Van Jacobson's network stack restructure
Bruce R. Montague
brucem at mail.cruzio.com
Thu Nov 30 06:08:34 UTC 2006
Hi, Frank. re:
> Who's calling? :-)
The original email to which you link above occurred
in a discussion regarding the performance, architecture,
evolution (or somesuch) of the FreeBSD network stack.
The FreeBSD network stack is arguably about the most
direct descendent of the TCP/IP stack that was done
(forked from a BBN stack, I guess) at UC Berkeley.
One reason the UCB (and FreeBSD) stack is of interest
is because it essentially became the "reference
implementation" for the modern TCP/IPv4 implementation.
In university networking classes, noting that the
first TCP link outside of a single lab was between
Stanford and London (and thus that the "Internet"
has always been "International") makes a good story.
Unfortunately it is hard to answer the invariable
follow-up questions. I found very little info
available the last time I looked (a few years ago).
But maybe I missed the obvious.
Did you do the UCL PDP-9 implementation on the first
link? Was it a stand-alone program? What did it do?
Kind of a ping? A test or performance program to
debug things? What was the "network device" like?
Did this program evolve, or was the PDP-9 just too
Was your TCP written in Babbage? Was Babbage an
assembler or a "structured assembly" language with
control flow and expressions? Is there any published
doc on this language (or programming environment)?
How did you work with the Stanford folks? Was the
work with the protocol done to a "wire spec", or did
you look at their implementation? Did you work with
their BCPL version of TCP, or hand-port BCPL to Babbage
assembly code? etc. etc...
Was anything written up and published? Where? (I did
try to contact UCL, to no avail.) Alas, all to often
today if it's not electronically indexed it's as if
it didn't exist. Was this info classified at the
time? (I saw somewhere that the big push for a
portable standard digital network link to Britain
was that Norway happened to have an existing
seismic-monitoring network close to a particularly
interesting Arctic test site... is this true?)
Sorry to go on at length with so many questions.
There was some nice information about a new study
of the Antikythera mechanism today, surely the
mysterious PDP-9 and it's Babbage programming
environment can yield a few clues! :)
Please correct me anyone if I've got something wrong.
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