Efficient buffer management and scheduling in a combined IntServ and DiffServ architecture: a performance study

The differentiated services (DiffServ) architecture promises the provision of QoS-enabled networks by following a simple approach that eliminates scalability concerns and which can be implemented and managed in large networks. However, for end-to-end QoS an appropriate signaling scheme, like the resource reservation protocol (RSVP), should be supported. In this combined approach, signaling messages, which are generated by hosts and interpreted by edge routers, are tunneled transparently through the DiffServ core network. The treatment of the signaling messages in the DiffServ cloud is a very important issue, since long delays in their delivery or a high percentage of drops could result in unpredictable and undesirable situations. In this paper, we define a DiffServ traffic class, herein called network control traffic class, that is used by all signaling messages travelling through the DiffServ network. We provide a simulation analysis which evaluates the key properties of the new DiffServ class including priority level, link-sharing bandwidth and link-sharing structure for an hierarchical class-based resource management mechanism referred to as class-based queuing (CBQ), employed by the DiffServ core routers.