Performance evaluation of scalable TCP and highspeed TCP over geostationary satellite links

In this paper we analyse the performance in a satellite environment of two recently proposed modifications to the TCP's congestion control algorithm, namely scalable TCP and highspeed TCP. These two protocols, originally designed for high-speed backbone links, appear to be major candidates for replacing in the next-generation Internet the current congestion control mechanism implemented by standard TCP. In this paper, we evaluate by means of ns2 simulations the performance of such protocols in a static as well as a mobile satellite environment. The results confirm that both protocols, and particularly S-TCP, may represent a viable alternative to standard TCP also in a satellite environment.