Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 7 Oct 1998 01:31:46 +0930 (CST)
From:      Kris Kennaway <kkennawa@physics.adelaide.edu.au>
To:        current@FreeBSD.ORG
Subject:   Improper sharing of modem bandwidth
Message-ID:  <Pine.OSF.4.03.9810070120160.32491-100000@mercury.physics.adelaide.edu.au>

next in thread | raw e-mail | index | archive | help
Recently I've noticed my system behaving differently during downloads; when I
initiate a file download it tends to consume all available modem bandwidth, to
the exclusion of all other things like open telnet sessions. Once the download
has started, my telnet sessions will usually freeze (during a download of a
1.5MB file just then over my 14.4k modem I didnt get a single character back
from one of my telnets open for more than 10 minutes, and another one was
giving me huge delays (a minute or more, to a host which is ~400ms away under
normal usage). I could also not manage to talk to the DNS (the modem dialin
server) to initiate any new connections during the download; the requests were
timing out.

Until recently, I was not experiencing anywhere near this kind of lag during a
single file transfer.

This is the source of the recent comment I made here re binary transfers
coming through at a faster rate than usual (1.7k, which is probably the
absolute limit for my modem when you include protocol overhead).

As soon as the download finishes, all other sessions return to normal within
a second or two.

Has anyone else seen this behaviour? I'm running behind a simple IPFW and
using user-mode ppp, but have not changed any of my config for months (kernel
also, beyond trivial changes). The recent bandwidth-limitation changes to ipfw
flag themselves as a possible source of the problem, to my untrained eye :-)

Kris


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.OSF.4.03.9810070120160.32491-100000>