Behavior of Competing TCP Connections on a Packet-Switched Ring: A Study Using the Harvard TCP/IP Network Simulator

This paper presents simulation results on the behavior of TCP connections when they compete on a packet-switched ring. These results were generated by the Harvard TCP/IP network simulator, which uses real-life TCP code to support high-fidelity simulation. There are two parts to the paper. The first part is a high-level description of the methodology for constructing the Harvard TCP/IP network simulator. The second part describes an application of the simulator in studying the behavior of competing TCP connections on a packet-switched ring. Simulation results show that TCP connections achieve various degrees of fairness under different packet scheduling methods used in the nodes of the ring. Under the FIFO scheduling, the connections exhibit serious unfairness. Under per-source queueing, per-source-destination-pair queueing, and 2-level queueing, the connections exhibit improved levels of fairness .