[e2e] Protocols breaking the end-to-end argument
William Allen Simpson
william.allen.simpson at gmail.com
Thu Oct 29 01:29:31 PDT 2009
Dave CROCKER wrote:
> Dave Eckhardt wrote:
>> Richard Bennett wrote:
>>> [...] Ethernet only became dominant when we dumped CSMA/CD for
>>> the collision-free, flow controlled, full duplex switches that
>>> we use today.
>> In the two environments I'm familiar with, Ethernet had firmly
>> crowded out everything else (and there were other things: IBM
>> Token Ring, Corvus OmniNet, AppleTalk over PhoneNet, LattisNet,
>> etc.) when it was still half-duplex thin-net, which was replaced
>> by 10-megabit twisted-pair into hubs, *then* 100-megabit
>> twisted-pair into switches.
> Yup. "Ethernet" collision-free switches came quite a bit after real
> ethernet dominated LANs.
Agreed, as to multi-point LAN technology, but only after circa 1990. One
of the environments that I wrestled with during the '80s was considered
the largest thicknet installation in the world. But even then, terminals,
computers, and entire facilities were primarily connected with one or
more variants of a poll-select protocol over RS-232. There were usually
two serial connectors on every machine (with no ethernet at all).
Even today, there are *far* more point-to-point WAN links than ethernet.
I have the advantage of working on far more than 2 facilities. Token
ring and related were never more than fragile and overpriced disasters.
The market spoke, even when big industry was trying to force them down
The pedant that interrupted this thread appears to be fairly clueless
about real deployment. And his economic analysis is ... ill-informed.
Perhaps that's a reason that IEEE 802 development in general was so
conservative and poorly done.
More information about the end2end-interest