Path: utzoo!attcan!uunet!cs.utexas.edu!swrinde!ucsd!ucbvax!hplabs!hpda!hpcupt1!hprnd!pat
From: pat@hprnd.HP.COM (Pat Thaler)
Newsgroups: comp.dcom.lans
Subject: Re: CSMA/CD algorithm/code needed
Message-ID: <2230098@hprnd.HP.COM>
Date: 28 Jun 90 00:54:15 GMT
References: <1990Jun25.182126.12942@brutus.cs.uiuc.edu>
Organization: HP Roseville Networks Division
Lines: 16

> 
> For a precise description of the CSMA/CD algorithm of Ethernet, read either
> the Ethernet spec, V2.0 (available from Digital, order number AA-K759B-TK)
> or the IEEE 802.3 standard (ISBN 0-471-82749-5).
> 
For a truely precise description you need to read the 802.3 specification.
An optional improvement to the deferral algorithm was added to 802.3 and
I don't know that it was ever added to the Ethernet spec.  Most controllers
which I know of implement the option.  The option prevents some lost
packets and CRC errors and does not affect interoperability.

For someone who is doing a simulation or trying to get a general understanding
of the 802.3/Ethernet access method, this difference is probably not
significant.  Someone doing a design would need to know about it.  

Pat Thaler