Nortel Networks Corporation

Rockstar Bidco, LP

Loa Andersson

Kent Felske

Guo-Qiang Q Wang

Anoop Ghanwani

Andre N Fredette

Naganand Doraswamy

Tove Madsen

Marcel Wiget

Cheng-Yin Lee

Cheng Yin Lee

Kenneth Gary Hayward

Jon Weil

Alex Morrall

David Odhams

Kenneth Sundell

Geoffery A Mattson

A computer network has a plurality of routers that deliver data packets to the network via a plurality of links. At least one router provides automatic protection switching in the event of a link failure. The at least one router includes a plurality of data interfaces for streams of data packets to enter and exit the at least one router; and a backup controller. The backup controller includes a backup path manager, a link monitor, and a backup packet processor. For at least one link of the routing node, the backup path manager identifies a backup routing path for forwarding affected data packets in the event of a failure of the at least one link. The link monitor monitors the plurality of links to determine when a link fails. When a link which has a backup routing path fails, the backup packet processor attaches backup routing path instructions to affected data packets routed over the failed link, and forwards the affected data packets via the backup routing path.

Automatic protection switching using link-level redundancy supporting multi-protocol label switching

A computer network processes data packets in the event of a network link failure. The network includes a plurality of routers that deliver data packets to the network via a plurality of links. At least one router includes a protection cycle manager. The protection cycle manager has a protection cycle packet identifier and a protection cycle packet processor. The protection cycle packet identifier identifies, as protection cycle packets, data packets having a specific protection cycle format. The protection cycle packet processor processes protection cycle packets to determine whether the packet destination corresponds to the routing node, and if the packet destination corresponds to the routing node, the protection cycle packet is treated by the routing node as a data packet received from the packet source via the failed link. Otherwise, if the packet destination does not correspond to the routing node, the protection cycle packet is sent to a protection cycle node for the routing node.

Network data routing protection cycles for automatic protection switching

A communications network comprises a lower transport layer and an upper overlay incorporating a plurality of routers. Adjacencies are defined between respective pairs of routers. Path protection is provided by defining a software model of the overlay of the network and defining in the model a hierarchy of protection levels for the main path. Each protection level is characterised by a respective set of one or more broken adjacencies in the model, the adjacencies to be broken being determined from a knowledge of the underlying topology. A protection level is selected and a protection path avoiding the broken adjacencies associated with that protection level is calculated. If this calculated path is not available in the real network, a lower protection level in the hierarchy is selected and the protection path calculation repeated. The process continues until a suitable protection path is identified.

Route protection in a communication network

A system, device, and method for establishing and removing a label switched path in a communication network uses a packet-driven mechanism rather than using an explicit signaling protocol to exchange label switching information from an upstream label switching device to a downstream label switching device. In order to establish a label switched path from the upstream label switching device to the downstream label switching device, the upstream label switching device allocates a new label for the label switched path, sets up the label switched path by adding the new label to its forwarding table, and forwards a labeled packet including the new label and an indicator indicating that the packet is labeled. Upon receiving the labeled packet from the upstream label switching device, the downstream label switching device sets up the label switched path by adding the new label to its forwarding table, and forwards the packet based upon network layer addressing information in the packet. In order to remove the label switched path, the upstream label switching device forwards unlabeled packets to the downstream label switching device, and both devices remove the label from its respective forwarding table.

System, device, and method for establishing and removing a label switched path in a communication network

A distributed LSR sends data from a first edge LSR, across a non-MPLS network, to a second edge LSR, thereby enabling a non-MPLS network to interface transparently with MPLS networks. This enables a VPN to use a public network to communicate from one portion of the network to another, remote portion. The distributed LSR includes an ingress gateway logically positioned between the first edge LSR and the non-MPLS network. This ingress gateway receives label requests from the first edge LSR. These label requests are multicast to several egress gateways. At least one egress gateway sends a message back indicating that it can transmit data to the destination. In response, the ingress gateway designates that egress gateway to be a designated gateway. The egress gateway then establishes a tunnel through the non-MPLS network to the ingress gateway.

Distributed label switching router

An apparatus and method of managing a virtual private network having a set of network devices maintains a network device memory set for storing a set of network device identifiers that identifies each of the set of network device. More particularly, a request to join the virtual private network is received from a given network device having a given network device identifier that identifies the given network device. The set of network device identifiers then is retrieved from the network device memory set to identify all network devices in the set of network devices. A notify message then is forwarded to each of the set of network devices, and a join message is forwarded to the given network device. The notify message includes the given network device identifier, while the join message includes the set of network device identifiers. The given network device identifier then is stored in the network device memory set.

Virtual private network management system

A method for avoiding loops from forming when setting up label switched paths is provided. The method uses a Label Splicing Message is followed by an Acknowledgment message to determine if loops are formed in the process of joining a new node or subtree to a multicast MPLS tree. By verifying that the path towards the root of the MPLS tree is loop-free during the construction of the tree, this method complements the loop detection mechanism provided by the label switched protocol (LDP).

System and method for loop avoidance in multi-protocol label switching

A method to engineer paths for multicast traffic in an IP network, by directing the control messages to setup multicast trees on engineered paths, is disclosed. The multicast traffic engineering process is separated from the multicast route setup and the resources and the paths for multicast data delivery can be aggregated and independently allocated. Resources are allocated on the same trip when paths are selected and setup, and this prevents data from being forwarded on branches where resources have not been yet allocated. The traffic can be statistically multiplexed enabling the network operators to have control over the topology of the multicast trees and to provide differentiated services in a scalable manner.

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Alvsjo, Sweden

Loa Andersson