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

[Vint Cerf]

thanks John -
the last point about speed adaptation is a key value in packet switching as
long as there is also adequate flow control.
The ability to link at different speeds and do store-and-forward is one of
the major attractions of packet switching.
v


On Wed, Jan 10, 2024 at 3:26 PM John Shoch via Internet-history <
internet-history at elists.isoc.org> wrote:

> 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
> --
> Internet-history mailing list
> Internet-history at elists.isoc.org
> https://elists.isoc.org/mailman/listinfo/internet-history
>


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