Measuring with JPerf and PsPing: Throughput and Estimated Packet Delivery Delay vs TCP Window Size & Parallel Streams

This work discusses how the TCP window size affects the throughput and its measurements and estimated packet delivery delay on two experimental setups using freely available tools JPerf and PsPing. The first setup is a direct connection between two PCs using gigabit Ethernet. The second setup uses a linked pair of Television White Space (TVWS) devices. The tools JPerf and PsPing are used to perform the throughput and latency measurements, respectively, over a range of different sizes of the TCP window. The results recommend specific ranges of TCP window size to either maximise the throughput or minimise latency. The results also suggest that performing valid measurements of peak throughput require careful consideration in selecting the TCP window size or usage of parallel streams.