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 datagram relaying apparatus includes a plurality of protocol terminating units, and a destination determining processor. The destination determining processor includes a path selecting section which determines a transfer destination route for a stream of packets received from any of the protocol terminating units. The path selecting section determines whether or not transfer of the received stream of packets to the transfer destination route is in an inhibition state, and selects another transfer destination route when the transfer of the packet to the transfer destination route is in the inhibition state.

Abstract: A device facilitates offset independent message filtering, and receives a filter registration request from a control software element, where the filter registration request includes at least a field name and a filter value. The device also identifies an offset value associated with the received field name, and filters a message based on the filter value and the identified offset value.

Abstract: Techniques are described for aggregating multiple media packets to improve end-to-end bandwidth efficiency. The techniques include using an RTP aggregation protocol that is not sensitive to packet loss to aggregate multiple media packets under a single header. According to the RTP aggregation protocol, the single header for an aggregated media packet comprises a version field, a zero field, a sequence number field and a trunk ID field. The single header encapsulates the aggregated payload, which is an aggregation of Real-Time Protocol (RTP) segments. An RTP segment either has a compressed format or an uncompressed format. The uncompressed RTP segment includes the complete uncompressed RTP packet copied from the original User Datagram Protocol (UDP) packet. The compressed RTP segment includes the payload of the original RTP rather than the complete original RTP packet.

Abstract: In general, techniques are described for packet queuing within ring networks. In accordance with the techniques, a network device of a ring network comprises a memory having a different queue for each order-dependent pair of the network devices. Each pair represents a different order-dependent combination of the network devices that includes an ingress network device that provides an ingress to the ring network and an egress network device that provides an egress from the ring network. The network device further comprises an interface for receiving a packet from a neighboring one of the plurality of network devices and a control unit that, in response to receiving the packet, stores the packet to one of the queues based on which network devices is the ingress and which network device is the egress for the packet. The control unit forwards the stored packet via the ring network according to a scheduling algorithm.

Abstract: A multi-chassis router allows an administrator to deliver commands from a single interface. Additionally, the multi-chassis router presents a software image consistent with that of a standalone router and uses commands and configurations consistent with those used by a standalone router. The multi-chassis router automatically distributes, processes and responds to administrator commands a single unit, minimizing time required to administer the multi-chassis router. In effect, an administrator does not need to account for the multiple chassis configuration, and an administrator familiar with the control and commands for a standalone router can use that knowledge to effectively control the operation of the multi-chassis router.

Abstract: An intermediate network device performs service aware path selection. For example, the intermediate network device comprises a network interface that receives network traffic and a control unit that couples to the network interface. The control unit comprises a storage medium that stores a first set of cost factors for a first path from the intermediate network device to another intermediate network device. The first set of cost factors includes at least one optimization cost factor corresponding to intermediate optimization capabilities available to the intermediate network device that offset other cost factors of the first set. The storage medium also stores a second set of cost factors for a second path between the devices. The control unit selects either the first path or the second path over which to forward the network traffic based on the first and second sets of cost factors.

Abstract: A system provides congestion control in a network device. The system includes multiple queues, a dequeue engine, a drop engine, and an arbiter. The queues temporarily store data. The dequeue engine selects a first one of the queues and dequeues data from the first queue. The drop engine selects a second one of the queues to examine and selectively drop data from the second queue. The arbiter controls selection of the queues by the dequeue engine and the drop engine.

Abstract: A network device comprises a service card (e.g., a dynamic flow capture (DFC) service card) executing a communication protocol to receive, from one or more control sources, flow capture information specifying at least one destination and criteria for matching one or more packet flows. The network device includes a network interface card to receive a packet from a network, a packet replication module to replicate the packet, and a control unit to provide the replicated packet from the interface card to the DFC service card. The network device includes a filter cache that caches flow capture information recently received from the CSs. The network device may provide real-time intercept and relaying of specified network-based communications. Moreover, the techniques described herein allow CSs to tap packet flows with little delay after specifying flow capture information, e.g., within 50 milliseconds, even under high-volume networks.

Abstract: A device may store a first and second queue of packets, calculate an average queue size based on the number of packets in the first and second queues and discard a packet when the packet is a session creation packet and the calculated average queue size is greater than a threshold value.

Abstract: In general, the invention is directed to techniques of dynamically balancing network traffic load among multiple paths through a computer network. The techniques distribute and redistribute flows of network packets between different paths based on dynamically measured path bandwidth and loads of each flow. In distributing the flows, Quality of Service (QoS) bandwidth requirements of the flows may be maintained.

