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- Newsgroups: comp.sys.sun.hardware
- Path: sparky!uunet!spool.mu.edu!uwm.edu!cs.utexas.edu!torn!utzoo!henry
- From: henry@zoo.toronto.edu (Henry Spencer)
- Subject: Re: To SQE or not SQE
- Message-ID: <BzBqy6.DKo@zoo.toronto.edu>
- Date: Tue, 15 Dec 1992 23:37:16 GMT
- References: <421@ftms.UUCP> <1992Dec11.163708.9208@lokkur.dexter.mi.us> <15876@auspex-gw.auspex.com> <1992Dec14.220053.7368@ccd.harris.com>
- Organization: U of Toronto Zoology
- Lines: 21
-
- In article <1992Dec14.220053.7368@ccd.harris.com> cone@controls.ccd.harris.com (Tom Cone) writes:
- >Case: SUN Sparcstation-2 with thick-net port.
- > When I connect it to the thick-net transceiver should I have SQE
- > (heartbeat) in or out? Why?
-
- In. This tests continuity of the collision-detect wires in the AUI cable
- and connectors on every packet sent. Most any modern machine expects this.
- It is desirable because it detects failures that are otherwise very hard
- to spot and can degrade network performance quite significantly.
-
- The only exception is that transceivers attached to repeaters should have
- SQE out; for complex reasons, repeaters are built to expect this.
-
- > I have heard you need it in to comply with IEEE802.3 standards. Is
- > this true? If so what section is it in?
-
- The SQE test is an integral part of the 802.3 base standard; it's mentioned
- all over the place in it, if I recall correctly.
- --
- "God willing... we shall return." | Henry Spencer @ U of Toronto Zoology
- -Gene Cernan, the Moon, Dec 1972 | henry@zoo.toronto.edu utzoo!henry
-