Improved TCP error control for heterogeneous WANs

Considers the internet transport protocol TCP for interconnection of Ethernets by satellite. Such an environment is an appropriate representative of currently available wide area networks. In this context, several approaches for extending TCP for use in a bandwidth-delay dominated network are considered. These are in particular the window scale, the NAK, the selective repeat and the Stutter XOR selective repeat option. A supplementary problem which arises in a satellite network is the differentiation of data losses due to congestion or noise. If a connection loses a packet due to the medium (a packet corrupted by an error), no congestion control is necessary. On the other hand, if a packet was dropped due to an overloading of limited resources in the network, congestion control has to be applied in order to give the network a chance to clear up. The simulative results show that in terms of performance the extensions and modifications yield remarkably better results than pure TCP