPEC is used and the SESSION
          type is GENERIC-AGGREGATE, each node MAY have a data
          classifier installed for the flow:

          * If the node needs to perform fine-grain classification (for
           example to perform fine-grain policing on ingress at a trust
           boundary) then the node MUST create a data classifier
           described by the 3-tuple <DestAddress, SrcAddress, DSCP>.

            Note that if multiple reservations are established with
           different Virtual Destination Ports (and/or different
           Extended Virtual Destination Ports) but with the same
           <DestAddress, SrcAddress, DSCP>, then those cannot be
           distinguished by the classifier. If the router is using the
           classifier for policing purposes, the router will therefore
           police those together and MUST program the policing rate to
           the sum of the reserved rate across all the corresponding
           reservations.

          * If the node only needs to perform Diffserv classification
           (for example inside the aggregation domain downstream of the
           trust boundary) then the node MUST rely on the Diffserv data
           classifier based on the DSCP only.


4.  Procedures for Aggregation over Generic Aggregate RSVP Reservations

   The procedures for aggregation of E2E reservations over generic
   aggregate RSVP reservations are the same as the procedures specified
   in [RSVP-AGG] with the exceptions of the procedure changes listed in
   this section.

   As specified in [RSVP-AGG], the Deaggregator is responsible for
   mapping a given E2E reservation on a given aggregate reservation. The
   Deaggregator requests establishment of a new aggregate reservation by
   sending to the Aggregator an E2E PathErr message with an error code
   of NEW-AGGREGATE-NEEDED. In [RSVP-AGG], the Deaggregator conveys the


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   DSCP of the new requested aggregate reservation by including a DCLASS
   Object in the E2E PathErr and encoding the corresponding DSCP inside.
   This document modifies and extends this procedure. The Deaggregator
   MUST include in the E2E PathErr message, a SESSION-OF-INTEREST object
   which contains the GENERIC-AGGREGATE Session to be used for
   establishment of the requested generic aggregate reservation. Since
   this GENERIC-AGGREGATE SESSION contains the DSCP, the DCLASS object
   need not be included in the PathErr message.

   Note that the Deaggregator can easily ensure that different
   Aggregators use different sessions for their Aggregate Path towards a
   given Deaggregator. This is because the Deaggregator can easily
   select VDstPort and/or Extended VDstPort numbers which are different
   for each Aggregator (for example by using the Aggregator address as
   the Extended VDstPort) and can communicate those inside the GENERIC-
   AGGREGATE SESSION included in the SESSION-OF-INTEREST object. This
   provides an easy solution to establish separate reservations from
   every Aggregator to a given Deaggregator. Conversely, if reservation
   sharing were needed across multiple Aggregators, the Deaggregator
   could facilitate this by allocating the same VDstPort and Extended
   VDstPort to the multiple Aggregators and thus including the same
   GENERIC-AGGREGATE SESSION inside the SESSION-OF-INTEREST object in
   the E2E PathErr messages sent to these Aggregators. The Aggregators
   could then all establish an Aggregate Path with the same GENERIC-
   AGGREGATE SESSION.

   Therefore various sharing scenarios can easily be supported. Policies
   followed by the Deaggregator to determine which aggregators need
   shared or separate reservations are beyond the scope of this document.

   The Deaggregator MAY also include in the E2E PathErr message (with an
   error code of NEW-AGGREGATE-NEEDED) additional RSVP objects which are
   to be used for establishment of the new needed generic aggregate
   reservation. For example, the Deaggregator MAY include in the E2E
   PathErr an RSVP Signaled Preemption Priority Policy Element (as
   specified in [RSVP-PREEMP]).

