Abstract: 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.

Abstract: Systems and methods are provided for providing data from a plurality of databases stored on a plurality of disparate servers. A query is received for data from a plurality of databases stored on a plurality of disparate servers. An address for a first server is resolved that stores a first database identified by the catalog field in the query using a logical name-to-connection metadata map. A first sub-query is transmitted to the first server based on the received query, and a first sub-query response is received from the first server. The resolving, transmitting, and receiving are repeated for a second server. The first sub-query response and the second sub-query response are combined to generate a query response according to the received query, and the query response is transmitted.

Abstract: Systems and methods are provided for providing data from a plurality of databases stored on a plurality of disparate servers. A query is received for data from a plurality of databases stored on a plurality of disparate servers. An address for a first server is resolved that stores a first database identified by the catalog field in the query using a logical name-to-connection metadata map. A first sub-query is transmitted to the first server based on the received query, and a first sub-query response is received from the first server. The resolving, transmitting, and receiving are repeated for a second server. The first sub-query response and the second sub-query response are combined to generate a query response according to the received query, and the query response is transmitted.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.