A core-stateless buffer management mechanism for differentiated services Internet

The IETF differentiated services (DiffServ) framework achieves scalability by moving complexity out of the core of the network into edge routers which process fewer number of flows. Previously, an end-to-end service called the premium service (PS) has been proposed under the DiffServ model to provide coarse grained guaranteed rate service. This paper presents a buffer management mechanism based on simple FIFO scheduling to support integrated transport of the PS and the traditional best effort (BE) service. A key feature in our buffer management is to perform selective packet discarding from an embedded queue at a shared buffer. We show that such a buffer management mechanism is capable of achieving the following objectives: (1) a core router does not maintain any state information for any flow (i.e., stateless); (2) the bandwidth for an PS flow is guaranteed (in conjunction with a bandwidth broker (BB) for admission control). Simulation results demonstrate that our buffer management mechanism can achieve integrated transport of the PS and the BE services.