Date: Tue, 3 Dec 1996 13:44:57 -0800 (PST) From: Wes Santee <wes@bogon.net> To: questions@freebsd.org Subject: Why such poor PPP throughput? Message-ID: <199612032144.NAA22399@bogon.net>
next in thread | raw e-mail | index | archive | help
'Lo all. I've been noticing over the past few months that the receive speed on my dedicated 28.8 PPP line has been less than stellar. For example, when ftping a pre-compressed file from my ISP (1 hop), I get a maximum of 2.14 kb/sec throughput, with an average of about 1.94 kb/sec. I've talked to my ISP about it several times but they're sure it's not happening at their end. All that they've been able to determine is that I'm registering lots of incoming packet errors at the terminal server (which I can verify -- see below), that my connection speed seems to retrain down to ~24.4 alot, and that no other subscribers have mentioned low transfer speeds as being a problem. Here is the edited output of a 'netstat -i' command issued 3 times at 10 second intervals while the system was under heavy network load (for a 28.8 connection). Notice that at each snapshot, the number of incomming packet errors has increased. Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll ppp0 1500 <Link> 47274 1736 40092 0 0 ppp0 1500 204.137.132.4 bogon.net 47274 1736 40092 0 0 ppp0 1500 <Link> 47312 1741 40130 0 0 ppp0 1500 204.137.132.4 bogon.net 47312 1741 40130 0 0 ppp0 1500 <Link> 47346 1744 40164 0 0 ppp0 1500 204.137.132.4 bogon.net 47346 1744 40164 0 0 For the record, I'm running 2.1-STABLE with kernel ppp with no special PPP settings. My question: How do I find the cause of this and fix it? Is it even a fair assumption that this is the root of my problems? I've tried watching packet dumps, switching modems, futzing with modem settings, etc. The interesting thing is that I get *great* throughput on the transmit channel. It's only the receive channel that sucks. Another interesting item is that I had to set tcp_extensions=NO in /etc/sysconfig or I'd get long pauses in the data stream. The fact that I'm retraining down in speed tells me that it may be line noise, but I don't know how to be sure. The fact that I have to set tcp_extensions=NO tells me that it's my ISP's equipment that's causing the problem, but I have no way of proving that either -- shy of switching ISP's (which get's expensive with dedicated connections). Are there any PPP and/or serial line guru's out there that may have an idea how to track down and solve this problem? Any help is appreciated. Cheers, -Wes -- ( -Wes Santee <wes@bogon.net> Homepageless - and proud ) ( PGP: email w/Subject: "Send PGP Key" Powered by FreeBSD )
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199612032144.NAA22399>