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Versions: 00 draft-ietf-bmwg-benchres-term

INTERNET-DRAFT  <draft-feher-bmwg-benchres-term-00.txt>   November 2000

Network Working Group                                  Gabor Feher, BUTE
INTERNET-DRAFT                                     Istvan Cselenyi, TRAB
Expiration Date: May 2001                               Peter Vary, BUTE
                                                       Andras Korn, BUTE

                                                           November 2000

  Benchmarking Terminology for Routers Supporting Resource Reservation
                <draft-feher-bmwg-benchres-term-00.txt>

1. Status of this Memo

   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 working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft shadow directories can be accessed at
   http://www.ietf.org/shadow.html

   This memo provides information for the Internet community. This memo
   does not specify an Internet standard of any kind. Distribution of
   this memo is unlimited.

2. Table of contents

   1. Status of this Memo.............................................1
   2. Table of contents...............................................1
   3. Abstract........................................................2
   4. Introduction....................................................2
   5. Existing definitions............................................3
   6. Definition of Terms.............................................3
      6.1 Resource Reservation Protocol Basics........................3
         6.1.1 Resource Reservation Session...........................3
         6.1.2 Multicast Resource Reservation Session.................3
         6.1.3 Reservation Capable Router.............................4
         6.1.4 Signaling End-point....................................5
         6.1.5 Reservation Initiator..................................5
         6.1.6 Signaling Path.........................................6
      6.2 Traffic Types...............................................7
         6.2.1 Premium Traffic........................................7

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         6.2.2 Best-Effort Traffic....................................8
      6.3 Router Load Types...........................................8
         6.3.1 Session Load...........................................8
         6.3.2 Signaling Load.........................................9
         6.3.3 Signaling Burst........................................9
      6.4 Performance Metrics........................................10
         6.4.1 Signaling Message Handling Time.......................10
         6.4.2 Premium Traffic Delay.................................11
         6.4.3 Best-effort Traffic Delay.............................11
         6.4.4 Signaling Message Loss................................12
         6.4.5 Scalability Limit.....................................12
   7. Acknowledgement................................................13
   8. References.....................................................13
   9. Authors' Addresses:............................................14

3. Abstract

   The purpose of this document is to define terminology specific to the
   performance benchmarking of the resource reservation signaling of IP
   routers. These terms are used in additional documents that define
   benchmarking methodologies for routers supporting resource
   reservation and define reporting formats for the benchmarking
   measurements.

4. Introduction

   The IntServ over DiffServ framework [3] outlines a heterogeneous
   Quality of Service (QoS) architecture for multi domain Internet
   services. Signaling based resource reservation (e.g. via RSVP [5]) is
   an integral part of that model. While this significantly lightens the
   load on most of the core routers, the performance of border routers
   that handle the QoS signaling is still crucial. Therefore network
   operators, who are planning to deploy this model, shall scrutinize
   the scalability limitations in reservation capable routers and the
   impact of signaling on the forwarding performance of the routers.

   An objective way for quantifying the scalability constraints of QoS
   signaling is to perform measurements on routers that are capable of
   resource reservation. This document defines a specific set of tests
   that vendors or network operators can use to measure and report the
   signaling performance characteristics of router devices that support
   resource reservation protocols. The results of these tests will
   provide comparable data for different products supporting the
   decision process before purchase. Moreover, these measurements
   provide input characteristics for the dimensioning of a network in
   which resources are provisioned dynamically by signaling. Finally,
   these test are applicable for characterizing the impact of control
   plane signaling on the forwarding performance of routers.

   This benchmarking terminology document is based on the knowledge
   gained by examination of (and experimentation with) several very
   different resource reservation protocols: RSVP [5], Boomerang [6],
   YESSIR [7], ST2+ [8], SDP [9], Ticket [10] and Load Control [11].


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   Nevertheless, this document aspires to compose terms that are valid
   in general and not restricted to these protocols.

5. Existing definitions

   RFC 1242 [1] "Benchmarking Terminology for Network Interconnect
   Devices" and RFC 2285 [2] "Benchmarking Terminology for LAN Switching
   Devices" contains discussions and definitions for a number of terms
   relevant to the benchmarking of signaling performance of reservation
   capable routers and should be consulted before attempting to make use
   of this document.

   For the sake of clarity and continuity this document adopts the
   template for definitions set out in Section 2 of RFC 1242.
   Definitions are indexed and grouped together in sections for ease of
   reference.

