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Internet Engineering Task Force                                J. Manner
Internet-Draft                                                 T. Suihko
Expires: November, 2002                                          M. Kojo
                                                            M. Liljeberg
                                                          K. Raatikainen
                                                            May 14, 2002


                             Localized RSVP
                      <draft-manner-lrsvp-00.txt>

Status of this Memo

   This document is a submission to the NSIS Working Group of the
   Internet Engineering Task Force (IETF). Comments should be submitted
   to the nsis@ietf.org mailing list.

   Distribution of this memo is unlimited.

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026. Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups. Note that other groups may also distribute
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   Internet-Drafts are draft documents valid for a maximum of six months
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   This Internet-Draft will expire in November, 2002.

   Copyright Notice

   Copyright (C) The Internet Society (2000). All Rights Reserved.


Abstract

   Guaranteed QoS for multimedia applications is based on reserved
   resources in each node on the end-to-end path. For stationary nodes
   this may be achieved but not so easily for mobile nodes. Many
   multimedia applications become less useful if the continuity of QoS
   is disturbed due to end-to-end signalling or slow re-reservations of
   resources after each handover. Additionally, if the correspondent
   node does not support QoS, it would be useful to be able to reserve
   at least local resources, especially wireless link resources.  This
   draft proposes small modifications to RSVP, so that initial resource

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   reservations and re-reservations due to host mobility can be done
   locally in an access network.


   Table of Contents


   1 Introduction .................................................    2
   1.1 Related work ...............................................    3
   2 Local QoS Support ............................................    4
   2.1 Upstream transfers .........................................    4
   2.2 Downstream transfers .......................................    5
   2.3 Additional functionality ...................................    5
   3 Fast local repair ............................................    7
   4 Issues with the localized signalling .........................    8
   5 Signalling diagrams ..........................................   10
   6 Security Consideration .......................................   10
   7 Summary and Future Work ......................................   11
   8 References ...................................................   12
   9 Author's Addresses ...........................................   13


1.  Introduction

   Future mobile networks will be based on IP technology. This implies
   that, on the network layer, all traffic, both traditional data and
   streamed data like audio or video, is transmitted as packets without
   knowledge of any higher layer data flows. At the same time different
   multimedia applications are becoming increasingly popular. These
   applications require better than best-effort service from the
   connecting network. They require strict Quality of Service (QoS) with
   guaranteed minimum bandwidth and maximum delay. Other applications,
   such as electronic commerce, network control and managment, and
   telnet-type applications, would also benefit from a differentiated
   treatment.

   The Internet Engineering Task Force (IETF) has proposed two main
   models for providing differentiated treatment of packets in routers.
   The Integrated Services (IntServ) model [1] together with the
   Resource Reservation Protocol (RSVP)  [2] [3] provides per-flow
   guaranteed end-to-end transmission service. The Differentiated
   Services (DiffServ) framework [4] provides non-signaled flow
   differentiation that usually provides but does not guarantee proper
   transmission service.  These architectures, however, have problems,
   for example, RSVP requires support from both communication end points
   and from the intermediate nodes. DiffServ, on the other hand,
   requires support from the sender of a stream and from the network
   nodes. The Internet Architecture Board has outlined additional issues
   related to these two architectures [5].

   Let's consider a scenario, where a fixed network correspondent node
   (CN) would be sending a data stream to a mobile node behind a
   wireless link. If the correspondent node does not support RSVP it
   cannot signal its traffic characteristics to the network and request

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   specific forwarding services. Likewise, if the correspondent node is
   not able to mark its traffic with a DiffServ Code Point (DSCP) to
   trigger service differentiation, the multimedia stream will get only
   best-effort service which may result in poor visual and audio quality
   in the receiving application. Even if the connecting wired network is
   over-provisioned, reserving local resources is especially important
   in wireless access networks, where the bottleneck resource is most
   probably the wireless link. For illustration purposes, we will only
   consider a scenario with a mobile access network that is aware of the
   proposed signaling mechanism and has mobile nodes as its clients.

