Analysis of Shared Finite Storage in a Computer Network Node Environment Under General Traffic Conditions

Nodal storage limitations in a store and forward computer network lead to blocking; this results in degradation of network performance due to the loss or retransmission of blocked messages. In this paper, we consider several schemes for sharing a pool of buffers among a set of communication channels emanating from a given node in a network environment so as to make effective use of storage in a variety of applications. Five sharing schemes are examined, analyzed, and displayed in a fashion which permits one to establish the tradeoffs among blocking probability, utilization, throughput, and delay. The key to the analysis lies in the observation that the equilibrium joint probability distribution of the buffer occupancy obeys the well-known product form solution for networks of queues. The study indicates advantages and pitfalls of each of the sharing schemes. We observe, in general, that sharing with appropriate restrictions on the contention for space is very much desirable.