Differentiated Services over Shared Media

The growing use of multimedia communication applications with specific bandwidth and real time delivery requirements has created the need for a new Internet in which traditional best effort datagram delivery can coexist with additional enhanced Quality of Service (QoS) transfers. There are many aspects in QoS control. In this article, we address the problem of the support of Expedited Forwarding over shared media. Shared media can be found in broadcast networks operating in packet mode. One problem in this environment is unsteady bandwidth. On these networks, the total bandwidth which is used depends on the offered load. In case of excess load, the total bandwidth decreases when it should be reaching its maximal value. Therefore, it is difficult to manage the bandwidth since it does not remain at the same level. In this article, we propose a distributed algorithm to manage the bandwidth efficiently and which enables QoS for a DiffServ environment.