A new protocol for route discovery in multiple-ring networks. 1. The basic protocol

Source routing requires that the source station knows a route to the destination. The paper presents a new bridge protocol for route discovery in multiple-ring networks, where several token-rings are connected by bridges. The protocol gives to the source station an indication of the availability of a route to the destination. If such a route exists, the source is supplied with a description-a list of ring and bridge identities-of the route that is fastest at the time of protocol execution. The main advantage of the new route discovery protocol over the existing one is its communication efficiency: the number of frames used is the sum of the number of rings and number of bridges in the network, as opposed to the exponential function required in the existing protocol. Another advantage of the new protocol is its option that allows determining routes to multiple destinations, thus supporting efficient multicast source routing