OpenBandAid currently includes a Bandwidth-Delay Product (BDP) calculator and Packet Loss Analysis calculator, it can help you discover network bottlenecks and fine tune different parameters, in order to achieve maximum network throughput and performance.

The Bandwidth-Delay-product (BDP) analysis can help determine TCP throughput. The first calculation result in the BDP tab, shows the maximum TCP throughput which can be achieved at the given TCP window size and RTT. This helps determine whether a circuit is underutilized beacause of a small tcp window size or high RTT.

The second result shows the actual Bandwidth-Delay product, which is the window size required for TCP to reach the full capacity of the circuit at the given RTT. To account for potential errors on the circuit the Packet Loss Analysis tab uses an equation published by M. Mathis, J. Semke, J. Mahdav and T. Ott in their paper "The Macroscopic Behavior of the TCP Congestion Avoidance".

The equation shows how the maximum segment size (MSS), errors and latency on a circuit affect TCP performance. For example, for a typical MSS of 1460 bytes (1500 bytes minus 40 bytes of TCP and IP headers), latency of 10ms, and probability for error 0.1% (One bad in a thousand packets, multiplied by 100 for percent), the maximum TCP throughput is 35.22Mbps. If this is a 100Mbps circuit then the errors are causing significant reduction in the throughput and they need to be addressed (improving hardware, checking the health of the physical circuit lines etc). Performance in this case can also be improved by increasing the MSS.

The license of this software is Free, you can free download and free use this network utility software.