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Versions: 01 02 03 rfc2902                                 Informational
Internet Architecture Board                                Steve Deering
INTERNET DRAFT                                             Cisco Systems
15 June 2000                                                   Sue Hares
                                                          Merit Networks
                                                      Charles E. Perkins
                                                   Nokia Research Center
                                                           Radia Perlman
                                           Sun Microsystems Laboratories

               Overview of the 1998 IAB Routing Workshop
                      draft-iab-rtrws-over-03.txt


Status of This Memo

   This document is a submission by the Internet Architecture Board
   Working Group of the Internet Engineering Task Force (IETF).
   Comments should be submitted to the
   iab-routing-workshop@external.cisco.com 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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   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.


Abstract

   This document is an overview of a Routing workshop held by the
   Internet Architecture Board during March 25-27, 1998.  The major
   points of discussion are listed, along with some conclusions and
   action items for many of the points of discussion.










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                                Contents


Status of This Memo                                                    i

Abstract                                                               i

 1. Introduction                                                       1

 2. Conclusions and Action Items                                       2
     2.1. Scaling of Unicast Routing and Addressing . . . . . . . .    2
           2.1.1. Unicast Routing - Conclusions . . . . . . . . . .    2
           2.1.2. Unicast Routing - Action Items  . . . . . . . . .    3
     2.2. Levels of Addressing of Addressing and Routing  . . . . .    3
     2.3. Network Address Translation (NAT) devices . . . . . . . .    3
           2.3.1. NAT devices - Conclusions . . . . . . . . . . . .    3
           2.3.2. NAT devices - Action Items  . . . . . . . . . . .    3
     2.4. Multicast . . . . . . . . . . . . . . . . . . . . . . . .    4
           2.4.1. Multicast - Conclusions . . . . . . . . . . . . .    4
           2.4.2. Multicast - Action Items  . . . . . . . . . . . .    5
     2.5. Routing Stability . . . . . . . . . . . . . . . . . . . .    5
           2.5.1. Routing Stability - Conclusions . . . . . . . . .    5
           2.5.2. Routing Stability - Action Items  . . . . . . . .    5
     2.6. ToS/CoS/QoS . . . . . . . . . . . . . . . . . . . . . . .    6
           2.6.1. ToS/CoS/QoS - Action Items  . . . . . . . . . . .    6
     2.7. Routing Protocol Security . . . . . . . . . . . . . . . .    6
           2.7.1. Routing Security - Conclusions  . . . . . . . . .    6
           2.7.2. Routing Security - Action Items . . . . . . . . .    7
     2.8. Routing Policy  . . . . . . . . . . . . . . . . . . . . .    7
           2.8.1. Routing Policy - Conclusions  . . . . . . . . . .    7
           2.8.2. Routing Policy - Action Item  . . . . . . . . . .    7
     2.9. Network to Host Flow of Information . . . . . . . . . . .    8
           2.9.1. Host Information - Conclusions  . . . . . . . . .    8
           2.9.2. Host Information - Action Items . . . . . . . . .    8
    2.10. Shorter Topics  . . . . . . . . . . . . . . . . . . . . .    8
          2.10.1. Multi-strand Trunking . . . . . . . . . . . . . .    8
          2.10.2. Routing Diagnostic and Development Tools  . . . .    9
          2.10.3. Anycast . . . . . . . . . . . . . . . . . . . . .    9
          2.10.4. Load Sensitive IGP routing for Best Effort Traffic   9
          2.10.5. Geographical Addresses and Renumbering  . . . . .   10

 3. Summary of Action items                                           10
     3.1. Action Items for the IAB  . . . . . . . . . . . . . . . .   10
     3.2. Action Items for IETF Working Group Chairs  . . . . . . .   10
     3.3. Action Items for the IRTF Routing Research Group  . . . .   11

 4. Security Considerations                                           11



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 A. Participants                                                      12

References                                                            12

Authors' Addresses                                                    14


1. Introduction

   From March 25 to March 27, 1998 the Internet Architecture Board
   (IAB) held a workshop on Routing.  The workshop focused on current
   problems within the Internet and the long term solutions that should
   be addressed.  This document summarizes the discussions the group
   had on routing, and lists the conclusions reached by the workshop.
   Section 2 lists the conclusions reached by the participants of the
   workshop and the suggestions for additional work or redirection of
   current work.  Sections 2.1-2.10 attempt to extract the major points
   of what was, in actuality, many multifaceted discussions, sometimes
   occuring all at the same time.  Appendix A contains a list of the
   participants who attended the workshop.  The full body of the report
   can be found at http://www.iab.org.

