Internet Draft                                          Jim Boyle
Expiration: Feb Apr. 1999                                       L3                                       Level3
File: draft-ietf-rap-cops-rsvp-00.txt draft-ietf-rap-cops-rsvp-01.txt                   Ron Cohen
                                                            Cisco
                                                        David Durham
                                                            Intel
                                                        Shai Herzog
                                                            IPHighway
                                                        Raju Rajan
                                                            IBM
                                                        Arun Sastry
                                                            Cisco

                          COPS usage for RSVP

                     Last Updated: August 19, November 18, 1998

Status of this Memo

   This document is an Internet Draft.  Internet Drafts are working
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   Distribution of this draft is unlimited.

Abstract

   This document describes usage directives for supporting COPS policy
   services in RSVP environments.

Table of Contents

Abstract.............................................................1
Table of Contents....................................................2
1.Introduction.......................................................3
2.RSVP values for COPS objects.......................................3
2.1.Context Object (Context).........................................3
2.2.Client Specific Information (ClientSI)...........................4
2.3.Decision Object (Decision).......................................4
3.Operation of COPS for Policy Control Over RSVP.....................5
3.1.RSVP flows.......................................................5
3.2.Expected Associations for RSVP Requests..........................5
3.3.RSVP's Capacity Admission Control: Commit and Delete.............6
3.4.Policy Control Over PathTear and ResvTear........................6
3.5.PEP Caching COPS Decisions.......................................6
3.6.Using Multiple Context Flags in a single query...................7
3.7.Trusted zones and secure policy tunneling........................7
4.Illustrative Examples, Using COPS for RSVP.........................8
4.1.Unicast Flow Example.............................................8
4.2.Shared Multicast Flows...........................................9
5.References........................................................13
6.Author Information and Acknowledgments............................13

1. Introduction

   The Common Open Policy Service (COPS) protocol is a query response
   protocol used to exchange policy information between a network
   policy server and a set of clients [COPS]. COPS is being developed
   within the RSVP Admission Policy Working Group (RAP WG) of the IETF,
   primarily for use as a mechanism for providing policy-based
   admission control over requests for network resources [RAP].

   This document is based on and assumes prior knowledge of RAP
   framework [RAP] and the basic COPS [COPS] protocol. It provides
   specific usage directives for using COPS in outsourcing policy
   control decisions by RSVP clients (PEPs) to policy servers (PDPs).

   Given the COPS protocol design, client specific functionality is
   mainly limited to interoperability usage guidelines as well as
   client specific examples.

2. RSVP values for COPS objects

   The format and usage of several COPS objects is affected when used
   for client type RSVP. This section describes these objects and the
   usage.

  2.1. Context Object (Context)

   The semantics of the Context object for RSVP is as follows:

   R-Type (Request Type Flag)

   0x01 = Incoming-Message request
          The arrival of an incoming RSVP message

          Allows processing of incoming policy information as well as
          the decision whether to accept an incoming message. If It is
          rejected, the message is treated as if it never Arrived.

   0x02 = Resource-Allocation request
          Applies only for Resv messages.

          The decision whether to admit a reservation and commit local
          resources to it is performed for the merge of all
          reservations that arrived on a particular interface
          (potentially from several Previous Hops). RSVP Next-Hops).

   0x04 = Outgoing-Message request
          The forwarding of an outgoing RSVP message.

          The Decision whether to allow the forwarding of an outgoing
          RSVP message as well as providing the relevant outgoing
          policy information.

   M-Type (Message Type)

   The M-Type field in the Context Object may have one of the
   Following values that correspond to supported RSVP messages
   In COPS:

   1 = Path
   2 = Resv
   3 = PathErr
   4 = ResvErr

   Note: The PathTear, ResvTear, and the Resv Confirm message types are
   not supported.

