Apparatuses and methods concerning routing of calls in an IPBX server are disclosed. A first processing circuit is communicatively coupled to an IPBX server that routes VoIP calls for a plurality of end-users having respective VoIP-enabled devices and generates call event messages for the routed calls. The first processing circuit generates call summary metrics from the call event messages. A second processing circuit evaluates the call summary metrics to identify a set of incoming calls to the IPBX that were missed and have not been returned by the end-users. The second processing circuit cross-correlates the identified set of incoming calls with a secondary data source to determine a respective priorities for the set of incoming calls. The second processing circuit stores data indicating calls of the identified set have a higher priority.