Cisco Technology, Inc.

Joseph O'Donnell

Guenter E Roeck

Mark E Millet

Feisal Y Daruwalla

James R Forster

Joanna Qun Zang

John K Chen

A CMTS redundancy technique requires at least two CMTS interfaces (e.g., line cards) on one or more CMTS chassis at the head end of a cable network. One of the CMTSs serves as a backup or 'protecting' CMTS. When another CMTS (a 'working' CMTS) becomes unavailable to service its group of cable modems, the protecting CMTS takes over service to those cable modems. The SWITCHOVER takes place transparently (or nearly transparently) to the cable modems. The protecting CMTS provides service on the same downstream channel as used by the working CMTS. The cable modems need not modify any settings pursuant to their cable modem communication protocol (e.g., DOCSIS ranging). This transparency to the cable modems is realized by keeping the working and protecting CMTSs in synchronization regarding service parameters for the cable modems. In other words, the protecting CMTS maintains a list of current parameters for allowing service to the cable modems.

Cable network redundancy architecture

Disclosed is an apparatus and method for simulating a plurality of cable modems for testing a device, such as a head end complex. In general terms, the present invention provides a multiple cable modem simulator and techniques for setting up and executing the same. In one implementation, the multiple cable modems are simulated by simulating multiple MAC (media access control) state machines for multiple cable modems. In other embodiments, a simulator of the present invention includes a mechanism for simulating physical operating conditions of the simulated cable modems. For example, even when the simulator is located at a single test location, different distances and power levels may be simulated for the different simulated cable modems.

Method and apparatus for simulating a plurality of cable modems

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Fremont, CA, United States of America

Joseph O'Donnell