  2.2. Client Specific Information (ClientSI)

   All objects contained that were received within an RSVP message that are
   associated with the RSVP messaging flow are encapsulated inside the Client
   Specific Information Object without alteration. The (See Section 3.1. on
   multiple flows packed in a single RSVP message). These RSVP objects
   are simply contained within a single Signalled Signaled Client Specific
   Information Object (Signaled (RSVP ClientSI) exchanged between the PEP and
   remote PDP.

   To prevent ambiguity, the number of object instances appearing in
   the ClientSI are restricted by the rules native to RSVP. For
   example, it is forbidden to include two different FlowSpec objects
   in one ClientSI encapsulation, while perfectly legal to include
   multiple FilterSpecs for a WF or SE reservation.

   For applicability example, see Section 3.6.

  2.3. Decision Object (Decision)

   COPS allows PDP to control RSVP’s response to messages. Beyond
   traditional accept/deny, PDPs may use the Trigger Error flag to
   allow a request yet trigger a warning at the same time. To allow
   resource allocation yet deny forwarding of a message, etc.

   Decision Flags

   The following decision flags apply to RSVP:

   0x01 = Signaled (RSVP) accept (deny if set)

          This flag should be interpreted with the decision context
          flag to figure out what it applies to.

   0x08 = Trigger Error (PathErr for Path query, or ResvErr for Resv)

   Client Specific Policy Information

   This object may include one or more policy elements (as specified
   for the RSVP Policy Data object [RSVP-EXT] which are assumed to be
   well understood by the client’s LDP. The PEP should consider these
   as if they arrived in the message Policy Data object.

   For example: Given Policy Elements that specify a flow’s preemption
   priority, these elements may be included in an incoming Resv message
   or may be also be provided by the PDP responding to a query.

   Replacement Data

   The Replacement object may contain multiple RSVP objects to be
   replaced (from the original RSVP request). Typical replacement is
   performed on the “Forward Outgoing” request (for instance, replacing
   outgoing Policy Data), but is not limited to this context flag.
   Another example, limited, and can also be performed
   on other contexts (such as “Allocate Resources”). Other examples,
   may require replacement of the RSVP FlowSpec object for controlling
   resources across a trusted zone (with PIN nodes) the RSVP FlowSpec object may need to be replaced. nodes).
   Currently, RSVP clients are only required to allow replacement of
   two objects: Policy Data and FlowSpec.

   Client Specific decision Object

   In support of the verification integrity of incoming RSVP messages,
   the COPS protocol may optionally return a security key

   Replacement is performed in the Client
   Specific Decision following manner:
   If Replacement Data decision doesn't appear in a decision message,
   all signaled objects are passed as if the PDP was not there. When an
   object (C-Type = 4) useful for future
   integrity checks by of a certain C-Num appears it replaces ALL the PEP. Refer to instances of
   C-Num objects in the document on User Identity
   Representation for RSVP [UserID] for details on the format and
   application message. If it appears empty (with a
   length of this security key when supported by the PEP. 4) it simply removes all instances of C-Num objects
   without adding a thing.

3. Operation of COPS for Policy Control Over RSVP

  3.1. RSVP flows

   Policy Control is performed per RSVP flow. An RSVP flow corresponds
   to an atomic unit of reservation as identified by RSVP (TC
   reservation). It should be noted that RSVP allows multiple flows to
   be packed (which is different from merged) into a single FF Resv
   message. To support such messages a separate COPS request must be
   issued for each of the packed flows as if they were individual RSVP
   messages.

  3.2. Expected Associations for RSVP Requests

   RSVP signaling requires the participation of both senders and
   receivers. RSVP processing rules define what is the subset of the
   Path state that matches each Resv state. In the common unicast case,
   the RSVP session includes one Path state and one Resv state. In
   multicast cases the correspondence might be many to many. Since the
   decision to admit a reservation for a session may depend on
   information carried both in Path and Resv messages, we term the Path
   States that match with a single Resv state as its associated states.
   It is assumed that the PDP is capable of determining these
   associations based on the RSVP message processing rules given the
   RSVP objects expressed in the COPS Client Specific Information
   Object.

