An Application-Level Solution to TCP’s Satellite Inefficiencies

In several experiments using NASA's Ad-vanced Communications Technology Satellite (ACTS), investigators have reported disappoint-ing throughput using the TCP/IP protocol suite over T1 satellite circuits. A detailed analysis of FTP le transfers reveals that the TCP receive window size, the TCP \Slow Start " algorithm, and the TCP acknowledgment mechanism con-tribute to the observed limits in throughput. To further explore TCP's limitations over satellite circuits, we developed a modied ver-sion of FTP (XFTP) that uses multiple TCP connections. By using multiple TCP connec-tions, we have been able to simulate a large, vir