Fairness analysis of TCP/IP

Bandwidth sharing between multiple TCP connections has been studied under the assumption that the windows of the different connections vary in a synchronized manner. This synchronization is a main result of the deployment of drop tail buffers in network routers. The deployment of active queue management techniques such as random early detection (RED) will alleviate this problem of synchronization. We develop in this paper a mathematical model to study how the bottleneck bandwidth will be shared if TCP windows are not synchronized. This permits to evaluate the improvement in fairness and utilization brought by the deployment of active buffers. Also, this indicates how much a synchronization-based study underestimates the performance of TCP in a nonsynchronized environment