   The topics covered at length during the IAB workshop were:

    1. Scaling of Unicast Routing and Addressing (section 2.1)
    2. Unicast Addressing Issues (Section 2.2)
    3. The Effect of extending IP version 4 in the Internet by using
       Network Address Transformation boxes (Section 2.3)
    4. Multicast Routing (Section 2.4)
    5. Routing Instability (Section 2.5)
    6. Quality of Service Routing (Section 2.6)
    7. Routing Security (Section 2.7)
    8. BGP Policy (Section 2.8)
    9. Flows of information from network routing to hosts for improved
       services (Section 2.9)

   In addition the following topics were briefly covered:

    a. Multi-strand trunking
    b. Better tools for monitoring and diagnosis of network problems
    c. Routing protocol bandwidth minimization
    d. Automatic renumbering and automatic organization
    e. Anycast
    f. Load-sensitive routing
    g. Geographical addressing

   These shorter topics are contained in section 2.10.





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   It would be unrealistic to assume that the workshop had definitive
   answers to all the technical problems that were raised.  The best
   that can be hoped is that we raised most of the relevant issues and
   gave opinions that were the best guess of the people at the meeting,
   keeping in mind that the attendees did not come armed with data to
   back up opinions.  Much of the discussion amounted to an exploration
   of the intuition of the experts in attendance, intuition gained
   after years of experience in making the Internet work.  More work is
   needed to validate the intuition and experience by way of scientific
   experimentation and analysis.  Unfortunately, it's not so easy to
   find a spare collection of global Internets upon which one might
   perform controlled experiments.


2. Conclusions and Action Items

   The participants came to a number of conclusions after the
   discussions referred to in sections 2.1-2.10.  These conclusions,
   presented in this document, provide summary statements and action
   items for the IETF community.


2.1. Scaling of Unicast Routing and Addressing

2.1.1. Unicast Routing - Conclusions

   The participants of the workshop came to the following conclusions

    1. Most of the current unicast routing stability problems can be
       fixed with improved implementation.

    2. Some long term systemic issues that may eventually overwhelm the
       unicast routing are:

        -  Flaps - which will only get worse unless work is undertaken
        -  Multi-homing

    3. We'd like more research into what's breaking; not just more data,
       but more analysis of the data

   The group reviewed the following potential solutions:

    -  Architected NAT (improving the existing Network Address
       Translation schemes to provide better scaling)
    -  IPv6 (deploying an IP version 6 infrastructure)
    -  MAP/Encap (map to aggregatable addresses and encapsulate the
       original packet)
    -  Do nothing




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    -  Aggressive renumbering (try to continue to encourage renumbering
       to improve utilization of the IP version 4 address space)
    -  Metro addressing (use a geographical or metropolitan based
       addressing scheme)


2.1.2. Unicast Routing - Action Items

   We recommend that the IRTF Routing Research group should encourage
   more analysis of routing data, not just the collection of more data.


2.2. Levels of Addressing of Addressing and Routing

   Levels of hierarchy do not matter to the customers.  Address
   hierarchy must be distinguished from routing hierarchy.  The group
   examined whether the current Internet has enough levels of hierarchy
   in Internet addresses or routing infrastructure.  The group did not
   find that levels of hierarchy should be added to the Internet, at
   least for now.  Flat routing at the AS level seems to be workable;
   if this changes in the future, hierarchy would need to be revisited,
   and studied with due consideration to convergence time for routing
   algorithms and trust management.  There is no universal agreement
   that adding levels of hierarchy at this point in time provides a
   well-defined benefit.  Furthermore, two levels is difficult for many
   people, and any more than that is difficult both to build and to use.


