Impact of location of bottleneck link on TCP-Tahoe performance

TCP (Transmission Control Protocol) is reliable and one of the main protocols of transmission layer in a communication system. Congestion control mechanisms in TCP allow a reliable flow of bursty traffic. This paper investigates the response of TCP-Tahoe connection to the location of bottleneck link on working path. Further analysis is performed for different size of current TCP window in the network. The network under consideration is NSFNET (National Science Foundation Network). Impact of the location of bottleneck link is analyzed for all the links on working path. Using the results obtained, it is observed that for current window size of 50 and 100 packets, network throughput is maximum when the position of bottleneck link is nearest to the destination node of working path. As window size is increased to 150, 200, 250, 300, 400 packets, maximum throughput is obtained when bottleneck link is located nearest to the source node. The present analysis provides an understanding of current window size selection and routing path to be adopted if bottleneck link in the network is pre-estimated.