Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!newstop!sun!amdcad!brahms!phil
From: phil@brahms.amd.com (Phil Ngai)
Newsgroups: comp.dcom.lans
Subject: Re: Ethernet "heartbeat"
Message-ID: <1991May20.164446.23372@amd.com>
Date: 20 May 91 16:44:46 GMT
References: <12164@uwm.edu> <1991May16.004523.21301@berlioz.nsc.com> <104479@sgi.sgi.com> <4682@alliant.Alliant.COM>
Sender: usenet@amd.com (NNTP Posting)
Organization: Advanced Micro Devices, Inc.
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werme@Alliant.COM (Ric Werme) writes:
>What I've never bothered to figure out is why the frames with SQE errors
>doesn't match the number for frames sent.  It may the that the SQE test is
>skipped if the board has another frame to send after one finishes.

SQE is there for the purpose of testing the collision path. If a
transmission is collided with (one or more times) and then later
succeeds, the controller does not require the "heartbeat" after a
successful transmission since the collision path is known to be working
for that packet.

I am not claiming that any particular device works this way, but that
is how it should work.

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