Abstract: A network device includes a main storage memory and a queue handling component. The main storage memory includes multiple memory banks which store a plurality of packets for multiple output queues. The queue handling component controls write operations to the multiple memory banks and controls read operations from the multiple memory banks, where the read operations for at least one of the multiple output queues alternates sequentially between the each of the multiple memory banks, and where the read operations and the write operations occur during a same clock period on different ones of the multiple memory banks.

Abstract: A method includes operating in a normal mode to receive and transmit packets, where the network device is one of multiple network devices that operate as a virtual chassis, where the virtual chassis corresponds to a single logical network device, and detecting when the network device crashes. The method further includes initiating a resetting process and operating in a pass through mode, during the resetting process, where the pass through mode permits packets to be received and transmitted to the network devices of the virtual chassis.

Abstract: A device may include polling logic configured to store a table of received addresses, sequentially receive sensor data from each address in the table via a serial data bus, store the sensor data in a memory, receive an address from a processor via a high speed data bus, and provide stored sensor data from the memory to the processor via a parallel data bus.

Abstract: A memory controller, such as a memory controller for reading data received from a DDR SDRAM memory, may detect the beginning and end of a read cycle. The memory controller may include a preamble detection circuit to receive a strobe signal and output a first control signal indicating detection of a preamble window in the strobe signal that indicates a beginning of the read cycle, where the first control signal is delayed based on a selectable delay period applied to the first control signal. The memory controller may further include a first gate to, based on the first control signal, either output the strobe signal for reading of the data lines or block the strobe signal, and the control logic to set an amount of the selectable delay period for the preamble detection circuit.

Abstract: An example network system includes a layer two (L2) device and a layer three (L3) device. The L2 device includes a control unit is configured to determine a preferred network path from a first L2 network in which the L2 device resides to an intermediate L3 network in which the L3 device resides that couples the first L2 network to a second L2 network having a second L2 device. The control unit includes a management endpoint (MEP) module. The MEP module executes an operations, administration, and management (OAM) protocol to monitor the first L2 network and output an L2 frame in accordance with the OAM protocol to the L3 device to notify the L3 device that it is within the preferred network path. A MEP module of the L3 device executes an OAM protocol that outputs L2 frames to the L2 device indicating the status of the L3 network.

Abstract: Systems and methods consistent with the present invention provide a mechanism that can efficiently manage multiple queues and maintain fairness among ports while not placing additional performance demands on the memory used to store the queue data structures. Within a port, high priority traffic is dropped only if it is consuming more than its fair share of bandwidth allocated to that port. Queue arbitration is of low performance cost and simple because it arbitrates only across queues per port, rather than across all the queues in parallel. Accordingly, fair arbitration with relatively little hardware cost.

Abstract: A communication node contains intelligence for directing both internet protocol (IP) packets and Asynchronous Transfer Mode (ATM) cells toward their destinations. The ATM cells and IP packets may be received within a common data stream. The respective devices process the ATM cells and IP packets to direct the cells and packets to the proper output ports towards their destinations. The device is capable of performing policing and quality of service (QOS) processing on both the ATM cells and the IP packets.

Abstract: An enhanced link state protocol is described for uniquely identifying broadcast networks having overlapping address spaces within a network system. A network device generates first and second link state advertisements (LSAs) in accordance with this link state protocol. The first LSA includes a first identifier dependent on layer 3 addressing information assigned to a physical interface of the first network device that interfaces with a layer 2 communication medium, e.g., an IP subnet address prefix. The second LSA includes a second identifier independent of the layer 3 addressing information assigned to the physical interface of the first network device that interfaces with the layer 2 communication medium, e.g., a unique network identifier associated with a broadcast network. By transmitting this second LSA to a second network device, the network device may uniquely identify broadcast networks having overlapping address spaces.

Abstract: In general, techniques are described for adaptively applying network acceleration services within an intermediate network device. In particular, the intermediate network device comprises a classifier module that receives network traffic and a servicing engine. The servicing engine applies the network acceleration services to the network traffic in accordance with a service configuration and monitors the application of network acceleration services to determine whether the application of each of the network acceleration services improves the efficiency with which the network traffic is serviced. The servicing engine then dynamically adapts the service configuration to alter the application of the network acceleration services based on the determination. Thereafter, the servicing engine applies the network acceleration services to the network traffic in accordance with the dynamically adapted service configuration to more efficiently service the network traffic.

Abstract: In general, techniques are described in which a plurality of network switches automatically configure themselves to operate as a single virtual network switch. A virtual switch is a collection of individual switch devices that operate like as single network switch. As described herein, network switches in a network that are capable of participating in a virtual switch may automatically discover one another. The participating network switches may then elect one of the participating switches as a master switch. The master switch may generate forwarding information and store the forwarding information in the participating switches, including the master switch. The forwarding information causes the participating switches to act like a single network switch.

