Patent ID: 6449249
Filing Date: 2002-09-10
Classification: H04L

Abstract:
A cable modem termination system for providing spare circuit availability to active cable modem circuits, the system comprising:a plurality of active circuit cards comprising cable modem signal processing circuitry having an output signal; a spare circuit card comprising circuitry that is substantially similar to a first active circuit card of the plurality of active circuit cards, the spare circuit card comprising a spare output signal; a plurality of switch cards, each switch card coupled to one of a corresponding active circuit card or the spare circuit card, each switch card that is coupled to its corresponding active circuit card comprising an input/output connection and a switch having a switch control input, each switch card coupled to a previous and a subsequent switch card; and a first controller circuit card coupled to the plurality of active circuit cards, the spare circuit card, and the plurality of switch cards, the first controller circuit card having a plurality of switch control outputs, each switch control output coupled to a switch control input of each of the plurality of switches, the first controller circuit card generating, in response to a failed first active circuit card, a switch control signal that activates the switch on the switch card corresponding to the first active circuit card such that the spare output signal is routed through its corresponding switch card and any intervening switch cards to the input/output connection of the switch card corresponding to the first active circuit card.