[ih] Internet-history Digest, Vol 50, Issue 6

[John Shoch]

I've gotten a little behind on the Internet History list.....let me try to
catch up.

John Day:  Thank you for providing more background on Cyclades, and its
underlying transport system, Cigale.
Louis Pouzin's group at IRIA was an early advocate of datagram-based
networking, and had the vision to see the importance of connecting diverse
networks into a "catanet" -- although they were not able to implement that
in France.
Vint has noted that Gerard Le Lann was a visitor at Stanford (and is
acknowledged on the Stanford Internet Plaque that Vint organized):
  http://ana-3.lcs.mit.edu/~jnc/history/Internet_plaque.jpg
The Cerf/Dalal/Sunshine early draft of a TCP spec., Dec. 1974, acknowledges
input from IRIA:
"In the early phases of the design work, R. Metcalfe, A. McKenzie, H.
Zimmerman, G. LeLann, and M. Elie were most helpful in explicating the
various issues to be resolved."
  https://datatracker.ietf.org/doc/html/rfc675

Dave Crocker:  You noted that, "... I guess PARC was doing
gatewaying/translation between Arpanet/XNS peers...."
Perhaps I can elaborate a little bit:
--PUP was the first generation of internetwork protocols, developed at
Xerox PARC;  XNS was the second generation, primarily developed at Xerox
SDD (building upon what was learned in Pup -- adding large unique
addresses, etc.).
--When the full PUP architecture was first implemented within Xerox, one
could use PUP FTP to move a file from an Alto to an account on PARC's
MAXC/Tenex machine, and one could use Arpa FTP to move that to another
Arpanet host.  I do not think there was a higher-level protocol translation
to automatically link PUP FTP with Arpa FTP.
--The Arpanet was added as a network within the PUP architecture, but
primarily as a transit network (as was the Packet Radio Network).  The
encapsulation of PUP internet packets within Arpanet messages is described
and diagrammed in the PUP paper by Boggs, et al.:
http://bitsavers.trailing-edge.com/pdf/xerox/parc/techReports/CSL-79-10_Pup_An_Internetwork_Architecture_Jul79.pdf
https://ieeexplore.ieee.org/document/1094684
--When Xerox gave Alto/Ethernet/Dover/PUP systems to a number of
universities (Stanford, MIT, CMU, CalTech, Rochester), I think it included
Nova-based PUP "gateways" (which later led to the Stanford/Cisco
multi-protocol routers).  Thus, a user on an Alto at Stanford could use PUP
FTP to retrieve a file from a PUP file server at CMU -- and the PUP
internet packets would transit through the Arpanet.  [Xerox, Arpa, and the
universities all worked together to enable this.]
--The universities had Xerox PUP file servers;  I don't know if any of them
ran the PUP code on their PDP-10s...maybe someone was there?
--XNS came later....

John Levine made a good observation:  "It occurs to me that it might not
have been obvious that you could run the same network protocol over a 56K
DDS line and a 3Mb Ethernet, glue the two together using simple minded
gateways, and it'd work."
--This is, of course, one of the things that motivated the separate
development of Xerox PUP -- we knew that we had to support 3Mbps local
Ethernet connections to file servers and print servers, while also
supporting 9.6 Kbps inter-site leased phone lines.  It was a design
objective, and it had to be made to work!
--Again, from the Boggs paper:
"The communications environment includes several different individual
network designs. The
dominant one is the "Ethernet" communications network, a local-area
broadcast channel with a
bandwidth of 3 megabits per second [Metcalfe & Boggs, 1976]. Long-haul
communication facilities
include the Arpanet, the ARPA Packet Radio network, and a collection of
leased lines implementing
an Arpanet-style store-and-forward network. These facilities have distinct
native protocols and
exhibit as much as three orders of magnitude difference in performance."

Cheers,

John Shoch