Patent ID: 8331244

Claim:
A communication system for propagating time division multiplexing (TDM) fault notifications, comprising: a first interworking function (IWF) node of a packet network, the first IWF node coupled to a first TDM node of a TDM network, the TDM network having a layer 2 protocol different than a layer 2 protocol of the packet network; and a second IWF node of the packet network, the second IWF node coupled to a second TDM node of the TDM network and configured to receive from the second TDM node TDM frames in accordance with the layer 2 protocol of the TDM network, the second IWF node configured to interwork payload of the TDM frames into data packets in accordance with the layer 2 protocol of the packet network for communication of the payload through the packet network via the data packets, the second IWF node further configured to detect a TDM fault of the TDM network based on a TDM frame received by the second IWF node from the second TDM node and to transmit continuity check messages (CCMs) in accordance with the layer 2 protocol of the packet network to the first IWF node, wherein the second IWF node is configured to control the CCMs in response to a detection of the TDM fault such that a TDM fault notification is propagated from the second IWF node to the first IWF node based on the CCMs, and wherein the first IWF node is configured to transmit to the first TDM node a TDM frame in accordance with the layer 2 protocol of the TDM network and indicative of the TDM fault notification.