The upstream performance characteristics of a network are measured by
looping a signal through both the downstream and upstream paths of the
network. Test equipment may be located at a headend of the network and
configured to transmit a signal downstream to a remotely located loopback
device that redirects the signal in the upstream path to the test
equipment. The upstream characteristics may be predominant in the
analysis of the return signal because the downstream path may be
relatively free from noise.