   In the absence of end-to-end QoS support, a mobile node could still
   want to reserve resources from the access network for both outgoing
   and incoming traffic. We propose a signaling mechanism based on a
   slightly modified RSVP. Access network specific reservations would be
   distinguished from the end-to-end reservations. The mobile node does
   not need to know the access network topology or the nodes that will
   reserve the local resources. The reservation message itself
   identifies the intention and the access network will find the correct
   network node(s) to respond to the reservation. However, the scheme is
   not tied to only mobile networks but can be used in any network that
   needs flexible local resource allocations.

   This would be very beneficial, even if the QoS support is only
   available in the access network. Furthermore, the same solution saves
   us from end-to-end signaling even if all intermediate nodes on the
   transmission path would support standard RSVP. This would allow, for
   example, the mobile node to reserve wireless resources separately
   from end-to-end resources.



1.1.  Related work

   Currently we can identify two ways to signal QoS requirements to an
   access network: DiffServ Code Points (DSCP) and RSVP with IntServ. In
   the DiffServ-based solution the mobile node can mark the upstream
   packets with proper DSCP values, but for the downstream the gateway
   on the edge of the access network must be able to identify and handle
   the prefered streams. This can be accomplished with default values
   for different micro flows in the Service Level Agreement negotiated
   between the client and the access network service provider.

   A second way to make use of DiffServ could be through a Bandwidth
   Broker [6] [7] [8] that dynamically returns the proper code point for
   each flow: when the first packet of a flow arrives at the access
   network edge router, it requests the proper code point from the
   Bandwidth Broker. The router maintains a mapping from micro flow
   identification to the DiffServ code point (soft state) so that future
   packets can be directly identified and labeled. Still, this would
   require a protocol that the mobile node could use to dynamically
   adjust the mapping information stored at the access network edge for
   the incoming traffic.


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   RSVP can provide the signalling mechanism for QoS requirements to the
   access network. For upstream reservations, the mobile node would send
   the PATH message to the access network edge router, which would
   return the RESV message and set up the reservations. The edge router
   would act as an RSVP proxy [9]. However, the reservation in the
   downlink direction is not as straightforward since the downlink
   reservation needs to be initiated by the RSVP proxy. We would need a
   way to trigger the proxy to initiate the RSVP signalling for a
   downlink flow.

   Thus, these mechanisms do not seem to solve the problem entirely. The
   DiffServ mechanisms cannot provide explicit resource reservations.
   The problem with the RSVP proxy approach is that the proxy cannot
   automatically distinguish reservations that would be answered by the
   correspondent node and reservations that would require interception.
   Additionally, the RSVP proxy needs a way to know when to allocate
   resources for incoming flows. Mobile access networks also add to the
   problems, since mobile nodes can frequently change their point of
   attachment in the network and resource allocations need to be re-
   arranged, including changing the serving RSVP proxy.


2.  Local QoS Support

   Our solution to the problem of localized QoS co-ordination is based
   on proxies and the RSVP local repair mechanism [2]. The proxy is
   running on an RSVP node and is called the Localized RSVP Proxy server
   (LRSVP proxy). In addition, we need a way to differentiate
   reservations that are internal to the access network. We suggest
   using one bit of the eight flag bits in the RSVP Session object for
   this purpose. We use the bit 0x8 and call the flag a Local Indication
   (LI).  We also add a new message type called "Path Request" message
   with an initial message type number 8 and a message called "Path
   Request Tear" with an initial message type number 9. The first sketch
   of this solution appeared in [10] and [11], although some
   implementation ideas have changed since.

   When a mobile node wants to reserve resources in the local network,
   it uses the LI flag in RSVP messages to indicate a local reservation.
   The structure of the RSVP messages follow the RSVP standard. The
   LRSVP proxy that receives an RSVP message with the LI bit set will
   notice that the flag was set, does not forward the message further to
   the next hop and responds according to the following description.


2.1.  Upstream transfers

   Setting upstream reservations is straightforward and follows the
   standard RSVP functionality. The mobile node sends the usual Path
   message, but sets the LI flag.  The Session Object defines the
   destination of the flow that will eventually be transmitted from the
   mobile, and the Sender Template provides information about the mobile
   itself.


