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From: gandrews@netcom.COM (Greg Andrews)
Newsgroups: comp.dcom.modems
Subject: Re: Problems between T2500 and Hayes V series modems?
Summary: Gotta set S50=3
Message-ID: <25116@netcom.COM>
Date: 22 Feb 91 02:19:28 GMT
References: <786@dynasys.UUCP>
Followup-To: comp.dcom.modems
Organization: Netcom - Online Communication Services  UNIX System {408 241-9760 guest}
Lines: 27

In article <786@dynasys.UUCP> jessea@dynasys.UUCP (Jesse W. Asher) writes:
>Has anyone had problems getting a T2500 and a Hayes V series modem
>connected?  I'm having a strange problem - the modems connect but
>connect at 300 or 2400 baud and sometimes the T2500 doesn't get a 
>CONNECT message.  Anyone have any ideas on what could be causing this?

I've seen this several times.  It only happens when the T2500 calls the
V-9600, and the V-9600 is *not* an Ultra 96.  If the V-9600 calls the
T2500, things are fine.  Setting S50=3 (limit the modem to V.22bis and
slower modulations) in the T2500 takes care of the problem and the modems 
connect at 2400 without a hitch.

My best guess is that it's due to a slight confusion between the modems 
when they try to handshake.  The T2500 thinks a V.32 modem answered, and 
the V-9600 seems to think that another V-9600 called.  The two modems try
to proceed with different handshake procedures, and encounter trouble.
By the time they recover, they can't get resynchronized, or they only
get a 300 bps link.  Maybe someone else (Toby?) can say whether this is
what's actually happening, or if it's something else...

Telling the T2500 to act like a plain old V.22bis modem seems to eliminate
the problem.

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| Greg Andrews      |   gandrews@netcom.COM |
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