MYERSTON@kl.sri.com (HECTOR MYERSTON) (06/26/89)
Here are (some) answers to your question, although I am sure,
not the one's you want to hear. :-(
The {{{{{s, as you surmised, are modem-generated characters
which indicate unhappiness with the incoming tones from the distant
end device.
The problem is often not noisy lines but phasing and timing
anomalies caused by Analog/Digital and Digital/Analog conversions
in the transmission path. Digital Devices in the path can include
Subscriber Loop Carriers, Central Offices themselves (like the
DMS-100) and inter-office Digital carrier trunks.
You have, for practical purposes, zero control over any of
these and they may, in fact, vary from call-to-call.
These disturbances do not affect voice calls to any appreciable
degree and, since that is what the telephone network is designed for,
are little cause for concern to the average telco (as you found out).
If it is any consolation, we periodically experience this
problem here (Palo Alto CA). Calls to some hosts never fail, others
are constantly thrashed by {{{{{{{{.
The last time we went through this exercise here the end
result was that:
o Yes it is a problem
o Data-grade local loops may (or may not) help
o We can't spend any more of the rate-payers money on this
issue
+HECTOR+
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