I have a machine running Fedora Core 1, and there seems to be some kind of limit on outgoing data transfers.

When I transfer files out of the machine, over our 100 Mbps network, the data transfer rate seems limited to about 40 KB/s per connection. I've tried over sftp, scp, ftp and http with the same results.

I can open two simultaneous transfers, and both of them transfer at around 40 KB/s, so I know the network bandwidth is there. There just seems to be a global per-connection limit set somewhere.

File transfers to the Fedora box go at hundreds of KB/s, as expected, so it seems this limit only applies to outgoing data.

The configuration is pretty much out-of-the-box (I've only done some tweaking with the mail delivery system). Has anyone else had this problem, and where would I start looking to turn this limit off? I've investigated iptables, tc and xinet a bit, but to be honest I'm not sure where to start, and where to find all the appropriate config files.

Any pointers gratefully received!

What is the other machine you're using? I had a similar issue scp-ing files from a debian box to a win2k laptop on a 10/100 lan. In my case the transfers were maxing out at around 90kB/s...

The solution?

Upgrade the version of PuTTY scp on the windoze machine. That brought me up to around 900kB/s, which seems to be limited by CPU power (uses about 60-70%).

YMMV.

In fact, I am using a Win2000 machine with Cygwin, but actually my main machine is my Apple Powerbook, running a variant of BSD, which doesn't go near 100% CPU usage during transfers. I have the same problem with both machines. Thanks for the tip, though!