A backup communication system and method provides communicating between a video doorbell and a doorbell sound output device when communication between the video doorbell and a remote server us unavailable. When a front button of the video doorbell is pressed or motion is detected in front of the video doorbell, the video doorbell attempts to send a message to the remote server via a wireless local area network (WLAN). The video doorbell determines when the message is not received by the remote server, such as when the WLAN is not connected to the internet and/or the remote server does not acknowledge the message, and sends, via the WLAN, a broadcast message to the doorbell sound output device. The doorbell sound output device detects the broadcast message from the video doorbell and generates the audio tone.