Abstract: A router for switching data packets from a source to a destination in a network in which the router includes a distributed memory. The distributed memory includes two or more memory banks. Each memory bank is used for storing uniform portions of a data packet received from a source and linking information for each data packet to allow for the extraction of the uniform portions of a data packet from distributed locations in memory in proper order after a routing determination has been made by the router.

Abstract: In one embodiment, an apparatus includes a switch core that has a multi-stage switch fabric physically distributed among a set of chassis. The multi-stage switch fabric has a set of input buffers and a set of output ports. The switch core can be configured to be coupled to a set of edge devices. The apparatus can also include a controller implemented in hardware without software during operation and with software during configuration and monitoring. The controller can be coupled to the set of input buffers and the set of output ports. The controller can be configured to send a flow control signal to an input buffer from the set of input buffers when congestion at an output port from the set of output ports is predicted and before congestion in the switch core occurs.

Abstract: A system selectively drops data from queues. The system includes a drop table that stores drop probabilities. The system selects one of the queues to examine and generates an index into the drop table to identify one of the drop probabilities for the examined queue. The system then determines whether to drop data from the examined queue based on the identified drop probability.

Abstract: In one embodiment, an apparatus includes a switch core that defines a single logical entity and has a multi-stage switch fabric physically distributed across a plurality of chassis. The multi-stage switch fabric has a plurality of ingress ports and a plurality of egress ports. The switch core is configured to be coupled to a plurality of peripheral processing devices via the plurality of ingress ports and the plurality of egress ports. The switch core is also configured to provide non-blocking connectivity at line rate between a first peripheral processing device disposed with a first chassis and a second peripheral processing device disposed within a second chassis.

Abstract: An access network is described in which a centralized controller provides seamless end-to-end service from a core-facing edge of a service provider network through aggregation and access infrastructure out to access nodes located proximate to the subscriber devices. The controller operates to provide a central configuration point for configuring aggregation nodes (AGs) of a network of the service provider so as to provide transport services to transport traffic between access nodes (AXs) and edge routers on opposite borders of the network.

Abstract: A multi-chassis network device includes a plurality of nodes that operate as a single device within the network and a switch fabric that forwards data plane packets between the plurality of nodes. The switch fabric includes a set of multiplexed optical interconnects coupling the nodes. For example, a multi-chassis router includes a plurality of routing nodes that operate as a single router within a network and a switch fabric that forwards packets between the plurality of routing nodes. The switch fabric includes at least one multiplexed optical interconnect coupling the routing nodes. The nodes of the multi-chassis router may direct portions of the optical signal over the multiplexed optical interconnect to different each other using wave-division multiplexing.

Abstract: An access network is described in which a centralized controller provides seamless end-to-end service from a core-facing edge of a service provider network through aggregation and access infrastructure out to access nodes located proximate to the subscriber devices. The controller operates to provide a central configuration point for configuring aggregation nodes (AGs) of a network of the service provider so as to provide transport services to transport traffic between access nodes (AXs) and edge routers on opposite borders of the network.

Abstract: An access network includes an access device having an optical interface module that outputs a plurality of pairs of optical communication signals, each of the pairs of optical communication signals comprising a modulated optical transmit signal and an unmodulated optical receive signal, each of the pairs of optical communication signals having a different wavelength. A customer premise equipment (CPE) comprises an optical interface module to receive the modulated optical transmit signal and the unmodulated optical receive signal for any of the plurality of pairs of optical communication signals. The optical interface module includes a receive module to demodulate the modulated optical transmit signal into inbound symbols and a transmit module having an optical modulator and reflective optics to modulate the unmodulated optical receive signal in accordance with a data signal and reflect a modulated optical receive signal to communicate outbound data symbols to the access device.

Abstract: A first network client requests initiation of a data transfer with a second network client. An admission control facility (ACF) responds to the initiation request by performing admission analysis to determine whether to initiate the data transfer. The ACF sends one or more packets to the second network client. In response, the second network client sends acknowledgment packets back to the ACF. The ACF performs admission analysis based on the packets sent and the acknowledgment packets, and determines whether the data transfer should be initiated based on the analysis. The admission analysis may be based on a variety of factors, such as the average time to receive an acknowledgment for each packet, the variance of the time to receive an acknowledgment for each packet, a combination of these factors, or a combination of these and other factors.