6. Definition of Terms

6.1 Resource Reservation Protocol Basics

   This group of definitions applies to various signaling based resource
   reservation protocols implemented on IP router devices.

6.1.1 Resource Reservation Session

   Definition:
      A resource reservation session (or shortly reservation) expresses
      that routers along the data path between two hosts apply special
      QoS treatment to a certain traffic flow.

   Discussion:
      The QoS treatment is specified by giving the amount of networking
      resources that are dedicated to the traffic flow during the length
      of the reservation session. Depending on the protocol, there are
      different approaches to define the network resource requirement of
      a traffic flow. It can be described by high-level parameters, like
      the required bandwidth, or the maximum traffic delay; or it can be
      low-level information, like the parameters of a leaky-bucket model
      of the traffic flow [12].

      Each resource reservation session has a unique flow descriptor
      that identifies the associated traffic flow to the router. In
      order to obtain unique flow descriptors, typically traffic flow
      parameters, such as the protocol number and the IP address and
      port of the source and the destination are used to generate them.

   See Also:
      Signaling Path

6.1.2 Multicast Resource Reservation Session

   Definition:


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      A multicast resource reservation session (or, in short, multicast
      reservation) denotes that certain QoS treatment is applied to the
      packets of every traffic flow related to a multicast group.

   Discussion:
      Usually, there are several traffic sources and destinations in a
      multicast group. In order to be able to guarantee the QoS
      parameters for each packet of the multicast flow, every router
      that forwards the multicast traffic must dedicate resources to the
      flow.

      Generally, there are two types of multicast resource reservation
      protocol: many-to-many multicast and one-to-many multicast
      protocols. Those of the first type allow reservations for traffic
      flows that originate from several traffic sources, while those of
      the second type allow only one traffic source in the whole group.
      In the case the many-to-many multicast protocols, the amount of
      resources dedicated to the reservation session does not have to be
      the same for every involved router. Depending on the capabilities
      of the resource reservation protocol, the traffic destinations in
      the multicast group may request different QoS parameters. In
      addition to the different QoS requirements for the destinations,
      the protocols may have more than one reservation models that
      express the resource requirement distribution among the involved
      routers. (e.g. RSVP SE/WF/FF [5])

   Issues:
      Naturally, many-to-many multicast protocols are bound to be more
      complex than one-to-many or non-multicast protocols. In the many-
      to-many case, each router has to calculate the resource
      requirements of the multicast reservation session based on the
      reservation model, the distribution of the traffic sources and
      destinations on its network interfaces. Either the router has to
      know all the resource requirements of the destinations at the time
      the reservation is made or it has to adjust the resource
      reservation of the multicast reservation session according to
      newly appearing traffic destination requirements. Both methods
      cause delays in the multicast reservation session setup.

   Also:
      Signaling Path

6.1.3 Reservation Capable Router

   Definition:
      By definition, a router is reservation capable if it understands a
      resource reservation protocol that signals the set-up or tear-down
      of resource reservation sessions or changes in an existing
      reservation session.

   Discussion:
      Reservation capable routers always maintain states for each
      reserved flow expressing the current condition of the reservation.


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      Based on the way these states are handled, resource reservation
      protocols are divided into two categories: soft-state protocols
      and hard-state protocols.

      In the case of hard-state protocols, the resource reservation
      session established by a set-up signaling primitive is permanent
      and is cancelled only when the corresponding tear-down signaling
      primitive arrives to the router. In the case of the soft-state
      protocols there are no permanent resource reservations, rather the
      resource reservation state must be regularly refreshed by
      appropriate signaling primitives. If no refresh signaling
      primitives arrives, this is assumed to indicate that the resource
      reservation session is not maintained any longer; and therefore,
      the router tears it down without waiting for any explicit request.
      For this reason, soft-state protocols exhibit more robust behavior
      than hard-state protocols, since failures in the participants of a
      reservation session does not cause resource stuck in the routers.

   Issues:
      Although soft-state protocols are more robust than hard-state
      protocols, they require that reservation sessions be maintained by
      regularly sending appropriate signals. These refresh signaling
      messages may cause a serious increase in router load. To decrease
      this kind of load, the resource reservation protocol may support
      various mechanisms to aggregate the refresh signaling messages.

6.1.4 Signaling End-point

   Definition:
      A signaling end-point is a network node capable of initiating and
      terminating resource reservation sessions.

