This thesis presents an evaluation of the performance of some ring local area network protocols, specifically the buffer insertion ring and the token ring. Both dual and single versions of each are considered, and performance statistics are obtained by measurements on real networks, by mathematical analysis, and by computer simulation. New packet routing protocols for dual contrarotating buffer insertion and token ring networks are described and their performance is examined. It is found that, due to the bandwith reuse properties of the routing methods, maximum throughputs of 800% and 200% are achievable, for the dual buffer insertion ring and the dual token ring respectively