   For example, the PDP should be able to recognize activation and
   deactivation of RSVP blockade state following discrete events like
   the arrival of a ResvErr message (activate the blockade state) as
   well as the change in the outgoing Resv message.

  3.3. RSVP's Capacity Admission Control: Commit and Delete

   In RSVP, the admission of a new reservation requires both an
   administrative approval (policy control) and capacity admission
   control. Once local admission control accepts the reservation, the
   PEP notifies the remote PDP by sending a report message specifying
   the Commit type. The Commit type report message is to be used to
   signify when billing should effectively begin, and performing
   heavier operations (e.g., debiting a credit card) is permissible.

   If instead a reservation approved by the PDP fails admission due to
   lack of resources, the PEP must resort issue a no-commit report and fold
   back and send an updated request to its previous state (previously
   installed reservation). If none no state was previously installed, the
   PEP should issue a delete. Otherwise, it should issue
   a report no-commit and then send a request update for the previously
   allocated reservation state.

  3.4. Policy Control Over Path PathTear and Resv Tear

   Path ResvTear

   PathTear and Resv Tear ResvTear messages are not controlled by this policy
   architecture. This relies on two assumptions: First, that MD-5
   authentication verifies that the Tear is received from the same node
   that sent the initial reservation, and second, that it is
   functionally equivalent to that node holding-off refreshes for this
   reservation. When a Resv ResvTear or Path Tear PathTear is received at the PEP, all
   affected states installed on the PDP should either be deleted or
   updated by the PEP.

  3.5. PEP Caching COPS Decisions

   Because COPS is a stateful protocol, refreshes for RSVP Path and
   Resv messages need not be constantly sent to the remote PDP. Once a
   decision has been returned for a request, the PEP can cache that
   decision and apply it to future refreshes. The PEP is only
   responsible for updating a request state if there is a change
   detected in the corresponding Resv or Path message.

   If the connection is lost between the PEP and the PDP, the cached
   RSVP state may be retained for the RSVP timeout interval. period. If no
   connection can be reestablished with the PDP or a backup PDP, PDP after
   the timeout period, the RSVP PEP is expected to default back to
   using its LDP. LDP results. Additionally, the LDP is to be used for the
   admission control of any new RSVP messages that may have arrived
   while connectivity was lost. If any
   such messages were admitted by the LDP, the PEP

   Once a connection is expected reestablished to a new (or the original) PDP
   the PDP may issue a SSQ request. In this case, the PEP must reissue
   requests that correspond to the PDP for them once a connection is reestablished and
   a COPS session for current RSVP is opened. state (as if all the
   state has been updated recently). It should also include as LDP the
   current (cached) decision regarding each such state.

  3.6. Using Multiple Context Flags in a single query

   RSVP is a store-and-forward control protocol where messages are
   processed in three distinctive steps (input, output and resource
   allocation). allocation,
   and output). Each step requires a separate policy decision as
   indicated by context flags (see Section 2.1). In many cases, setting
   multiple context flags can serve as a mean for bundling two of or three operations together
   in one request (for instance, validating both an
   incoming message as well as allocating resources for it). may significantly optimize protocol operations.

   The following rules apply when for setting multiple Context flags are set: flags:

   a. Multiple context flags can be set simultaneously when their merge
      doesn’t create ambiguity only in ClientSI interpretation. Two context
      flags become mutually exclusive for a specific REQ or DEC message
      when identical ClientSI objects carry different values for each
      of them.

   b. The DEC message contains a context object that correspond two generic cases which
      are guaranteed not to all
      or a subset cause ambiguity and represent substantial
      portion of expected COPS transactions.

