mike@amdcad.UUCP (Mike Parker) (02/28/86)
We are considering connecting 7 buildings in Sunnyvale with
fiber optic cable and DEC DEREP-RA's. I have a lot of confidence
in DEC, but I thought I ought to seek user testimonials anyway.
I'd like to hear of your experiences, good and bad, with the RA,
or any other fiber repeater. However, I am most interested in
what I consider large installations. We will have six pairs of
RA's ( glass repeaters ) and one AA ( local repeater ) connected
to a short coax segment, these seven connections will be the
only connections on this segment. The AA will be connected by a
30 meter drop to a 480 meter coax. The RA's will be connected
with 100/140 fiber to remote RA's, the closest is about 250 meters,
the farthest is about 800 meters. The remote RA's will be connected
to coax segments, some as short as 23 meters, one is 460 meters.
Please don't point out that these numbers all meet the ethernet spec,
I know that. I've had experience with other peoples equipment and
it works on small systems, but dies before it gets to spec maximum
numbers. I am hoping that someone will contact me to say "well, I
have 37 buildings connected with DEREP-RA's and it works fine".
Any takers? I am also interested in comments alomg the lines of,
"My RA's work great on 999.99 meters of fiber".
All of the DEREP's will be connected to DEC H4000 transceivers.
But, the system has lots of non-DEC equipment. We have transceivers
from TCL, Interlan, DEC, and probably Excelan and BICC in the
future. We have controllers from DEC ( DEUNA and DEQNA ), 3Com
( 3C400 Multibus and older IBM PC cards ), Interlan ( Auscom,
Spartacus, 1010's in the Vaxen, Calmanet, whatever ), and
Excelan ( in Vaxen ). Now theory has it that ethernet is ethernet,
and everything is compatible at the coax, and this stuff will all
talk to the DEREP's just fine. Experience tells me that ethernet is
50% voodoo and that what works with some might not work with others.
So whose stuff have you got talking through your DEREPs????
Have you found anything that won't???
Thanks for your help.
Mike
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