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Date:      Sat, 21 Dec 1996 19:49:58 +0100 (MET)
From:      J Wunsch <j@uriah.heep.sax.de>
To:        freebsd-current@FreeBSD.org (FreeBSD-current users)
Cc:        dicen@hooked.net
Subject:   Re: User ppp not hanging up modem.
Message-ID:  <199612211849.TAA12073@uriah.heep.sax.de>
In-Reply-To: <199612211751.KAA27123@rocky.mt.sri.com> from Nate Williams at "Dec 21, 96 10:51:29 am"

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As Nate Williams wrote:

> That's *NOT* the correct thing.  What happens when for some reason
> PPP happens to send the sequence '+++' to the modem?  All of a sudden
> it'll drop into command mode and you're screwed.  User-PPP (as well as
> all other PPP/SLIP implementations I've worked with) assumes that you've
> disabled the escape sequence at least temporarily.

That's why they protect it by requiring 500 ms spaces before and after
the +++.  I think AT&T even has a patent on this escaping scheme.

Still i don't agree that IIJPPP should send this sequence, though.
The heavy preference of +++ ATH does IMHO only arise out of messy DOS
poor DTR handling.  Dropping DTR on each device close is a very much
cleaner policy than messing around with the command set of a modem
(which cannot be done by the kernel or a multipurpose library anyway
since there is no `standard command set', and a tty device might as
well end up in any other communication endpoint that doesn't have a
command set at all).

-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)



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