      Unicast FF:

              [Incoming + Allocation + Outgoing]

      Multicast with only one Resv message received on the interface

              [Incoming + Allocation]

   b. Context events are ordered by time since every message processing
      must first be processed as Incoming, then as Resource allocation
      and only then as Outgoing. When multiple context flags set are set,
      all ClientSI objects included in original REQ. A DEC is the request are assumed to be complete (as far
      processed to the latest flag. This rule applies both to request
      (REQ) context as well as reuse of handles) only when all
      flags have been replied to (set decision (DEC) context.

      For example: when combining Incoming + Allocation for an incoming
      Resv message, the Flowspec included in the following DEC message). ClientSI would be the
      one corresponding to the Resource-Allocation context (TC).

   c. The PEP may act based on partial (context subset) Each decision and is
      not required bound to wait for a context object, which determines
      which portion of the others, although request context it may. Consistency
      is an issue for applies to. When
      different decisions apply to different sub-groups of context the
      PDP should send each group of decision objects encapsulated or
      separated by the context flags object with the context flags
      applicable to worry about. these objects set. (See the examples in Section 4).

  3.7. Trusted zones and secure policy tunneling
  Security for RSVP messages is provided by inter-router MD5
  authentication [MD5], assuming a chain-of-trust model.
  A possible deployment scenario calls for PEPs to be deployed at the
  network edge (boundary nodes) while PINs are deployed in the core of
  the network (backbone). In this case, MD5 trust (authentication) must
  be established between boundary (non-neighboring) PEPs, which is
  achieved through internal signing of the Policy Data object. [RSVP-
  EXT].

4. Illustrative Examples, Using COPS for RSVP

  This section details both typical unicast and multicast scenarios.

  4.1. Unicast Flow Example

   This section details the steps in using COPS for controlling a
   Unicast RSVP flow. It details the contents of the COPS messages
   with respect to the following figure.

                                     PEP (router)
                                 +-----------------+
                                 |                 |
                  R1 ------------+if1           if3+------------           if2+------------ S1
                                 |       if2       |
                                 +--------+--------+
                                          |                 |
                                         PDP (server)

                    figure
                                 +-----------------+

                    Figure 1: Unicast Example: a single router PEP view

   The PEP router has three two interfaces (1,2,3). (if1, if2). Sender S1 sends to
   receiver R1.

   A Path message arrives from S1:

       PEP --> PDP   REQ := <Handle A><Context in&out, A> <Context: in & out, Path>
                            <In-Interface if3> if2> <Out-Interface if1>
                            <ClientSI: all objects in Path message>

       PDP --> PEP   DEC := <Handle A>><Context in&out, A> <Context: in & out, Path>
                            <Decision accept> flags: Accept>

   A Resv message arrives from R1:

       PEP --> PDP   REQ := <Handle B><Context in&merge&out, B>
                            <Context: in & allocation & out, Resv>
                            <In-Interface if1> <Out-Interface if3> if2>
                            <ClientSI: all objects in Resv message>
       PDP --> PEP   DEC := <Handle B>
                               <Context in&merge&out,
                            <Context: in, Resv>
                               <Decisions: accept, Priority=7,
                                Replace: POLICY.DATA1>
                            <Decision flags: accept>
                            <Context: allocation, Resv>
                            <Decision flags: accept>
                            <Decision: ClientSI, Priority=7>
                            <Context: out, Resv>
                            <Decision flags: accept>
                            <Decision replace: POLICY-DATA1>

       PEP --> PDP   RPT := <Handle B>
                            <Report type: commit>

   Notice that the Decision was split because of the need to specify
   different decision objects for different context flags.

   Time Passes, the PDP changes its decision:

       PDP --> PEP   DEC := <Handle B>
                               <Context in&merge&out,
                            <Context: allocation, Resv>
                               <Decisions: accept, Priority=3,
                                Replace: POLICY.DATA2>
                            <Decision flags: accept>
                            <Decision: ClientSI, Priority=3>

   Because the priority is too low, the PEP preempts the flow:

       PEP --> PDP   DRQ := <Handle B>
                            <Reason Code: Preempted>

   Time Passes, the sender S1 ceases to send Path messages:

       PEP --> PDP   DRQ := <Handle A>
                            <Reason: Timeout>

  4.2. Shared Multicast Flows

   This section details the steps in using COPS for controlling a
   multicast RSVP flow. It details the contents of the COPS messages
   with respect to the following figure.

