The scope of ED-137 is to define the rules for VoIP implementations to support ATM communications and their interoperability. ED-137 is composed of multiple Volumes, each of which is dedicated to a specific application. The objective of Volume 5 (Supervision) is to provide the Network Supervision Component with a common informative description of the supervised objects, so as to allow its users to understand how the overall VoIP ATM Network is performing, to identify faulty elements, and to possibly propose/implement corrective actions.