[comp.dcom.modems] Any way to get rid of 'end of session' gobbly goop on v.32

rickt@wybbs.mi.org (Rick Tucker ) (05/01/91)

I have recently started using v.32 modems and have noticed that
when you terminate the connection(via loging out of the host) 
that you get a steady stream of 'the unknown'.
Any way to prevent this.
It really freaks out the terminal, and attached printer.

I am using a MultiModem V32 (mt932ea)
The other(host) sites are using mt932ea and a US Robitics V.32(whatever)

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Rick Tucker                        |     ^^  T W I N   P E A K S  ^^ 
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ho@hoss.unl.edu (Tiny Bubbles...) (05/01/91)

rickt@wybbs.mi.org (Rick Tucker ) writes:

>I have recently started using v.32 modems and have noticed that
>when you terminate the connection(via loging out of the host) 
>that you get a steady stream of 'the unknown'.

>I am using a MultiModem V32 (mt932ea)
>The other(host) sites are using mt932ea and a US Robitics V.32(whatever)

That's very strange.  The V.32 spec is *supposed* to kill connections
cleanly, without any garbage.  You will, however, get a LOT of garbage
after using a V.32 modem on non-reliable connections.

Does this happen when you're going MT<->MT, or only when one of the
modems is a USR?

>========================================================================
>Rick Tucker                        |     ^^  T W I N   P E A K S  ^^ 
                        alas...     |     "Dead, wrapped in plastic."
                                    |           quote from ABC
--
        ... Michael Ho, University of Nebraska
Internet: ho@hoss.unl.edu  |  Harry was too homely for Sally.  (I have proof.)
Disclaimer:  Views expressed within are purely personal and should not be
	     applied to any university agency.

gandrews@netcom.COM (Greg Andrews) (05/02/91)

In article <422@wybbs.mi.org> rickt@wybbs.UUCP (Rick Tucker ) writes:
>I have recently started using v.32 modems and have noticed that
>when you terminate the connection(via loging out of the host) 
>that you get a steady stream of 'the unknown'.
>Any way to prevent this?
>

If your modem has error correction (a la MNP or V.42) and the other modem(s)
can support it, then try turning it on.  If not, then your best bet is to
beat the host to the punch and make YOUR modem disconnect before the
garbage characters begin to show up.

>Rick Tucker                        |     ^^  T W I N   P E A K S  ^^ 

-- 
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 |  Greg Andrews   |       UUCP: {apple,amdahl,claris}!netcom!gandrews    |
 |                 |   Internet: gandrews@netcom.COM                      |
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fg041@unocss.unomaha.edu (fg041) (05/06/91)

>>I have recently started using v.32 modems and have noticed that
>>when you terminate the connection(via loging out of the host) 
>>that you get a steady stream of 'the unknown'.

>That's very strange.  The V.32 spec is *supposed* to kill connections
>cleanly, without any garbage.  You will, however, get a LOT of garbage
>after using a V.32 modem on non-reliable connections.

>Does this happen when you're going MT<->MT, or only when one of the
>modems is a USR?

I have noticed this frequently when calling Intel 9600ex modems from the 
USR Courier HST.  I'm not sure which modem is at fault (both ??) but I will
often get half a screenful of garbage before the session dies.

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.
 
Good day!       JSW

tnixon@hayes.uucp (05/10/91)

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).

-- 
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