Dummy Probe Re-Transmission Algorithm for Available Bandwidth

TCP-shape algorithm is used to control the network congestion and regulate the transmission rate of packets based on available bandwidth. The TCP-shape algorithm sends the dummy probes to detect the background flow and obtains the network congestion status with the return value. But the TCP-shape algorithm cannot consider some relationship between packets and dummy probe. This paper improves the TCP-shape algorithm. First, we adjust the dummy probe´s sending time and record the dummy probe number. Second, we match dummy probe number and gap with source and destination to resolve the problem of packets lost. Finally, do experiments to compare the improved algorithm with the TCP-shape algorithm. The transmission rate and return value of the packets can be observed favorably, and the result shows the improved algorithm is more accurate then TCP-shape algorithm.