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   When the LRSVP proxy receives the Path message, it notes due to the
   LI bit that the reservation is meant to stay within the access
   network and responds with a Resv message. It will not forward the
   Path message further to the next hop. If a Resv message arrives at
   the mobile, the resources for the session defined in the Path message
   have been allocated.


2.2.  Downstream transfers

   Before setting a downstream resource reservation, the mobile needs to
   be aware of the data senders. For multimedia communications, a
   session is usually initiated up with application layer protocols like
   SIP or RTSP [12].  From that correspondence, the mobile knows the
   necessary information about the sender. Another, more coarse
   reservation could be set, for example, for browsing different audio
   servers; the mobile node would indicate in the RSVP messages that the
   sender will use UDP. It is thus possible to make resource
   reservations for any sender that wants to communicate with the
   mobile. However, in order to allow for more accurate QoS support,
   more information should be given.

   In order to set up the downstream reservation we need a way to signal
   the LRSVP proxy to initiate the RSVP reservation setup on behalf of
   the sender(s), that is, to send a Path message. To achieve this, the
   mobile node sends the Path Request message with the LI flag set.  The
   Path Request message is identical to a standard Path message apart
   from the message type field. The Session Object must include
   information about the recipient, the mobile in this case, and the
   Sender Template must define expected sender(s).  The Traffic
   specification (TSpec) can either be based on the mobile users wishes
   or a best estimate of the incoming traffic characteristics, or on
   application level session signalling prior to the transfer.

   When the LRSVP proxy receives this message, it detects that the
   message is meant to stay within the access network. The message type
   indicates that the proxy should initiate an RSVP reservation for a
   downstream flow and use the information in the message to fill the
   field in a Path message. The proxy can now change the message type
   from Path Request to Path, keep the LI flag, and send this Path
   message towards the mobile node. Since the Session Object and Sender
   Template were originally set "backwards", the proxy can copy these
   entries directly as-is to the Path message.

   When the mobile node receives the Path message, it responds with a
   Resv message with the LI flag set. This reserves the downstream
   resources within the access network for the senders originally
   identified by the mobile.


2.3.  Additional functionality

   All the other features of RSVP are used with LRSVP in the standard
   way including the local repair mechanism and reservation tear down.

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   Downstream reservations are torn down with the Path Request Tear
   message.  All messages used for local reservations must have the LI
   flag set in order to keep the signaling within the access network.
   Intermediate RSVP routers between the mobile node and the LRSVP proxy
   must not process the Path Request message and they must forward it as
   an ordinary IP packet.

   The proposed scheme also allows RSVP to be used to signal DiffServ
   Code Points in a DiffServ access network using the RSVP DCLASS object
   [13]. The DCLASS object is used to represent and carry DiffServ code
   points within RSVP messages.  The mobile node can use the DCLASS
   object to instruct the LRSVP proxy to mark incoming traffic with
   certain DiffServ code points to trigger different forwarding behavior
   within the DiffServ access network.  The mobile node, however, needs
   to be aware of the different code point values and the related
   services, especially if other than standardized code points are used.
   This information can be part of host auto-configuration, for example.

   In addition, the LRSVP proxy may need information on how to map RSVP
   requests to proper DiffServ classes if it wants to have closer
   control of downstream resource allocations. This can be accomplished
   by using standardized code point values for the DiffServ Assured
   Forwarding service.  Thus, our signalling mechanism can also be used
   to give relative priority to specific flows without explicit resource
   reservations.

   Furthermore, the proposed signalling can be used at both ends of a
   data stream. For example, if two mobile nodes in different access
   networks are communicating with each other, both of them could use
   the mechanism to allocate resources, for example on their own access
   networks, independently of each other. This could happen, if the two
   access networks had a different view of QoS, one uses only IntServ
   and RSVP, while the other also uses DiffServ. In such a scenario,
   however, it may be more practical to use RSVP end-to-end, even if the
   core network connecting the two access networks does not support
   RSVP.

