a system for monitoring quality of calls in a network . a server receives information concerning calls which begin or end in a network and at the same time receives measurements of a quality parameter such as bandwidth . this measurement data is provided by a probe , so that the server is able to correlate calls which are placed through the network with the quality of service in the network at that time . when the quality falls below a desired level , the server notifies the customer or the network operator so that appropriate action may be taken .