Method for use in a predetermined ring node of a plurality of ring nodes and method for deterministically squelching a communication circuit in a ring node transmission system

摘要

A method and apparatus for deterministically squelching communications circuits transported by a ring transmission system (100), including communications circuits with combinations of multiple drops, multiple sources and/or multiple broadcasts (in 101-104), is provided, in accordance with the invention, by a) identifying failed ring nodes (101-104) in the ring transmission system including locations of the failed ring nodes; b) identifying communications circuits active in the predetermined ring node; c) squelching a communications circuit active in the predetermined ring node in response to the identifications in steps a) and b) if a first ring node that is downstream from, and adjacent to, the predetermined ring node has failed, and an exit ring node for the communications circuit which is furthest downstream from the predetermined ring node has failed; and d) if no squelching is performed on the communications circuit in accordance with step c), then squelching the communications circuit active in the predetermined ring node if a second ring node that is upstream from, and adjacent to, the predetermined ring node has failed, and an entry ring node for the communications circuit which is furthest upstream from the predetermined ring node has failed. IMAGE