Abstract: Techniques are described for monitoring performance of a network. Particularly, network devices within the network exchange routing communications in accordance with one or more routing protocols, such as the Border Gateway Protocol (BGP), to automatically establish a community for monitoring performance throughout the network. Upon establishing the community, the network devices of the community exchange performance probes to collect comprehensive performance information for the network. This performance information may be aggregated via one or more computing devices. Using the aggregated performance information, numerous network performance characteristics may be computed, including delay, jitter, throughput, availability and packet loss.

Abstract: A transmitting system inserts runt abort packets in an outgoing data stream during idle time inter-frame time fill. The runt abort packets cause the receiving system to synchronize itself to the transmitting system so that even if an error during inter-frame time fill causes the receiving system to go into an erroneous state, the receiving system will be synchronized with the transmitting system before receiving valid data. In one embodiment, the transmitting system transmits data in packets over SONET. The packet data is scrambled at the transmitting end and descrambled at the receiving end. Runt abort packets sent during inter-frame time fill resynchronize the descrambler. If there is an error in the inter-frame time fill bytes, causing the receiving end descrambler to no longer be synchronized with the transmitting end scrambler, the runt abort packets will cause the descrambler to resynchronize state with the transmitting scrambler.

Abstract: A network device includes one or more sprayers, multiple packet processors, and one or more desprayers. The sprayers receive packets on at least one incoming packet stream and distribute the packets according to a load balancing scheme that balances the number of bytes of packet data that is given to each of the packet processors. The packet processors receive the packets from the sprayers and process the packets to determine routing information for the packets. The desprayers receive the processed packets from the packet processors and transmit the packets on at least one outgoing packet stream based on the routing information.

Abstract: Techniques are described for dynamically building an Ethernet virtual local area network (VLAN) interface in a network device. The techniques allow dynamic building of a second VLAN interface over a first VLAN interface statically built over an Ethernet port configured to support dynamic VLANs in a network device. A network device may receive a plurality of Ethernet packets from subscriber devices and dynamically build a second VLAN interface over the first VLAN interface for each of the subscribers. Once the second VLAN interface is built, the network device dynamically builds interface columns over the second VLAN interface for each protocol associated with the Ethernet packets. The network device may then authenticate a user associated with the plurality of Ethernet packets. Once the user has logged out of the network device, the network device may tear down the interface columns while persistently maintaining the corresponding second VLAN interface.

Abstract: A data prefetching technique optimizes the batch size of prefetch requests. The optimized batch size may be determined based on a prefetch transfer time of a previous prefetch operation, where the prefetch transfer time is measured as an elapsed time interval from when data from the previous prefetch operation is first received to when the data from the previous prefetch operation is finished being received.

Abstract: A network device includes an input device configured to receive a data packet, where the input device includes a number of interfaces and the data packet includes a source address and a destination address. The network device also includes processing logic configured to generate forwarding information identifying a next hop for the data packet and determine whether an interface on which the data packet was received is a same interface on which the data packet is to be forwarded to the next hop. The processing logic is also configured to determine whether the data packet originated from a device that is part of a same subnet as the next hop.

Abstract: Principles of the invention are described for providing multicast virtual private networks (MVPNs) across a public network that are capable of carrying high-bandwidth multicast traffic with increased scalability. In particular, the MVPNs may transport layer three (L3) multicast traffic, such as Internet Protocol (IP) packets, between remote sites via the public network. The principles described herein may reduce the overhead of protocol independent multicast (PIM) neighbor adjacencies and customer control information maintained for MVPNs. The principles may also reduce the state and the overhead of maintaining the state in the network by removing the need to maintain at least one dedicated multicast tree per each MVPN.

Abstract: A device may include an interface to send policy information to an evaluation module, where the policy information is related to a group of policies, and receive a group of results from the evaluation module, where the group of results indicates whether the status of a source device complies with the croup of policies. The interface may send an instruction to a destination device configured to implement at least a subset of the policies with respect to the source device based on the instruction.

Abstract: A method may include counting the number of times each of a plurality of entries in a content addressable memory (CAM) matches one or more searches; grouping entries in the CAM into a first subset and a second subset based on the number of times each of the plurality of entries in the CAM matches one or more searches; and searching the first subset for a matching entry and, if no matching entry is found, searching the second subset for the matching entry.

Abstract: A reversible airflow fan tray assembly is provided for an electronic device. The fan tray assembly includes a face plate to be removably mounted to the electronic device and a fan tray cassette to be removably mounted to the face plate in multiple orientations. The fan tray cassette includes a fan unit to provide airflow through the electronic device, and an interconnection board to provide an electrical connection between the fan unit and the electronic device, where the interconnection board mates with a connector on the electronic device when the fan tray cassette is in any of the multiple orientations. The interconnection board provides an airflow direction indication to the electronic device for a current orientation of the multiple orientations.