   If the reserved bits in the RSVP Session Object are deemed too
   valuable to be used for this kind of signaling, the RSVP CAP-object
   [14] could be used to carry the bit that identifies the signaling as
   local. The CAP object can be used in the RSVP Path message to convey
   end host/upstream node capabilities to the downstream network/nodes.
   This would, however, add another eight bytes of headers in order to
   carry a single bit of information. In addition, the processing of the
   messages is more time consuming due to the extra header.  In any
   case, a new Path Request message is still needed, because it would
   complicate the message processing in routers if the "request to send
   a Path"  was indicated as another bit in the CAP object. With the new
   message type intermediate routers on the uplink can forward the RSVP
   packet to the LRSVP proxy faster, since the router does not need to
   examine the whole packet and the CAP object in order to find the same
   information, just the message type.



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3.  Fast local repair

   The RSVP standard [2] defines that Path messages can perform a local
   repair of reservation paths. When the route between the communicating
   end hosts changes, a Path message will set the state of the
   reservation on the new route and a subsequent Resv message will make
   the resource reservation. Therefore, by sending a Resv message a host
   cannot alone update the reservation, and thus perform a local repair,
   before a Path message has passed. It is also said in the RSVP
   specification that in order to provide fast adaptation to routing
   changes without the overhead of short refresh periods, the local
   routing protocol module can notify the RSVP process of route changes
   for particular destinations. The RSVP process should use this
   information to trigger a quick refresh of state for these
   destinations, using the new route (Chapter 3.6, RFC2205 [2]).
   However, not all local mobility protocols, or even Mobile IP, affect
   routing directly in routers, and thus mobility may not be noticed at
   RSVP routers.

   When the mobile has moved, it can send a Path message for each
   upstream resource reservation and initiate the local repair
   mechanism. But for the downstream, the mobile will need to wait until
   it receives a Path message, refreshing the reservation states on the
   new route. Only after receiving the Path message, the mobile can send
   a Resv message to re-reserve the downstream resources. The Path
   Request message could potentially be used in mobile networks to
   initiate a faster local repair on behalf of a mobile node that
   changed access points during an ongoing RSVP session.

   When the mobile node changes its access point in the network, it
   should send the Path Request message immediately after the handover.
   The Path Request message is forwarded through the intermediate RSVP
   routers until it arrives at the cross-over RSVP router that has the
   reservation for the mobile node stored on a different interface. The
   message would then instruct the cross-over router to initiate a local
   repair by sending the needed Path message.

   The cross-over router may be located between the LRSVP proxy and the
   mobile node and will therefore respond to the message. Otherwise, the
   Path Request message will arrive at an LRSVP proxy, which will
   initiate a reservation refresh for the mobile.  Thus, the closest
   node to the mobile, the LRSVP proxy or cross-over router, will
   respond to the routing change.

   In some access networks, the access network gateways could also act
   as LRSVP proxies. If the movement of the mobile node results in
   packets to flow through a new gateway (and new proxy), the Path
   Request message would re-reserve the local resources for the new
   path.


   However, the faster local repair scheme has the requirement that the
   RSVP daemon running on the mobile needs to get an indication when a
   handover has occurred. The change of access points is best noticed by

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   the link layer, through the actual wireless device. When the link
   layer address of the access point changes, this event could trigger a
   signal to the higher layers, including the RSVP-daemon that a
   handover has happened. The way the higher layers then take this
   signaling into account is not a concern of the link layer.

   Initiation of the local repair must be done every time the access
   point changes, regardless of whether the access router changes or
   remains the same after the handover. If the access router remains the
   same, the access router itself is the crossover router. The Path
   Request message sent will be intercepted by this access router, which
   will reply with the Path message and therefore initialize the
   resource sharing through its new interface. (Note, that we make the
   assumption, that each access point has its own dedicated network
   interface on the access router.)  If the access router changes, the
   local repair mechanism will eventually arrive at either the crossover
   router or at the access network gateway.

   If the whole access network changes as a result of a handover, the
   situation becomes more complex, and may require a full authentication
   and admission control procedure to be initiated. From the QoS point
   of view, the situation does not differ from a situation, where both
   the access router and the network gateway changed.

