Optimal local flow control of a general multiple data link with limited buffers

Abstract

The problem of optimal local flow control of a general multiple data link with limited buffers is investigated. The maximum entropy model is used to approximate the general (G-type) distributions. It is shown that the local flow control mechanism maximising the throughput, under a bounded time delay criterion is of window type (bang-bang control). The optimal input rate and the maximum number of packets in the system (i.e., sliding window size) are derived in terms of the maximum input rate and the second moment of the interinput time, the maximum allowed average time delay, the first two moments of the service times and the number of data links. Consequently, the relationship between the maximum throughput and maximum time delay is determined. Numerical examples provide useful information on how critically the optimal throughput is affected by the distributional form of the input and service patterns and the limited buffers of the links.