Abstract: An inter-network method for distributing a path-vector routing protocol within a multi-processor router has steps of running an instance of a router-distributed Border Gateway Protocol (rdBGP) on each of a plurality of processors of the multi-processor router, establishing routing sessions between individual instances of rdBGP running on separate processors of the multi-processor router, and between individual ones of the instances of rdBGP and external protocol peers, exchanging routing information between instances of rdBGP and the external protocol peers, wherein the instances of rdBGP learn, from the external protocol peers, routes for a plurality of destinations, calculating independently, by each instance of rdBGP, a set of routes, including a best route, from each of the plurality of destinations learned from the external protocol peers, and sharing route information determined with the other instances of rdBGP running on separate processors in the multi-processor router, and updating route information

Abstract: An apparatus and method for forwarding data on a network are described. A label-switching subnetwork within the network includes an ingress node and an egress node coupled to source and destination nodes, respectively, on the network. The ingress node sends a signal along a route within the subnetwork through a plurality of subnetwork nodes to the egress node. In response, the subnetwork nodes transmit response signals back along the route toward the ingress node which define the route through the subnetwork and simultaneously allocate a plurality of paths within the route. A single path can be selected for forwarding of data packets associated with a source/destination pair, ensuring that data packets arriving at the destination are not misaligned.

Abstract: A control system is disclosed for controlling data flow over a data-packet-network according to specific destinations. The system has a network monitoring system for monitoring network performance parameters; a network access system for accessing specific nodes in the network; and a control software executable on the network access system for assigning and changing cost parameters at selected nodes in the network. A network administrator uses the network access system and control software to assign and implement cost values at the selected nodes, the values associated individually with a specific destination or destinations, the values establishing forwarding costs to be incurred at the selected nodes, and link costs to be incurred per data link between the nodes such that manipulation of such cost value assignments enables load balancing of data traveling through the network. In one embodiment the data-packet-network is internal to a router and nodes comprise internal router cards.

Abstract: In a network packet router having one or more ingress and egress ports, a method is implemented at an ingress port for egress pass/drop determination for packets, comprising the steps of (a) noting header combinations and values, and egress port destination for incoming packets; (b) comparing the header combinations and values with rule sets associated with the header combinations and values including egress port identities, and (c) returning a determination of pass or drop for the packet.

Abstract: In a network node having one or more packet processors and at least one CPU required to process specific types of packets, a system for managing the specific types of packets for CPU processing has one or more packet processors enabled to sort the specific types of packets into two or more categories of different priority for processing; and a queue set for queuing the sorted packets according to priority ahead of the CPU. The system is characterized in that the CPU processes the queued packets according to priority. In a special case the queues are a part of network access controller (NAC). Also in some cases a software component is provided for configuring the hardware.

Abstract: In a data packet router, a method for redirecting packets destined for a port comprises steps of monitoring port status on a continuing or periodic basis, updating a port-status table, listing port status as active or failed and an alternative destination for each port, checking the table by circuitry along a packet route for a packet en route, and sending the received packet to the predestined port if the port is listed in the table as active, and sending the received packet to the alternative destination if the port is listed in the table as failed. The method can be implemented essentially anywhere along a routing path where circuitry may support a table look-up and re-tagging packets for alternative destinations. In one embodiment the automatic protection switching is performed in a fabric card, and in another on a line card.

Abstract: A modular and adjustable backplane assembly for providing a fiber-optics backplane interface to a plurality of router cards functioning as a data router is provided. The assembly includes a first portion having a first array of connectors for interfacing with a compatible array of second connectors engaging specific ones of the router cards, and a second portion having a second array of connectors for interfacing with a compatible array of second connectors engaging specific others of the router cards. The mechanics of the assembly enable a moveable attachment with respect to the first and second portions such that they may be positionally adjusted during mounting, and wherein external data paths are provided from individual ones of the connectors to individual others of the connectors by fiber-optic conductors.

Abstract: A method for routing packets in a multipath network of nodes balances the loading of system resources while guaranteeing a FIFO network (i.e., First In First Out). Acyclic directed graphs based on local network information are used at each node with routing bias tables that allow for local preferences. A randomizing function may be used throughout the network to allow uniform utilization of system resources. A normalizing function may be used throughout the network to reduce bit operations in routing packets.

Abstract: A network comprises a plurality of switching nodes interconnected by communication links for transferring digital packets. At least one switching node in the network pre-establishes a bypass virtual circuit through the network to bypass an element of the network, such as a switching node or a communication link, in the network. The bypass virtual circuit defines a path to another switching node in the network. The first switching node uses the bypass virtual circuit so constructed in forwarding of a packet in the event of a failure or other malfunction of the element if the first switching node would otherwise transfer the packet over that element.

Abstract: A method and apparatus for reallocating switching circuitry in a switching fabric are disclosed. The switching fabric is used to permit data transfer among a plurality of interface units each having a plurality of data ports. The switching fabric is partitionable into a plurality of switch planes such that each switch plane can be assigned to transfer data associated with like data ports of the interface units. Each switch plane includes multiple switching channels each assignable to transfer data associated with one data port of one of the interface units, in a full implementation. The number of interface units is less than the number of switching channels in a switch plane, then the reallocation is performed such that multiple channels of at least one switch plane can be assigned to transfer data of multiple ports of at least one of the interface units. This results in switch plane channels that would otherwise be unused being utilized to transfer data.

