Service differentiation with MEDF scheduling in TCP/IP networks

The Differentiated Services architecture implements appropriate Per Hop Behaviors (PHBs) for service differentiation to achieve Quality of Service (QoS) in Next Generation Networks (NGNs). In this paper, we review several buffer management and scheduling algorithms that may be applied in this context. The major part of this work focuses on the interaction between TCP and the Modified Earliest Deadline First (MEDF) scheduling algorithm. It is an appealing option for service differentiation because it relies on a single parameter only and because this parameter can be configured independently of the current share of high priority traffic in the network. This is contrary to many other scheduling disciplines or buffer management strategies. The unavailability of this information in today's Internet makes MEDF an interesting candidate for commercial application.