J. Postel
IEN 134                                                              ISI
                                                        29 February 1980

            Internet Meeting Notes - 4, 5, & 6 February 1980

I.  INTRODUCTION - Kunzelman, Shoch

   This meeting was held at SRI on Monday and Wednesday and at XEROX
   PARC on Tuesday.  Ron Kunzelman was the coordinator at SRI, and John
   Shoch was the coordinator at XEROX.


   Vint briefly restated the current issues of concern in the internet
   program.  The principal issue is now performance.  The Fort Bragg
   users and the european users depend on the internet for access to
   their host computers.


   A.  DARPA - Cerf

      Vint reported that ARPA as a whole had been reorganized to better
      balance the various offices.  IPTO itself had not been affected.
      Vint noted that in the last few years IPTO had put more emphasis
      on test beds and demonstration projects to promote technology
      transfer, and that this had hurt basic research.  Vint thinks that
      there will be an increase in support for research.

      Vint reported that the protocol standardization effort in DOD is
      moving forward, and that IP and TCP as documented in IENs 128 and
      129 form the basis for the standards.

      Vint repeated his desire for each contractor to identify
      milestones and to make monthly progress reports.  Jon Postel will
      coordinate these reports.

   B.  BBN - Plummer, Strazisar, Haverty, Wingfield, McNeill, Brescia,
   Flood Page, Nelson

      Bill reported that TCP and IP on TOPS 20 are working and that he
      is begining work on the Tenex versions.  For this he is using a
      new host at BBNG.  The XNET program has been converted.  FTP on
      TCP is in the queue but not top priority.

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      Ginny reported that all gateways but one have been converted to
      MOS based systems, and that conversion of the bootstraps and
      loaders to use IP is in progress.  The gateways do participate
      with the CMCC by sending the monitoring reports.  A port expander
      has arrived at BBN.

      Jack reported on the development of XNET programs in the UNIX
      environment.  The Unix debugger has been extended to allow
      debugging of processes on another machine via XNET.  Two XNET
      servers have been created, one for debugging at the system level,
      and another for debugging at the process level.

      Jack also discussed the problems with connecting things via 1822
      style interfaces.  The problems arise because the available
      specification is for a host side interface, and the host side is
      allowed to be sloppy about its signals while the IMP side is not.
      Plugging two host side interfaces together sometimes doesn't work
      due to differences in signal levels allowed by the host side
      specification.  If these interfaces were built to the more
      stringent (and undocumented) IMP side specification these problems
      could be avoided.  ACTION:  Vint will investigate provision of
      1822 interfaces that meet IMP side specification.

      Jack noted that BBN is implementing IP and TCP for an HP3000 data
      management system for ARPA.

      Mike Wingfield reported that the "C" version of the unix IP and
      TCP will be used for both the ARPA Internet and AUTODIN II
      environments, and the macro version will be phased out.  MOS2 has
      been rewritten in "C."  The TCP has been studied for performance
      bottlenecks, with the current suspicion falling on the
      interprocess communication facility.  Fragmentation and reassembly
      are being added to TCP.  The AUTODIN II FTP is being implemented.

      Dale reported that SATNET is working well except for a 5 day
      period where there were hardware problems at Goonhilly.  SATNET
      continues to support ARPANET traffic to/from Europe via "line 77."
      Performance between the channel protocol modules has been
      measured.  A gateway between MATNET (a secure shipboard SATNET)
      and a secure subset of the ARPANET will come into existence.

      Mike Brescia discussed gateway operation and monitoring
      operations.  An NCC style gateway monitoring center is being
      setup.  A gateway is being developed for connecting the ARPANET
      and an X.25 net.  The X.25 side is still under development.

      David briefly mentioned the status of the Catenet monitoring
      programs.  These are discussed in another session of the meeting.

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      Ruth reported on the development of a local net for the ACCAT
      testbed at NOSC.  There will be a gateway to the secure subset of
      the ARPANET.  An MBB Unix will be used.  This work is in the
      design stage.  IP and TCP will be used in the local network, which
      uses an 8 megabit base band cable with collision detection.  This
      is based on the MIT CHAOS net experience.

   C.  DCA - Cain

      Ed reported that the local net which has operated for several
      years based on an old version of the ARPANET IMPs will now have to
      be brought up to date to use 96 bit leaders so this net can
      participate in experiments with BCRs.

