Performance analysis of token bus protocol with maintenance functions
Douglas W. Jacobson
An analytic model for the token bus protocol with the consideration of maintenance functions has been proposed in this dissertation. Analysis of the performance is done in the aspects of average message delay and normalized throughput or channel utilization;The problem of analyzing a working token bus system, which often requires maintenance of logical ring, became a new topic in local area network field. The maintenance functions of token bus protocol have been overlooked in most performance analyses. They need to be defined clearly and quantified properly to be considered in the performance analysis;This problem of maintenance functions is investigated indirectly in this dissertation. First, an analytic model for normal operational mode is developed. This model is an unique one in the sense that it contains a variable whose value depends on the maintenance functions implemented in the network. Later, the quantified delays due to maintenance functions are reflected back in to the normal case model to complete the analysis;The first half of the dissertation includes definitions of maintenance functions and their quantifications and an analytic model development and performance analysis comprises second half of the dissertation;The result of the performance analysis with certain assumptions shows considerable increase in average message delay in the system varying from 3.8% to 5744% in the worst case. The importance of considering maintenance functions on network performance is clearly demonstrated by the result obtained in this research;The analytic model developed is a flexible model which can encompass the effects of maintenance functions in the token bus protocol.