Abstract: A method for performing an in-service software upgrade to a data router follows steps of (a) providing a source node hosting an upgrade software package; (b) causing an upgrade command to be executed; (c) establishing, as a result of the upgrade command, a network session between the data router and the source node; (d) receiving the upgrade software at the router; (e) copying and distributing, within the router, the upgrade software to designated components slated for upgrade; (f) designating one or more components in the router as backups for each component to be upgraded; (g) backing up services and software running on each target element to be upgraded to designated backup element or elements while upgrade proceeds for the target element; (h) causing a switchover at the target element to the new software; and (i) repeating steps (g) and (h) until all the components slated for upgrade are upgraded.

Abstract: A method of and apparatus for distributing data for a database between a plurality of processors in a distributed processor system involves running a database management system on a first plurality of processors in conjunction with a plurality of protocols that generate or amend data for the database. Data is distributed from servers to clients registered in a server-client relationship. Server-client relationships may also be registered between a second, and a third plurality of processors that do not run protocols generating or amending data for the database. Fault tolerant redundancy is provided by clients registering with two or more servers, one as a primary and another as a secondary, and activating the secondary if the primary fails. The method is particularly applicable to scalable data packet routers having a plurality of processors operating on different line and control cards.

Abstract: A data structure has a list of event objects, one or more producers creating the event objects for the list, and a finite set of consumers accessing the object list. The structure is characterized in that the event objects are each associated with a first reference number indicating the number of consumers currently accessing the event object, and in that, as each consumer completes access the reference number is decremented, and when the reference number for an event object is zero, and the event object is at the head of the list, indicating that all consumers have accessed the object, that event object is removed from the list. A use of the structure for propagating route changes to nodes in a multiple-processor router, and to peer routers in a network is also taught.

Abstract: A modular and adjustable backplane assembly for providing a fiber-optics backplane interface to a plurality of router cards functioning as a data router is provided. The assembly includes a first portion having a first array of connectors for interfacing with a compatible array of second connectors engaging specific ones of the router cards, and a second portion having a second array of connectors for interfacing with a compatible array of second connectors engaging specific others of the router cards. The mechanics of the assembly enable a moveable attachment with respect to the first and second portions such that they may be positionally adjusted during mounting, and wherein external data paths are provided from individual ones of the connectors to individual others of the connectors by fiber-optic conductors.

Abstract: A method for providing fault-tolerance for Multi-Path Label Switching (MPLS) functionality in a multi-processor network routing node has the steps of (a) implementing an MPLS server application including state information, on a first and a second processor in the node; (b) designating the MPLS server on the first processor as a master server and the MPLS server on the second processor as a backup server, and providing MPLS functionality in the node with the master MPLS server; (c) directing all required MPLS events to both the master and the backup MPLS servers during operation; (d) monitoring operation of the master server; and (e) in the event of failure of the master server, designating the backup server as the master, allowing MPLS functions to continue on the routing node.

Abstract: A method and apparatus for reallocating switching circuitry in a switching fabric are disclosed. The switching fabric is used to permit data transfer among a plurality of interface units each having a plurality of data ports. The switching fabric is partitionable into a plurality of switch planes such that each switch plane can be assigned to transfer data associated with like data ports of the interface units. Each switch plane includes multiple switching channels each assignable to transfer data associated with one data port of one of the interface units, in a full implementation. The number of interface units is less than the number of switching channels in a switch plane, then the reallocation is performed such that multiple channels of at least one switch plane can be assigned to transfer data of multiple ports of at least one of the interface units. This results in switch plane channels that would otherwise be unused being utilized to transfer data.

Abstract: A multicast engine is provided in plurality within a router for replicating and/or modifying packets identified as multicast packets. In preferred embodiments the engine is integrated with one or more ports of a router, particularly with one or more ports of fabric cards. In one implementation the multicast engine is associated with a table having instructions for replicating or modifying multicast packets received, and forwarding the packets accordingly.

Abstract: A line card for a data packet router interfaces to a high-speed standard data link, and has a first portion interfacing to the router and having a plurality of slower ports, and a second portion having a framer compatible with and coupled to the data link. The framer is coupled through an ingress and an egress data path between the framer and the slower ports, each with separate ingress buffers and egress buffers for each port. An interface control circuit controls data packet transfers between the slower ports and the framer in both directions. In a preferred embodiment a function is used by the control circuit to map packets from the link to the ports, using keys extracted from the incoming packets. For an IP packet the key is the source address, destination address (SA/DA)pair, which constrains packets for same IP conversations to be routed by the same path.

Abstract: A method for managing data traffic in nodes in a fabric network, each node having internally-coupled ports, follows the steps of establishing a managed queuing system comprising one or more queues associated with each port, for managing incoming data traffic; and accepting or discarding data directed to a queue according to the quantity of data in the queue relative to queue capacity. In one preferred embodiment the managed system accepts all data directed to a queue less than full, and discards all data directed to a queue that is full. In some alternative embodiments the queue manager monitors quantity of data in a queue relative to queue capacity, and begins to discard data at a predetermined rate when the quantity of queued data reaches the threshold. In other cases the queue manager increases the rate of discarding as the quantity of queued data increases above the preset threshold, discarding all data traffic when the queue is full.

Abstract: A switching node for transferring addressed packets in a network includes a plurality of input port modules, a plurality of output port modules and a switching fabric, including a packet meta-data processor and a packet switch. Each input port module, upon receiving a packet, buffers the packet and generates a meta-data packet identifying an output port module that is to transmit the packet and packet identifier information, and provides it to the packet meta-data processor. The packet meta-data processor processes the meta-data packets received from all of the input port modules in connection with operational status information to determine whether the packet should be passed or dropped. If to be dropped, the packet is dropped at the input, otherwise enqueued for the proper output port.