RE: Wide Area Networking for the Rest of US - the debate on BER a nd other issues

[Rohit Sharma <RSharma@xxxxxxxxxxxxxxxxxxx>]

Its hard to see whether such a "knob" would do anything for optical gear
(Tx, Rx, amps) under operation.  I agree with Drew that the most one can
gain is looser specs on the design end...

Also, remember that the difference between a 10^-12 and 10^-10 BER is merely
a few dB at best (in absence of floors) if you look at the 'waterfall' BER
curves.  Once the Tx, Rx, amps are designed (and installed) for a certain
BER objective, operating them for a worse BER (e.g. reducing the launch
power at the transmitter) doesn't result in cost savings.... so the "knob"
is fairly static in any case.

-rohit
Optical Networks

> -----Original Message-----
> From: Drew Perkins [mailto:drew.perkins@xxxxxxxxxxxx]
> Sent: Friday, June 04, 1999 10:24 AM
> To: 'bill.st.arnaud@xxxxxxxxxx'; 'Larry Miller';
> 'stds-802-3-hssg@xxxxxxxx'
> Subject: RE: Wide Area Networking for the Rest of US - the 
> debate on BER
> a nd other issues
> 
> 
> 
> Bill,
> 	I concur completely with your analysis of BER vs. RED. 
> But I still
> don't believe that a BER "knob" would be very useful to anyone. BER is
> really a side-effect of controlling something else, so you 
> really can't
> control BER directly. The other things that could be 
> controlled include:
> output launch power, loss (distance) between transmitter and receiver,
> receiver sensitivity, bit rate, and probably a few other 
> things. Some of
> these things, such as output launch power or receiver sensitivity, are
> controllable at the time equipment is designed. Thus I don't 
> see these as a
> "knob" so much as simply a looser spec. Other things, such as loss
> (distance) between  are in the direct control of the end-user, but are
> fairly static. I don't see these as "knobs" either.
> 
> How are you defining "knob"? Is it a setting that can be controlled by
> network management? Is it a design parameter that can be 
> controlled by the
> equipment designer? The network designer?
> 
> Drew
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