[Users] TCP problems under high load

[Klaus Darilion]

Hi!

I suspect openser to have TCP problems under high load:
Scenario: sipp sends INVITE to openser, which replies with 404
I have 4x sipp with 1000 INVITEs/s and 1x sipp with 3000INVITEs/s, thus 
5 TCP connections

After some time, I get error on the TCP connection with 3000INVITEs/s:
-->syslog.txt

Looks like the first part of the request is missing, but sniffing 
revealed that the request is proper formated as you see in the TCP 
packet -->ngrep.txt

Are there known high-load problems?

Any ideas how I can debug this?

regards
klaus