[ISDN appears shafted] Re: Linux-2.1.125 ... pre-2.2 imminent

David Woodhouse (David.Woodhouse@mvhi.com)
Mon, 12 Oct 1998 10:35:58 +0100


leitner@math.fu-berlin.de said:
> Right now, the ISDN support in 2.1 is broken. I have tons of
> mysterious TCP stalls over an ISDN PPP line to another Linux box on
> the other end.

> Just typing this mail over my PPP ISDN link is a real pain, it feels
> like a 300 baud line with error correction eating 80% of the
> throughput.

I'd be inclined to agree.

devel2 /homes/dwmw2 $ ssh firewall dmesg | grep -c "TCPv4 bad checksum"
47
devel2 /homes/dwmw2 $ ssh firewall dmesg | wc -l
48
devel2 /homes/dwmw2 $ ssh firewall dmesg | grep -v "TCPv4 bad checksum"
cksum from 208.210.111.121:0050 to 158.152.16.50:044a, len=20/20/40

This problem is quite recent, and is entirely separate to the problem that's
been occurring for a long time, where it seems that the outgoing queue isn't
being flushed properly. People have been inserting mark_bh() in seemingly
appropriate places for some time, but we still haven't located the problem.

---- ---- ----
David Woodhouse David.Woodhouse@mvhi.com Office: (+44) 1223 810302
Project Leader, Process Information Systems Mobile: (+44) 976 658355
Axiom (Cambridge) Ltd., Swaffham Bulbeck, Cambridge, CB5 0NA, UK.
finger dwmw2@ferret.lmh.ox.ac.uk for PGP key.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/