Juniper Networks, Inc.

Michael Beesley

Lawrence Hui

Ashok Krishnamurthi

Ross Heitkamp

Unmesh Agarwala

Scott Chew

Anis Haq

Kenneth Richard Powell

Anurag P Gupta

Song Zhang

Michael Armstrong

Phil Lacroute

Kireeti Kompella

Dennis C Ferguson

Ramalingam Krishnamurthi Anand

Mike M Wu

Timothy D Kolar

A router includes multiple routing engines. If the active routing engine fails, a backup one of the routing engines detects the failure and assumes the role of active routing engine. A redundancy controller circuit, connected to the multiple routing engines, facilitates the selection and switching of the routing engines. Portions of the packet forwarding engine, in addition to the routing engine, may be redundantly implemented. The active routing engine controls the selection of the redundant portion of the packet forwarding engine.

High capacity router having redundant components

A fabric request controller implements flow control for data cells to a network or switch fabric. The fabric request controller issues request messages to the fabric switch and receives back corresponding grant messages. The fabric request controller includes a credit counter for metering the number of allowable outstanding requests. A fake request vector component periodically issues fake requests to compensate for information loss on the switch fabric.

Credit-based flow control over unreliable links

A network device, such as a router, utilizes a virtual interface to hide the presence of redundant backup physical interfaces from a router control unit. If traffic needs to be redirected from a primary physical interface, the router remaps the virtual interface to the backup physical interface without needing to update routes and select one or more alternative routes due to the need to redirect traffic. Instead, the router control unit redirects network traffic associated with the primary physical interface to the associated backup physical interface. In this manner, delays associated with route updating can be avoided, and a relatively seamless switchover can be achieved from the primary to the backup physical interface.

Virtual interface with active and backup physical interfaces

A network device supports an interface by which a user enters text-based configuration input that describes the channelization of a network link. The configuration input includes one or more text blocks of that define and hierarchically relate a data channel and at least one data sub-channel. The network device may include a control unit to communicate data packets over a channelized network link according to the configuration input. Accordingly, the user can view the text block for a particular channel or sub-channel without having to significantly scroll the display. In addition, the configuration input for the channels can readily be stored in multiple configuration files, and need not be maintained in a single file having continuous, nested levels configuration input.

Network device channel configuration

A two wire serial bus is connected between different circuit boards in a complex electrical system. The two wire serial bus may be used to receive status information about each of the circuit boards in the system. A master control processor on one of the circuit boards controls which of the other circuit boards are active on the serial bus. Each of the non-master circuit boards includes a series of switches that electrically isolate or connect portions of the two wire serial bus from one another. Through the series of switches, both the master control processor and processors local to each of the other circuit boards may simultaneously access different portions of the serial bus.

Multi-master and diverse serial bus in a complex electrical system

A network device includes redundant buses, redundant master controllers, and slave controllers. Each of the master controllers connects to a corresponding one of the buses. One of the master controllers acts as an active master and the other master controllers act as standby masters. The active master commences a bus cycle that includes an address interval and a data interval, provides a destination address on the corresponding bus during the address interval, and transmits or receives a command or data during the data interval. The slave controllers connect to the bus, detect commencement of the bus cycle, sample the destination address from the bus a predetermined amount of time after commencement of the address interval, and transmit or receive a command or data during the data interval.

Reliable and redundant control signals in a multi-master system

A debugging and diagnostic system allows a developer to receive low-level diagnostic information from multiple processors in a complex electrical system. A bus connects a master processor to the processors to be debugged via corresponding receiver/driver circuits. The receiver/driver circuits receive serial information from the processors and transmit it to the bus. The master processor controls the receiver/driver circuits through a control logic circuit.

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Hillsborough, CA, United States of America

Michael Beesley