Modularity versus efficiency in OSI system implementations

Abstract

Modularity and efficiency, in protocol implementations, do not go hand in hand. A tradeoff is inevitable between good structure and good performance. Although a layered architecture has been proposed for open communications, it is generally unknown as to how the layer entities ought to be structured and what the appropriate strategies are that could be adopted in implementations. This paper examines a number of possible implementation strategies based on the various prevailing system facilities: processes, threads, kernel and front-end processors. The pros and cons of the strategies are analysed showing their relative merits in implementations. The analysis leads to the recommendation of an enhanced subsystem architecture that holds the best compromise of the conflicting requirements of modularity and efficiency. © 1997 Elsevier Science B.V.