2.3. Network Address Translation (NAT) devices

2.3.1. NAT devices - Conclusions

   Upon reviewing the NATs, the group

    1. Noted that NAT devices are fairly widely deployed
    2. Identified various problems with the use of NAT devices within
       the internet
    3. Discussed the interaction between NAT devices and applications
    4. Listed the following options regarding NAT devices:
        -  Eliminate NATs
        -  Fix NATs to interact better with the rest of the Internet
        -  Fix applications to interact better with NAT boxes
        -  Don't do certain things -- like IP Security (IPSec)


2.3.2. NAT devices - Action Items

    1. Forward our concerns, problems and suggestions to the appropriate
       working groups



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    2. Note architectural work outside the NAT working group
    3. Suggest to the IAB that it continue to be concerned about the
       issues involving NATs


2.4. Multicast

2.4.1. Multicast - Conclusions

   Since the multicast model was created, many multicast applications
   have been tried over the Internet multicast routing fabric.  The
   group began to discuss the multicast model in terms of enabling
   multicast applications to run efficiently, and scale favorably with
   future growth.  Multicast applications place varying requirements on
   multicast routing.

   Multicast applications may have a variable:

    -  number of sources,
    -  number of receivers,
    -  amount of data,
    -  amount of data in a burst, and length of quiet periods
    -  number of groups utilized per application or per set of
       cooperating applications, and
    -  amount of time during which the group exists
    -  topological distance between members of the group.
    -  volatility of membership

   Multicast routing must provide the flexibility to support the varying
   requirements of different multicast applications.  The current
   multicast model establishes multicast routing paths upon reception
   of a data packet.  The discussion on the viability of the multicast
   model examined the viability of the model in terms of the uses
   of multicast routing by applications and the scalability to full
   Internet usage.  For example, providing for many groups of small
   conferences (a small number of widely-dispersed people) with global
   topological scope scales badly given the current multicast model.

   The group felt the existing multicast protocols and multicast should
   be evaluated in terms of the requirements listed above.  The group
   suggested that the evaluation should include the multicast protocols
   DVMRP [11], MOSPF [7], PIM [4], CBT [2], and Express (an unpublished
   single-source multicast model proposed by Hugh Holbrook and David
   Cheriton), as well as the following mechanisms used by multicast
   applications:

    1. Registering with the core or the RP (Rendezvous Point),
    2. Having the ID of the group include the core, and having joins
       specify the core



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    3. Having the ID of the group include the core, and having joins and
       data specify both
    4. Sending data via unicast to all members, and
    5. Sending data via unicast transport to the RP.

   The group acknowledged that the current multicast model does not
   scale well for all scenarios that applications use.

   The group noted that reliable multicast is surprisingly orthogonal to
   the issues about the scaling of the multicast model to all possible
   applications.


2.4.2. Multicast - Action Items

   Encourage evaluation and written reports on these multicast
   protocols, and mechanisms for different types of protocols.

   Notify the IRTF Routing Research Group of the need to charter
   activity in this area.


2.5. Routing Stability

2.5.1. Routing Stability - Conclusions

   Damping the effects of route updates enhances stability, but possibly
   at the cost of reachability for some prefixes.  A prefix can be
   damped and reachable via another path, so that for such prefixes the
   effects of damping are less serious than for other prefixes.  The
   performance of various algorithms for enhancing stability should
   be measured by recording whether the affected route prefixes are
   reachable or not reachable.  Using current damping approaches,
   approximately 1% of the prefixes are affected at any one point in
   time.  We should try to find out how many prefixes are unreachable
   because of damping.


2.5.2. Routing Stability - Action Items

   The conclusion is that this effort merits continued investigation.

   The IRTF Routing Research Group should measure how stable things are,
   and if stability is an issue, to study methods of making them more
   stable.







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2.6. ToS/CoS/QoS

   The group noted that the terms Type of Service (ToS), Class of
   Service (CoS), and Quality of Service (QoS) are imprecise as
   currently used.  The discussion started by defining the terminology
   as follows:

 ToS:  hop by hop routing based on destination plus ToS bits [8]
 CoS:  classes of service based on service contracts.  These classes
       of service are enabled by a variety of mechanisms which include
       queueing, and multiple physical or link level paths.
 QoS:  managing routes that meet certain quality of service constraints,
       and involving the following steps:
        *  routing the resource requests
        *  setting up a path that satisfies the constraints
        *  routing the data

   There is no smooth dividing line between between ToS and QoS. ToS is
   relative.  QoS is absolute.  The group discussed whether there is a
   demand for ToS, CoS and QoS. Differentiated-services [3] as discussed
   in the IETF is ToS++.