   The [RSVP-AGG] procedures for processing of an E2E PathErr message
   received with an error code of NEW-AGGREGATE-NEEDED by the Aggregator
   are extended correspondingly. On receipt of such a message containing
   a SESSION-OF-INTEREST object, the Aggregator MUST trigger
   establishment of a generic aggregate reservation. In particular, it
   MUST start sending aggregate Path messages with the GENERIC-AGGREGATE
   SESSION found in the received SESSION-OF-INTEREST object. When an
   RSVP Signaled Preemption Priority Policy Element is contained in the
   received E2E PathErr message, the Aggregator MUST include this object
   in the Aggregate Path for the corresponding generic aggregate
   reservation. When other additional objects are contained in the
   received E2E PathErr message and those can be unambiguously


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                 Generic Aggregate RSVP Reservations   September 2006


   interpreted as related to the new needed generic aggregate
   reservation (as opposed to related to the E2E reservation), the
   Aggregator SHOULD include those in the Aggregate Path for the
   corresponding generic aggregate reservation. The Aggregator MUST use
   as the Source Address (i.e. as the Aggregator Address in the Sender-
   Template) for the generic aggregate reservation, the address it uses
   to identify itself as the PHOP when forwarding the E2E Path messages
   corresponding to the E2E PathErr message.

   The Deaggregator follows the same procedures as described in [RSVP-
   AGG] for establishing, maintaining and clearing the aggregate Resv
   state. However, in this document, the Deaggregator MUST use the
   generic aggregate reservations and hence use the GENERIC-AGGREGATE
   SESSION specified earlier in this document.

   This document also modifies the procedures of [RSVP-AGG] related to
   exchange of E2E Resv messages between Deaggregator and Aggregator.
   The Deaggregator MUST include the new SESSION-OF-INTEREST object in
   the E2E Resv message, in order to indicate to the Aggregator the
   generic aggregate session to map a given E2E reservation onto. Again,
   since the GENERIC-AGGREGATE SESSION (included in the SESSION-OF-
   INTEREST object) contains the DSCP, the DCLASS object need not be
   included in the E2E Resv message. The Aggregator MUST interpret the
   SESSION-OF-INTEREST object in the E2E Resv as indicating which
   generic aggregate reservation session the corresponding E2E
   reservation is mapped onto. The Aggregator MUST not include the
   SESSION-OF-INTEREST object when sending an E2E Resv upstream towards
   the sender.

   Based on relevant policy, the Deaggregator may decide at some point
   that an aggregate reservation is no longer needed and should be torn
   down. In that case, the Deaggregator MUST send an aggregate ResvTear.
   On receipt of the aggregate ResvTear, the Aggregator SHOULD send an
   aggregate PathTear (unless the relevant policy instructs the
   aggregator to do otherwise or to wait for some time before doing so,
   for example in order to speed-up potential re-establishment of the
   aggregate reservation in the future).

   [RSVP-AGG] describes how the Aggregator and Deaggregator can
   communicate their respective identity to each other. For example the
   Aggregator includes one of its IP addresses in the RSVP HOP object in
   the E2E Path which is transmitted downstream and received by the
   Deaggregator once it traversed the aggregation region. Similarly, the
   Deaggregator identifies itself to the Aggregator by including one of
   its IP addresses in various fields, including the ERROR SPECIFICATION
   of the E2E PathErr message (containing the NEW-AGGREGATE-NEEDED Error
   Code) and in the RSVP HOP object of the E2E Resv message. However,
   [RSVP-AGG] does not discuss which IP addresses are to be selected by
   the aggregator and Deaggregator for such purposes. Because these


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                 Generic Aggregate RSVP Reservations   September 2006


   addresses are intended to identify the Aggregator and Deaggregator
   and not to identify any specific interface on these devices, this
   document RECOMMENDS that the Aggregator and Deaggregator SHOULD use
   interface-independent addresses (for example a loopback address)
   whenever they communicate their respective identity to each other.
   This ensures that respective identification of the Aggregator and
   Deaggregator is not impacted by any interface state change on these
   devices. In turns this results in more stable operations and
   considerably reduced RSVP signaling in the aggregation region. For
   example, if interface-independent addresses are used by the
   Aggregator and the Deaggregator, then a failure of an interface on
   these devices may simply result in the rerouting of a given generic
   aggregate reservation but will not result in the generic aggregate
   reservation having to be torn down and another one established, nor
   will it result in a change of mapping of E2E reservations on generic
   aggregate reservations (assuming the Aggregator and Deaggregator
   still have reachability after the failure and the Aggregator and
   Deaggregator are still on the shortest path to the destination).

