Relative differentiated services in the Internet: issues and mechanisms

In the context of relative differentiated services the network traffic is grouped in N classes of service which differ in their relative forwarding quality, i.e., class i is better than class i 1 in terms of local (per-hop) forwarding measures of the queueing delays and packet losses. Users and applications, on the other hand, select adaptively the class that best meets their requirements and/or cost constraints. In this short paper we present, focusing on queueing delays only, four different service models that offer such a class relative differentiation. Simulation results illustrate that a predictable and controllable delay differentiation can be achieved in only one of these models. A more complete treatment of this subject appears in [I].