   The group also discussed a more general concept of "Constraint
   Based Routing" which was defined as traffic engineering on large
   aggregated flows.  Constraint based routing allows the providers
   to better utilize the bandwidth in their network to handle traffic
   requests from users.  Besides enabling policy management techniques,
   constraint based routing allows providers to route traffic based on
   the characteristics of the traffic flows.


2.6.1. ToS/CoS/QoS - Action Items

   We recommend that IETF should look into the issue of Constraint Based
   Routing.


2.7. Routing Protocol Security

2.7.1. Routing Security - Conclusions

   After a lengthy discussion of the various problems of network
   security, the group notes that:

    1. Routers need intrinsic system security as good as or better than
       any host computer.
    2. Improving router security will not solve all problems.
    3. Console access to the router can do everything.
    4. One compromised router can create disaster.



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    5. ISPs and vendors should consider taking some control traffic out
       of band, due to lack of wire speed authentication.
    6. We discussed other issues that will be passed on to the
       appropriate people involved with network security.
    7. Identified areas of work to improve things (e.g., wire speed
       authentication).


2.7.2. Routing Security - Action Items

   The IETF should encourage work on "wire speed" authentication,
   pair-wise authentication of routers in routing protocols, and
   Byzantine robustness [5] in routing protocols.


2.8. Routing Policy

2.8.1. Routing Policy - Conclusions

   During our discussion on routing policy the group reviewed what could
   be done with BGP. The group noted that:

    1. Some routing policies requested by ISPs or NSPs are not solvable
       with BGP. Some of these "unsolvable" routing policies can be put
       into effect using tunnels and static configuration.
    2. BGP is only a mechanism for announcing reachability
    3. BGP routing controls traffic direction without regard to traffic
       volume.
    4. BGP policy management is too delicate, too easy to mess up, and
       fragile.
    5. Router Configuration Language is very complex and error-prone
    6. We can't count on symmetric routing, so ISPs/NSPs/Enterprise nets
       should deal with it.

   The group concluded the Internet needed a better routing policy
   specification language.


2.8.2. Routing Policy - Action Item

   Pass the concerns about the Routing Policy Syntax Language (RPSL) [1]
   to chairs of the Routing Policy Syntax (RPS) working group [10].










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2.9. Network to Host Flow of Information

2.9.1. Host Information - Conclusions

   Publishing information about traffic statistics along backbone routes
   could improve the way Internet services replicate data for retrieval
   from various sites.  This replication could be especially important
   for the retrieval of information off the web.  Currently, web pages
   refer people to caches local to their sites; for instance, a European
   site might be used for United Kingdom customers and a North American
   site for North American customers.  Proponents of web caches want to
   auto-configure the locations of web caches so a user's web browser
   can automatically discover the local cache.  Other applications share
   this need for finding the best cache for a particular service.


2.9.2. Host Information - Action Items

   The group recommends a BOF be held on Measuring Path Characteristics.
   Measurement of path characteristics should include:

    -  format for exchange of measurement data
    -  mechanisms for distribution of measurement data

   IPPM working group [6] is dealing with issues within the measurement
   problem space.


2.10. Shorter Topics

2.10.1. Multi-strand Trunking

   PPP did multi-link in a way that required too much computation and
   could not be used for faster links.  Internet technology should
   treat multiple parallel trunks as 1 link at the IP layer, but with
   multi-dimensional metrics.


Multi-strand Trunking - Action Items

   There is design and development work at layer two which should be
   done to support the multiple parallel trunks.  This layer two work
   is outside the scope of the IETF. Layer three routing should support
   richer metrics in OSPF.








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2.10.2. Routing Diagnostic and Development Tools

2.10.2.1. Routing Diagnostics - Conclusions

    1. It would be nice to have an Authoritative Database listing those
       prefixes permitted from each AS. The authoritative data base was
       attempted before without success, but the group felt it might be
       useful to try again.
    2. SNMP version 3 should be deployed in order to make use of its
       improved authentication, scope and rate limiting
    3. Remotely-controlled traffic monitors should be used to measure
       traffic
    4. Better tools are needed for preventative problem detection


2.10.2.2. Routing Diagnostics - Action Items

    1. Encouraged an authoritative database within the Internet
    2. Notify SNMP version 3 working groups regarding needs for
       authentication, scope, and rate limiting.
    3. Encourage funding of better tools for remotely controlled traffic
       sources and pro-active problem detection.


