Hi

Then, I use mldonkey (that it is a client for Emule network), but, every
time that I try to get an high number of download, and the number of tcp
active connections up to 200-300, whichever program that uses the
network (mldonkey too) gives me "sendto: Not buffer space available"
error, the net goes in congestion for some second and then it resumes
itself.

All that cycles every 2-3 minutes.
I start mldonkey option "ulimit - n 256" in order to increase the
possible openfiles.

However the problem is general of my OpenBSD when the network go "under
stress" with many tcp connections.
The solutions that I have tried are following:

Set in kernel config these option:
option NMBCLUSTERS=16384
option NKMEMPAGES=32768
option NBUF=4096

I have try to increase the values of kernel setting through sysctl
net.inet.tcp.recvspace, net.inet.tcp.sendspace,
net.inet.udp.recvspace,net.inet.udp.sendspace
doubling or quadruplicating the default value

I have tried also to change net card.
But anithing change... the problem persist.

Someone can help me with this problem ?

The problem was the same in Openbsd 3.4-current and in Openbsd
3.5-current too.

Very Tnx
Daniele Busana