Flow control in metropolitan area networks

Two flow control schemes are investigated. In Scheme A, messages are allowed into the gateway buffer until it reaches its capacity, at which point they are blocked and made to wait at their respective input buffers. When capacity becomes available at the output buffer, the messages are allowed into the output again on a first-come-first-serve basis. Scheme B is based on an optimal throughput scheme which is derived using a process involving linear programming. In this scheme, the output buffer reserves its spaces for those input buffers that have a temporarily higher demand for spaces than their own buffers can offer. Simulation results confirm that Scheme B produces a better throughput performance than Scheme A. However, this is obtained at the expense of a higher delay. A constraint on the delay can be introduced when deriving Scheme B, but this is expected to lower the maximum throughput achievable