Date: Sat, 10 May 1997 16:38:35 +0200 (MET DST) From: Luigi Rizzo <luigi@labinfo.iet.unipi.it> To: hackers@freebsd.org Subject: sio flow control problems with 2.2? Message-ID: <199705101438.QAA19811@labinfo.iet.unipi.it>
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Hi, I am a bit afraid to ask since this might be a configuration problem on my side, but after a week of tests and tens of wasted calls I think I need some advice. Since when I upgraded our ppp server to a P6-200 running FreeBSD 2.2.1R, using a 28.8 modem (which reports 24000 bps at connect) I am having problems with modem flow control. I am using the same modems and serial port setup as on our previous server (a P5-133 w/ FreeBSD 2.1) and client (a P5-133, w/ 2.1 and 2.2, both of which worked), which has been working for months with iijppp. But now, even if, on the client, I start ppp, log into the server (using mgetty), and then start elm, the output is a total mess, I have missing lines, etc. as if flow control were not working. The only way to make things work is to reduce the speed to 9600 at the server side (and still... I suspect it just happens to work..). PPP fails with packets longer than ~750 bytes. On both sides, cuaa1 is set with -clocal crtscts, the internal modems are (apparently) set properly (AT&K3 or AT\Q3, "enable RTS/CTS flow control"), as in the past, and they are recognised as 16550 at boot. What I suspect is that the new machine might be too fast in pumping data to the modem, and for some reason it might miss the handshake thus overflowing the receiver. It might be a broken modem or something wrong in the sio code, has anyone suggestions where to look at ? 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/ _____________________________|______________________________________
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