   D.  COMSAT - Mills

      Dave reported that work continues on the PSP and NET, however the
      main effort in recent months has been the demonstration for the
      NTC.  The "demo" system has been configured to run on a variety of
      PDP-11 models.  In the process of preparing for the demo some
      performance problems were detected, and since the demo some study
      has been done to isolate them (more on this in a later session).
      These performance issues also prompted some tuning of parameters
      and strategy in the MOS TCP.  On another front Dave found a way to
      decode compressed FAX files.  Dave has several written reports
      giving more detail on the work of COMSAT.

   E.  DOD - McFarland

      Ray reported that Ken Shotting is attempting a formal
      specification of IP in SPECIAL, and may be ready to give a report
      at the next meeting.

   F.  ISI - Postel

      Jon noted that ISI is working in three task areas:  (1) Protocol
      Development, which includes the work on IP and TCP specifications;
      (2) Internet Mail, which includes development of mechanisms for
      delivery of mail in an internet and provision for multi-media data
      in the mail; and (3) protocol verification, which aims at the
      analysis of IP and TCP for correct operation.

   G.  Linkabit - Hoversten

      Estil noted Linkabit's involvement in SATNET and the WBC
      experiment, and his participation in the development of the ST
      protocol.  Estil claimed to be the advocate of wild ideas.  [Danny

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      Cohen immediately claimed to be the advocate of tame ideas.]
      Linkabit is also considering a set of local networks.

   H.  LL - Forgie

      Jim reported on efforts to make the SATNET voice conferencing more
      robust.  Dale McNeill helped by fine tuning the SATNET but there
      were still problems in the overall path.  It seems that the ELF
      based gateway introduces too much delay into the system.  The idea
      of a film on SATNET conferencing has been canceled due to the poor
      performance of the system.  There appears to be no further need
      for the ELF gateway in SATNET.

      Jim also briefly mentioned the status of the ST protocol, which
      will be reviewed in a later session.  Jim did discuss the WBC
      experiment and indicated the goals of having the LL, ISI, and SRI
      sites up for point-to-point packet voice by September 1980, and
      multiplexing of cells through a Voice Funnel by September 1981.

   I.  MIT - Clark

      Dave noted that version 1 of the LCSNET is in operation with a PDP
      11 Unix system and a VAX connected, and the MIT-XX TOPS 20 to be
      connected in April.  Version 2 of the LCSNET is being debugged.
      Version 2 operates the cable at 8 megabits (version 1 operates at
      1 megabit).

      Dave described the development of a personal terminal to be built
      for LCS by Zenith.  The prototype was built by Steve Ward at MIT.
      LCS expects to have 10 of these by the end of May, 40 by the end
      of 1980 and 150 by the end of 1981.  These personal computers will
      interface directly to the LCSNET.

      Dave also reported continuing problems with the port expander and
      ARPANET hosts.  A testing session will be set up at BBN involving
      people from BBN and SRI.  ACTION:  Ron Kunzelman and Bill Plummer
      will test port expander with BBNF.

      Dave also noted that MIT received a gift of 20 Altos and an
      ethernet from XEROX, and that some effort will be needed to
      integrate them into the environment.  A common Trivial FTP is in
      progress, the plan is to develop IP, TCP, and Telnet for the

      There will be an improved Telnet server on Multics soon, and a
      mail queuer for local net users.  IP reassembly code will be

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      Dave did not prepare a memo for this meeting on congestion
      control, but expects to have a presentation on the topic for the
      next meeting.

   J.  NDRE - Lundh

      Yngvar reported that the plans of NDRE are quite behind schedule
      due to lack of staff.  The problems with the VDH connection have
      been solved and TCP is working.  NDRE is developing a local net
      involving NORD-10 and NORD-100 computers.

   K.  RSRE - Davies

      Brian reported on the development of the RSRE gateway and the
      experiences with the gateway-gateway protocol and CMCC monitoring
      protocol.  Things seem to work well except for a few special
      cases.  For example, when a "tail" gateway crashes it takes many
      gateway routing update steps to get the hop count up to
      "infinity."  The temporary fix is to use a smaller value for
      "infinity" (today "infinity" = 5).

      Another problem is that the host routing in TOPS 20s does not
      switch to the NDRE gateway when the BBN gateway is down.  ACTION:
      Bill Plummer to change TOPS 20 host routing procedures, Vint Cerf
      to get the priority for this task.

      RSRE has also experienced problems using TCP between RSRE and
      ISIE.  There may be a data stream capture problem.  Even when all
      is going well there are many duplicates, seemingly due to the
      round trip time being longer than the TOPS 20 TCP retransmission
      timeout.  Brian estimates the delay at six (6) seconds.

