[e2e] Protocols breaking the end-to-end argument
William Allen Simpson
william.allen.simpson at gmail.com
Mon Oct 26 06:54:09 PDT 2009
Craig Partridge wrote:
>> It wasn't until CLNP that I ever perceived a 'war' (or competition). To
>> me, it was always apparent that the war wasn't with the protocols per
>> se, but rather the corporate entities that wanted to control pricing.
> I find this historical discussion interesting because it suggests some
> very different vantage points.
Yes. Mine was much closer to the view of Noel Chiappa, where he says:
# Frankly, for most of us, we were up to our asses in alligators getting all
# these various new technologies (LANs, etc) up and running, and didn't have a
# lot of time to worry about anything else anyway. What little time we did have
# for deep thinking went to things like how to better organize OS software to
# deal with networking, etc, etc.
But I'd also the experience of actually trying to order links. It was
quite difficult. Then, AT&T required putting these little gray boxes on
every data line, and charging double (or more) the usual voice rate. We
took the box apart, and discovered that we could build the same thing for
less than 35 cents retail, but they were charging hundreds of dollars per
So, for me, the Green decision couldn't have come soon enough. And we
did everything under the sun to avoid AT&T links. Maybe that's the
underlying reason that X.25 wasn't a competitor, as we were using it as
little as possible.
> My vantage point was close to John Day's. I was at BBN (arrived in 1983)
> and there were internal debates of TCP/IP vs. TP0/X.25 with the additional
> twist that folks like John and Ross Callon were working to develop TP4/CLNP
> to compete with TP0/X.25.
By 1981, I'd left the University for a small startup that did front-end data
concentrators (using the HP 21MX with nicely re-programmable microcode for
handling data). Over a couple of years, we did a couple of dozen protocols,
none of which were X.25.
By 1983, I'd become a full-time consultant. Auto companies and suppliers,
political campaigns -- none of them ever expressed any interest in X.25.
Lots of serial multi-point cabling connected to front-ends talking to
back-ends over various proprietary data channels or (thick) ethernet in
electronically noisy, chaotic environments.
> But the big fight was TCP/IP vs. TP0/X.25 (or, more truthfully, my recollection
> was the fight was TCP vs. X.25 -- where to put the smarts...)
Believe me, there is nothing that can better reinforce the absolute
necessity for end-to-end transmission control than heterogeneous networking
on a factory floor over multiple hops, or with a satellite link in the
middle. Nothing else actually works! More important, nothing else is
testable by a factory electrician or (usually mechanical) engineer that
has to debug and fix the link. The smarts has to be located in the CPE.
If folks at BBN were still talking about X.25, they were way behind the
curve, or were badly infected with severe standard-committee-itis.
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