Re: Download speed and TCPIP window sizing

Thanks for reply.

Nicolas Gieczewski wrote:
On Thu, 31 May 2007 22:06:39 +0800, Pang <freebsd@xxxxxxx> wrote:
Recently, I have leased a rack in Asianetcom and some bandwidth.
However, the speed for my curcuit is substantially slower than my
provider's company site.
[...]
*This server is using FreeBSD 6.2 patch 4 with Apache in the port tree.
The kernel is custom built but I haven't made any modification in sysctl

I have asked many techs in Asianetcom and they blamed on TCPIP window
sizing.

I used to have the same problem with my FreeBSD dedicated servers in the U.S. when I was living in South America with a latency of ~200 ms. Given identical hardware and connectivity, I could max out my download speed when downloading from a server running Linux, but would get no more than 100-150 KB/s when downloading from an otherwise identical FreeBSD box.

The solution was to increase the size of the TCP send window on the FreeBSD server to about 128 KB--the default of 32 KB turned out to be way too small.

# sysctl net.inet.tcp.sendspace=131072

After modifying this value, you need to restart any processes (e.g. Apache) that you want to take advantage of the change.

It doesn't work. I am still getting ~10KB/s speed.


Hope it helps.

_______________________________________________
freebsd-questions@xxxxxxxxxxx mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "freebsd-questions-unsubscribe@xxxxxxxxxxx"

Thanks
Pang
_______________________________________________
freebsd-net@xxxxxxxxxxx mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-net
To unsubscribe, send any mail to "freebsd-net-unsubscribe@xxxxxxxxxxx"

Relevant Pages