Slow transfers to 5.4 / 4.11 is ok

Lowell Gilbert freebsd-questions-local at
Sun Sep 11 06:42:41 PDT 2005

"Jan-Peter Koopmann" <Jan-Peter.Koopmann at> writes:

> we are experiencing a very strange problem. All transfers from
> Windows XP boxes to our new FreeBSD 5.4 installation seem to be
> quite slow. The 5.4 is located in a housing center and we try to
> access it from behind 3MBit DSL lines. Instead of the expected
> ~320KByte/sec we only get 220KByte/sec. If I use a FreBSD, OSX or
> linux machine behind the same router to download stuff from our 5.4
> machine, everything is in perfect order. If I access 4.11
> installations from the same Windows XP machines, everything is fine
> as well:
> Linux -> 5.4: ~320K
> FreeBSD 4 -> 5.4: ~320K
> Windows XP -> 5.4: ~220K
> Windows XP -> 4.x: ~320K
> Prior to the 5.4 box we had a 4.11 machine at the same location,
> same routers clients etc. Again: Until we changed the box download
> speed were ok. MTU etc. seem to be correct as well. This also
> happens from several locations with different setups, providers
> etc. always with the results shown above. So we are pretty confident
> that some change between 4.X and 5.4 breaks the transfer rates when
> it comes to Windows XP.
> Do any of you have an idea where we could/should look for? Are there any timing issues corrected/changed in 5.X?

What protocols are you using?
NIC cards?

Are you seeing collisions?  
What is the overall utilization of the links involved?

Lowell Gilbert, embedded/networking software engineer, Boston area

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