A controller for calibrating a videoconferencing system is disclosed. The system includes a first codec connected to a second codec through a videoconferencing connection. The controller includes an output in communication with the first codec for controlling the first codec to transmit a videoconferencing signal to the second codec through the videoconferencing connection, and an input for receiving a calibration adjustment value from another controller over a network, where the other controller is in communication with the second codec. The controller is configured to adjust a signal level setting of the first codec using a level adjustment command of the first codec, and the level adjustment command is determined according to the calibration adjustment value transmitted by the other controller.