   Discussion:
      Typically, signaling end-points have a separate protocol stack
      that is capable of generating and understanding the signaling
      messages. However, in some special cases, the resource reservation
      initiation is carried out without the notice of the network node.
      For example, the Boomerang resource reservation protocol
      encapsulates the reservation requests in an ICMP Echo message.
      This message is bounced back from the destination network node and
      as a result the node becomes a signaling end-point without
      understanding the reservation protocol.

      Reservation gateways are protocol translators that translate the
      signaling messages of one resource reservation protocol into
      messages of another resource reservation protocol. Thus the
      reservation gateway represents two signaling end-points in one, as
      it is both a signaling terminator and a signaling initiator.

6.1.5 Reservation Initiator

   Definition:



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      The reservation initiator is the signaling end-point that
      initiates the resource reservation session setup.

   Discussion:
      Resource reservation protocols can be classified depending on the
      relationship between the reservation initiators and their role in
      the traffic flow.

      In the case of receiver-oriented protocols, the traffic
      destinations, which are the receivers of the data traffic,
      initiate the reservation session setup, unlike the sender-oriented
      protocols where this is done by traffic sources. There also are
      protocols where both the traffic source and destination can act as
      the reservation initiator.

      The importance of the reservation initiator orientation is only
      dominant in case of multicast reservation sessions. Generally, in
      multicast groups the number of traffic destinations changes more
      frequently than the number of traffic sources. The receiver-
      oriented protocols do not require the traffic sources to change
      their state and generate signaling messages when a new traffic
      destination joins or an existing one leaves the group, it is
      enough that the traffic destination node sends its reservation or
      tear-down request.

   See Also:
      Signaling end-point
      Signaling path

6.1.6 Signaling Path

   Definition:
      A signaling path is a sequence of network nodes and links along
      which signaling messages travel from one signaling end-point to
      the other.

   Discussion:
      In the case of sender-oriented protocols, the data traffic and the
      signaling messages are addressed to the IP address of the
      destination and therefore routed on the same path. Thus the
      signaling messages are delivered to every router that handles the
      traffic flow to which the reservation session refers. No more and
      no fewer routers are affected. However, in the case of receiver-
      oriented protocols, the reservation request and the data traffic
      are forwarded in opposite directions. And since Internet routing
      is asymmetric, it is not mandatory that they go through the same
      routers. To assure that the signaling messages reach every router
      that handles the traffic flow from the source to the destination,
      the traffic source issues a special message addressed to the
      destination marking the path for the reservation. This message is
      called PATH message in the RSVP protocol. Each router that
      receives a PATH message remembers the address of the node where
      the message came from, and when a signaling message arrives


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      carrying reservation information it is forwarded to the stored
      address, which is the address of the previous node. Thus the PATH
      message marks out a path along which the reservation message
      travels backward.

      In the case of a multicast reservation session, the situation is
      slightly more complicated. The signaling path is rather a
      signaling mesh where the signaling messages travel from the
      sources to the destinations.

   Issues:
      It is not unusual for routers to change their routing from time to
      time. The reason for the change can be a failure of a neighboring
      router; the router may also choose an alternative route because of
      changed traffic conditions. When the routes change, the data
      traffic will be forwarded along a different path than the
      signaling messages used in establishing the resource dedications
      for the reservation session. In order to properly handle this
      situation, hard-state protocols have to be extremely sophisticated
      in order to detect the route change and to re-reserve the
      resources on the new path. However, soft-state protocols do not
      have to worry about this situation, since the refresh messages can
      be used to set up the reservation on the new path and the
      dedicated resources will eventually disappear from routers of the
      obsoleted path.

      Nowadays, routers capable of load balancing are emerging. This
      means that when there is more than one route to the destination,
      the router can share the packets of the traffic flow among the
      alternative routes. In this case the unaware resource reservation
      protocols are helpless, since the mechanism allows making a
      reservation setup along one of the paths only. Additionally, the
      refresh messages of a soft-state protocol might be shared among
      the paths, making it impossible to refresh the existing
      reservation.

6.2 Traffic Types

   This group of definitions defines traffic types forwarded by resource
   reservation capable routers.

6.2.1 Premium Traffic

   Definition:
      Premium traffic is a traffic type that the router distinguishes
      from best-effort traffic (to be defined later) and forwards its
      packets according to a QoS agreement.

   Discussion:
      Traffic that corresponds to a resource reservation session in the
      router is premium traffic. The QoS treatment is defined in the
      associated flow descriptor that is established by the signaling
      messages during the reservation session setup.


