Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!hayes!tnixon
From: tnixon@hayes.uucp
Newsgroups: comp.dcom.modems
Subject: Re: Any way to get rid of 'end of session' gobbly goop on v.32
Message-ID: <3939.282a9a30@hayes.uucp>
Date: 10 May 91 13:03:44 GMT
References: <422@wybbs.mi.org> <1991May1.160650.7799@unlinfo.unl.edu> <3267@unocss.unomaha.edu>
Organization: Hayes Microcomputer Products, Norcross, GA
Lines: 24

In article <3267@unocss.unomaha.edu>, fg041@unocss.unomaha.edu
(fg041) writes: 

> I have never heard of the v.32 standard including a 'sanitary' session
> shutdown.  I would think that SOME noise would be unavoidable if the line
> is simply broken.  On the other hand I can visualize some kind of
> termination handshake which prevents it.  Anyway, you got me very curious
> about it.

Well, it's not called "sanitary session shutdown" in V.32.  It's 
known as "GSTN Cleardown".  What the modem does is initiate a 
retrain request, but turn off all of the "rate bits" that indicate 
the speeds at which it is willing to operate.  This condition 
(unwilling to operate at any speed) is defined as requesting the 
call to be cleared.  Most modems WILL properly hang up if they 
RECEIVE such as cleardown sequence, but not all modems generate it 
in response to a request for disconnection from their local DTE 
(with DTR drop or ATH command).

-- 
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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