A dual-mode broadband modem operative to operate in a service mode and a surveillance mode is disclosed. Generally, the dual-mode broadband modem comprises a primary communication device; a secondary communication device; a central processing unit in communication with the primary and secondary communication devices; and a memory unit in communication with the central processing unit. In the service mode, the primary communication device communicates with a broadband service provider and the central processing unit stores historical information regarding performance of the primary communication device in the memory unit. If an interruption in broadband service is detected, or the performance of the primary communication device falls below a predetermined threshold, the dual-mode broadband modem switches to surveillance mode and the secondary communication device is activated. The secondary communication device communicates with the broadband service provider to send at least a portion of the historical information regarding performance of the primary communication device to the broadband service provider for processing to determine a source of the interruption in broadband service or a source of the decreased performance of the primary communication device.