Apparatuses and methods concerning routing of calls in an IPBX server are disclosed. As an example, one apparatus includes a first processing circuit communicatively coupled to an IPBX server. The IPBX server is configured to route VoIP calls for a plurality of end-users having respective VoIP-enabled devices and generate call event messages for the routed calls. The first processing circuit is configured to generate call summary metrics from the call event messages. The call summary metrics indicate respective sets of call data for participants of the calls routed by the IPBX server. A second processing circuit is configured to evaluate 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 is further configured to cross-correlate the identified set of incoming calls with a secondary data source to determine a respective priorities for the set of incoming calls. The respective priorities include a higher priority for at least one call and a lower priority for at least one call. The second processing circuit stores data indicating calls of the identified set determined to have the higher priority.