[ih] Baran and arbitrary reliability from arbitrarily unreliable components
jnc at mercury.lcs.mit.edu
Thu Mar 12 00:01:41 PDT 2009
> From: <mbaer at cs.tu-berlin.de>
> I gather from your responses that the intellectual influence of Baran
> is significant, and that many of the now commonplace ideas about
> networking are due largely to him (and Pouzin).
Well, many, but not all. I don't have time right now to accurately assign
credit for all of contemporary networking... :-)
> I recall having read in several places that ARPA had not been
> influenced by Baran's work at all, and Roberts only had been made aware
> of Baran's work by Davies in the 1967.
This is a complex subject, and I think it's fair to say that most historians
of technology who have looked at this think Baran's work _probably_ (more
about this below) did have considerable influence on the ARPAnet work, as do
To start with, I will point you at the two best academic histories (Arthur
Norberg, Judy E. O'Neill, "Transforming Computer Technology: Information
Processing for the Pentagon" and Janet Abbate, "Inventing the Internet"),
both of which give the history in quite some detail. M. Mitchell Waldrop's
biography of Licklider, "The Dream Machine", also covers it.
There was a lengthy discussion of the topic of credit for the concepts of
packet switching at:
and although you can't trust anything you read in Wikipedia, the debate there
cites sources you can go read for yourself. You might also want to look at
this oral history interview with Baran:
where he does things like list entries from his personal calendars showing
various ARPA network luminaries visiting him, in the period before the ARPA
network was specified. (Human memories are so fallible, _contemporary_
written records are the 'gold standard' for historians.)
However, having said all that... I don't think that at this distance we will
ever be able to say with _absolute certainty_ what his influence was.
That is because we'll never be able to find/prove things like 'A read Baran's
document, and mentioned it in the hallway to B, who then said something to C
at ARPA', or 'P read the Baran document, forgot the details in his concious
mind, but then subconciously reused the ideas later when they started thinking
All we can say _for sure_ is 'these ideas were laid out by Baran before
anyone else that we have definite record of, and his ideas were _widely_
propogated some years before the ARPA network work'.
Although that's not necessarily definitive as to influence, because Davies was
pretty sure he'd never heard of Baran's work when he started to think about
networking some years later. (Davies heard about Baran from someone at the
MoD, when he gave a presentation there.) So clearly not everyone heard about
them. But maybe he just didn't remember a fifth-hand conversation in a hallway
some years before... :-(
> Has the RFQ in 1968 been written in complete ignorance of Baran's work?
My recollection (from reading the stuff above) some years ago that by the
time they got to the stage of writing the RFQ, Baran had been 'discovered'
and consulted. But read the histories above, they will have the detail.
> After all, it envisages packet orientation and distributed routing.
Yes... but the routing mechanism (and many of the other details) of the
ARPAnet were rather different. (Read the IMP paper in IFIPS to find out
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