Telefonaktiebolaget Lm Ericsson (Publ)

Alcatel Lucent

Luca Valcarenghi

Piero Castoldi

Filippo Cugini

Annikki Welin

David Elie-Dit-Cosaque

Nicola Sambo

Maher Ali

Andrea Fumagalli

Isabella Cerutti

Francesco Paolucci

Alessio Giorgetti

Sandeep Darisala

Parthasarathy Kothandaraman

Marco Tacca

David Eli-Dit-Cosaque

Kothandaraman Parthasarathy

A method of restoration for an optical network, the network comprising a plurality of nodes () interconnected with each other by optical links (), a subset of the nodes () each comprising a regenerator, the method comprising: storing) a quality of transmission parameter and a regenerator availability at each of the plurality of nodes (); notifying () a branch node () in response to detecting a failure () within a link () forming part of the path between a source node () and a destination node (), wherein the branch node () is the neighbouring upstream node () upstream of the link failure (), the branch node () having a regenerator; the branch node () computing () a restoration segment () to a merge node () having a regenerator which is a neighbouring downstream node which is downstream of the link failure (), the restoration path () being based on the quality of transmission parameter and regenerator availability information; restoring () the path between the source node () and the destination node () using the restoration segment ().

Restoration scheme for an optical network and method of using such a scheme

A method of load balancing zero-bandwidth Traffic Engineering Label Switching Paths (0-bw TE LSPs) in a communication network having a plurality of network nodes and a plurality of network links connecting the nodes. The method may be implemented in a centralized Path Computation Element (PCE) or in an ingress router. Each equal cost path from a source node to a destination node is identified from network topology information. A probability of selecting each equal cost shortest path is determined using an iterative Global Load balancing Algorithm (GLA) and each 0-bw TE LSP is provisioned with a specific probability such that the 0-bw TE LSPs are uniformly distributed over all network links.

Global provisioning of zero-bandwidth traffic engineering label switched paths

Method and apparatus for dynamic provisioning of reliable connections in the presence of multiple failures in optical networks are described. One embodiment is a method for allocation of protection paths after a failure in an optical network. The method comprises, responsive to a failure in an active lightpath, switching traffic on the active lightpath to a protection path; subsequent to the switching, identifying all active lightpaths in the network that no longer have an available protection path; and attempting to allocate a protection path to each of the identified active lightpaths.

Method and apparatus for dynamic provisioning of reliable connections in the presence of multiple failures

Growing community of inventors

Vercelli, Italy

Luca Valcarenghi