[ih] early networking

[John Day]

This has been my contention for decades. There is considerable evidence that it was independently invented several times. Stat muxes were basically packet switches and there were a couple of other places where it appears it was independently invented.  To someone with a computing background, when presented the problem of communicating with another machine. The data is in a buffer, the obvious thing is to pick up the buffer and send it!  Why go to the work of making it look continuous like voice?  ;-)

> On Apr 8, 2024, at 22:51, John Levine <johnl at iecc.com> wrote:
> 
> It appears that John Day via Internet-history <jeanjour at comcast.net> said:
> w>Then the light dawned, as the video relates, message switching was analogous to FCFS batch processesing. Packet switching was analogous to
>> multiprogramming (timeslicing) round-robin scheduling. (To continue the operating system analogy, long messages take a little longer but the
>> completion time for short messages is shorter.) And virtual circuit was round-robin with contiguous memory allocation, and datagrams were a
>> tool for exploring the next step,  but because they handled the immediate problem that step was never taken.
> 
> I suspect this sort of thing has been invented many times.
> 
> In 1956, TAT-1 was the first telephone cable between North America and
> Europe (well, Newfoundland to Scotland) using highly reliable vacuum
> tube amplifiers* to provide 37 voice channels in each direction. It
> was a huge improvement over the former SSB radio and 37 channels
> wasn't enough.
> 
> In 1960 Bell Labs invented Time Assiged Speech Interpolation (TASI.)
> They knew that in a phone conversation each person is only speaking
> about 40% of the time, so when someone paused talking, they'd swap
> another conversation into the channel, and when they resumed, they'd
> put the paused conversation onto a free channel. This smells sort of
> like packet multiplexing although done almost entirely with analog
> equipment. TASI worked well enough that they could put 74
> conversations on the 37 channels with no noticable loss of quality.
> 
> Here's some BSTJ articles about TASI:
> 
> https://archive.org/details/bitsavers_BellSystemJV41N04196207_12232730/page/1438/mode/2up
> 
> R's,
> John
> 
> * - in the two decades TAT-1 was in use there were zero amplifier
> failures. They stopped using it because TAT-6 and -7 each had
> thousands of channels making the early cables irrelevant.
>