TCP Fairness in Ethernet over Passive Optical Networks (EPON)

The Ethernet Passive Optical Network (EPON) is a promising solution of metropolitan optical networks. In this paper, we model the performance of TCP over EPON in terms of fairness. We identify the fairness problem suffered by EPON using the existing polling scheme. We then derive two tight bounds of fairness indices for downloading users, and propose two polling mechanisms to improve unfair resource sharing among multiple TCP flows. The performance of the proposed mechanisms is evaluated by simulations via ns2. ne results show that our mechanisms can improve fairness among the downloading flows without degrading the aggregate throughput and the fairness of the uploading flows.