DiffServ node with join minimum cost queue policy and multiclass traffic

DiffServ, the vehicle for providing relative QoS in the Internet is also easily amenable to simple and effective pricing mechanisms. By pricing access to a relative QoS, we can model a DiffServ node as a ‘Join Minimum Cost Queue’ in which an arriving customer (packet or connection) determines the relative cost as a function of the congestion in the different queues and their access prices and decides to take service from that queue for which the cost is minimum. The Paris Metro pricing system and its work conserving variant called the Tirupati pricing are analyzed in this paper in the presence of multiclass traffic and for static pricing using an infinite buffer model. Extensive numerical results help describe the behavior of the performance measures like mean queue lengths, revenue rates and customer disutility rates as functions of the various system parameters. Two of the more interesting observations are that the disutility and revenue rate are not monotonic or convex functions of price and the revenue rate is very sensitive to the behavior of the delay sensitive class. We also analyze the finite buffer case and study the loss rate, revenue rate and also the convergence of these performance measures to the infinite buffer values as the buffer sizes increase.