Juniper Networks, Inc.

British Telecommunications Public Limited Company

British Telecommunications Corporation

David Charles Wood

Jonathan C Barth

Stephen A Cassidy

Paul F McKee

Keith J Blow

Ping Wang

Mark Robert Wilkinson

Peter Healey

Peter Paul Smyth

Massimiliano Salsi

David Cotter

Steven B Alleston

Roderick Peter Webb

Nicholas J Doran

Edward G Scott

Marek A Rejman-Greene

Keith James Blow

Nicholas John Doran

In some examples, a controller for a network includes a path computation module that determines, for a plurality of LSPs or other flows having a common source, shortest paths of the network from the common source to respective destinations of the plurality of LSPs based at least on a minimum bandwidth. The path computation module further determines, after determining the shortest paths, a shortest path for the LSP of the plurality of LSPs as the shortest path of the shortest paths of the network from the common source to a destination for the LSP. A path provisioning module of the controller, after the path computation module determines the shortest path for the LSP and in response to the path computation modules routing the LSP to the shortest path for the LSP on a network model of the network, installs the LSP to the network as routed to the shortest path.

Batched path computation in resource-constrained networks

In some examples, a controller for a network includes a path computation module configured for execution by one or more processors to obtain configuration information for at least one point-to-multipoint label switched path (P2MP LSP); obtain, from the network via at least one protocol, network topology information defining a network topology for the network; determine, based on the network topology, a first solution comprising first respective paths through the network for the at least one P2MP LSP; determine, after generating a modified network topology based on the network topology, a second solution comprising second respective paths through the network for the at least one P2MP LSP. The controller also includes a path provisioning module configured for execution by the one or more processors to configure the network with the solution of the first solution and the second solution having the lowest total cost.

Point-to-multipoint path computation for wide area network optimization

In some examples, a network device is configured to obtain a set of N paths between a pair of nodes of a network topology model for a network of routers interconnected by a plurality of links in a network topology, where N&#x3e;2, and configured to, for each label switched path from a plurality of label switched paths to be routed to the network topology: in response to identifying, from the set of N paths, a path for the label switched path that has capacity for a required bandwidth of the label switched path, deduct the required bandwidth of the label switched path from one or more links of the path of the network topology model to modify the network topology model and output data to the network for programming the label switched path in the network on the path; and in response to failing to identify a path for the label switched path from the set of N paths, add the label switched path to a set of failed label switched paths.

Path selection and programming of multiple label switched paths on selected paths of multiple computed paths

In some examples, a path computation device is configured to compute, for a network of routers interconnected by a plurality of links in a network topology and based on a network topology model for the network topology, a first path that is a shortest path of the network topology model between a pair of nodes of the network topology model that represent a pair of the routers; increase, based on the first path, respective metrics for one or more links in the network topology model by respective finite values to obtain a modified network topology model; compute a second path that is a shortest path of the modified network topology model between the pair of nodes; and output data for at least one path of the first path and the second path to the network for programming a label switched path in the network on the at least one path.

Heuristic multiple paths computation for label switched paths

In general, techniques are described for identifying a result set of multiple paths through a network for one or more label switched paths between a source node and a destination node. In some examples, the identified paths are computed to be broadly separate to avoid overlapping network elements. A device that routes the label switched paths to the network may select from the result set of multiple paths to route each of the label switched paths. In response to detecting a failure of a network element along the routed path for a label switched path, the device may select a new path from the result set that includes already-identified paths.

Multiple paths computation for label switched paths

In general, techniques are described for dynamically determining a logical network topology for more efficiently transporting network traffic over a physical topology based on end-to-end network traffic demands and optical transport network (OTN) characteristics of the network. The techniques may be applicable to meeting network traffic demands placed upon a multi-layer network having a base transport layer and a logical or overlay Internet Protocol (IP) layer routed on the transport layer.

Network topology optimization with feasible optical paths

In some examples, a controller for a multi-layer network comprising a network layer and an underlying transport layer is configured to obtain abstract link data describing a plurality of candidate links; determine, based at least on the abstract link data, a first solution comprising a network topology for the network layer that includes a first selected subset of the candidate links; determine, after generating a modified network topology based at least on the network topology and the abstract link data, a second solution comprising the modified network topology for the network layer that includes a second selected subset of the candidate links; and output, for configuring the multi-layer network, topology data for one of the first solution or the second solution having a lowest total cost, the lowest total cost including a total resource cost to the network for the one of the first solution or the second solution.

Network topology optimization

An optical grating includes a sequence of grating lines, the sequence being such that each grating line is centered on a position which is an integer multiple of a line spacing distance from a datum position on the grating, the sequence of grating lines is non-periodic and the sequence of the grating lines is formed from N concatenated sub-sequences. Each sub-sequence includes a series of one or more instances of a respective grating line pattern. Such an optical grating has a structure that is more amenable to calculation of the grating lines necessary to achieve a desired characteristic. A method of calculating and fabricating such a grating is also disclosed.

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Woodbridge, United Kingdom

David Charles Wood