A new protocol for route discovery in multiple-ring networks. II. Multicast, recovery and high-speed processing

A new MAC protocol for route discovery in multiple-ring network, called the FTRD-protocol, was introduced in Part I. The present paper shows how the FTRD-protocol can find a description of a tree that spans a group of destinations. By placing such a description in the header of its frame, a source station can efficiently multicast the frame to the destination group. This requires no change in the operation of the source routing bridges. Another issue addressed in the paper is the recovery of the FTRD-protocol from error and failure conditions. When a bridge or the source suspects that the protocol is dead-locked, it initiates an independent recovery protocol that clears the network and prepares it for a new execution of the FTRD-protocol. The last issue addressed in the paper is the execution of the FTRD-protocol in a network with high-speed rings. The problem in such a network is that the bridges do not have sufficient time, after recognizing the route identity, to look in the local table and decide whether the relevant fields in the received frame need to be altered