An Efficient Reliable Ring Protocol

In slotted- and token-rings, transmission errors and station failures may induce livelocks and deadlocks. In the present paper we address the problem of ring recovery from such faulty situations. We present a new protocol and prove that it recovers from any combination of transmission errors and station failures in at most five-ring revolutions. The protocol requires no information about the current topology of the ring, like the number of stations or the ring revolution propagation time. It uses only two frame bits for access control and achieves minimum delay at the ring stations. © 1991 IEEE