With the introduction of fiber-optic trunk systems and fiber-to-the-bridger system design concepts, tapped-feeder cascade lengths have doubled. As a result, feeder performance has become a more critical factor in overall system performance. Seasonal temperature changes can cause significant variations in distribution signal levels. Considering the presence of taps, tapped feeder level changes have different characteristics than level changes in conventional trunk lines. These changes are magnified by the longer feeder cascades which are common in modern system designs. Consideration of feeder level changes must therefore become an integral part of modern system performance evaluation.