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Path: utzoo!utgpu!water!watnot!watcgl!onfcanim!dave
From: dave@onfcanim.UUCP
Newsgroups: comp.graphics,comp.unix.questions,comp.sys.misc
Subject: Re: Silicon Graphics Iris 3130 Reliability
Message-ID: <15247@onfcanim.UUCP>
Date: Tue, 10-Mar-87 10:31:25 EST
Article-I.D.: onfcanim.15247
Posted: Tue Mar 10 10:31:25 1987
Date-Received: Tue, 10-Mar-87 21:35:53 EST
References: <4916@bu-cs.BU.EDU> <9914@sri-spam.istc.sri.com>
Reply-To: dave@onfcanim.UUCP (Dave Martindale)
Organization: National Film Board / Office national du film, Montreal
Lines: 20
Keywords: Iris,Silicon Graphics
Xref: utgpu comp.graphics:365 comp.unix.questions:1309 comp.sys.misc:434

In article <9914@sri-spam.istc.sri.com> brunner@sri-spam.UUCP (Thomas Eric Brunner) writes:
>
>Due to the SGI-only XNS dependency, and the TCP-on-a card of the 1986 IRIS,
>it is a very hard machine to use in a distributed workstation environment,
>where some of the workstations just happen to be very sharp color graphics
>boxes.

Until the current (3.5) release, TCP was done via some code that was
downloaded into the Ethernet controller.  It was a dog - we were pushing
a lot of data through the ethernet, and the controller (or just a current
TCP connection) would hang quite regularly.  We actually had to have
a background process that would detect a hung connection and reboot the
machine in order to get it back.  It was slow too - about half the
throughput of XNS.  We eventually switched back to XNS, even though
getting SGI's binary distribution of their 4.2BSD XNS driver to work
with our modified 4.2 kernel was a lot of work.

The current version of TCP is in the UNIX kernel, not the Excelan one.
Also, SGI has switched to TCP as their standard protocol, making XNS
an option.