   However, when identifying themselves to real RSVP neighbors (i.e.
   neighbors which are not on the other side of the aggregation region),
   the Aggregator and Deaggregator SHOULD continue using interface-
   dependent addresses as per regular [RSVP] procedures. This applies
   for example when the Aggregator identifies itself downstream as a
   PHOP for the generic aggregate reservation or identifies itself
   upstream as a NHOP for an E2E reservation. This also applies when the
   Deaggregator identifies itself downstream as a PHOP for the E2E
   reservation or identifies itself upstream as a NHOP for the generic
   aggregate reservation. As part of the processing of generic aggregate
   reservations, interior routers (i.e. routers within the aggregation
   region) SHOULD continue using interface-dependent addresses as per
   regular [RSVP] procedures.

   More generally, within the aggregation region (ie between Aggregator
   and Deaggregator) the operation of RSVP should be modeled with the
   notion that E2E reservations are mapped to aggregate reservations and
   are no longer tied to physical interfaces (as was the case with
   regular RSVP). However, generic aggregate reservations (within the
   aggregation region) as well as E2E reservations outside the
   aggregation region, retain the model of regular RVSP and remain tied
   to physical interfaces.

   As discussed above, generic aggregate reservations may be established
   edge-to-edge as a result of the establishment of E2E reservations
   (from outside the aggregation region) which are to be aggregated over
   the aggregation region. However, generic aggregate reservations may
   also be used end-to-end by end-systems directly attached to a
   Diffserv domain, such as PSTN Gateways. In that case, the generic
   aggregate reservations may be established by the end-systems in


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   response to application-level triggers such as voice call signaling.
   Alternatively, generic aggregate reservations may also be used edge-
   to-edge to manage bandwidth in a Diffserv cloud even if RSVP is not
   used end-to-end. A simple example of such a usage would be the static
   configuration of a generic aggregate reservation for a certain
   bandwidth for traffic from an ingress (Aggregator) router to an
   egress (Deaggregator) router.

   In this case, the establishment of the generic aggregate reservations
   is controlled by configuration on the Aggregator and on the
   Deaggregator. Configuration on the Aggregator triggers generation of
   the aggregate Path message and provides sufficient information to the
   Aggregator to derive the content of the GENERIC-AGGREGATE SESSION
   object. This would typically include Deaggregator IP address, DSCP
   and possibly VDstPort. Configuration on the Deaggregator would
   instruct the Deaggregator to respond to a received generic aggregate
   Path message and would provide sufficient information to the
   Deaggregator to control the reservation. This may include bandwidth
   to be reserved by the Deaggregator (for a given
   Deaggregator/DSCP/VDstPort tuple).

   In the absence of E2E microflow reservations, the Aggregator can use
   a variety of policies to set the DSCP of packets passing into the
   aggregation region and how they are mapped onto generic aggregate
   reservations, thus determining whether they gain access to the
   resources reserved by the aggregate reservation. These policies are a
   matter of local configuration, as usual for a device at the edge of a
   Diffserv cloud.


5.  Example Usage Of Multiple Generic Aggregate Reservations Per DSCP
   From a Given Aggregator to a Given Deaggregator

   Let us consider the environment depicted in Figure 2 below. RSVP
   aggregation is used to support E2E reservations between Cloud-1,
   Cloud-2 and Cloud-3.


