Exploitation of redundancy for throughput increase in a high speed LAN

Different techniques for improving the exploitation of resources in a high-speed local area network (LAN) are assessed. The techniques analyzed are all based on the exploitation of the redundant resources often introduced in the transmission system to increase the network´s fault tolerance. The different strategies are defined for a 100-Mb/s token ring LAN. In order to assess the different strategies, the network is modeled using generalized stochastic Petri nets; the model allows evaluation of the increase in throughput and the construction of diagrams relating access delay to throughput. In comparing the different solutions, the fairness among the various users of the network is also considered. The technique of access to independent channels is shown to be excellent as far as available throughput is concerned, but it introduces unfairness in access to the network and requires particularly complex management strategies. The technique of access to correlated channels, on the other hand, has performance levels which are similar to those provided using the other technique. In addition, it exhibits intrinsic fairness in the access mechanism and does not require complex network management