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.
II. OVERVIEW AND OBJECTIVES - Cerf
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.
III. STATUS REPORTS
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
Altos.
There will be an improved Telnet server on Multics soon, and a
mail queuer for local net users. IP reassembly code will be
added.
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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
interconnection.
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
driver.
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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IV. DOCUMENT STATUS - Postel
Jon reported that the following documents were issued since the last
meeting:
IEN 120 by Radia Perlman on "Internet Routing and the Network Portion
Problem."
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
Discussion)."
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
versions.
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
Meeting."
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
and
"Congestion Control" by Dave Clark.
V. FAX STATUS - Cerf
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.
VI. INTERNET MAIL - Postel
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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VIII. GATEWAY MONITORING - Flood Page
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.
IX. DEMOS
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.
XI. PUP-IP COEXISTENCE - Cohen
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.
XII. DELTA-T PROTOCOL - Watson
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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XIII. LIMITING PACKET LIFETIMES - Sloan
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
ISI.
XV. PORT EXPANDER - Lieb
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.
XVI. SERVICES IN AN INTERNET ENVIRONMENT - Rom
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."
XVII. NBS STANDARDIZATION - Wingfield
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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XVIII. INTERNET PERFORMANCE - Davies
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.
XIX. CONGESTION CONTROL - Mills
Dave described some measurements of TCP traffic between the COMSAT
DEMO Terminal and ISIE. There is evidence of lost and delayed
packets.
It seems clear from this and the preceeding discussion that a
definite effort is needed to isolate and correct these performance
problems.
XX. MISCELLANEOUS - Cerf
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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XXI. NEXT MEETING - Cerf
The next meeting is scheduled for 14 & 15 May at MIT. The contact is
Dave Clark (Clark@MIT-Multics).
XXII. DOCUMENTS DISTRIBUTED
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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XXIII. ATTENDEES
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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