[ih] Early interconnection between Ethernets and Arpanet

Thu Mar 11 14:53:53 PST 2010

thanks for the lovely details! apologies to Larry Stewart - I knew it was
Larry something....

v

On Thu, Mar 11, 2010 at 4:02 PM, John Shoch <shoch at alloyventures.com> wrote:

>  Friends,
>
> As I recall, Parc's initial Arpanet connection came via an IMP provided by
> Arpa.  The Xerox MAXC machine (a micro-programmed pseudo-PDP10) had a Data
> General Nova as a front-end, and that was outfitted with an IMP interface.
> Thus, we had Arpanet access for Maxc -- and email!  But that was not an
> internet.
>
> Although the work started much earlier, the PUP architecture was first
> publically described in a Xerox PARC blue-and-white report in 1979,
> available here:
> http://www.bitsavers.org/pdf/xerox/alto/pupArch.pdf
>
> The following year, the full paper was published in the IEEE Trans. on
> Comm.
> D. R. Boggs, J. F. Shoch, E. A. Taft, and R. M. Metcalfe, "Pup: An
> Internetwork Architecture," IEEE Transactions on Communications, April 1980.
> [I'm not sure what it takes to access an online version of this, through
> the IEEE.]
> [We really do need to get a scanned, OCR'd version of this online......]
>
> The system initially used a set of "gateways" (now called routers)
> connecting end-user machines on Ethernets, on the Data General MCA, and
> other systems.  The gateways were connected by leased lines, to provide our
> own packet-switched backbone;  we also used the ARPANET and the Packet Radio
> Network as transit networks, between PUP gateways.
>
> Some excerpts from the paper:
>
> "This work serves as the basis for a functioning internetwork system that
> provides service to about 1000 computers, on 25 networks of 5 different
> types, using 20 internetwork gateways."
>
> "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 bandwidth."
>
> "We distinguish two kids of gateways:  media translators and protocol
> translators. Media gateways are hosts with interfaces to two or more packet
> transport mechanisms among which they forward internet datagrams, using the
> appropriate encapsulation for each. ... Protocol gateways are hosts which
> speak two or more functionaly similar but incompatible higher-level
> protocols used to transport information within networks, mapping one higher
> level abstraction into the other."  [Our gateways were packet-style media
> translators;  I don't believe we ever built a PUP-to-TCP protocol
> translator.]
>
> "ARPANET:  To cover longer distances, Pups can be routed throug the
> ARPANET;  the format for encapsulating a Pup in an ARPANET message is shown
> in Fig. 2."
>
> "Packet Radio Network:  On an experimental basis, the ARPA packet radio
> network has been used to carry traffic among local networks in the SF Bay
> area."
>
> "The Pup archiecture emerged against a background of ARPANET protocols.
> Many of its important ideas -- and those of its key relative, TCP -- first
> appeared during the coure of a series of meeting[s] of the International
> Network Working Group (IFIP TC-6 WG6.1) during 1973.  Pup and TCP share a
> number of important principles....."
>
> Hope this helps.
>
> John Shoch
> Alloy Ventures
>
> PS:  Use of the Packet Radio net (based at SRI) as a transit network for
> Pup was driven by "the other Larry" -- Larry Stewart.  That work was also
> published in 1979:
> http://portal.acm.org/citation.cfm?id=800092.802993  Thanks again, Vint,
> for helping to make the PRNet available for our experiment!
>
> PPS:  I met Danny Cohen through the TCP working group meetings;  he and I
> had fun figuring out how you might encapsulate Pup packets in TCP packets,
> and TCP packets in Pup packets -- what we called mutual encapsulation.  The
> paper, with Ed Taft, was published in 1981:  Shoch, Cohen, and Taft,
> Mutual Encapsulation of Internetwork Protocols", Computer Networks 5,
> North-Holland, 1981, 287-300.
>
>
>
>
>
> -----Original Message-----
> *From:* Vint Cerf [mailto:vint at google.com]
> *Sent:* Thursday, March 11, 2010 3:32 AM
> *To:* Matthias Bärwolff; Bob Metcalfe; John Shoch; Yogen Dalal; Larry
> Masinter
> *Cc:* internet history
> *Subject:* Re: [ih] Early interconnection between Ethernets and Arpanet
>
> there were gateways into the ARPANET from the Xerox PARC Ethernet. At least
> one of gateway was built using a packet radio as part of an early internet
> experiment. What I don't recall is whether this was a protocol converting
> gateway (from Xerox' PARC Universal Packet and associated TCP-like protocol
> to TELNET/NCP for example or whether there was an early TCP running on,
> e.g., either an ALTO work station or the MAXC server). PARC also had an
> ARPANET IMP (or TIP?) and connected the MAXC into the ARPANET as an NCP
> host. The Ethernet would have linked the ALTOs into the MAXC machine. PUP
> was being developed at the same time as TCP/IP so I expect there was
> protocol conversion going on somewhere; possibly in MAXC.
>
> I am not sure whether Bob Metcalfe, Yogen Dalal and John Shoch are on the
> history list so I am copying them directly. Bob and John were at PARC during
> the TCP/IP and PUP developments; Yogen was at Stanford working on TCP/IP
> during the 1974-1976 period and later joined PARC to work on XNS (Xerox
> Network System) that grew out of the PUP experiments. If I remember
> correctly, Larry Masinter did the work to link the Ethernet at PARC with the
> Bay Area Packet Radio network with a packet radio on the premises.
>
> vint
>
>
> On Thu, Mar 11, 2010 at 6:00 AM, Matthias Bärwolff <mbaer at cs.tu-berlin.de>wrote:
>
>> Dear all,
>>
>> is there any documentation (or tacit knowledge on this list) on early
>> Ethernet-Arpanet gateways (obviously other than those built using IP in
>> the late 1970s)? I found some documentation on how Alohanet terminals
>> connected to the Arpanet, and how the NPL guys in the UK connected their
>> IBM machines to their TIP, plus some notes on how people struggled to
>> get the SRI port expanders working; but nothing on the much more obvious
>> candidate, Ethernet, given its early popularity.
>>
>> Sorry if I've just been lazy. Thanks for all hints.
>>
>> Matthias
>>
>> --
>> Matthias Bärwolff
>> www.bärwolff.de <http://www.xn--brwolff-5wa.de>
>>
>>
>
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