   The LI flag must be set in all RSVP refresh messages if the
   reservation is set for the local access network.  This will prevent
   refresh message, like the Path Request message, to be routed out of
   the access network.


4.  Issues with the localized signalling

   An important question remains with the localized signalling
   mechanism:  what destination address should the mobile use, when
   initiating a downstream reservation setup? This has implications on
   the network path, on which the reservation will be set up.

   The Session object and the Sender Template define the parties
   involved in the reservation. Thus, the destination IP address is not
   needed in the reservation set up but has an effect on the routing of
   the packets. The issue concerns the situations, where there are
   several ingress routes to the access network. In such a scenario,
   LRSVP proxies might be situated further away from the access routers,
   closer to the edge of the access network, for example.

   There are two fundamentally different options for the IP destination
   address.  The first option is that the mobile node can use the IP
   address of the host that it intends to communicate with. This has the
   benefit that a Path message will be routed according to the usual IP
   routing mechanisms. Thus, the Path message will be routed to the
   proxy that will eventually also receive the upstream data flow.

   However, if the mobile wants to set up a reservation for the
   downlink, on behalf of the correspondent node, there is a potential

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   problem. If the access network has several ingress routes, and hence,
   most probably, several LRSVP proxies, the data flow may eventually
   arrive through a path different from the path that had the
   reservation in place. This can happen due to the basic property of
   asymmetricy in IP routing.

   The mobile node might set up a reservation on behalf of the
   correspondent node through a path using LRSVP proxy A but the data
   will actually arrive through a path using proxy B. A same problem
   arises if the mobile node wants to reserve resources without an exact
   sender IP address. The mobile might want resources for audio streams
   initiated while browsing the Internet without specifying all possible
   web servers that it may be using.

   A solution to this problem is, that the mobile directs the localized
   RSVP messages to all LRSVP proxies. This can be achieved using a
   multicast address of all the LRSVP proxies. As a result, each LRSVP
   in the access network would receive the RSVP packets, a Path or a
   Path Request, and respond to the mobile. Since resource reservations
   are set up on several paths but only some are actually needed in the
   end, we need a way to remove unnecessary reservations. This can be
   accomplished through the RSVP soft state mechanism: Unused
   reservations are revoked using a timeout mechanism, no refresh
   messages are sent for those paths. This is possible if the
   reservation refresh is coupled with actual data transfered through
   that reservation. Reservations are only kept alive if data is
   actually sent through a particular path.

   The multicast functionality can be further modified, so that a proxy
   will not even send the Path message if it does not receive packets
   from the specified sender within a timeout. Thus, no downstream
   reservations are initialized for paths that are not carrying packets
   belonging to the request.

   It seems that there is no best solution to the destination problem.
   Both solutions have their benefits and drawbacks. The first solution
   has problems with asymmetric routing and undefined IP destinations
   (the data senders). The second solution can create a lot more
   signalling messages and a lot of unnecessary resource reservations.
   The second solution also requires that the access network supports
   multicast. Furthermore, one of the original design criteria for the
   localized signalling was to make the design to transparently co-
   operate with standard end-to-end RSVP. Now it seems that the
   localized signalling needs a separate mechanism although the changes
   required in standard RSVP routers and mobile nodes RSVP daemons are
   small.

   Regardless of the exact solution, an important functionality is that
   the implementation should be transparent to the mobile node. The
   mobile node would always operate in the same way when it wants to
   setup QoS for downstream flows. The access router can help in
   supporting the localized RSVP scheme.

   Thus, when the mobile node wants to reserve resources for the

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   downstream, it will should as IP destination address either an LRSVP
   proxy address provided as part of host autoconfiguration or the
   default router address. The LRSVP proxy address can be a unicast or
   multicast address, and it is up to the access network to take care of
   removing unneeded reservations. If the mobile node does not have the
   LRSVP proxy address configured, it will use the default router
   address, which all IP hosts know. The access router can then perform
   routing lookup and address translation and forward the Path Request
   message to the correct proxy. Alternatively, it can just forward the
   message as any IP packet. Thus, the mobile node will always have an
   address to use as the recipient of the Path Request and the access
   network nodes will take care of proxy discovery.

