[ih] TCP adoption in 1984

[Noel Chiappa]

    > From: Bill Nowicki

    > PUP (and I think ChaosNet?) did not require ARP

I originally skimmed past this message, but on seeing it again, it has some
confusions in it that I ought to correct, so there's no error in the record.


First, I personally have no experience at all with PUP running over 10MB
Ethernet; I'd never even heard of it being done. Obviously, if it were done,
it would have needed something with the functionality of ARP, to turn PUP
addresses into 48-bit addresses (for wrapping packets with, for
transmission). I looked to see if there was such a thing, and found this:

  When a PUP level one packet is transported by an Ethernet, or an NS level
  one packet is sent on Experimental Ethernet, the level one host number cannot
  be used as the level zero address, but rather some means must be provided
  to determine the correct level zero address. Xerox solved this problem by
  specifying another level-one protocol called {it translation} to allow
  hosts on an Experimental Ethernet to announce their NS host numbers, or
  hosts on an Ethernet to announce their PUP host numbers. Thus, both the
  Ethernet and Experimental Ethernet Level Zero Protocols totally support
  both families of higher level protocols.

    https://xeroxparcarchive.computerhistory.org/erinyes/lispmanual/EtherOverview.im!2

So, something like ARP, but not ARP.


Second, the CHAOS protocol (something different from Chaosnet hardware - the
MIT AI Lab guys unwisely used the same name for both) definitely did use ARP,
because ARP was created in part to allow the CHAOS protocol to run on 10MB
Ethernets (same issue - where does one get the 48 bits from, given the 16-bit
addresses in CHAOS protocol). DCP and I had CHAOS protocol _and_ IP in mind
as clients for ARP when we designed it.

DCP was a CHAOS guy; he was part of the MIT AI Lab crowd, and they wanted
nothing to do with TCP/IP at the time when ARP was done - November, 1982. He
wound up writing the RFC, not me, is all (I'm not positive why; I was
probably too busy, or something like that). One can tell I had a lot to do
with the design, because of the generality - an attempt to make sure it had
the maximal lifetime - at which I think it succeeded.

	Noel