MTP2:Signal Unit Error Rate Threshold

The MTP2 layer is responsible for retransmitting missing MSUs to the remote peer to ensure a valid flow of data. However, when the error rate of MSUs (the number of errored MSUs per unit of time) crosses a defined threshold, the link is taken out of service automatically (usually by the upper MTP3 layer).

The Signal unit error rate threshold parameter defines this threshold estimate to be monitored by the MTP2 layer before declaring the link as down.