2.10.3. Anycast

2.10.3.1. Anycast - Conclusions

    1. We need to describe the advantages and disadvantages of anycast.
    2. Local-scoped well-known anycast addresses will be useful to
       applications.


2.10.3.2. Anycast - Action Items

   A BOF should be held to plan work on anycast.

   If a working group forms, a paper on the advantages and disadvantages
   of anycast should be included as part of the charter.


2.10.4. Load Sensitive IGP routing for Best Effort Traffic

2.10.4.1. Load Sensitive IGP - Conclusions

   While load sensitive routing is interesting in some ways, it cannot
   be considered until certain problems are worked out.  Currently,
   constraint based routing is assigning administrative metrics to allow
   routing to adapt to different traffic patterns.  Load sensitive



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   routing may increase oscillation and instability of routes.  This
   instability of routes, sometimes called churn, may affect the ability
   of the routing infrastructure to scale.

   Load sensitive routing would allow IGPs to better utilize links.
   Past and current efforts in load sensitive routing include:  QoS
   OSPF [9], Q-OSPF [9], and load sensitive routers developed by BBN.


2.10.4.2. Load Sensitive IGP - Action items

   The IRTF Routing Research group chair and Routing Area Director
   should discuss this subject and determine what techniques from
   Load Sensitive IGP routing are ready for IETF, and what requires
   additional research.


2.10.5. Geographical Addresses and Renumbering

   This topic was discussed, but without any conclusions or action
   items.


3. Summary of Action items

3.1. Action Items for the IAB

    1. The IAB should be concerned about the issues involving NATs
    2. Authoritative Database (for addresses within domains) should be
       encouraged within the Internet
    3. Encourage funding of better tools for remotely controlled traffic
       sources and pro-active problem detection.


3.2. Action Items for IETF Working Group Chairs

    1. NAT: Forward our concerns, problems and suggestions to the
       appropriate working groups
    2. We recommend that IETF should work the issue of Constraint Based
       Routing.
    3. The IETF should encourage work on "wire speed" authentication,
       pair-wise authentication of routers in routing protocols, and
       Byzantine robustness in routing protocols.
    4. Concerns about the Routing Policy Specification Language (RPSL)
       should go to the Routing Policy Systems (RPS) working group
       chair.
    5. The group recommends a BOF be held on Measuring Path
       Characteristics.  The BOF should consider the data exchange
       format of measurement and mechanisms to distribution of data



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       mechanism.  It is noted that the IPPM working group is dealing
       with issues within the measurement problem space.
    6. There is layer two work which should be done to support the
       multiple parallel trunks which is outside the scope of the IETF.
       Layer three routing should support richer metrics in OSPF.
    7. SNMP version 3 working groups should be notified about the issues
       about authentication, scope, and rate limiting.
    8. A BOF should be held to plan work on anycast.  A document on
       anycast should be part of the proposed working group charter.


3.3. Action Items for the IRTF Routing Research Group

    1. We recommend that the IRTF Routing Research working group try to
       encourage more analysis of routing data, not just the collection
       of more data.

    2. Encourage evaluation and written reports on the evaluation
       of multicast protocols and mechanisms for different types of
       protocols

    3. The IRTF Routing Research group chair and the Routing Area
       Director should discuss Load Sensitive IGP routing and determine
       whether it is ready for the IETF.


4. Security Considerations

   Security considerations were an important part of the discussions
   at the workshop, but the workshop decided not to publish a summary
   of these discussions.  Other documents that address the issues of
   routing infrastructure security have recently been published.




















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A. Participants

      Harald Alvestrand               Harald.Alvestrand@maxware.no,
      Fred Baker                      fred@cisco.com,
      Jeff Burgan                     burgan@corp.home.net,
      Brian Carpenter                 brian@hursley.ibm.com,
      Noel Chiappa                    jnc@ginger.lcs.mit.edu,
      Rob Coltun                      rcoltun@fore.com,
      Steve Deering                   deering@cisco.com,
      Deborah Estrin                  estrin@usc.edu,
      Dino Farinacci                  dino@cisco.com,
      Paul Francis                    francis@slab.ntt.co.jp,
      Elise Gerich                    epg@home.net,
      Joel Halpern                    jhalpern@newbridge.com,
      Sue Hares                       skh@merit.edu,
      Cyndi Jung                      cmj@3Com.com,
      Dave Katz                       dkatz@jnx.com,
      Tony Li                         tli@juniper.net,
      Peter Lothberg                  roll@stupi.se,
      Louis Mamakos                   louie@uu.net,
      Dave Meyer                      dmm@cisco.com,
      Keith Moore                     moore@cs.utk.edu,
      Bob Moskowitz                   rgm@htt-consult.com,
      Thomas Narten                   narten@raleigh.ibm.com,
      Vern Paxson                     vern@ee.lbl.gov,
      Charlie Perkins                 Charles.Perkins@iprg.nokia.com
      Radia Perlman                   Radia.Perlman@East.Sun.COM,
      Yakov Rekhter                   yakov@cisco.com,
      Allyn Romanow                   allyn@MCI.NET,
      Martha Steenstrup               msteenst@bbn.com,
      George Swallow                  swallow@cisco.com,



