A method and system for enabling firewall traversal of media communications from a client device. The firewall infers authentication or validation of the client device based upon communications between the client device and a device controller known to the firewall. The firewall monitors packets sent from the device controller to the client device. If the device controller sends packets to the client device for a sufficiently long period of time and with sufficient frequency, or if the packets are of a certain type, then the firewall deems the client device to be validated and permits the client device to send data packets through the firewall. The device controller may include a media gateway controller, a port discovery server, or similar such device controllers. The device controller and client device communicate based upon a protocol, which need not be understood by the firewall.