Abstract: A hierarchical traffic policer may include a first policer configured to pass first packets when a first condition is met. The first policer also may alter selection information within the passed first packets. A second policer may be configured to pass second packets when a second condition is met. The second policer may be further configured to pass all of the passed first packets from the first policer based on the altered selection information within the passed first packets.

Abstract: In one embodiment, a method, comprising producing a first policy vector based on a first portion of a data packet received at a multi-stage switch. The method also includes producing a second policy vector based on a second portion of the data packet different than the first portion of the data packet. A third policy vector is produced based on a combination of at least the first policy vector and at least the second policy vector. The third policy vector including a combination of bit values configured to trigger an element at the multi-stage switch to process the data packet.

Abstract: A method and a network device for sharing bandwidth among a group of classes of traffic for an interface are provided. Bandwidth may be allocated to at least one traffic class of a first priority for the interface. At least some unused bandwidth of the at least one traffic class may be allocated to at least one other traffic class of a second priority for the interface. In some implementations, weighted constituents may be allocated unused interface bandwidth based on an assigned weight of each of the weighted constituents of the interface.

Abstract: The invention relates to a universal Address Pool Manager (APM) for processing network access address requests from clients operating at one of many access protocols. The APM, located within a network device, such as a router, manages an aggregated pool of network addresses and assigns addresses to the clients from the pool in accordance with the multiple access protocols. The aggregated address pool may be co-located within the network device with the APM, or alternatively, the address pool may be located within an off-box network device, such as an off-box authentication server or an off-box DHCP server. Utilization of an APM that manages an aggregated address pool for processing requests from multiple access protocols may reduce operational costs for network service providers that support multiple access networks.

Abstract: A network device includes multiple packet processing engines implemented in parallel with one another. A spraying component distributes incoming packets to the packet processing engines using a spraying technique that load balances the packet processing engines. In particular, the spraying component distributes the incoming packets based on queue lengths associated with the packet processing engines and based on a random component. In one implementation, the random component is a random selection from all the candidate processing engines. In another implementation, the random component is a weighted random selection in which the weights are inversely proportional to the queue lengths.

Abstract: Methods for optimizing the media path between multimedia endpoints in a network are described. One embodiment allows avoiding having to relay the media traffic through a central device, such as a border controller's media controller element, and lets endpoints communicate directly under various conditions.

Abstract: In an asynchronous transfer mode switch, a plurality of queues is provided for accumulating transfer cells, and a queue assignment processing section, receives a message for establishing a connection and assigns to the connection one of the queues having a forwarding rate close to a declared rate included in the message and not exceeding the declared rate.

Abstract: A router receives destination address information for a packet and determines, among entries in a first forwarding table, a closest match for the received destination address information. The router receives a pointer to a second forwarding table in accordance with the closest match determined in the first forwarding table and determines, among entries in the second forwarding table, a closest match for the received destination address information.

Abstract: In general, techniques are described to dynamically redefine a preference value used during route resolution. A network device, such as a router, may implement the techniques to improve a usability aspect of the router. The router may comprise an interface card that receives messages describing one or more of a plurality of routes. The router may also include a control unit that stores data defining a policy. The policy may comprise rules by which the router determines the preference value for one of the plurality of routes. The policy dynamically redefines the preference value as two or more bit fields rather than viewing the preference value as an integer value. The control unit further sets each of the two or more bit fields of the local preference value in accordance with the policy and associates the at least one of the routes with the determined local preference value.

Abstract: In a network device, a line card includes a first scheduler configured to perform scheduling for data units of a first type and a second scheduler that is connected in series to the first scheduler and configured to perform scheduling for data units of a second type. The schedulers may be configured in a variety of ways to achieve certain data unit flow characteristics.

Abstract: A method for enabling autonegotiation over an interface for which no autonegotiation standard exists comprises establishing network communication between a first network device and a second network device over a communication link. The first network device includes a first media access controller (MAC) associated with a communication port coupled to the communication link and a second MAC positioned between the first MAC and the communication port, and the second MAC operates as a proxy MAC for the first MAC. The first MAC outputs an outbound data communication to the communication port at a first communication rate. The proxy MAC intercepts the outbound data communication. The proxy MAC then outputs the outbound data communication to the communication port at a second communication rate different from the first communication rate.