                 I----------I               I----------I
                 I  Cloud-1 I               I  Cloud-2 I
                 I----------I               I----------I
                       |                      |
                    Agg-Deag-1------------ Agg-Deag-2
                       /                        \
                      /      Aggregation         |
                     |         Region            |
                     |                           |
                     |                       ---/
                      \                     /


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                 Generic Aggregate RSVP Reservations   September 2006


                       \Agg-Deag-3---------/
                             |
                        I----------I
                        I  Cloud-3 I
                        I----------I


                        Figure 2 : Example Usage of
                     Generic Aggregate IP Reservations

   Let us assume that:

       o the E2E reservations from Cloud-1 to Cloud-3 have a preemption
          of either P1 or P2

       o the E2E reservations from Cloud-2 to Cloud-3 have a preemption
          of either P1 or P2

       o the E2E reservations are only for Voice (which needs to be
          treated in the aggregation region using the EF PHB)

       o traffic from the E2E reservations is encapsulated in Aggregate
          IP reservations from Aggregator to Deaggregator using GRE
          tunneling ([GRE]).

   Then, the following generic aggregate RSVP reservations may be
   established from Agg-Deag-1 to Agg-Deag-3 for aggregation of the end-
   to-end RSVP reservations:

   A first generic aggregate reservation for aggregation of Voice
   reservations from Cloud-1 to Cloud-3 requiring use of P1:

          *  GENERIC-AGGREGATE-IP4 SESSION:
                  IPv4 DestAddress= Agg-Deag-3
                  vDstPort=V1
                  DSCP=EF
                  Extended VDstPort= Agg-Deag-1

          *  STYLE=FF or SE

          *  IPv4/GPI FILTER_SPEC:
                  IPv4 SrcAddress= Agg-Deag-1

          *  POLICY_DATA (PREEMPTION_PRI)=P1

   A second generic aggregate reservation for aggregation of Voice
   reservations from Cloud-1 to Cloud-3 requiring use of P2:

          *  GENERIC-AGGREGATE-IP4 SESSION:


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                  IPv4 DestAddress= Agg-Deag-3
                  vDstPort=V2
                  DSCP=EF
                  Extended VDstPort= Agg-Deag-1

          *  STYLE=FF or SE

          *  IPv4/GPI FILTER_SPEC:
                  IPv4 SrcAddress= Agg-Deag-1

          *  POLICY_DATA (PREEMPTION_PRI)=P2

      where V1 and V2 are arbitrary VDstPort values picked by Agg-Deag-3.

   The following generic aggregate RSVP reservations may be established
   from Agg-Deag-2 to Agg-Deag-3 for aggregation of the end-to-end RSVP
   reservations:

   A third generic aggregate reservation for aggregation of Voice
   reservations from Cloud-2 to Cloud-3 requiring use of P1:

          *  GENERIC-AGGREGATE-IP4 SESSION:
                  IPv4 DestAddress= Agg-Deag-3
                  vDstPort=V3
                  DSCP=EF
                  Extended VDstPort= Agg-Deag-2

          *  STYLE=FF or SE

          *  IPv4/GPI FILTER_SPEC:
                  IPv4 SrcAddress= Agg-Deag-2

          *  POLICY_DATA (PREEMPTION_PRI)=P1

   A fourth generic aggregate reservation for aggregation of Voice
   reservations from Cloud-2 to Cloud-3 requiring use of P2:

          *  GENERIC-AGGREGATE-IP4 SESSION:
                  IPv4 DestAddress= Agg-Deag-3
                  vDstPort=V4
                  DSCP=EF
                  Extended VDstPort= Agg-Deag-2

          *  STYLE=FF or SE

          *  IPv4/GPI FILTER_SPEC:
                  IPv4 SrcAddress= Agg-Deag-2

          *  POLICY_DATA (PREEMPTION_PRI)=P2


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      where V1 and V4 are arbitrary VDstPort values picked by Agg-Deag-3.

   Note that V3 and V4 could be equal to (respectively) V1 and V2 since,
   in this example, the Extended VDstPort of the GENERIC-AGGREGATE
   Session contains the address of the Deaggregator and, thus, ensures
   that different sessions are used for each Deaggregator.


