[IP] Re: NSF and the Birth of the Internet

[David Farber <dave@farber.net>]

Begin forwarded message:

From: Seth <sethb@panix.com>
Date: August 20, 2008 4:25:16 PM EDT
To: dave@farber.net
Cc: steve@shinkuro.com
Subject: Re: [IP] NSF and the Birth of the Internet

Steve Crocker <steve@shinkuro.com> wrote:

> Western Electric series 303 modem.  12 voice grade lines multiplexed
> to achieve 50,000 bits per second.

Conditioned voice-grade lines.  In those days, if you claimed you
couldn't get 300 baud on a voice-grade line, they'd tell you that such
lines were rated at 110 baud, and you needed to pay for a better grade
if you wanted 300.

> (Not 56Kbps.  56Kbps came later when digital lines came along.)

Thank you.  I remembered 50,000 (from my days at BBN), but everyone
else kept claiming 56K.

> They partitioned the eight bit field into a six bit IMP address and
> a two bit host address, so the maximum number of sites was 63.  (I
> don't think 0 was a permitted address, but I don't recall why.)

IMP 0 was the Network Control Center (a PDP-1, IIRC).  It ran special
software.

Back in those days (early 1970's), ATT Long Lines didn't like to
believe us when they got a phone call from Cambridge MA telling them
that a line in California was down.  They didn't see how we could
possibly know that.

Seth Breidbart




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