[ih] Fwd: early networking

[John Day]

Sorry forgot to hit reply-all

> Begin forwarded message:
> 
> From: John Day <jeanjour at comcast.net>
> Subject: Re: [ih] early networking
> Date: April 9, 2024 at 06:19:40 EDT
> To: "John R. Levine" <johnl at iecc.com>
> 
> Could you elaborate a bit?  What is S/F?
> 
> There seems to be a convergence of ideas here. 
> 
> As to the operating system analogy, it is also interesting that the developments in communications seem to track the developments in operating systems reasonably closely.
> 
> John
> 
>> On Apr 8, 2024, at 23:55, John R. Levine <johnl at iecc.com> wrote:
>> 
>>> 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?  ;-)
>> 
>> If you look at that BSTJ, the article before the one about TASI is about sharing trunks between direct (i.e. voice) and store/forward traffic, using the S/F to fill in the gaps between direct uses.  So, yeah.
>> 
>> R's,
>> John
>> 
>>>> 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.
>>>> 
>>> 
>>> 
>> 
>> Regards,
>> John Levine, johnl at taugh.com, Primary Perpetrator of "The Internet for Dummies",
>> Please consider the environment before reading this e-mail. https://jl.ly
>