References

    [1] C. Alaettinoglu, T. Bates, E. Gerich, D. Karrenberg, D. Meyer,
        M. Terpstra, and C. Villamizar.  Routing Policy Specification
        Language (RPSL).  Request for Comments (Proposed Standard) 2280,
        Internet Engineering Task Force, January 1998.

    [2] A. Ballardie.  Core Based Trees (CBT) Multicast Routing
        Architecture.  Request for Comments (Experimental) 2201,
        Internet Engineering Task Force, September 1997.

    [3] S. Blake, D. Black, M. Carlson, E. Davies, Z. Wang, and
        W. Weiss.  An Architecture for Differentiated Service.  Request
        for Comments (Informational) 2475, Internet Engineering Task
        Force, December 1998.



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    [4] D. Estrin, D. Farinacci, A. Helmy, D. Thaler, S. Deering,
        M. Handley, V. Jacobson, C. Liu, P. Sharma, and L. Wei.
        Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol
        Specification.  Request for Comments (Experimental) 2362,
        Internet Engineering Task Force, June 1998.

    [5] Charlie Kaufman, Radia Perlman, and Mike Speciner.  Network
        Security:  Private Communication in a Public World, pages
        462--465.  Prentice-Hall, Inc., 1995.

    [6] W. Leland and M. Zekauskas (chairs).  IP Performance Metrics
        (IPPM), October 1997.
        http://www.ietf.org/html.charters/ippm-charter.html.

    [7] J. Moy.  Multicast Extensions to OSPF.  Request for Comments
        (Proposed Standard) 1584, Internet Engineering Task Force, March
        1994.

    [8] K. Nichols, S. Blake, F. Baker, and D. Black.  Definition of
        the Differentiated Services Field (DS Field) in the IPv4 and
        IPv6 Headers.  Request for Comments (Proposed Standard) 2474,
        Internet Engineering Task Force, December 1998.

    [9] H. Sandick and E. Crawley (chairs).  QoS Routing (qosr), April
        1997.  http://www.ietf.org/html.charters/qosr-charter.html.

   [10] C. Villamizar and C. Alaettinoglu (chairs).  Routing Policy
        Syntax (RPS), July 1995.
        http://www.ietf.org/html.charters/rps-charter.html.

   [11] D. Waitzman, C. Partridge, and S. E. Deering.  Distance Vector
        Multicast Routing Protocol.  Request for Comments (Experimental)
        1075, Internet Engineering Task Force, November 1988.



















Deering, Hares, Perlman, Perkins   Expires 15 December 2000    [Page 13]


Internet Draft               Routing Workshop               15 June 2000


Authors' Addresses

   Questions about this memo can be directed to:

      Stephen E. Deering                 Susan Hares
      Cisco Systems, Inc.                Merit, Inc.
      170 West Tasman Drive              1071 Beal Avenue,
      San Jose, CA 95134-1706            Ann Arbor, MI 48109
      USA                                USA

      Phone:  +1 408 527-8213            Phone:  +1 313 936-2095
      EMail:  deering@cisco.com          EMail:  skh@merit.edu





      Radia Perlman                      Charles E. Perkins
      Sun Microsystems Laboratories      Nokia Research Center
      2 Elizabeth Drive                  313 Fairchild Drive
      Chelmsford, MA 01824               Mountain View, CA 94043
      USA                                USA

      Phone:  +1 978 442-3252            Phone:  +1 650 625-2986
      EMail:  Radia.Perlman@sun.com      EMail:  charliep@iprg.nokia.com
                                         Fax:  +1 650 691-2170


























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