US Patent 7639944 Method for protecting cross-ring service in optical network

A method for protecting a cross-ring service in an optical network includes the steps of: determining whether a configured working path crosses different rings; and in the case that the working path crosses different rings, establishing a cross-ring protection path which bypasses an off-ring node or an on-ring node of the working path on a ring, and binding the cross-ring protection path and the working path, wherein the cross-ring protection path and the working path is bound, and thus a protection can be implemented for the cross-ring service when the off-ring node or the on-ring node fails, with a reduced occupancy of bandwidth in comparison with the conventional DNI method.