NETWORK CONFIGURATION PROTOCOL AND METHOD FOR RAPID TRAFFIC RECOVERY AND LOOP AVOIDANCE IN RING TOPOLOGIES

摘要

A network configuration protocol and algorithm are described which resolve deficiencies with existing protocols. A large network having many bridges may be built as a combination of smaller networks, many of which may be arranged in a ring topology. Each ring may be monitored by a single master bridge (20) regularly sending control packets, and each other bridge (10) in the ring does not make decisions with respect to its status. A loop free topology is achieved by selectively blocking (20b) and unblocking (20a) data traffic in one of the ring ports of the single master bridge (20) for the ring, while all other bridges (10) in the ring keep their ports in non-blocked states. In multiple ring topologies, each ring has a single master bridge which chooses one of its ports to be blocking. When rings are connected through a shared link formed between two shared bridges, rings with higher priorities carry control packets of rings with lower priorities so that, in case of failure of the shared link, a single ring may be formed from the connected rings with only the master bridge of the higher priority ring aware of and monitoring the larger ring. In case of any link failure inside a given ring, the master bridge quickly detects the failure and automatically changes its blocking port to a non-blocking state in which traffic may flow and follow an alternate path, avoiding the failed link.