Abstract: Explicit signaling mechanisms facilitate automatic stitching for both packet and non-packet label switched paths (LSPs). Extensions to resource reservation protocol signaling are utilized to include explicit signaling mechanisms that setup and maintain LSPs. An inter-domain LSP may be created by automatically stitching independent LSP segments within separate domains. Stitching the intra-domain LSP segments creates an end-to-end LSP in the data plane with continuous label swapping across the different domains. An intra-domain LSP may be created by automatically stitching independent LSP segment within a single domain. A network device, such as a router, at an ingress of an LSP segment utilizes the signaling extensions to notify a network device at an egress of the LSP segment to prepare for a stitching procedure. In return, the egress network device utilizes the signaling extensions to inform the ingress network device whether the LSP segment is ready for the stitching procedure.

Abstract: A network device receives control plane packets and data plane packets from a network. The network device includes a forwarding component that forwards the data plane packets in accordance with routing information maintained by a routing component. The forwarding component directs the control plane packets to a firewall component that processes the control plane packets to apply firewall services and detect network attacks. After processing, the firewall component loops the control plane packets back to the forwarding components for forwarding to the routing component. The firewall component may be a security service card.

Abstract: A scheduling system may include a read sequence management table that includes a group of positions for arranging data received from a group of lines and a schedule management table to store a group of peak rate values that are each associated with one of the group of positions of the read sequence management table. The scheduling system may further include a schedule computation section to determine the association between each of the group of peak rate values and the group of positions based on an availability of the group of positions, store each of the associations in the schedule management table, and select one of the group of positions in the read sequence management table as a starting position to arrange data from a new line, where the selected position is based on a comparison of a peak rate value of the new line and the group of peak rate values stored in the schedule management table.

Abstract: A route for a data unit through a network may be defined based on a number of next hops. Exemplary embodiments described herein may implement a router forwarding table as a chained list of references to next hops. In one implementation, a device includes a forwarding table that includes: a first table configured to store, for each of a plurality of routes for data units in a network, a chain of links to next hops for the routes; and a second table configured to store the next hops. The device also includes a forwarding engine configured to assemble the next hops for the data units based on using the chain of links in the first table to retrieve the next hops in the second table and to forward the data units in the network based on the assembled next hops.

Abstract: A system controls the transfer of data. The system receives a request to transfer data and determines whether a counter value equals or exceeds a threshold. The counter value represents an amount of time since a previous data transfer. When the counter value equals or exceeds the threshold, the system transmits the data. In another implementation, the system tracks the amount of data read from a buffer. The system reduces the speed at which data is read when the amount of data read from the buffer exceeds a threshold.

Abstract: A network device may include logic configured to receive a problem report from a second network device, where the problem report includes event data, determine at least one of an action to perform or whether reconfiguration information is associated with the event data in the received problem report and add information to the received problem report to provide a reformatted problem report and transmit the reformatted problem report to a third network device when it is determined that reconfiguration information is not associated with the event data in the problem report.

Abstract: A system balances bandwidth used by a data stream. The system receives data in the data stream and partitions the data into bursts. The system then identifies whether a size of a current one of the bursts is less than a size of a maximum burst associated with the data stream and schedules an additional burst in the data stream when the current burst size is less than the maximum burst size. The system transmits the current burst and the additional burst to balance bandwidth used by the data stream.

Abstract: Techniques are described for synchronizing state information between a plurality of control units. A router, for example, is described that includes a primary control unit and a standby control unit. The primary control unit maintains router resources to ensure operation of the router. To ensure operation, the primary control unit receives state information from the router resources and maintains the state information for consumers, i.e. router resources that require or “consume” state information. The primary control unit performs this state information maintenance process by transmitting update operation messages to consumers and the standby control unit. The consumers respond with an acknowledgement message to both the primary control unit and the standby control unit to inform them that the update has been successfully. The control units use the sequence of these messages to keep all components within the router in sync.

Abstract: A router comprises a route resolution module to maintain routing information in accordance with a topology of a network, and an indirect next hop manager to maintain indirect next hop data that associates protocol next hops with forwarding next hops. The route resolution module invokes an application programming interface (API) of the indirect next hop manager for associating and disassociating protocol next hops and forwarding next hops. In response to a network event, the route resolution module can modify the indirect next hop data to reduce the time and resources necessary to perform route resolution.

Abstract: A system permits queues to use more than an allocated amount of bandwidth. The system allocates an amount of bandwidth to each of the queues and determines whether any of the queues is using less than the allocated amount of bandwidth. If so, the system reallocates the allocated bandwidth from one of the queues to at least one other one of the queues based on the amount of bandwidth used by each of the queues.