Abstract: A system establishes a virtual private network (VPN) tunnel to a destination and determines a next hop for the VPN tunnel. The system inserts the next hop, and an address associated with the destination, into an entry of a first table. The system inserts the next hop, and a tunnel identifier corresponding to the established VPN tunnel, into an entry of a second table. The system associates one or more security parameters, used to encrypt traffic sent via the VPN tunnel, with the tunnel identifier.

Abstract: Methods and apparatus for transferring packets in a packet switched communication system. A system is provided that includes an L2 device including a controller determining for each packet received whether the received packet is to be inspected, an inspection device operable to inspect and filter packets identified by the controller including using a zone specific policy and an L2 controller for transferring inspected packets in accordance with L2 header information using L2 protocols.

Abstract: A gateway for screening packets transferred over a network. The gateway includes a plurality of network interfaces, a memory and a memory controller. Each network interface receives and forwards messages from a network through the gateway. The memory temporarily stores packets received from a network. The memory controller couples each of the network interfaces and is configured to coordinate the transfer of received packets to and from the memory using a memory bus. The gateway includes a firewall engine couples to the memory bus. The firewall engine is operable to retrieve packets from the memory and screen each packet prior to forwarding a given packet through the gateway and out an appropriate network interface. A local bus is coupled between the firewall engine and the memory providing a second path for retrieving packets from memory when the memory bus is busy.

Abstract: The invention provides a device for reducing ingress noise in a digital signal, comprising a noise predictor for predicting an amount of ingress noise in the digital signal based on past samples of the ingress noise, and a subtractor for subtracting the predicted amount of ingress noise from the digital signal. Channel distortion is compensated for by a noise-independent equalizer, such as a ZF equalizer, placed upstream of the noise predictor. The device may be incorporated, for example, in a cable modem termination system (CMTS) of an hybrid fiber/coax (HFC) network.

Abstract: A network device is configured to receive a registration message from a private user device including a private internet protocol (IP) address associated with the private user device. A public IP address and discrete port number are assigned to the private user device and private IP address and stored in an incoming call table. The registration message is translated to include the public IP address and discrete port number. The registration message is forwarded to a proxy server for registration. An incoming call invitation message is received from a public user device, where the call invitation message is directed to the public IP address and discrete port number associated with the private user device. The call invitation message is translated to include the private IP address associated with the private user device based on the received public IP address and discrete port number and the incoming call table. The call invitation message is forwarded to the private user device.

Abstract: A router receives a control plane message for constructing a first LSP to a destination within a network that conforms to a first type of LSP. The control plane message includes a label for the first LSP and an identifier that identifies a first type of data traffic. The router receives a second control plane message for constructing a second LSP that conforms to the first type of LSP. The second control plane message includes a label for the second LSP and an identifier that identifies a second type of data traffic. The router installs forwarding state in accordance with policies that associate the first and second types of data traffic with different LSPs of a second type that each traverse different paths through the network, and forwards packets via the interface in accordance with the installed forwarding state.

Abstract: In general, the invention is directed to techniques for improving memory utilization in a priority queuing system of a network device. More specifically, a priority queue memory management system is described in which memory pages are assigned to the various priority queues in order to implement an efficient first in, first out (FIFO) functionality. The dynamic memory techniques described herein allow the multiple priority queues to share a common memory space. As a result, each priority queue does not require a pre-allocated amount of memory that matches the aggregate size of the packets that must be buffered by the queue.

Abstract: A front-to-back cooling system allows cooling of an apparatus containing two orthogonal sets of modules. Each set of modules is independently cooled. A vertical set of modules is cooled with vertical air flow across the modules that enters from a front of the apparatus and exhausts from a back of the apparatus. A horizontal set of modules is cooled with horizontal front-to-back air flow. When the horizontal set of modules is at the front of the apparatus, a plenum extending exterior to the vertical set of modules allows exhausting horizontally flowing air to the rear of the apparatus. When the horizontal set of modules is at the rear of the apparatus, a plenum extending exterior to the vertical set of modules allows moving air from the front of the apparatus to a chamber holding the horizontal modules.

Abstract: Techniques are described that increase the reliability and quality of data transmissions of computer networks. The techniques provide for the generation of at least two duplicate data flows for carrying data in a computer network. The duplicate data flows are transmitted to a receiving device along paths within one or more intermediate networks. In addition, network devices, such as routers or switches within the network, for example, may cooperate to select paths for the data flows that have reduced or minimal common network elements. The network devices may share “fate-sharing” information that relates groups of network elements according to common characteristics, attributes or shared resources, e.g., a shared power supply, close proximity, common physical interface, for the purposes of facilitating selection of independent paths.