UEK2 is a kernel version 2.6.39 and ttcp an old tcp/udp performance testing tool created in the 1980's. Depending on what distribution and architecture you are using, e.g. OL 5 or OL 6, x86 or x64, you can probably install ttcp from http://pkgs.repoforge.org/ttcp/ or check the iperf package available from the EPEL project: http://fedoraproject.org/wiki/EPEL
Dude - thank you. We were able to set it up and run tests. However - TCP performance between 2 UEK servers over 10Gbit - is only medium.
Since the utility measures memory-to-memory over the link - the server hardware should be less of an issue - and it should mostly be about the OS stack, correct ?
I find it hard to believe that UEK can't be tuned to be top notch on this. Any words of wisdom on UEK stack tuning?
What does "medium" mean in numbers and what are you expecting? What are you using? Hardware and software certainly affect performance even when traffic is generated in memory. There still is some adapter, network, server hardware, cabling and software involved. There are simply too many unknowns.
If you suspect a kernel problem, I suggest to boot the system using the supplied original RHEL kernel and compare the performance. At least this might give you some idea if the problem is perhaps kernel version or driver specific.
Have you tried to search for information in Google? Searching for RHEL 10GB tuning returns several presentations, case studies and documents that seem to be useful.