Achieving proportional DiffServ per-hop behaviour with PLQF

We propose a novel scheme that can provide both delay and loss proportional DiffServ per-hop behaviour. DiffServ is a framework that can provide different QoS levels to different groups of network users, and eliminate the shortcoming of the best-effort delivery in today's Internet. The scheme employs probabilistic longest queue first (PLQF) as its forwarding and dropping mechanism. PLQF mainly reacts immediately to the queue-length fluctuation of each service class, and then decides the probability for each QoS class, which determines the forwarding or dropping behaviour. We couple delay and loss differentiated services in one scheme. The proposed scheme is proven to achieve proportional differentiated services after detailed evaluations. Furthermore, the implementation cost of PLQF is much less than that of the previously proposed schemes, such as WTP and PLR.