                               -----------------
                     r1

                                  PEP (router)
                              +-----------------+
                              |                 |
               H1-------------|i1
               R1-------------+ if1         if3 +--------- S1
                              |      r4                 |              o1 |---------------- S1
                     r2
               R2----+        |     Router                 |
               H2 ------------|i2
                     |        |                 |              o2 |----------------
                     +--------+ if2         if4 +--------- S2
                     | r3        |                 |
                     |         -----------------
                    H3

                figure 1: 2 senders and 3 receivers
               R3----+        +-----------------+
                Figure 1 2: Multicast example: a single PEP view

   Figure 2 shows an RSVP router PEP (router) which has two senders (S1, S2)
   and three receivers (R1, R2, R3) for the same multicast session.
   Interface i2 if2 is connected to a shared media. H1, H2, and H3 are all receivers
   In this example, we assume that send the
   corresponding reservations r1, r2, and r3 for the flows for senders
   S1 & S2.

   First detailed multicast membership is the request message content for a Path sent by
   sender S1, assuming that both receivers have already joined
   in place, no previous RSVP messages were received, and the
   multicast session, but haven't sent a Resv message as yet. Assume
   sender S2 has not yet sent first to
   arrive is a path message. The Path message arrives on interface o1: if3 from sender S1:

       PEP -----> --> PDP   REQ := <handle A><context <Handle A> <Context: in, Path>
                                  <in-interface o1><client info:
                            <In-interface if3>
                            <ClientSI: all objects in Path message> incoming Path>

       PDP -----> --> PEP   DEC := <handle A><context <Handle A> <Context: in, Path>
                            <Decision flags: accept>

   Here the PDP decides to allow the Path message. Next, the Router

   The PEP consults its forwarding table, and finds two outgoing  interfaces,
   i1 and i2,
   interface for the path. path (if1, if2). The exchange below is for
   interface i1, if1, another exchange would likewise be completed for i2 if2
   using the new handle B2.

       PEP -----> --> PDP   REQ := <handle B1><context <Handle B1> <Context: out, Path>
                                  <out-interface i1><client info:
                            <Out-interface if1>
                            <clientSI: all objects in outgoing Path message> Path>

       PDP -----> --> PEP   DEC := <handle B1><Decision forward>
                                  <context <Handle B1>
                            <Context: out, Path>
                            <Decision replacement object:
                                   policy object> flags: accept>
                            <Decision Replacement: POLICY-DATA1>

   Here, the PDP decided to allow the forwarding of the Path message
   via interface i1,
   and determined provided the appropriate policy objects policy-data object for
   the message going out on this interface. interface if1.

   Next, the receiver r2 sends a Resv message of WF style. The Resv message from receiver R2 arrives on interface i2. Here the if2.

       PEP queries the PDP which decides
   to accept this reservation with priority 5 as shown below.

       PEP -----> --> PDP   REQ := <handle C><context in, <Handle C> <Context: in & allocation, Resv>
                                  <in-interface i2><client info:
                            <In-interface if2>
                            <ClientSI: all objects in Resv message> message
                             including RSpec1 >

       PDP -----> --> PEP   DEC := <handle C><Context <Handle C>
                            <Context: in, Resv>
                            <Decision flags: accept>

   This assumes the PEP is not itself capable of merging priority
   information, and, thus, must make another query for the incoming
   interface merge.
                            <Context: allocation, Resv>
                            <Decision flags: accept>
                            <Decision ClientSI: priority=5>

       PEP -----> --> PDP    REQ   RPT := <handle D><context merge, Resv>
                                  <in-interface i2><client info: all
                                  objects in merged Resv message> C> <Commit>
   Here, the PDP -----> PEP    DEC   := <handle D><context merge, Resv>
                                  <Decision Priority: 5>

   After PEP successfully admitted approves the reservation and assigned it sends a report
   message that signals to the PDP that it can start an accounting log
   for this reservation. preemption
   priority of 5. The PEP -----> PDP    RPT   := <handle D>
                                  <commit> responded with a commit report.

