Abstract: Cable modems are provided for measuring a noise signal power level on the upstream side of the cable network. The cable modem may be configured to make the signal power measurements at a variety of frequencies and at a selected bandwidth during a specified test time period responsive to a request received from the cable network. Methods and systems are provided for identifying a noise signal source on a cable network including specifying a time window for measurements, the desired measurements and the cable modems from which measurements are desired when the need to initiate a test to identify a noise source is detected. Tests may be initiated based on noise signal measurements by individual cable modems or by the cable services provider which indicate an unacceptable noise level. In addition, the reliability of the test measurements may be improved by not allowing any transmissions on the upstream side during the concurrent test window while cable modems are making the requested measurements.