[2183] in Athena Bugs
un0: Ethernet Jammed
daemon@ATHENA.MIT.EDU (Jeffrey I. Schiller)
Fri May 5 19:33:43 1989
From: Jeffrey I. Schiller <jis@ATHENA.MIT.EDU>
Date: Fri, 5 May 89 19:33:22 EDT
To: mk@ATHENA.MIT.EDU
Cc: bugs@ATHENA.MIT.EDU
In-Reply-To: <mk@ATHENA.MIT.EDU>'s message of Thu, 4 May 89 17:19:24 EDT <8905042119.AA21540@MOONROACH.MIT.EDU>
This is caused by the fact that your ethernet transceiver is
in W91 and your equipment is located in Next House. The fiber optic
connection in essence extends the transceiver cable. Unfortunately the
interface boards in the RT (and Vax for that matter) don't understand
that this cable is so long, so they think the packets are taking too
long to be acknowledged by the transceiver.
There are two fixes for this problem:
1) Hardware: Purchasing an $8,000.00 piece of equipment, which has
been giving us trouble in other locations where we use it (for other
reasons).
2) The VAX kernel doesn't flame about these delays (it just increments
an internal counter). Change the RT to also not flame on the console
about them.
I prefer the second solution and will suggest it for the next
system release.
-Jeff
