Priority-based protocol for transmission of real-time traffic

This paper describes a protocol for handling traffic while satisfying various requirements, for example, the traffic generated by distributed real-time applications. First, the concept of an ideal protocol for handling different classes of priority messages is introduced. A virtual-token protocol is then introduced as an attempt to approach the performance of the ideal scheme with minimal overhead. A description of the protocol operations and the major issues involved in the design of the protocol are discussed. The major contribution of the proposed protocol is its efficient priority-handling mechanism, which is not available in the CSMA/CD bus and which is poorly provided in the token-passing schemes. The proposed priority mechanism more closely satisfies the requirements of a general priority scheme than currently existing methods. This allows the protocol to handle real-time requirements more efficiently. Simulation results have shown that the overhead spent in implementing the protocol is relatively small.