Ensuring fairness among ECN and non-ECN TCP over the internet

Explicit Congestion Notification (ECN) has been proved to provide a fast indication of incipient congestion and thus better the performance of a TCP/IP network. In this work, we carry out investigations on gateway or router performance in providing fairnesss when both FIM ECN-capable and non-ECN-capable connections are employed. We propose a new packet-dropping scheme called Fair In-time Dropping (FID) which drops packets from a connection upon detecting an incipient indication of congestion depending on its share of gateway or router buffer occupancy. We also show that a combination of FIM and FID offers the best fairness compared with a combination of FIM along with other dropping schemes.