Abstract: In one aspect the invention provides a method for allocating bandwidth in a network appliance where the network appliance includes a plurality of guaranteed bandwidth buckets used to evaluate when to pass traffic through the network appliance. The method includes providing a shared bandwidth bucket associated with a plurality of the guaranteed bandwidth buckets, allocating bandwidth to the shared bandwidth bucket based on the underutilization of bandwidth in the plurality of guaranteed bandwidth buckets and sharing excess bandwidth developed from the underutilization of the guaranteed bandwidth allocated to the individual guaranteed bandwidth buckets. The step of sharing includes borrowing bandwidth from the shared bandwidth bucket by a respective guaranteed bandwidth bucket to allow traffic to pass immediately through the network appliance.

Abstract: The invention provides a PVC switching control method for an ATM communication network which allows high speed changeover of a connection upon occurrence of/release from a trouble and is superior in reliability and maintenance facility and simple in control. A master PVC connection and an OAM connection are set between two ATM exchanges, and a bypassing PVC connection and an OAM connection prepared in advance for bypassing are set between the two ATM exchanges. If occurrence of/release from a trouble with and of the master PVC connection is recognized by the ATM exchanges using an OAM function, then the operative PVC connection is switched between the master PVC connection and the bypassing PVC connection.

Abstract: In a PPP terminating equipment connected with a switch fabric and terminating PPP link, the PPP terminating equipment has an LCP echo requirement detecting section detecting whether or not a received packet is the LCP echo requirement packet, and an LCP echo response producing section producing a response packet to the LCP echo requirement by rewriting the LCP header of the received LCP echo requirement packet. The PPP terminating equipment thereby produces and returns the response packet to the LCP echo requirement.

Abstract: A network device comprises a service card (e.g., a dynamic flow capture (DFC) service card) executing a communication protocol to receive, from one or more control sources, flow capture information specifying at least one destination and criteria for matching one or more packet flows. The network device includes a network interface card to receive a packet from a network, a packet replication module to replicate the packet, and a control unit to provide the replicated packet from the interface card to the DFC service card. The network device includes a filter cache that caches flow capture information recently received from the control sources. The network device may provide real-time intercept and relaying of specified network-based communications. Moreover, the techniques described herein allow control sources to tap packet flows with little delay after specifying flow capture information, e.g., within 50 milliseconds, even under high-volume networks.

Abstract: An apparatus and method are described for compensating for frequency and phase variations of electronic components by processing packet delay values. In one embodiment, a packet delay determination module determines packet delay values based on time values associated with a first and a second electronic component. A packet delay selection module selects a subset of the packet delay values based on the maximum frequency drift of the first electronic component. A statistical parameter determination module evaluates a first and a second parameter based on portions of the subset of packet delay values A validation module validates the parameters when each portion the subset of packet delay values includes a minimum of at least two packet delay values. An adjustment module compensates for at least one of a frequency variation and a phase variation of the first electronic component based on the parameters if the parameters are both validated.

Abstract: In some embodiments, a network management module is operatively coupled to a set of edge devices that are coupled to a set of peripheral processing devices. The network management module can receive a signal associated with a broadcast protocol from an edge device from the set of edge devices in response to that edge device being operatively coupled to a switch fabric. The network management module can provision that edge device in response to receiving the signal. The network management module can define multiple network control entities at the set of edge devices such that each network control entity from the multiple network control entities can provide forwarding-state information associated with at least one peripheral processing device from the set of peripheral processing devices to at least one remaining network control entity from the multiple network control entities using a selective protocol.

Abstract: In general, techniques are described for managing distributed address pools within network devices. A network device that includes a control unit and at least one interface may implement these techniques. The control unit stores data defining a network address pool shared by both the network device and another network device. The control unit includes a shared pool manager module that evaluates the data defining the network address pool to determine a block of addresses of the network address pool that is not in use by the other network device. The at least one interface transmits a request to the other network device requesting the determined block and receives a response from the other network device indicating whether one or more addresses of the requested block are available. The control unit then allocates one or more addresses from the requested block to subscriber devices based on the indication in the response.

Abstract: A check of a processing device is performed. A device may receive a network access request to access a network from a first processing device. A security check may be caused to be performed on the first processing device. Whether to grant the network access request to the first processing device is based on a result of the security check.

Abstract: Rolling software upgrades may be employed for a network device in a modular chassis and/or virtual chassis. The network device may include memory devices to store a software upgrade package and a group of instructions, and a processor. The processors may install the software upgrade package on a backup routing engine; determine subsets of multiple line cards on which to perform a software upgrade, where ports in each of the multiple line cards are part of a link aggregation group (LAG); initiate a reboot process for each of the subsets of multiple line cards, in sequence, where the reboot process for each of the line cards results in a software upgrade without deactivating any LAG. The processors may also switch the backup routing engine and a master routing engine to create a new master routing engine and a new backup routing engine, and install the upgrade package on the new backup routing engine.