We investigate four major characteristics of the performance of UDT.
We expect UDT to reach high bandwidth utilization with reasonable CPU cost.
All concurrent UDT flows should share the bandwidth fairly. This means to share the bandwidth equally if there is a single bottleneck in the system.
We also want UDT to be friendly to co-existing TCP flows. We consider this property in two separate situations. Because most TCP flows on the Internet are short lived flows, we check the influence of multiple background UDT flows on the short-lived TCP flows. Meanwhile, we also check the competence of concurrent TCP bulk flows and UDT bulk flows.
Finally, we also considered the stability for each UDT flow. Here a better stability means less oscillations in the throughput.
We have either defined or borrowed a quantitative approach for each of these performance characteristics.