The disclosed systems and methods provide intelligent device inspection and interrogation in an application layer system to route packet-based network calls. These systems and methods can be used to detect the status of a specified endpoint. Endpoint devices can be configured to communicate status information to a central call manager. Endpoints can also be periodically polled to request device information. Pre-defined rules applied at the central call manager can be used to process call flow based on the device information. These rules can be configured so that a call that is not completed for any reason can be transferred to another destination such as a video mail service or an automated or live operator service.