AAUI - test-drb@ccmp.vtda.org

27 Mar 2001

On Mar 28,  1:33, Tony Duell wrote:
...
 On Mar 28,  0:52, Iggy Drougge wrote: 
...
  > As for impedance, I was under the impression,
judging from the current
 > discussion on the topic of 10B5 wiring, that the actual work of making the
AUI
...
   output
ethernet-worthy lay in the transceiver. 
 That's one part of it. But the AUI interface is part of the standard too
 -- any device should be able to work with any transceiver. The AUI
 interface consists of 3 differential ECL signals (AC coupled
 essentially), which should be carried on twisted-pair transmission lines
 (I think the characteristic impedance is somewhere around 100 Ohms, but
 don't quote me on that). 
78 ohms.  The standard also specifies maximum length of 50m for the thick
AUI cable, but "office grade" cables have higher losses and are typically
only rated for a quarter of that.

-- 

Pete						Peter Turnbull
						Network Manager
						Dept. of Computer Science
						University of York