[ih] Arpanet line speed

[Vint Cerf]

Noel, wasn't it GTE (General Telephone and Electric)?

v


On Wed, Jan 18, 2017 at 9:29 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:

>     > From: Paul Ruizendaal
>
>     > - if the modem from the IMP to the Bell System was analog, the best
>     > technology of the time was perhaps 2.4kb/s ... a speed of 50kb/s is
> not
>     > a multiple of 2.4kb/s, and it would have required 21 parallel lines
>
> If you read the 303 manual, it's clear that i) the signal between a pair of
> 303 modems was analog, not digital, and ii) there was a single line, with a
> wide enough bandpass to carry signals of high enough frequency to carry
> that
> bit rate - it didn't glue together a bunch of slower lines.
>
>     > if the modem from the IMP to the Bell System was digital, it would
> most
>     > likely have used a single channel of a T1 connection
>
> The whole T hierarchy was just getting started then (initial deployment in
> the
> early 1960s), and I'm not sure if it was deployed widely enough to have
> made
> it possible to lease a T1 line from one coast to another.
>
> Also, many of these lines would have crossed non-AT+T local phone companies
> (the Bell System did not control all of the US phone system, although some
> people don't realize that). The "History of the ARPANET: The First Decade"
> (which I have previously pointed you at on another list), pg. III-32, says
> "In the case of a circuit from UCLA to RAND ... the service would be
> procured
> from General Telephone" - GT was the largest independent telephone company
> in
> the US at that point. It's not clear that those local carriers would have
> supported T1.
>
>
> Moral of the story: when doing history, it's bad to make assumptions about
> what was and wasn't possible, and about what did and did not happen. Find
> contemporary documentation.
>
>         Noel
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