Patent ID: 7602706

Claim:
A method for providing inter-ring protection in shared packet rings, the method comprising: utilizing a spanning tree protocol to identify a first node as a root node; operating the first node in an active mode, the first node connected to a ring interconnect node on the same ring as the first node and to a peer node on a different ring, the ring interconnect node in a standby mode, the first node configured to exchange control messages with the ring interconnect node during a failure of the peer node or a ring interconnecting link connecting the first node to the peer node; forwarding packets from the first node to the peer node on the ring interconnecting link in the active mode; receiving at the first node, notification of a failure of the ring interconnecting link or the peer node; and in response to said notification of a failure: sending said control message from the first node to the ring interconnect node instructing the ring interconnect node to switch from the standby mode to the active mode, wherein the ring interconnect node forwards packets in the active mode; and changing the first node to the standby mode and changing a port path cost of the first mode from a default port path cost associated with the active mode to a standby port path cost associated with the standby mode; wherein packets received at the first node or the ring interconnect node are blocked from being forwarded to said different ring when the node is in the standby mode.