   Similarly, in an unlikely but still possible case that a mobile would
   want to set QoS parameters for several upstream paths, it can use the
   configured LRSVP proxy address or the default router address in the
   Path message. The access router can then forward the Path to the
   correct number of LRSVP proxies, and these can then respond with the
   Resv message. However, how the unneeded reservations are rewoked is
   unknown. Thus, it seems, that an access network should consider
   allowing multiple local upstream reservations.

   Furthermore, if the host is mobile and is using Mobile IP to acquire
   the address, it must use the Care-of-Address as the address in the
   Session Object address field. If the CoA changes after a handover,
   the mobile node must create a new Path message, and hence Path state,
   to set up new upstream reservations. A new Path state is needed, if
   the filters in the old Path state used the mobile node's CoA as
   partial information.

   For local downstream reservations, the mobile node can send a new
   Path Request with the new CoA in the Session Object, and
   simultaneously send a Path Request Tear for the old reservation. The
   LRSVP proxy will thus create a new downstream reservation and must
   remove the old reservation state. For end-to-end reservations, an
   IPv6 correspondent node should use the MIPv6 Binding Update message
   as an indication to re-establish the Path state using a new
   destination address in the Session Object.


5.  Signalling diagrams

   <TBD>


6.  Security Consideration

   The localized signalling does not raise new securiy issues. The
   security considerations with standard RSVP apply.






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7.  Summary and Future Work

   In summary, the Localized RSVP requires the following changes in the
   standard RSVP protocol:

   a) A new message type and number, named Path Request, number 8.

   b) A new message type and number, named Path Request Tear, number 9.

   c) One bit from the Session Object for the use as the Local
   Indication (LI), bit 0x8

   d) An RSVP router must keep the LI bit set in all messages belonging
   to that session, if it encounters packets with the bit set.

   e) An RSVP router that is not also a proxy, must forward an RSVP
   packet with a message type "Path Request" without storing state.

   f) An AN RSVP router should be able to use the Path Request as an
   indication of the need for a local repair. This can enable faster
   reservation set up following a handover. This affect point e),
   because the router that receives a Path Request must first check if
   it has the Path state stored on another network interface. If one is
   present, the Path Request message must not be forwarded to the next
   hop and instead the router must send a Path message towards the
   mobile node.

   g) Refresh of the soft state for downstream reservations should be
   tied to actual data flow. Alternatively, the soft state can be kept
   up by periodic Path Request messages sent by the mobile node.

   To summarize, these changes are small and would make RSVP more
   appealing as a signalling protocol for IP access networks.

   We still have to study the interactions between local and end-to-end
   reservations, for example, whether an existing local reservation
   could be upgraded into a full end-to-end reservation. Similary, we
   need to study whether an initial end-to-end reservation attempt could
   be changed flexibly into a local reservation in case the end-to-end
   reervation was not succesfull, for example, within the core network
   connecting the two access networks.

   Furthermore, we need to study, whether there could be need for nested
   proxies, so more than one proxy per path. In addition, a possibility
   to manage the communication between the end host and the LRSVP
   proxies would be to use UDP and a wellknown port number. Thus,
   "local" messages would be sent encapsulated in UDP packets.








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8.  References

   [1] R. Braden, D. Clark, S. Shenker, "Integrated Services in the
   Internet Architecture: an Overview". Internet Engineering Task Force,
   Request for Comments 1633, June 1994.

   [2] R. Braden, L. Zhang, S. Berson, S. Herzog, S. Jamin. "Resource
   ReSerVation Protocol (RSVP), Version 1 Functional Specification.
   Internet Engineering Task Force, Request for Comments 2205,
   September, 1997.

   [3] J. Wroclawski, "The Use of RSVP with IETF Integrated Services.
   Internet Engineering Task Force, Request for Comments 2210,
   September, 1997.