   The reservation r2 PEP needs to be sent upstream towards sender S1 out
   interface o1. An outgoing Resv request is made which carries the
   associated handle of forward the Path message for which this Resv is being
   forwarded. message upstream toward S1:

       PEP -----> --> PDP   REQ := <handle E><context out,Resv> <Handle E> <Context: out, Resv>
                            <out-interface o1><client if3>
                            <Client info: all objects in outgoing Resv message> Resv>

       PDP -----> --> PEP   DEC := <handle E><Context <Handle E>
                            <Context: out, Resv>
                            <Decision forward><Decision
                                  replacement object: policy object>

   Next, receiver H3 sends flags: accept>
                            <Decision replacement: POLICY-DATA2>

   Note: The Context object is part of this DEC message even though it
   may look redundant since the REQ specified only one context flag.

   Next, a new WF Resv message r3. from receiver R3 arrives on interface
   if2 with a higher RSpec (Rspec2). Given two reservations arrived on
   if2, it cannot perform a request with multiple context flags, and
   must issue them separately.

   The PEP sends re-issues an
   incoming request for updated handle F and the PDP decides to accept the Resv
   (as before). The C REQ with a new reservation also requires the context object
   <Context: in , Resv>, and receives a DEC for handle C.

       PEP to update the
   merged request (handle D) due to the modified flowspec. The --> PDP now
   gives this request priority 7. If accepted by local admission
   control, a report is again sent.   REQ := <Handle F> <Context: in , Resv>
                            <In-interface if2>
                            <ClientSI: all objects in Resv message
                             including RSpec2 >

       PDP --> PEP   DEC := <Handle F> <Context: in , Resv>
                            <Decision flags: accept>

       PEP -----> --> PDP   REQ := <handle D><context merge, <Handle G> <Context: allocation, Resv>
                                  <in-interface i2><client info:
                            <In-interface if2>
                            <ClientSI: all objects in merged Resv message w/
                                  new merged FLOWSPEC>
                             including RSpec2 >

       PDP -----> --> PEP   DEC := <handle D><Context merge, <Handle G>
                            <Context: allocation, Resv>
                            <Decision priority 7> flags: accept>
                            <Decision ClientSI: priority=5>

       PEP -----> --> PDP   RPT := <handle D>
                                  <commit>

   Now G> <Commit>

   Given the outgoing request for handle E is reissued for change in incoming reservations, the merged (R2
   & R3) PEP needs to forward
   a new outgoing Resv message upstream toward S1. This repeats exactly
   the previous interaction of Handle E, except that the ClientSI
   objects now reflect the merging of two reservations.

   If an ResvErr arrives from S1, the PEP maps it to be sent towards sender S1 due to R3 only (because
   it has a modified
   flowspec. higher flowspec: Rspec2) the following takes place:

       PEP -----> --> PDP   REQ := <handle E><context out,Resv>
                                  <out-interface o1><client info: <Handle H> <Context: in, ResvErr>
                            <In-interface if3>
                            <ClientSI: all objects in incoming ResvErr>

       PDP --> PEP   DEC := <Handle H> <Context: in, ResvErr>
                            <Decision flags: accept>

       PEP --> PDP   REQ := <Handle I> <Context: out, ResvErr>
                            <Out-interface if2>
                            <clientSI: all objects in outgoing Resv message w/
                                  new merged FLOWSPEC> ResvErr>

       PDP -----> --> PEP   DEC := <handle E><Context <Handle I>
                            <Context: out, Resv> ResvErr>
                            <Decision forward><Decision
                                  replacement object: policy object> flags: accept>
                            <Decision Replacement: POLICY-DATA3>

   When S2 joins the session by sending a Path message, incoming and
   outgoing Path requests are issued for the new Path. The two incoming
   Resv requests may then be reissued for handle C and handle E if
   there is a change in their shared sender filter list (e.g. if this
   was a SE filter example) specifying the new sender. A new outgoing
   Resv request would then be issued for the Resv to be sent to s2 out
   interface o2. S2.

