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From: davidg%aegis.or.jp@kyoto-u.ac.jp (Dave McLane)
Newsgroups: comp.dcom.modems
Subject: Controlling answer tone sequence
Message-ID: <22HgZ1w163w@aegis.or.jp>
Date: 26 Mar 91 07:16:24 GMT
Organization: Aegis Society
Lines: 27

But while we're talking about USRobotics that's always
puzzled me: I take it that they are used for UNIX where everything
has to be set into the RAM with AT&W so UNIX doesn't allow any
modem init each call (as far as I know). 

But the USR DS I have will start it's answer tone cycle at the 
speed of the previous caller.  That is, if somebody linked at, say, 
1200 BPS and logs off, the next caller gets an answer tone sequence 
of 1200->300->HS->9600->2400->1200...  Thus if the next caller
wants to link at, say, 2400 BPS, they must lock their speed at 2400
BPS (a feature not available on a lot of the modems for sale here)
or the calling modem changes speed to the first answer tone (1200)
and there is a mismatch.

Two questions come from this:

My solution for this is has always been to re-init the modem to the 
highest speed with at least an ATH command so the answer tones
always go from high to low.  But this isn't possible with UNIX, is it?

Somebody has suggested that it is only Japanese-made modems that 
change speed on call as well as answer. The USRobotics I have 
doesn't change on call but all the Japanese modems I've tested do
(Aiway, Omron, Epson). What about other US-made modems, do they
change speed on call as well as on answer?

--Dave