Abstract: A system selectively drops data from queues. The system includes a drop table that stores drop probabilities. The system selects one of the queues to examine and generates an index into the drop table to identify one of the drop probabilities for the examined queue. The system then determines whether to drop data from the examined queue based on the identified drop probability.

Abstract: A laser system includes an array of lasers that emit light at a number of different, fixed wavelengths. A group of optical transport systems connect to the laser system. Each of the optical transport systems is configured to modulate data signals onto the light from the laser system to create optical signals and transmit the optical signals on one or more optical fibers.

Abstract: A first network client requests initiation of a data transfer with a second network client. An admission control facility (ACF) responds to the initiation request by performing admission analysis to determine whether to initiate the data transfer. The ACF sends one or more packets to the second network client. In response, the second network client sends acknowledgment packets back to the ACF. The ACF performs admission analysis based on the packets sent and the acknowledgment packets, and determines whether the data transfer should be initiated based on the analysis. The admission analysis may be based on a variety of factors, such as the average time to receive an acknowledgment for each packet, the variance of the time to receive an acknowledgment for each packet, a combination of these factors, or a combination of these and other factors.

Abstract: In general, the invention is directed to techniques for reducing deadlocks that may arise when performing fabric replication. For example, as described herein, a network device includes packet replicators that each comprises a plurality of resource partitions. A replication data structure for a packet received by the network device includes packet replicator nodes that are arranged hierarchically to occupy one or more levels of the replication data structure. Each of the resource partitions in each of the plurality of packet replicators is associated with a different level of the replication data structure. The packet replicators replicate the packet according to the replication data structure, and each of the packet replicators handles the packet using the one of the resource partitions of the packet replicator that is associated with the level of the replication data structure occupied by the node that corresponds to that particular packet replicator.

Abstract: A system determines bandwidth use by queues in a network device. To do this, the system determines an instantaneous amount of bandwidth used by each of the queues and an average amount of bandwidth used by each of the queues. The system then identifies bandwidth use by each of the queues based on the instantaneous bandwidth used and the average bandwidth used by each of the queues.

Abstract: In one embodiment, a method includes sending a configuration signal to a virtual network switch module within a control plane of a communications network. The configuration signal is configured to define a first network rule at the virtual network switch module. The method also includes configuring a packet forwarding module such that the packet forwarding module implements a second network rule, and receiving status information from the virtual network switch module and status information from the packet forwarding module. The status information is received via the control plane.

Abstract: In one embodiment, a processor-readable medium can store code representing instructions that when executed by a processor cause the processor to receive a value representing a congestion level of a receive queue and a value representing a state of a transmit queue. At least a portion of the transmit queue can be defined by a plurality of packets addressed to the receive queue. A rate value for the transmit queue can be defined based on the value representing the congestion level of the receive queue and the value representing the state of the transmit queue. The processor-readable medium can store code representing instructions that when executed by the processor cause the processor to define a suspension time value for the transmit queue based on the value representing the congestion level of the receive queue and the value representing the state of the transmit queue.

Abstract: Methods and devices for processing packets are provided.

Abstract: A system provides congestion control and includes multiple queues that temporarily store data and a drop engine. The system associates a value with each of the queues, where each of the values relates to an amount of memory associated with the queue. The drop engine compares the value associated with a particular one of the queues to one or more programmable thresholds and selectively performs explicit congestion notification or packet dropping on data in the particular queue based on a result of the comparison.

Abstract: A multi-chassis network device includes a plurality of nodes that operate as a single device within the network and a switch fabric that forwards data plane packets between the plurality of nodes. The switch fabric includes a set of multiplexed optical interconnects coupling the nodes. For example, a multi-chassis router includes a plurality of routing nodes that operate as a single router within a network and a switch fabric that forwards packets between the plurality of routing nodes. The switch fabric includes at least one multiplexed optical interconnect coupling the routing nodes. The nodes of the multi-chassis router may direct portions of the optical signal over the multiplexed optical interconnect to different each other using wave-division multiplexing.

Abstract: A method performed by an I/O unit connected to another I/O unit in a network device. The method includes receiving a packet; segmenting the packet into a group of data blocks; storing the group of data blocks in a data memory; generating data protection information for a data block of the group of data blocks; creating a control block for the data block; storing, in a control memory, a group of data items for the control block, the group of data items including information associated with a location, of the data block, within the data memory and the data protection information for the data block; performing a data integrity check on the data block, using the data protection information, to determine whether the data block contains a data error; and outputting the data block when the data integrity check indicates that the data block does not contain a data error.