5. References

  [RSVP-EXT]  Herzog, S. "RSVP Extensions for Policy Control",
         Internet-Draft, draft-ietf-rap-rsvp-ext-00.txt, Apr. 1998.

   [UserID]  Yadav, S., Pabbati, R., Ford, P., Herzog, S., "User
          Identity Representation for RSVP", Internet-Draft, draft-
          ietf-rap-user-identity-00.txt, March 1998.

  [RAP]  Yavatkar, R., et al., "A Framework for Policy Based Admission
         Control",IETF <draft-ietf-rap-framework-00.txt>, November,
         1997.

  [COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Raja,n R.,
         Sastry, A., "The COPS (Common Open Policy Service) Protocol",
         IETF <draft-ietf-rap-cops-02.txt>, Aug. 1998.

  [RSVP] Braden, R., Zhang, L., Berson, S., Herzog, S., and Jamin, S.,
         "Resource Reservation Protocol (RSVP) Version 1 Functional
         Specification", IETF RFC 2205, Proposed Standard, September
         1997.

6. Author Information and Acknowledgments

   Special thanks to Timothy O'Malley our WG Chair, Raj Yavatkar,
   Russell Fenger, Fred Baker, Laura Cunningham, Roch Guerin, Ping Pan,
   and Dimitrios Pendarakis for their valuable contributions.

       Jim Boyle                        Ron Cohen
       Level 3 Communications           CISCO Systems
       1450 Infinite Drive13            Hasadna St.
       Louisville, CO 80027             Ra'anana 43650 Israel
       303.926.3100                     972.9.7462020
       email: jboyle@l3.net             ronc@cisco.com

       David Durham                     Raju Rajan
       Intel                            IBM T.J. Watson Research Cntr
       2111 NE 25th Avenue              P.O. Box 704
       Hillsboro, OR 97124              Yorktown Heights, NY 10598
       503.264.6232                     914.784.7260
       David_Durham@mail.intel.com      raju@watson.ibm.com

       Shai Herzog                      Arun Sastry
       IPHighway                        Cisco Systems
       2055 Gateway Pl., Suite
       400 Kelby St., Suite 1500         506210 W Tasman Drive
       San Jose, CA 95110
       Fort-Lee, NJ 07024               San Jose, CA 95134
       408.390.3045
       201.585.0800                     408.526.7685
       herzog@iphighway.com             asastry@cisco.com
   Table of Contents

Abstract..............................................................1
1. Introduction.....................................................2
2. RSVP values for COPS objects.....................................2
2.1. Context Object (Context)........................................2
2.2. Client Specific Information (ClientSI)..........................3
2.3. Decision Object (Decision)......................................3
3. Operation of COPS for Policy Control Over RSVP...................4
3.1. RSVP flows......................................................4
3.2. Expected Associations for RSVP Requests.........................4
3.3. RSVP's Capacity Admission Control: Commit and Delete............4
3.4. Policy Control Over Path and Resv Tear..........................5
3.5. PEP Caching COPS Decisions......................................5
3.6. Using Multiple Context Flags in a single query..................5
3.7. Trusted zones and secure policy tunneling.......................6
4. Illustrative Examples, Using COPS for RSVP.......................6
4.1. Unicast Flow Example............................................6
4.2. Shared Multicast Flows..........................................7
5. References......................................................10
6. Author Information and Acknowledgments..........................10