Unique identification of resources of a PBX system in a PBX network with telephony server

摘要

Communication systems (1,2,3) identify and differentiate the resources (5-19) based on assigned ID codes. An application (20) communicates to the resources through the messages with the communication systems. The extension units in the communication systems add extensions to the same ID codes of the resources and to the sent messages to the application to identify the message transmitting system.