[ih] invention of multicast addressing
jnc at mercury.lcs.mit.edu
Sat May 8 14:24:07 PDT 2010
> From: Dave Crocker <dcrocker at gmail.com>
>> there was an earlier UC Irvine ring (in the early 70s), and the
>> Mockapetric design that MIT implemented (starting in the fall of '77)
>> was a second-generation design?
> As I recall, the MIT version of the Irvine ring tossed out the process
> addressing table
Ah, no, that was the _second_ ring done at MIT (the so-called 'V2' ring, a
10MBit/second ring done by an MIT/Proteon collaboration), which deleted all
the loadable addressing stuff.
The first ring done at MIT (the so-called 'V1' ring, a 1MBit/second design)
_was_ an Irvine design, and _did_ have all the loadable addressing stuff.
My point (above) was that that 'first' ring at MIT was actually the second
Irvine-designed ring, and there had been an _earlier_ one, at Irvine only.
Exactly what _that_ ring had I don't know, although I have this vague memory
that it had some sort of loadable addressing stuff - but someone who is
familiar with it will have to provide exact details. The details in my first
message (about the 32-bit name and mask) are accurate for the so-called 'V1'
The two 'V1' and 'V2' rings were very different in many other significant
ways too - e.g. the method of dealing with clock variations between stations
(both in speed and phase) were totally different.
> which had taken about a quarter of the board's real estate.
A little more than 1/4, I think, but I don't recall exactly. Ken might
remember in detail.
(And the V1 ring wasn't a plug-in board, but an entire half-height rack unit,
although inside it was just one big horizontal wire-wrapped board. I think
only about 8 were ever made, of which a couple [two, I think] went to UCLA.)
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