On the Use of Queueing Network Models to Predict the Performance of TCP Connections

In this paper we describe an analytical approach to estimate the performance of greedy and short-livedTCPconnections, assuming that only the primitive network parameters are known, and deriving from them round trip time, loss probability and throughput of TCP connections, as well as average completion times in the case of short-lived TCP flows. It exploits the queuing network paradigm to develop one or more ‘TCP sub-models’ and a ‘network sub-model,’ that are iteratively solved until convergence. Our modeling approach allows taking into consideration different TCP versions and multi-bottleneck networks, producing solutions at small computational cost. Numerical results for some simple single and multi-bottleneck network topologies are used to prove the accuracy of the analytical performance predictions, and to discuss the common practice of applying to short-lived TCP flows the performance predictions computed in the case of greedy TCP connections.