6.  Security Considerations

   In the environments concerned by this document, RSVP messages are
   used to control resource reservations for generic aggregate
   reservations and may be used to control resource reservations for E2E
   reservations being aggregated over the generic aggregate reservations.
   To ensure the integrity of the associated reservation and admission
   control mechanisms, the mechanisms defined in [RSVP-CRYPTO1] and
   [RSVP-CRYPTO2] can be used. Those protect RSVP messages integrity
   hop-by-hop and provide node authentication, thereby protecting
   against corruption and spoofing of RSVP messages. These hop-by-hop
   integrity mechanisms can naturally be used to protect the RSVP
   messages used for generic aggregate reservations, to protect RSVP
   messages used for E2E reservations outside the aggregation region, or
   for both. These hop-by-hop RSVP integrity mechanisms can also be used
   to protect RSVP messages used for E2E reservations when those transit
   through the aggregation region. This is because the Aggregator and
   Deaggregator behave as RSVP neighbors from the viewpoint of the E2E
   flows (even if they are not necessarily IP neighbors nor RSVP-TE
   neighbors). It that case, the Aggregator and Deaggregator need to use
   a pre-shared secret. Where the dynamic Deaggregator determination
   procedure defined in [RSVP-AGG] are used, the Aggregator does not
   know ahead of time which router is going to act as the Deaggregator.
   Thus, use of the mechanisms of [RSVP-CRYPTO1] and [RSVP-CRYPTO2] for
   protection of RSVP E2E messages (e.g. E2E Path) while they transit
   through the aggregation region may require the use of a secret pre-
   shared across the Aggregator and all Deaggregators.

   When generic aggregate reservations are used for aggregation of E2E
   reservations, the security considerations discussed in [RSVP-AGG]
   apply.

   The security considerations discussed in [SIG-NESTED] apply when the
   generic aggregate reservations are used in the presence of IPsec
   gateways.


7.  IANA Considerations




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                 Generic Aggregate RSVP Reservations   September 2006


   This document requests that IANA allocates two new C-Types under the
   existing SESSION Class (Class 1) for the two new RSVP objects
   defined in section 2.1: GENERIC-AGGREGATE-IP4 SESSION and GENERIC-
   AGGREGATE-IP6 SESSION. This allocation is in accordance with [RSVP-
   MOD] which defines the default assignment policy as Standards Action
   for new Class-Type values under an existing class.

   This document also requests that IANA allocates one new Class-Num for
   the SESSION-OF-INTEREST class, and two new C-Types for the two new
   RSVP objects under that class defined in section 2.2: GENERIC-AGG-
   IP4-SOI and GENERIC-AGG-IP6-SOI. The Class-Num for the SESSION-OF-
   INTEREST class is to be allocated in the range from 128 to 183
   defined in [RSVP-MOD] as to be assigned by Standards Action. In
   accordance with [RSVP-MOD], the Class-Type values under the SESSION-
   OF-INTEREST class are to be allocated according to the following
   policy:
     o C-Type values from 0 through 127 are to be assigned by Standards
        Action
     o C-Type values from 128 through 191 are to be assigned by Expert
        Review
     o C-Type values from 192 through 255 are reserved for Vendor
        Private use
     o C-Type value 1 is to be allocated to the GENERIC-AGG-IP4-SOI
        object defined in this document
     o C-Type value 2 is to be allocated to the GENERIC-AGG-IP6-SOI
        object defined in this document.


8.  Acknowledgments

   This document borrows heavily from [RSVP-AGG]. It also borrows the
   concepts of Virtual Destination Port and Extended Virtual Destination
   Port respectively from [RSVP-IPSEC] and [RSVP-TE].

   Also, we thank Fred Baker, Roger Levesque, Carol Iturralde, Daniel
   Voce, Anil Agarwal, Alexander Sayenko and Anca Zamfir for their input
   into the content of this document. Thanks to Steve Kent for
   insightful comments on usage of RSVP reservations in IPsec
   environments.