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      The router may distinguish several types of premium traffic (e.g.
      delay sensitive traffic, loss sensitive traffic, etc.). Different
      types of premium traffic may receive different QoS treatment.

   Issues:
      The router has to identify every packet whether it belongs to a
      resource reservation session or not. This is usually not
      complicated, as usually packets that are part of a premium traffic
      flow are often marked in a way that is detected easily (e.g. IP
      TOS field). However, if a packet claims that it has an associated
      resource reservation session in the router, the router has to find
      the flow descriptor, which might be time consuming in routers with
      vast amounts of resource reservation sessions.

6.2.2 Best-Effort Traffic

   Definition:
      Best-effort traffic is a traffic type that has no reservation
      entry in the router.

   Discussion:
      Traffic flows that do not require QoS guarantees along their path
      are considered to be best-effort traffic. "Best–effort" means that
      the router makes its best effort to forward every data packet, but
      does not guarantee anything. This is the most common type of
      traffic on today’s Internet.

6.3 Router Load Types

   This group of definitions describes different load component types
   that are independent of each other and impact only a specific part of
   the resource reservation capable router's control plane. A
   combination of such independent load types is used to generate
   arbitrary load distribution on the router, forming the input function
   during the benchmarking

6.3.1 Session Load

   Definition:
      Session load is the load that manifests itself as the excess
      processing power required to keep track of many reservation
      session.

   Discussion:
      All signaling based resource reservation protocol implementation
      employ a packet classifier algorithm that distinguishes the flows
      having reservations in the router from the others that do not.
      Therefore each implementation maintains a list of flow descriptors
      that is instrumental in keeping track of the resource reservation
      sessions. Obviously, the more reservation sessions are set up on
      the router, the more complex traffic classification becomes, and



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      the more time it takes for the classification algorithm to
      identify a flow.

      Moreover, in most protocols, not only the traffic flows, but also
      signaling messages that manipulate resource reservations on the
      router have to identify themselves first, before taking any other
      actions. This kind of classification gives extra work for the
      router.

   Measurement unit:
      The session load is represented by the number of reservation
      sessions in the router.

6.3.2 Signaling Load

   Definition:
      Signaling load is the load that manifests itself as the time
      required to process the incoming signaling messages.

   Discussion:
      The processing of signaling messages requires processing power
      that raises load on the control plane of the router. In the case
      of routers where the control plane and the data plane are not
      totally independent (for example, certain parts of them are served
      by the same processor) the signaling load can have an impact on
      the router's packet forwarding performance as well.

      Most of the resource reservation protocols have several protocol
      primitives realized by different signaling message types. Each of
      these message types may require a different amount of processing
      power from the router.

   Measurement unit:
      The signaling load is characterized by the signaling intensity,
      which expresses how many signaling messages arrive to the router
      within a time unit. The typical unit of the signaling intensity is
      [1/s], which is the number of signaling messages that arrive
      within one second.

6.3.3 Signaling Burst

   Definition:
      The signaling burst denotes a certain number of signaling messages
      that arrive to the input port(s) of the router without
      interruption, causing persistent load on the signaling message
      handler.

   Discussion:
      Back-to-back signaling messages on one port of the router form a
      typical signaling burst. However, other cases are imaginable, for
      example when signaling messages arrive on different ports
      simultaneously or with an overlap in time (i.e. when the tail of



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      one signaling message is behind the head of another one arriving
      on another port).

   Measurement unit:
      The signaling burst is characterized by its length, which is the
      number of messages that have arrived during the burst.

6.4 Performance Metrics

   This group of definitions is a collection of the measurable effects
   of the impact a resource reservation protocol has on the router
   device it is running on.

6.4.1 Signaling Message Handling Time

   Definition:
      The signaling message handling time (or, in short, signal handling
      time) is the time that a signaling message spends inside the
      router before it is forwarded to the next node on the path.

   Discussion:
      Usually, signaling messages are issued by a signaling end-point
      and forwarded along the signaling path by the routers. However, in
      addition to the usual message forwarding, the router also
      interprets the messages and acts on them. Thus the message
      handling time is longer than forwarding time of data packets of
      the same size. Moreover, there are signaling message primitives
      that are altered during the processing and there may also be
      messages that are drained by the router or ones that are generated
      by the router. Thus, the signal message handling time is the time
      difference between the time when a signaling message is received
      and the time the corresponding processed signaling message is
      transmitted. If a message is not forwarded on the router, the
      signal handling time is immeasurable; therefore it is not defined
      for such messages.

