Ciena Corporation

Equipe Communications Corporation

Chris R Noel

Brian Branscomb

Corey Simons

Nicholas A Langrind

Joseph D Kidder

Peter B Everdell

Terrence S Pearson

Daniel J Sullivan, Jr

Barbara A Fox

Colin Bell

Larry B Manor

Jonathan D Madsen

Joe Whitehouse

The present invention provides a method and apparatus for improving transmission of control information within a network device and between multiple connected network devices. Specifically, a control path is included within a network device that is independent of the data path and dedicates control path resources to each distributed processor within the network device. Dedicating resources insures that each processor has sufficient bandwidth on the control plane to transmit control information at high frequencies. This may prevent starvation of data transmissions during periods of high control information transfers and may also reduce the likelihood or further spreading of control information storms when one or more network devices in a network experiences a failure.

Network device including dedicated resources control plane

The present invention provides an upper layer network device with one or more physical layer data test ports. The data supplied to the test ports reflects the data received by the network device with minimal modification and no upper layer translation or processing, and supplying the data to the test ports does not impact or disrupt the service provided by the network device. Only a small portion of the network device need be operable to send data to the test ports. In addition, the test ports are programmable while the network device is operating and without impacting its operation. Moreover, because the test ports are programmable&#x2014;that is, they are not dedicated&#x2014;they may be re-programmed for normal device operation.

Upper layer network device including a physical layer test port

The present invention reduces the cost of a minimally configured network device by providing a network device with a distributed switch fabric. Such a network device locates a portion of the switch fabric functionality on each forwarding card allowing the minimal network device configuration to include less than the entire switch fabric functionality. The cost of the minimal configuration is, therefore, reduced allowing network service providers to more quickly recover the initial cost of the network device. As new services are requested, additional functionality, including both forwarding cards and universal port cards may be added to the network device to handle the new requests, and the fees for the new services may be applied to the cost of the additional functionality. Consequently, the cost of the network device more closely tracks the service fees received by network providers.

Network device including central and distributed switch fabric subsystems

The present invention provides a high switching capacity network device in one telco rack including both physical layer switch/router subsystems and an upper layer switch/router subsystem. Instead of providing a single physical layer switch/router subsystem, multiple physical layer switch/router subsystems are provided. Segmenting the physical layer switch/router into multiple, for example, four, subsystems better utilizes routing resources by allowing etches for the physical layer subsystems to be moved away from the center of the mid-plane/back-plane of the network device. Moving the physical layer subsystem etches away from the center of the mid-plane enables the network device to include an upper layer/switch router subsystem with etches toward the center of the mid-plane. Providing a multi-layer network device in one telco rack allows for intelligent layer 1 switching (for example, dynamic network connection set up), allows for one network management system to run both layer 1 and upper layer networks and eliminates grooming fees. Compared with separate layer 1 and upper layer network devices or a multi-layer network device occupying multiple telco racks, a single network device saves valuable telco site space and reduces expenses by sharing overhead such as the chassis, power and cooling.

Multi-layer network device in one telecommunications rack

The present invention provides a method and apparatus for supporting multiple redundancy schemes in a single network device. In one network device, various redundancy schemes are supported including 1:1, 1&plus;1, 1:N, no redundancy or a combination of redundancy schemes. In addition, the redundancy scheme or schemes for physical network device cards (i.e., universal port cards) or ports may be different from the redundancy scheme or schemes for forwarding network device cards. For example, a network manager may want to provide 1:1 or 1&plus;1 redundancy for all universal port cards and/or ports but only 1:N redundancy for each N group of forwarding cards. As another example, the network manager may provide certain customers with 1:1 redundancy on both universal port cards (or ports) and forwarding cards to ensure that customer's network availability while providing other customers, with lower availability requirements, with various other redundancy scheme combinations, for example, 1:1, 1&plus;1, 1:N or no redundancy for port cards or ports and 1:N or no redundancy for forwarding cards. The present invention allows customers having different availability/redundancy needs to be serviced by same network device.

Network device for supporting multiple redundancy schemes

Growing community of inventors

Acton, MA, United States of America

Chris R Noel