configuring QNET parameters

What is the optimum values for QNET parameters other than default values to get maximum performance?

I will assume that by performance you mean number of bytes per seconds. Aside using jumbo frame I’m not sure there is any general way to increase performance. Depending on you network card you may be able to tune how the interrupts are handled but AFAIK that’s about it.

You could use two NIC connected to separate network to slip the load resulting in twice the available bandwidth.

You have QNET performance related problem?

That’s a very generic question. What are the parameters you seek to optimize? Latency/throughput/failure detection,etc.