      RSRE will be working on a connection to PSS and a new X.25-TCP

   L.  SRI - Kunzelman, Cone, Nelson, Frankel

      Ron discussed the status of the TIU, and reported that it is now
      fully converted to IP and TCP.  The PRNET at SRI has been
      converted to the CAP5 protocol.  A PDP-11/44 will be installed as
      a PRNET measurement facility.

      Don reported that six port expanders have been delivered and that
      five more are in the works.

      Holly discussed the state of the port expander software.

      Mike discussed the Ft. Bragg PRNET status.  Six radio units are

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      installed.  There are problems of response delays to the users
      from Ft. Bragg to ISIE.  There may be a data stream capture
      problem.  The gateway seems to be a thruput bottleneck.

      Raphi reported on a local network development at SRI.  This will
      be based on XEROX Ethernet PDP-11 interface boards.  These come
      from XEROX with a unibus interface, SRI will convert them to Qbus
      interface to be able to use LSI-11s to front end the host systems.
      The hosts will be the TOPS20, Unix, B6700 systems now at SRI.  The
      first service will be computer mail based on the Deleware MMDF and
      the SRI Deafnet.  Telex and TWX will also be connected into the
      online mail system.

   M.  UCL - Jones

      Ron discussed the UCL involvement in the NTC demonstrations, and
      in the RSRE interconnection to the internet.  Several tasks were
      delayed due to the development machine being out of service for 6
      weeks.  An ARPANET/PSS gateway is under development.  This will be
      a protocol translation gateway converting between X.25 and TCP and
      eventually up to the Telnet protocol level.  Experiments are
      beginning with a connection to IPSS.  An NCP/TCP gateway was
      demonstrated on ISIE.  The NIFTP now runs on both ISIE and UCL
      Unix.  UCL has also been active with the development of a FAX
      protocol.  The UCL local net (a cambridge ring) now has 5
      stations.  It is planned to use TCP as the protocol above the ring

   N.  MITRE - Skelton

      Anita reported that the local net (a cable bus) is up and running.
      There is work to upgrade the BIUs to allow larger packets and
      higher data rates on the net.  A second net is to be installed at
      DCEC.  There is also work to create an X.25 BIU interface.

   O.  UCLA - Braden

      Bob reported that the machine at UCLA-CCN is now a 3033 running
      OS/MVT.  IP and TCP are up, and a server telnet is in place.

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   Jon reported that the following documents were issued since the last

   IEN 120 by Radia Perlman on "Internet Routing and the Network Portion

      This memo discusses ways in which gateway routing data could be
      used to overcome the problems of partitioned networks.

   IEN 121 by Postel on "Internet Meeting Notes - 10, 11, 12, 13
   September 1979."

      This is simply the notes of the last meeting.

   IEN 122 by Cohen on "Addressing and Related Issues (or Fuel for a

      A suggestion that not all local networks need to be registered as
      full networks in the internet and some ways of addressing the
      hosts on such unregistered networks.

   IEN 123 and 124 were the December versions of the IP and TCP
   specifications.  These were the first try at the DOD Standard

   IEN 125 by Cerf on "Pre-emption."

      This is a note detailing how pre-emption can be handled at the
      application level.

   IEN 126 by Cohen on a "Summary of the ARPA/ETHERNET Community

      This describes a plan for the co-existence of the PUP internet and
      the ARPA internet protocols.

   IEN 127 by Postel on "Assigned Numbers."

      This is the latest edition of the list of network, protocols,
      ports socket, and links.

   IEN 128 and 129 by Postel on IP and TCP.

      These are the second try at the DOD Standard versions of the IP
      and TCP specifications.  These are also the current specifications
      for our own (ARPA internet) use.

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   In addition to these, four more IENs were received since the Thursday
   before the meeting:

   IEN 130 is a "Comparison of X.25 and TCP as Cable Bus Network
   Protocols" by International Computing.

   IEN 131 and IEN 132 by David Flood Page on "Gateway Monitoring
   Protocol" and "The CMCC Terminal Process."

   IEN 133 by Karen Sollins on "The TFTP Protocol."

   Two IENs which were desired but not produced were:

   "How to Build a Host IP" by Bill Plummer


   "Congestion Control" by Dave Clark.


   Vint reported that Duane Adams of ARPA/IPTO is starting a program on
   graceful interaction and the test application will be multi-media
   computer mail.  Since some of the internet project participants have
   FAX equipment there was a small meeting on how to cooperate to
   exchange FAX data.  The internet program has interest in seeing that
   the exchange of multi-media data is possible in the internet and that
   the representation of such data is compatible between these programs.


