Cisco Technology, Inc.

Cisco Systems Inc.

Roland G Chan

John T Chapman

Hon Wah Chin

Feisal Y Daruwalla

William E Jennings

Richard Meller

Nicos Achilleoudis

William L Quackenbush

John L Wong

The present disclosure relates an improved cable data switching unit that provides a fail-over system whereby one line card can protect a plurality of US (upstream) or DS (downstream) channel line cards, providing N+1 protection, with one linecard being able to protect N number of working linecards. When a failure is detected in a working linecard, the signals being routed by the failing linecards are re-routed seamlessly to a protect linecard. This disclosure provides for data to be passively routed, providing for data flow even if power is lost.

Method and apparatus for N+1 RF switch with passive working path and active protection path

A lossless arbitration scheme combines IEEE 802.3 compliant Medium Access Controllers (MACs) with a centralized arbiter and out of band access control signaling to achieve a spatially confined LAN that looks to attached devices like an IEEE 802.3 LAN, but has no bandwidth loss due to collisions, no excessive collisions and greater short term access fairness than standard Carrier Sense Multiple Access with Collision Detection (CSMA/CD) LANs. Two such spatially confined LANs are combined with an IEEE 802.3 compatible full-duplex point to point link to provide communication between two spatially confined groups of devices without bridges and buffering even when the separation of the groups is not spatially confined.

Lossless arbitration scheme and network architecture for collision based network protocols

A system including primary and secondary PCI (Peripheral Component Interconnect) buses which do not 'livelock'. The system includes two PCI to PCI bridges between the primary and secondary buses. One of the bridges is configured to only act as a target on the primary bus and as a master on the secondary bus, the second bridge is configured to only act as master on the primary bus and as a target on the secondary bus. The determination of which data path is chosen is not made by the bridges and thus the bridges do not bias the direction of transmissions to one bus or to the other bus.

Computer system with cascaded peripheral component interconnect (PCI)

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Mountain View, CA, United States of America

Roland G Chan