the present invention customizes a network connection to customer premises equipment using a calibration signal . a network signal processor emits a tag signal indicating that a signal processing platform is in use . customer premises equipment issues a calibration signal to the network signal processor based on detection of the tag signal . the customer premises equipment outputs the calibration signal to the network signal processor which measures the signal loss , adjusts the gain mapping and issues a calibration signal to the customer premises equipment . the customer premises equipment then estimates spectral shaping based on the calibration signal from the network signal processor and equalizes the receive path so that the signal processing platform is detected and implemented . embodiments of the present invention are illustrative of a more general concept of the use of cpe as an agent in telephone network maintenance .