Messages in this thread | | | Date | Sun, 10 Oct 1999 22:08:49 +0200 | From | Peter Steiner <> | Subject | Re: [2.2.{12,13p15}] PPP uploads fizzle out and die (tcpdump info incl.) |
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>>check your -rtscts. and the cable and the at& command that deals with it, > >I am forcing a slow connection rate via the at&n command to be sure it's >not the DA/AD conversion that is dropping data.
It happened here with an ISDN connection between an ISDN card and an ISDN modem (with built in sync-async conversion). Kernel versions were 2.2.12 and AFAIK 2.2.5.
Judging from the LEDs on the modem the transfer rate constantly increased until it reached a certain point, then it collapsed. After 1-2 seconds it resumed at a very slow rate and then started to speed up until next collapse. The result was about 1kByte/s.
ifconfig didn't show any overruns, 'cat /proc/tty/driver/serial' didn't either. 'echo "0" > /proc/sys/net/ipv4/tcp_timestamps' made things better (4kBytes/s).
With 2.3.20 things speed up to >6.5kB/s (echo 1 > tcp_timestamps). And even bidirectional ftp transfer is now about 5 kB/s for each direction. 2.2.12 did hardly do any bidirectional transfers (except for ping with big packetsizes).
Peter -- _ x ___ p.steiner@t-online.de (Peter Steiner) / \_/_\_ /,--' \/>'~~~~// \_____/ perl -e'while(<>){s/=\n//g;s/=([\dA-F]{2})/chr(hex($1))/eg;print;}'
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