9.  Normative References

   [KEYWORDS] "Key words for use in RFCs to Indicate Requirement Levels",
   Bradner, RFC2119

   [RSVP] "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional
   Specification", Braden et al, RFC2205



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                 Generic Aggregate RSVP Reservations   September 2006


   [RSVP-AGG] "Aggregation of RSVP for IPv4 and IPv6 Reservations",
   Baker et al, RFC3175

   [RSVP-CRYPTO1] Baker at al, RSVP Cryptographic Authentication, RFC
   2747, January 2000.

   [RSVP-CRYPTO2] Braden and Zhang, RSVP Cryptographic Authentication -
   Updated Message Type Value, RFC 3097, April 2001.

   [RSVP-IPSEC] "RSVP Extensions for IPsec Data Flows", Berger et al,
   RFC2207

   [RSVP-PROCESS] "Resource ReSerVation Protocol (RSVP) -- Version 1
   Message Processing Rules", Braden et al, RFC2209

   [RSVP-MOD] "Procedures for Modifying the Resource reSerVation
   Protocol (RSVP)", Kompella and Lang, RFC 3936, BCP 96


10.  Informative References

   [BW-REDUC] "A Resource Reservation Extension for the Reduction of
   andwidth of a Reservation Flow", Polk et al, RFC 4495

   [GRE] "Generic Routing Encapsulation (GRE) ", Farinacci et al, RFC
   2784

   [RSVP-PREEMP]  Herzog, S., "Signaled Preemption Priority Policy
   Element", RFC 3181, October 2001.

   [RSVP-TE] Awduche et al, RSVP-TE: Extensions to RSVP for LSP Tunnels,
   RFC 3209, December 2001.

   [RSVP-TUNNEL] "RSVP Operation Over IP Tunnels", Terzis et al., RFC
   2746, January 2000.

   [SIG-NESTED] "QoS Signaling in a Nested Virtual Private Network",
   Baker et al, draft-ietf-tsvwg-vpn-signaled-preemption, work in
   progress


11.  Authors' Addresses


   Francois Le Faucheur
   Cisco Systems, Inc.
   Village d'Entreprise Green Side - Batiment T3
   400, Avenue de Roumanille
   06410 Biot Sophia-Antipolis


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   France
   Email: flefauch@cisco.com


   Bruce Davie
   Cisco Systems, Inc.
   300 Beaver Brook Road
   Boxborough, MA 01719
   USA
   Email: bdavie@cisco.com


   Pratik Bose
   Lockheed Martin
   22300 Comsat Drive Clarksburg, MD 20814
   USA
   Email: pratik.bose@lmco.com


   Christou Christou
   Booz Allen Hamilton
   8283 Greensboro Drive
   McLean, VA 22102
   USA
   Email: christou_chris@bah.com


   Michael Davenport
   Booz Allen Hamilton
   8283 Greensboro Drive
   McLean, VA 22102
   USA
   Email: davenport_michael@bah.com


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   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


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                 Generic Aggregate RSVP Reservations   September 2006


   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.


Disclaimer of Validity

   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
   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.


Copyright Notice

   Copyright (C) The Internet Society (2006).  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.




Appendix A: Example Signaling Flow

   This Appendix does not provide additional specification. It only
   illustrates the specification detailed in section 4 through a
   possible flow of RSVP signaling messages. This flow assumes an
   environment where E2E reservations are aggregated over generic
   aggregate RSVP reservations. It illustrates a possible RSVP message
   flow that could take place in the successful establishment of a
   unicast E2E reservation which is the first between a given pair of
   Aggregator/Deaggregator.


