The multi-token ring network protocol

Abstract

Abstract High speed networks require that bandwidth management be as less dependent on the medium propagation delay as possible. Token rings, although usually very efficient at high load, are less efficient at light and moderate loads, especially in the short packet environment. This paper proposes a solution to the token ring inefficiency under the aforementioned conditions: a medium access protocol using multiple tokens. The paper first shows how the medium access can be managed in a distributed way, using two tokens. The overhead is kept to a minimum. It is shown that the performance of this protocol is superior to that of the single-token ring protocol under light to medium loads, while it is slightly worse at higher loads. The protocol is then extended to an arbitrary number of tokens. It is shown that increasing the number of tokens improves the performance at light load, but degrades the performance at high load. This protocol is not just an improvement over the token ring protocol, but is a general suite of protocols of which the well known token ring is a special case.