      In the case of signaling messages that carry information
      pertaining to multicast flows, the router might issue multiple
      signaling messages after processing. In this case, by definition,
      the signal handling time is the time interval elapsed between the
      arrival of the incoming signaling message and the departure of the
      last related signaling message.

      Signal handling time is an important characteristic as it directly
      affects the setup time of a session. It is also an indication of
      the signal processing capacity of the router as it is correlated
      to the maximum number of signaling messages that can be processed
      within a time unit.

      This metric depends on the load on the router, as other tasks may
      limit the processing power available to signaling message
      handling. In addition to the router load, the signal handling time
      may also be dependent on the type of the signaling message. For


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      example, it usually takes a shorter time to tear down a resource
      reservation session within a router node than to set it up.

   Issues:
      In the case of soft-state protocols, the refresh messages are
      usually generated automatically by the protocol stack and
      propagated along the signaling path based on internal timers
      without user interaction. Moreover, each network node along the
      signaling path might have an individual agreement on the refresh
      time interval with its neighboring nodes. Thus, the incoming
      refresh message is not forwarded on; instead, a new message is
      generated when the internal timer expires. Other soft-state
      protocols do not stop the refresh messages, rather let them
      refresh the whole signaling path. In the former case it is
      impossible to measure the signaling message handling time of a
      refresh message.

   Measurement unit:
      The typical unit of the signaling message handling time is
      microseconds.

6.4.2 Premium Traffic Delay

   Definition:
      Premium traffic delay is the forwarding time of a packet that
      belongs to a premium traffic flow passing through a resource
      reservation capable router.

   Discussion:
      Premium traffic packets must be classified first in order to find
      the resources dedicated to the flow. The time of the
      classification is added to the usual forwarding time that a router
      would spend on the packet without any resource reservation
      capability.

      There are routers where the processing power is shared between the
      control plane and the data plane. This means that the processing
      of signaling messages may have an impact on the data forwarding
      performance of the router. In this case the premium traffic delay
      metric reflects the influence the two planes have on each other.

   Measurement unit:
      The typical unit of the premium traffic delay is the microsecond.

6.4.3 Best-effort Traffic Delay

   Definition:
      Best-effort traffic delay is the forwarding time of a packet that
      does not belong to any premium traffic flow passing through a
      resource reservation capable router.

   Discussion:



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      It is obvious that the classification algorithms do not have any
      influence on the best-effort traffic. However, the processing
      power sharing between the control and data plane may cause delays
      in the forwarding procedure of each packet.

   Measurement unit:
      The typical unit of the best-effort traffic delay is the
      microsecond.

6.4.4 Signaling Message Loss

   Definition:
      Signaling message loss is the ratio of the expected and the actual
      number of signaling messages leaving a resource reservation
      capable router.

   Discussion:
      Signaling messages are generally generated at signaling end-points
      and forwarded through routers. However, traffic congestion can
      arise in heavily loaded routers, and, as a result, signaling
      messages might be lost. This metric is therefore suitable for
      sounding out the scalability limits of a resource reservation
      capable router.

      However, in the case of soft-state protocols where the refresh
      messages generated individually, it may be difficult to detect
      lost signaling messages. Thus, signaling loss only considers
      signaling messages that leave the router as a consequence of
      processing an entering signaling message. Note that signaling
      messages in a multicast reservation session might trigger several
      signaling messages.

   Issues:
      In the case of routers where network packets are queued in several
      places, we have to be aware that a signaling message may be
      delayed seriously. Therefore, it may be hard or impossible to
      determine whether the signaling message is still in the queues or
      whether it was dropped due to the congestion. By definition we say
      that a signaling message is lost in either of the following cases:
      when a signaling message of the same type that arrived later than
      the investigated signaling message leaves the router; when the
      signaling message handling time would exceed the triple of the
      signaling message handling time measured on other signaling
      messages under same conditions.

   Measurement unit:
      Usually, we measure the signaling loss over a longer period of
      time and then we express it as a percentage value of packet lost.
      However, in many cases it is enough to know that there was
      signaling loss.

6.4.5 Scalability Limit



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   Definition:
      The scalability limit is the threshold between the steady state
      and the overloaded state of the tested equipment.

