Cable data network architecture

A cable data network architecture includes a master head-end, at least one distribution hub connected to the master head end via a first communication link, and one more more user modems connected to the distribution hub(s) via a second communication link. The master head end includes an inter-hub communications switch, a network controller, a network element manager, and one or more external communication links. The distribution hub includes at least one radio frequency modulators for modulating and transmitting data, at least one demodulator for receiving and demodulating return data, a link access control computer for controlling transmission and reception of data by the distribution hub, a hub element manager for detecting faulty communications to and from the distribution hub, and a local switch for switching data between the modulators, the demodulators, the link access computer and the hub element manager within the distribution hub. The user modem(s) includes a tuner for determining a channel for receiving data from the distribution hub, a demodulator for demodulating the received data, an address recognition circuit for determining whether an address associated with the data corresponds to an address served by the user modem, a modulator for modulating transmission data to be transmitted by the user modem, a tuner for determining a transmission channel for transmitting the transmission data, and a timing and control circuit for determining when the user modem transmits the transmission data to the distribution hub over the second communication link.