   Jon presented the current status of the internet mail system.  The
   system replaces the traditional "Mailer-FTPSRV" processes with new
   processes called MPM's.  The MPM exchange messages which are list
   structured data of various types (not just text).  The MPMs use TCP
   to transmit these messages.  Some other programs have been modified
   or created to create test messages in this new format.  No user
   interface to this new system exists yet.

VII.  BBN - FAX - MAIL - Myer

   Ted described BBN's work on a user interface program to manipulate
   messages composed of mixtures of text and FAX data.  The focus is on
   the creation of such messages and on their presentation.  The RAPICOM
   450 will be used experimentally, and the files will be kept in a
   format very close to that used by Postel's MPMs.

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   David reviewed the operation of the Catenet monitoring center and the
   terminal process, indicating the types of information available.
   Please see IENs 131 and 132 for more details.


   A.  David Flood Page gave a demo of the CMCC by using a terminal
       process to examine the statistics sent in by various gateways.

   B.  Greg Finn gave a demo of the Internet Mail system by running
       instrumented versions of the MPMs such that the progress of
       message processing could be followed.

X.  PUP - Shoch, Taft, Boggs, Stewart

   John presented a review of the PARC developed ETHERNET and PUP
   protocol environment.  This was a very thorough presentation.  Rather
   than try to capture it here the reader is referred to "PUP - An
   Internetwork Architecture", a paper to appear in the IEEE
   Transactions on Communication in April, and available as a Xerox
   report from John.

   John demonstrated some simple programs which use the PUP protocols
   and some monitoring programs.  Ed demonstrated the Laural Mail
   Program, Dave demonstrated a cross network debugger, and Larry
   demonstrated the PRNET/ETHERNET interconnection and some digital
   audio transmission on the ETHERNET.


   Danny presented the scheme described in IEN 126 for the "mutual
   encapsulation" (credit Bob Metcalfe for the term) of PUP in IPs and
   IPs in PUPs.


   Dick made a presentation highlighting the critical assumptions about
   time in both the Delta-T protocol and TCP.  The claim is that for
   either of these protocols to operate correctly these critical time
   factors must exceed specific minimum values based on the Maximum
   Packet Lifetime, the retransmission time, and the Ack holding time.

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   Lansing presented a scheme for measuring the time a packet spends on
   a link.  This would enable a network to age packets and if necessary
   kill them off if they get older than an established maximum packet
   lifetime.  This method will be reported in a paper to appear in
   Computer Networks.

XIV.  ST - Forgie

   Jim reviewed the discussion and evolution of ST since last meeting.
   IEN 119 remains a reasonable reference to the intention and general
   mechanisms of ST, though some details may now differ.  A revised
   version is to be issued soon.  Plans are moving ahead for
   implementations of a host and a gateway ST at LL and a host ST at


   Jim presented a very detailed explanation of the Port Expander.  This
   simple concept of multiplexing the IMP port for a set of host becomes
   fairly tricky when all the IMP emulation tasks are identified.


   Raphi proposed that some gateways may wish to offer services to
   higher level protocols by having application-dependent modules that
   could be invoked to process messages of that application.  These
   modules could be called "functional agents."


   Mike reported that BBN is under contract to NBS to prepare a
   host-to-host protocol specification to be a Federal Information
   Processing Standard.  This is part of a larger effort by NBS which
   includes the following contractors and protocols:

      BBN - Host, FTP, IP, Interprocess.

      SDC - Telnet, Remote Job Entry, Common Command Language.

      SEI - Computer Mail.

      NAC - Cost/Benefit of Standards.

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   Brian discussed some measurements of TCP conducted by RSRE to various
   other places in the internet.  The performance is regular for round
   trips from RSRE to various points at UCL, and is consistent with the
   physical facilities.  Once the round trip path includes the SATNET,
   however, the performance becomes irregular, with a few messages
   subject to very high delay.  Also some unnecessary retransmissions
   are detected in the tests form RSRE to ISIE and back, these may be
   due to a too low retransmission threshold.

   This prompted some discussion of the source of the variability in the
   delay.  Jim Forgie presented some data from the SATNET speech testing
   that seemed to confirm Brian's data.  Dale McNeill showed some data
   on the SATNET channel delays which show performance at that level to
   be very regular.  Suspicion seems to be cast on the SIMPs or the
   Gateways or their interface.


   Dave described some measurements of TCP traffic between the COMSAT
   DEMO Terminal and ISIE.  There is evidence of lost and delayed

   It seems clear from this and the preceeding discussion that a
   definite effort is needed to isolate and correct these performance


   Vint noted the following loose ends that need to be tied up:

      1.  96 bit leader changes to all ARPANET hosts, and carried
      through system and application software.

