Integration of a Synchronous and Asynchronous Traffic on the MetaRing Architecture and Its Analysis

In this paper, we describe and evaluate a protocol for integrating two types of traffic on the MetaRing Architecture. Synchronous (reserved or real-time) traffic which is periodic and requires a connection set-up and will have guaranteed bandwidth and bounded delay, and asynchronous or bursty traffic with no real-time constraints that can use the remainder of the bandwidth in a fair manner. The integration mechanism is functionally equivalent to the Timed-Token Function in FDDI, which is a shared media ring protocol. The MetaRing is a slotted or buffer insertion ring with fairness and spatial bandwidth reuse. Concurrent access and spatial bandwidth reuse enable the simultaneous transmissions over disjoint segments of a bidirectional ring and therefore, can increase the effective throughput in each direction. The fairness mechanism for this architecture is simple and robust, and it is based on a 1-bit control signal that regulates the acess to the ring. A Markovian state space formulation of the integration protocol is given. This compact and efficient formulation which uses only a few state equations is used for the simulation of the network with arbitrary number of nodes. An upper bound on the delay of the synchronous traffic is provided to demonstrate the importance of the integration algorithm. Simulation results are also presented to show the effects of the fairness and flow control signals on the performance of the network.