Abstract: In a cable modem system, increasing or decreasing the rate of an MPEG Transport Stream involves two separate, but related, tasks: 1) incorporating a sufficient number of additional packets (or discarding packets) to make up for the difference in data rates between input and output, and 2) altering timing information (for instance, PCR (Program Clock Reference) values) present in some incoming packets to reflect their altered positions in the output stream. Both of these tasks can be facilitated by the use of a FIFO (First-In, First-Out) structure, through which the data flows.

Abstract: Multiple subscriber devices are connected to a network device via one or more network switches. The network device transmits multicast traffic to the subscriber devices. In particular, the network device may receive membership requests for a multicast group from the subscriber devices via the network switch on a first interface, i.e., a mapping interface. The network device sends a multicast stream associated with the multicast group to the network switch on a second interface, i.e. an outgoing interface (OIF). Upon receiving a membership request, the network device maps the membership request to an OIF dedicated to the multicast group. In this way, when multiple subscriber devices connected to the same switch request the same multicast stream, each membership request will map to the same OIF. The network device sends one copy of the multicast stream to the network switch on the dedicated OIF.

Abstract: A network device may implement packet scheduling with administrator-configurable packet scheduling policies. In one implementation, the network device includes a filter component configured to assign priority levels to data units, the priority levels defining traffic classes for the data units. The network device may also include a scheduler component configured to schedule transmission of the traffic classes based on an assignment of weights to the traffic classes using at least one bandwidth allocation policy that exhibits a bandwidth allocation profile that varies based on one or more parameters of the bandwidth allocation policy that are configurable by an administrator.

Abstract: A network device may include an input device and a packet forwarding engine. The input device receives a data packet. The packet forwarding engine includes logic configured to determine that the data packet is to be multicast. The logic is also configured to identify one of multiple forwarding schemes, where each of the forwarding schemes is configured such that the packet forwarding engine generates and forwards no more than two copies of the data packet.

Abstract: A transport LAN segment service is provided over a transport network. The transport network will include edge devices configured to support one or more transparent LAN segments. Configuration is simplified by advertising TLS-port-label information, layer 2 address learning, and multicasting when the needed configuration information has not yet been learned or discovered.

Abstract: In one example, a backup intrusion detection and prevention (IDP) device includes one or more network interfaces to receive a state update message from a primary IDP device, wherein the state update message indicates a network session being inspected by the primary IDP device and an identified application-layer protocol for the device, to receive an indication that the primary device has switched over or failed over to the backup device, and to receive a plurality of packets of the network session after receiving the indication, each of the plurality of packets comprising a respective payload including application-layer data, a protocol decoder to detect a beginning of a new transaction from the application-layer data of one of the plurality of packets, and a control unit to statefully process only the application-layer data of the network session that include and follow the beginning of the new transaction.

Abstract: A system facilitates initialization of devices in a cable modem network. The system may provide downstream channels for transmitting data to the devices and upstream channels for receiving data from the devices. At least one of the upstream channels may be dedicated to providing initialization opportunities. This dedicated upstream channel(s) includes less than all of the upstream channels. The system may transmit upstream channel identifiers on the downstream channels, where each of the upstream channel identifiers identifies one of the upstream channels. The system receives initialization data on the dedicated upstream channel(s).

Abstract: Techniques are described for dynamically constructing a label switching protocol interface in a network device. For example, the techniques allow dynamic construction of a Multi-Protocol Label Switching (MPLS) interface. According to some embodiments, upon receiving a network communication from a subscriber, a network device determines whether the subscriber requires support for the label switching protocol. If the subscriber requires such support, the network device creates an interface stack for the subscriber that includes an interface for the label switching protocol. In this way, the network device may route packets from the subscriber across a network of computing devices that use the label switching protocol, and forward packets from such a network to the subscriber. The subscriber and the network device need not communicate according to the label switching protocol and, in example embodiments, instead communicate according to a layer 2 communication protocol.

Abstract: A method may include detecting an event, determining whether the event correlates to a hard disk access, requesting a wake-ahead of a hard disk drive if it is determined that the event correlates to a hard disk access, weighing a performance improvement of the hard disk drive if the wake ahead request is granted against a life of the hard disk drive if the wake ahead request is not granted, and waking ahead the hard disk drive if the performance improvement outweighs the life of the hard disk drive.

Abstract: A packet scheduler is configured to perform quality of service (QoS) scheduling on a per-data unit basis. A downstream processing engine is operatively connected to the packet scheduler for receiving forwarded packets. A feedback path is operatively connected between the downstream processing engine and the packet scheduler for transmitting a net data unit change value reflecting a change in packet size between an output of the packet scheduler and an output of the downstream processing engine.