Use netstat and traceroute to cut down on the number of hops. Set timers everywhere to prevent deadlock from congested ACKs. Some of these issues can be addressed with technical measures, including coding strategies, test driving your apps, diagnostics and the re-tune your application. Once you know throughput, you can match it to the pipe size you will need. Another data flow that can be improved is movement from memory to network card.
Whole pages are DMA'd and partial pages are byte copied at a much slower rate.
Test drives - this is mostly a process of coordinating the WAN, prescribing the routing, and having a good measure of what bandwidth will be needed. Readjust the TCP window size. Under Nagle's Algorithm, TCP will wait and accumulate small packets. Path MTU can discover these for you, and you can upgrade the device. This technology can be transmitted to the desktop, where researchers can use it to analyze data or design and test applications.