The untimely occurrence of an event or a combination of events that, according to the protocol, should result in a disconnection. In addition, the occurrence of one or more of the following criteria generated between the portion boundaries is defined to be a premature disconnect stimulus: (a) bit error ratio worse than 10nb, for Xb number of consecutive observation periods of Nb duration; (b) block error ratio worse than 10nB, for XB number of consecutive observation periods of NB duration; (c) more than X number of consecutive severely errored units of time. Receipt of a premature disconnect stimulus may result in a connection being disconnected and then reestablished. Note: Only that subset of these criteria specified for a given service is considered.