Ignatius, Nimalkumar Guy Maritius creator Skjesol, Trond Chairperson Nanda, Navnit Kumar Examination Committee Huynh, Ngoc Phien Examination Committee German Academic Exchange Service (DAAD) Scholarship Donor text th Bangkok Asian Institute of Technology 1988 monographic eng

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104 p. The purpose of this thesis is to evolve a simulator for performance analysis, for the bus and ring medium access protocols and also to derive an analytical model to study the relationships between the simulation and analytical models. The medium access control protocol considered are tolcen-ring and CSMA/CD. Analytical Model for CSMA/CD protocol assumes infinite number of stations and when there is a collision no specific back-off algorithm is used. Analytical model for token-ring protocol assumes infinite buffer size. Simulation and analytical models of both access control mechanisms assume the arrival rate distribution to be Poisson distribution. The simulation model is used to compare the performance between token-ring and CSMA/CD. The performance parameters considered are delay, throughput and utilisation. The networks compared s h ould be of the same size. The performance parameters obtained from analytical and simulation models are compared for both token-ring and CSMA/CD, to find out the relationship and the range within which the analytical model agrees with the simulation model. Simulation model simulates the real conditions which prevail in these respective networks as far as possible, whereas the analytical model makes assumptions to malce the model simple and possible. These assumptions malce the analytical model more vulnerable and accounts for the mismatch between this and the simulation model. The simulator can be used to predict the delay, throughput or utilisation of token-ring or CSMA/CD network of any length, with any number of stations and for any transmission speeds. It can also be used to find the fairness of the network, because it gives the statistics of each terminal in the network (i.e. whether each terminal is given fair access to the network). It was found that for token-ring, the analytical model delay matched with the simulation model delay when the load is small (less than 60 per ·cent). For CSMA/CD the analytical model throughput does not match with the simulation model throughput. In this case simulation throughput is larger than the analytical throughput because simulation back-off algorithm is more effective and also by the fact that analytical model does not handle retransmissions. Both these models together can be used to determine transmission and retransmission for any given load. The analytical throughput is modified to give results which are more close to the expected throughput (same as simulation throughput) A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1988 Computer networks Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18767 http://203.159.5.9/ait-thesis/detail.php?q=B18767 280898 20260818214050.0