Abstract: Cable modems and CMTS modules, connected to a single cable so as to provide cable modem service to a respective set of the cable modems, are arranged so one of the CMTSs can backup the other. Each of the CMTSs simultaneously broadcasts its downstream channel on its own assigned one of the cable channels that is accessible by the cable modems for which it is assigned to provide the primary downstream channel, and each cable modem is assigned in addition to its primary downstream channel at least one alternative downstream channel which is supplied by a CMTS other than its primary CMTS, so that when the primary downstream channel of a cable modem becomes invalid the cable modem switches to the alternative downstream channel. When doing so, the cable modem employs many of the parameters that were established during the initialization it performed with the primary CMTS.