rfc2961.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

   "rapid" retransmission interval.  Lastly, since the MESSAGE_ID_ACK
   class can only be issued in response to the MESSAGE_ID object, there
   are no possible issues with this class or Ack messages.  A node MAY
   support the MESSAGE_ID Extension without supporting the other refresh
   overhead reduction extensions.







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RFC 2961       RSVP Refresh Overhead Reduction Extensions     April 2001


5. Summary Refresh Extension

   The summary refresh extension enables the refreshing of RSVP state
   without the transmission of standard Path or Resv messages.  The
   benefits of the described extension are that it reduces the amount of
   information that must be transmitted and processed in order to
   maintain RSVP state synchronization.  Importantly, the described
   extension preserves RSVP's ability to handle non-RSVP next hops and
   to adjust to changes in routing.  This extension cannot be used with
   Path or Resv messages that contain any change from previously
   transmitted messages, i.e., are trigger messages.

   The summary refresh extension builds on the previously defined
   MESSAGE_ID extension.  Only state that was previously advertised in
   Path and Resv messages containing MESSAGE_ID objects can be refreshed
   via the summary refresh extension.

   The summary refresh extension uses the objects and the ACK message
   previously defined as part of the MESSAGE_ID extension, and a new
   Srefresh message.  The new message carries a list of
   Message_Identifier fields corresponding to the Path and Resv trigger
   messages that established the state.  The Message_Identifier fields
   are carried in one of three Srefresh related objects.  The three
   objects are the MESSAGE_ID LIST object, the MESSAGE_ID SRC_LIST
   object, and the MESSAGE_ID MCAST_LIST object.

   The MESSAGE_ID LIST object is used to refresh all Resv state, and
   Path state of unicast sessions.  It is made up of a list of
   Message_Identifier fields that were originally advertised in
   MESSAGE_ID objects.  The other two objects are used to refresh Path
   state of multicast sessions.  A node receiving a summary refresh for
   multicast path state will at times need source and group information.
   These two objects provide this information.  The objects differ in
   the information they contain and how they are sent.  Both carry
   Message_Identifier fields and corresponding source IP addresses.  The
   MESSAGE_ID SRC_LIST is sent in messages addressed to the session's
   multicast IP address.  The MESSAGE_ID MCAST_LIST object adds the
   group address and is sent in messages addressed to the RSVP next hop.
   The MESSAGE_ID MCAST_LIST is normally used on point-to-point links.

   An RSVP node receiving an Srefresh message, matches each listed
   Message_Identifier field with installed Path or Resv state.  All
   matching state is updated as if a normal RSVP refresh message has
   been received.  If matching state cannot be found, then the Srefresh
   message sender is notified via a refresh NACK.






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RFC 2961       RSVP Refresh Overhead Reduction Extensions     April 2001


   A refresh NACK is sent via the MESSAGE_ID_NACK object.  As described
   in the previous section, the rules for sending a MESSAGE_ID_NACK
   object are the same as for sending a MESSAGE_ID_ACK object.  This
   includes sending MESSAGE_ID_NACK object both piggy-backed in
   unrelated RSVP messages or in RSVP ACK messages.

5.1. MESSAGE_ID LIST, SRC_LIST and MCAST_LIST Objects

   MESSAGE_ID LIST object

   MESSAGE_ID_LIST Class = 25

      Class = MESSAGE_ID_LIST Class, C_Type = 1

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     Flags     |                      Epoch                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Message_Identifier                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                 :                             |
      //                                :                            //
      |                                 :                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Message_Identifier                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Flags: 8 bits

         No flags are currently defined.  This field MUST be zero on
         transmission and ignored on receipt.

      Epoch: 24 bits

         The Epoch field from the MESSAGE_ID object corresponding to the
         trigger message that advertised the state being refreshed.

      Message_Identifier: 32 bits

         The Message_Identifier field from the MESSAGE_ID object
         corresponding to the trigger message that advertised the state
         being refreshed.  One or more Message_Identifiers may be
         included.







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RFC 2961       RSVP Refresh Overhead Reduction Extensions     April 2001


   IPv4/MESSAGE_ID SRC_LIST object

      Class = MESSAGE_ID_LIST Class, C_Type = 2

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     Flags     |                      Epoch                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              Source_                          |
      |                      Message_Identifier_Tuple                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                 :                             |
      //                                :                            //
      |                                 :                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                              Source_                          |
      |                      Message_Identifier_Tuple                 |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where a Source_Message_Identifier_Tuple consists of:

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Message_Identifier                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Source_IP_Address (4 bytes)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
























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RFC 2961       RSVP Refresh Overhead Reduction Extensions     April 2001


   IPv6/MESSAGE_ID SRC_LIST object

      Class = MESSAGE_ID_LIST Class, C_Type = 3

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     Flags     |                      Epoch                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                            IPv6_Source_                       |
      |                      Message_Identifier_Tuple                 |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                 :                             |
      //                                :                            //
      |                                 :                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                            IPv6_Source_                       |
      |                      Message_Identifier_Tuple                 |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where a IPv6 Source_Message_Identifier_Tuple consists of:

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Message_Identifier                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                      IPv6 Source_IP_Address                   |
      |                            (16 Bytes)                         |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      Flags: 8 bits

         No flags are currently defined.  This field MUST be zero on
         transmission and ignored on receipt.

      Epoch: 24 bits

         The Epoch field from the MESSAGE_ID object corresponding to the
         trigger message that advertised the state being refreshed.





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RFC 2961       RSVP Refresh Overhead Reduction Extensions     April 2001


      Message_Identifier

         The Message_Identifier field from the MESSAGE_ID object
         corresponding to the trigger message that advertised the Path
         state being refreshed.  One or more Message_Identifiers may be
         included.  Each Message_Identifier MUST be followed by the
         source IP address corresponding to the sender described in the
         Path state being refreshed.

      Source_IP_Address

         The IP address corresponding to the sender of the Path state
         being refreshed.

      IPv4/MESSAGE_ID MCAST_LIST object

      Class = MESSAGE_ID_LIST Class, C_Type = 4

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     Flags     |                      Epoch                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             Multicast_                        |
      |                        Message_Identifier_                    |
      |                               Tuple                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                 :                             |
      //                                :                            //
      |                                 :                             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                             Multicast_                        |
      |                        Message_Identifier_                    |
      |                               Tuple                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Where a Multicast_Message_Identifier_Tuple consists of:

      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Message_Identifier                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Source_IP_Address (4 bytes)                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 Destination_IP_Address (4 bytes)              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+






Berger, et al.              Standards Track                    [Page 21]

RFC 2961       RSVP Refresh Overhead Reduction Extensions     April 2001