           Aggregator                              Deaggregator

    E2E Path
   ----------->
                (1)
                           E2E Path


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                   ------------------------------->
                                                       (2)
                    E2E PathErr(New-agg-needed,SOI=GAx)
                   <----------------------------------
                    E2E PathErr(New-agg-needed,SOI=GAy)
                   <----------------------------------
                (3)
                         AggPath(Session=GAx)
                   ------------------------------->
                         AggPath(Session=GAy)
                   ------------------------------->
                                                       (4)
                                                           E2E Path
                                                          ----------->
                                                       (5)
                         AggResv (Session=GAx)
                   <-------------------------------
                         AggResv (Session=GAy)
                   <-------------------------------
                (6)
                     AggResvConfirm (Session=GAx)
                   ------------------------------>
                     AggResvConfirm (Session=GAy)
                   ------------------------------>
                                                       (7)
                                                           E2E Resv
                                                          <---------
                                                       (8)
                           E2E Resv (SOI=GAx)
                   <-----------------------------
                (9)
      E2E Resv
   <-----------


   (1) The Aggregator forwards E2E Path into the aggregation region
   after modifying its IP Protocol Number to RSVP-E2E-IGNORE

   (2)  Let's assume no Aggregate Path exists. To be able to accurately
   update the ADSPEC of the E2E Path, the Deaggregator needs the ADSPEC
   of Aggregate PATH. In this example the Deaggregator elects to
   instruct the Aggregator to set up Aggregate Path states for the two
   supported DSCPs. To do that, the Deaggregator sends two E2E PathErr
   messages with a New-Agg-Needed PathErr code. Both PathErr messages
   also contain a SESSION-OF-INTEREST (SOI) object. In the first E2E
   PathErr, the SOI contains a GENERIC-AGGREGATE SESSION (GAx) whose
   DSCP is set to x. In the second E2E PathErr, the SOI contains a
   GENERIC-AGGREGATE SESSION (GAy) whose DSCP is set to y. In both
   messages the GENERIC-AGGREGATE SESSION contains an interface-


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   independent Deaggregator address inside the DestAddress and
   appropriate values inside the vDstPort and Extended vDstPort fields.

   (3)  The Aggregator follows the request from the Deaggregator and
   signals an Aggregate Path for both GENERIC-AGGREGATE Sessions (GAx
   and GAy).

   (4)  The Deaggregator takes into account the information contained in
   the ADSPEC from both Aggregate Path and updates the E2E Path ADSPEC
   accordingly. The Deaggregator also modifies the E2E Path IP Protocol
   Number to RSVP before forwarding it.

   (5)  In this example, the Deaggregator elects to immediately proceed
   with establishment of generic aggregate reservations for both DSCPs.
   In effect, the Deaggregator can be seen as anticipating the actual
   demand of E2E reservations so that resources are available on
   the generic aggregate reservations when the E2E Resv requests arrive,
   in order to speed up establishment of E2E reservations. Assume
   also that the Deaggregator includes the optional Resv Confirm
   Request in these Aggregate Resv.

   (6)  The Aggregator merely complies with the received ResvConfirm
   Request and returns the corresponding Aggregate ResvConfirm.

   (7)  The Deaggregator has explicit confirmation that both Aggregate
   Resv are established.

   (8)  On receipt of the E2E Resv, the Deaggregator applies the mapping
   policy defined by the network administrator to map the E2E Resv
   onto a generic aggregate reservation. Let's assume that this policy
   is such that the E2E reservation is to be mapped onto the generic
   aggregate reservation with DSCP=x. The Deaggregator knows that a
   generic aggregate reservation (GAx) is in place for the corresponding
   DSCP since (7). The Deaggregator performs admission control of the
   E2E Resv onto the generic aggregate Reservation for DSCP=x (GAx).
   Assuming that the generic aggregate reservation for DSCP=x (GAx) had
   been established with sufficient bandwidth to support the E2E Resv,
   the Deaggregator adjusts its counter, tracking the unused bandwidth
   on the generic aggregate reservation and forwards the E2E Resv to the
   Aggregator including a SESSION-OF-INTEREST object conveying the
   selected mapping onto GAx (and hence onto DSCP=x).

   (9)  The Aggregator records the mapping of the E2E Resv onto GAx (and
   onto DSCP=x). The Aggregator removes the SOI object and forwards the
   E2E Resv towards the sender.






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