Abstract: An arrangement for monitoring for degraded signals in the loop distribution plant of a telecommunications network. Network interface units (NIUs) are used as an interface between a transmission medium, such as a coax cable or a radio channel, and customer premises equipment. One of these NIUs are assigned an additional task, that of generating up stream performance monitor singals, to be monitored by a centralized performance monitor and control unit, and of monitoring downstream signals to determine their performance characteristics, such as error rate, and to report that performance to the centeralized unit.