The linux kernel has hundreds of tunable settings. Some can be modified on the fly with sysctl; others require reboots, loading modules and so on.
Your job is to come up with a self-tuning system that does all the analysis it needs and finds the optimum settings to maximize throughput and/or latency for well defined workloads. One of the must be BitTorrent, since that one uses a lot of traffic and it can just be tested with real data instead of synthetic tests.
Take a look at this page.