Subject: Are framing errors and collision errors normal?
To: None <tech-kern@NetBSD.ORG>
From: Dave Huang <khym@bga.com>
List: tech-kern
Date: 12/12/1997 21:15:58
Are framing errors, FCS errors, and collision errors fairly normal on a
busy ethernet? I've had some reports of those from people who are using my
AMD MACE driver on a busy network. I notice that the AMD LANCE doesn't
print collision errors at all (in am7990_intr(), the check for LE_C0_CERR
is in an #if 0 block); the framing error (LE_R1_FRAM) and crc mismatch
(LE_R1_CRC) messages are only printed #ifdef LEDEBUG (see am7990_rint).

Should I do the same in the MACE driver? According to the MACE
documentation:

CERR  Collision Error. CERR indicates the absence of the Signal Quality
      Error Test (SQE Test) message after a packet transmission. The
      SQE Test message is a transceiver test feature. Detection depends
      on the MACE network interface selected. In all cases, CERR will
      be set if the MACE device failed to observe the SQE Test message
      within 20 network bit times after the packet transmission ended.

FRAM  Framing Error flag. Indicates that the received frame contained a
      non-integer multiple of bytes and an FCS error. If there was no
      FCS error then FRAM will not be set. FRAM is not valid during
      in-ternal loopback. FRAM will not be set if OFLO is set.

FCS   FCS Error flag. Indicates that there is an FCS error in the
      frame. The receive FCS is computed and checked normally when
      ASTRP RCV = 1, but is not passed to the host. FCS will not be set
      if OFLO is set.
--
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