Aspects of methods and systems for frequency multiplexing suitable for Data Over Cable Service Interface Specification (DOCSIS) are provided. A system for multiplexing signals according to frequency comprises a DOCSIS port interface, an upstream interface, a downstream interface, and a circulator subsystem. The DOCSIS port interface comprises a plurality of channel filters. The upstream interface is operably coupled to a first channel filter of the plurality of channel filters, and the downstream interface is operably coupled to a second channel filter of the plurality of channel filters. The circulator subsystem is able to direct a first signal from the upstream interface to the DOCSIS port interface and is able to direct a second signal from the DOCSIS port interface to the downstream interface.