   Discussion:
      All existing routers have finite buffer memory and finite
      processing power. In the steady state of the router, the memory
      buffers are not fully utilized and the processing power is enough
      to cope with all tasks running on the router. As the router load
      increases the router has to postpone more and more task. These
      tasks (e.g. forwarding certain packets) are stored into the
      buffers, and processed later. However, there is a certain point
      where no more buffer memory is available; thus, the router becomes
      overloaded and is unable to store any more tasks for future
      processing, so it is forced to drop them. Therefore the overloaded
      state of the router can be recognized by the fact that some kind
      of data loss occurs. A resource reservation capable router may
      drop signaling messages, data packets or entire resource
      reservation sessions.

      The critical load condition when the router is still in the steady
      state but the smallest amount of constant load increase would
      drive it to the overloaded state is the scalability limit of the
      router.

7. Acknowledgement

   We would like to thank the following individuals for their help in
   forming this document: Joakim Bergkvist and Norbert Vegh from Telia
   Research AB, Sweden, Balazs Szabo, Gabor Kovacs from High Speed
   Networks Laboratory of BUTE.

8. References

   [1]  S. Bradner, "Benchmarking Terminology for Network
        Interconnection Devices", RFC 1242, July 1991

   [2]  R. Mandeville, "Benchmarking Terminology for LAN Switching
        Devices", RFC 2285, February 1998

   [3]  Y. Bernet, et. al., "A Framework For Integrated Services
        Operation Over Diffserv Networks", Internet Draft, May 2000,
        <draft-ietf-issll-diffserv-rsvp-05.txt>

   [4]  S. Bradner, J. McQuaid, "Benchmarking Methodology for Network
        Interconnect Devices", RFC 2544, March 1999

   [5]  B. Braden, Ed., et. al., "Resource Reservation Protocol (RSVP) -
        Version 1 Functional Specification", RFC 2205, September 1997.

   [6]  J. Bergkvist, I. Cselenyi, "Boomerang Protocol Specification",
        Internet Draft, June 1999, <draft-bergkvist-boomerang-spec-
        00.txt>


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INTERNET-DRAFT  <draft-feher-bmwg-benchres-term-01.txt>   November 2000

   [7]  P. Pan, H. Schulzrinne, "YESSIR: A Simple Reservation Mechanism
        for the Internet", Computer Communication Review, on-line
        version, volume 29, number 2, April 1999

   [8]  L. Delgrossi, L. Berger, "Internet Stream Protocol Version 2
        (ST2) Protocol Specification - Version ST2+", RFC 1819, August
        1995

   [9]  P. White, J. Crowcroft, "A Case for Dynamic Sender-Initiated
        Reservation in the Internet", Journal on High Speed Networks,
        Special Issue on QoS Routing and Signaling, Vol 7 No 2, 1998

   [10] A. Eriksson, C. Gehrmann, "Robust and Secure Light-weight
        Resource Reservation for Unicast IP Traffic", International WS
        on QoS'98, IWQoS'98, May 18-20, 1998

   [11] L. Westberg, Z. R. Turanyi, D. Partain, Load Control of Real-
        Time Traffic, A Two-bit Resource Allocation Scheme, Internet
        Draft, <draft-westberg-loadcntr-03.txt>, April 2000

   [12] J. Wroclawski, "The Use of RSVP with IETF Integrated Services",
        RFC 2210, September 1997

9. Authors' Addresses:

   Gabor Feher
   Budapest University of Technology and Economics (BUTE)
   Department of Telecommunications and Telematics
   Pazmany Peter Setany 1/D, H-1117, Budapest, Hungary
   Phone: +36 1 463-3110
   Email: feher@ttt-atm.ttt.bme.hu

   Istvan Cselenyi
   Telia Research AB
   Vitsandsgatan 9B
   SE 12386, Farsta
   SWEDEN,
   Phone: +46 8 713-8173
   Email: istvan.i.cselenyi@telia.se

   Andras Korn
   Budapest University of Technology and Economics (BUTE)
   Institute of Mathematics, Department of Analysis
   Egry Jozsef u. 2, H-1111 Budapest, Hungary
   Phone: +36 1 463-2475
   Email: korn@math.bme.hu

   Peter Vary
   Budapest University of Technology and Economics (BUTE)
   Department of Telecommunications and Telematics
   Pazmany Peter Setany 1/D, H-1117, Budapest, Hungary
   Phone: +36 1 463-3110
   Email: kanya@iq.sch.bme.hu


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