      2.  TCP implementations brought up to the JAN 80 specifications.

      3.  IP implementations brought up to the JAN 80 specifications,
      and modified to including reassembly/fragmentation, gateway
      routing advice, alternate gateway selection, and source quenching.

      4.  Gateway addresses needed in all host IP tables.

   Vint also noted that work on a TCP TIP has been started.  That an
   ARPANET/TELENET gateway is in progress, and that an ARPANET AUTODIN
   II gateway is expected in first quarter of 1981.

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   The next meeting is scheduled for 14 & 15 May at MIT.  The contact is
   Dave Clark (Clark@MIT-Multics).


   IEN        Author       Title
   ---        ------       -----
   127        Postel       Assigned Numbers
   128        Postel       IP Spec
   129        Postel       TCP Spec
   130                     Comparison of TCP & X.25
              Watson       Comparison of TCP & Delta-T
              Lieb         Port Expander
              Mills        COMSAT Reports
              Postel       Internet Host and Gateways
              Postel       IEN Index

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   Vint Cerf                ARPA               Cerf@ISIA
   Mike Brescia             BBN                Brescia@BBNE
   Jack Haverty             BBN                JHAVERTY@BBND
   Dale McNeill             BBN                DMCNEILL@BBNE
   David Flood Page         BBN                DFLOODPAGE@BBNE
   Ted Myer                 BBN                Myer@BBNA
   Ruth Nelson              BBN                RNelson@BBND
   William Plummer          BBN                Plummer@BBNA
   Bob Resnick              BBN                Resnick@BBNA
   Virginia Strazisar       BBN                STRAZISAR@BBNA
   Mike Wingfield           BBN                Wingfield@BBND
   Hoi Y. Chong             COMSAT             Chong@ISIE
   David Mills              COMSAT             Mills@ISIE
   Chris Elliott            CTEC           c/o Chips@BBNC
   Ed Cain                  DCEC               DCEC-R850@BBNB
   Ray McFarland            DoD                McFARLAND@ISIA
   Danny Cohen              ISI                Cohen@ISIB
   Greg Finn                ISI                Finn@ISIE
   Jon Postel               ISI                Postel@ISIE
   Carl Sunshine            ISI                Sunshine@ISIE
   Lansing Sloan            LLL                DWatson@BBNB
   Dick Watson              LLL                DWatson@BBNB
   Estil Hoversten          Linkabit           Hoversten@ISIA
   Jim Forgie               Lincoln Lab        FORGIE@BBN
   David Clark              MIT                Clark@MIT-Multics
   Anita Skelton            MITRE              Anita@MITRE
   Frank Deckelman          NAVELEX            DECKELMAN@ISIA
   Yngvar Lundh             NDRE               Yngvar@SRI-KA
   Paal Spilling            NDRE/SRI           Spilling@SRI-KL
   Merle Neer               NOSC               Neer@ISIA
   Brian Davies             RSRE               RSRE-T4@ISIA
   John Laws                RSRE               RSRE-T4@ISIA
   David Kaufman            SDC                Kaufman@ISIE
   Don Cone                 SRI                Cone@SRI-KL
   William Croft            SRI                Croft@SRI-KL
   Elizabeth Feinler        SRI                Feinler@SRI-KL
   Mike Frankel             SRI                Frankel@SRI-KL
   Michael Heathman         SRI                Heathman@SRI-KL
   Ron Kunzelman            SRI                Kunzelman@SRI-KL
   Jim Mathis               SRI                Mathis@SRI-KL
   Stevan Milunovic         SRI                Milunovic@SRI-KL
   Holly Nelson             SRI                HNelson@SRI-KL
   Ed Perry                 SRI                Perry@SRI-KL
   John Pickens             SRI                Pickens@SRI-KL
   Raphael Rom              SRI                Rom@SRI-KL
   Ron Jones                UCL                UKSAT@ISIE

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   Peter Kirstein           UCL                Kirstein@ISIA
   Steve Treadwell          UCL                UKSAT@ISIE
   Bob Braden               UCLA OAC           Braden@UCLA-CCN
   David Boggs              Xerox              Boggs@PARC
   Steve Butterfield        Xerox              Butterfield@PARC
   Dave Redell              Xerox              Redell@PARC
   John Shoch               Xerox              Shoch@PARC
   Larry Stewart            Xerox              LStewart@PARC
   Ed Taft                  Xerox              Taft@PARC

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