Newsgroups: comp.dcom.lans
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: yet another problem with Ethernet transceiver-cable clips
Message-ID: <1988Sep15.191100.17488@utzoo.uucp>
Organization: U of Toronto Zoology
Date: Thu, 15 Sep 88 19:11:00 GMT

This is probably of more general applicability...  We recently had a nasty
problem with an Interlan NI1010A Ethernet interface:  lots and lots of
collisions, to the point where packet transmission was seriously hampered.
This (Unibus) controller brings the signals off the board using a flat
cable that is easy to run out through a card cage; the flat cable ends in
a little panel with a normal transceiver-cable connector.  We'd tacked
that panel up on the back of one of our racks.  I'd noticed earlier that
the #@#$%$%@# clips were not holding the cable onto the connector quite
as tightly as they could, and in particular the connector was a bit
farther out from the panel at the top than at the bottom, due to the
weight of the cable pulling on it.  Just on a hunch, I walked back and
pressed the connector firmly in.  Suddenly the console chatter ceased.
Presto, no more collisions.  Needless to say, there is now a nice tight
cable tie holding that connector firmly against the panel.

Note that the contact was not bad enough to actually make transmission
impossible!  This was what had me fooled for the longest time; I knew
from our Suns that the stupid clips didn't always hold snugly enough to
maintain contact, but I had sort of thought that contact was boolean:
either yes or no.  Silly me...
-- 
NASA is into artificial        |     Henry Spencer at U of Toronto Zoology
stupidity.  - Jerry Pournelle  | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
