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From: tnixon@hayes.uucp
Newsgroups: comp.dcom.modems
Subject: Re: Penril Alliance V32 and Zoom Modem problem
Message-ID: <3789.27c251f8@hayes.uucp>
Date: 20 Feb 91 10:39:52 GMT
References: <5975@oasys.dt.navy.mil>
Organization: Hayes Microcomputer Products, Norcross, GA
Lines: 34

In article <5975@oasys.dt.navy.mil>, lrogers@oasys.dt.navy.mil
(Larry Rogers) writes: 

> a) Does the reciving modem initiate the discussion of what protocols are to be
> used?

The answering modem always transmits first, and the calling modem 
listens.  I don't know whether or not the Alliance V.32 uses the 
CCITT Automode procedure, but if it does, it interworks with V.22bis 
modems by first sending an answer tone (with phase reversals in it, 
in case the calling modem is V.32), the follows this by three 
seconds of the Unscrambled Binary 1 signal (2250Hz plus 2850Hz 
together) that a V.22bis modem expects to see.  Perhaps the Zoom 
needs more than three seconds, or perhaps it is confused by the 
phase reversals in the answer tone.  Hard to say.

> b) Are there any known problems with these two modems talking to each other?
> 
> c) Are there any Penril paramters i should try changing to accomodate this
> problem?  

If I were in your situation, I would call Penril Technical Support 
and ask these questions.  It's possible that Penril has a parameter, 
as do Hayes modems, to extend the USB1 transmission time from 3 
seconds to a larger value, in case your Zoom modems need more time 
(but they shouldn't; the standard says they should respond after 
only about 600 msec of USB1).  Unfortunately, Zoom is not known for 
quality.

-- 
Toby Nixon, Principal Engineer    | Voice   +1-404-840-9200  Telex 151243420
Hayes Microcomputer Products Inc. | Fax     +1-404-447-0178  CIS   70271,404
P.O. Box 105203                   | UUCP uunet!hayes!tnixon  AT&T    !tnixon
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