An analysis of TCP startup over an experimental DVB-RCS platform

Satellite systems are evolving towards higher available bandwidths and dynamic allocation based on instantaneous traffic rates offered at the stations, so called BoD (bandwidth on demand) channel sharing. This trend is paired with more and more powerful error correcting schemes, like those adopted in the recent DVB-S2 standard, which promise to make the channel virtually immune from packet errors. These factors, together with the significant round-trip delay of geostationary satellites, combine so that most TCP connections would send all of their data during the Slow Start phase. We investigate the performance of TCP during startup on recent BoD system by observing and explaining the behavior of different TCP flavors on different systems when transmitting data over the Eutelsat's Skyplex Data satellite system. We make recommendations for choosing and improving TCP implementations and for future BoD allocation schemes.