   [4] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, W. Weiss, "An
   Architecture for Differentiated Services", Internet Engineering Task
   Force, Request for Comments 2475, December, 1998.

   [5] G. Huston, "Next Steps for the IP QoS Architecture". Internet
   Engineering Task Force, Request for Comments 2990, November 2000.

   [6] K. Nichols, V. Jacobson, L. Zhang, "A Two-bit Differentiated
   Services Architecture for the Internet". Internet Engineering Task
   Force, Request for Comments 2638, July 1999.

   [7] R. Yavatkar, D. Hoffman, Y. Bernet, F. Baker, M. Speer,"SBM
   (Subnet Bandwidth Manager): A Protocol for RSVP-based Admission
   Control over IEEE 802-style networks". Internet Engineering Task
   Force, Request for Comments 2814, May 2000.

   [8] Phil Chimento and Ben Teitelbaum, "QBone Bandwidth Broker
   Architecture". The Internet2 initiative, June 2000.
   (http://qbone.internet2.edu/bb/bboutline2.html).

   [9] S. Gai, D. G. Dutt, N. Elfassy, Y. Bernet, "RSVP Proxy". Internet
   Draft (work in progress), July 2001 (draft-ietf-rsvp-proxy-02.txt).

   [10] Jukka Manner and Kimmo Raatikainen, "Extended Quality-of-Service
   for Mobile Networks". Proceedings of the 9th International Workshop
   on Quality of Service (IWQoS), June 2001, pp. 275-280. Published in
   the series Springer Lecture Notes in Computer Science (LNCS) 2092.

   [11] IST-BRAIN Project, "Deliverable D2.2: BRAIN architecture
   specifications and models, BRAIN functionality and protocol
   specification".  March 2001, (available at: http://www.ist-
   brain.org).

   [12] H. Schulzrinne, A. Rao, R. Lanphier, "Real Time Streaming
   Protocol (RTSP)". Internet Engineering Task Force, Request for
   Comments 2326, April 1998.

   [13] Y. Bernet,"Format of the RSVP DCLASS Object". Internet
   Engineering Task Force, Request for Comments 2996, November 2000.

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   [14] Hamid Sued, "Capability Negotiation: The RSVP CAP Object".
   Internet Draft (work in progress), February 2001 (draft-ietf-issll-
   rsvp-cap-02.txt).



9.  Author's Addresses

   Questions about this document may be directed to:

   Jukka Manner
   Department of Computer Science
   University of Helsinki
   P.O. Box 26 (Teollisuuskatu 23)
   FIN-00014 HELSINKI
   Finland

   Voice:  +358-9-191-44210
   Fax:    +358-9-191-44441
   E-Mail: jmanner@cs.helsinki.fi

   Markku Kojo
   Department of Computer Science
   University of Helsinki
   P.O. Box 26 (Teollisuuskatu 23)
   FIN-00014 HELSINKI
   Finland

   Voice:  +358-9-191-44179
   Fax:    +358-9-191-44441
   E-Mail: kojo@cs.helsinki.fi


   Kimmo Raatikainen
   Department of Computer Science
   University of Helsinki
   P.O. Box 26 (Teollisuuskatu 23)
   FIN-00014 HELSINKI
   Finland

   Voice:  +358-50-483-6275
   Fax:    +358-9-191-44441
   E-Mail: kraatika@cs.helsinki.fi

   Tapio Suihko
   VTT Information Technology
   P.O. Box 1203
   FIN-02044 VTT
   Finland

   Voice:  +358-9-456-6078
   Fax:    +358-9-456-7028
   E-Mail: tapio.suihko@vtt.fi


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   Mika Liljeberg
   Nokia Research Center
   P.O. Box 407
   FIN-00045 Nokia Group
   Finland

   Voice: +358-50-4836791
   Fax: +358-
   E-Mail: Mika.Liljeberg@nokia.com

   Acknowledgement

   This work has been partially performed in the framework of the IST project
   IST-2000-28584 MIND, which is partly funded by the European Union.
   The authors would like to acknowledge the help of their colleagues
   in preparing this document, in particular Eleanor Hepworth and
   Alberto Lopez.


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