Experimental Validation of TCP Performance in GEO Satellite link Conditions

Transmission Control Protocol was designed to work over the networks characterized by low delay and negligible bit error rates. Transmission Control Protocol (TCP) performance degrades when TCP traffic is carried over the satellite networks that have large latency, high bit error rates and path asymmetry. To comprehend the effect of satellite conditions over TCP, we have evaluated the TCP performance by three universally accepted methodologies i.e. Simulation, emulation and experimentation. The experimentation has been carried out over actual geostationary earth orbit (GEO) satellite link equipped with tangible hardware at ground station. This paper discusses each of the three methods used to evaluate the TCP and describes the results that clearly bring out the degree of performance degradation and the impact of various link parameters on the TCP performance. Experiments based analysis of the TCP over satellite network assist to gather the more realistic statistics for benchmarking that will be useful guide to understand the protocol limitations that further steer in enhancing its capabilities by make it an efficient protocol for satellite networks. Emulation and Simulation results clearly demonstrate the effect of latency and bit errors of satellite links. Simulation results, in particular bring out the effect of various error levels in satellite links over TCP flavors working in well known operating systems.