Date: Sun, 11 May 1997 11:56:05 -0700 (PDT) From: Tom Samplonius <tom@sdf.com> To: Brian Somers <brian@awfulhak.org> Cc: Luigi Rizzo <luigi@labinfo.iet.unipi.it>, hackers@freebsd.org Subject: Re: sio flow control problems with 2.2? Message-ID: <Pine.NEB.3.94.970511115255.22294A-100000@misery.sdf.com> In-Reply-To: <199705111142.MAA14168@awfulhak.demon.co.uk>
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On Sun, 11 May 1997, Brian Somers wrote: ... > It's theoretically impossible to give the modem too much data - > the next character is only sent on receipt of an interrupt (maybe > you've got something else causing interrupts ?) that says the > transmit buffer is empty. Not quite. Generally you drive a modem at 115200 bps, while the line rate is only 28800 bps (plus some extra for compression). When the modem's internal buffer fills up, it asserts flow control. If the computer doesn't see it, it will keep pumping data to the modem at 115200, which the modem will likely discard. > > Thanks > > Luigi > > -----------------------------+-------------------------------------- > > Luigi Rizzo | Dip. di Ingegneria dell'Informazione > > email: luigi@iet.unipi.it | Universita' di Pisa > > tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) > > fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ > > _____________________________|______________________________________ > > I think your first step should be to prove you can log in using > kermit or some such and see that flow control works there. > > Then you can put ppp and tcp/ip on top. > > -- > Brian <brian@awfulhak.org>, <brian@freebsd.org> > <http://www.awfulhak.org>; > Don't _EVER_ lose your sense of humour.... > > > > Tom
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