Nortel Networks Corporation

Rockstar Consortium US LP

Rockstar Bidco, LP

Rpx Clearinghouse LLC

Ciena Corporation

Robert Friskney

Simon P Parry

Nigel Lawrence Bragg

David Allan

Simon Daniel Brueckheimer

Marc Holness

Florin S Balus

Nigel Baker

John J Osswald

Michael K Poon

Peter J Ashwood-Smith

Peter Ashwood Smith

Paul Allen Bottorff

Adrian Paul Sparks

Christopher Phillips

Song Dong

Fiona Davis

Roy Harold Mauger

Robin Paul Rickard

Nigel Robert Davis

Mark Robert Gibson

Dave J Stacey

Robert William Spagnoletti

Douglas Fisher

David Allen

A method for determining a path in an optical network, implemented by one or more controllers associated with a control layer, includes receiving a path request specifying start and end points, an associated bandwidth, and a longevity parameter providing an anticipated length during which the path is required; determining a route in the optical network through a routing algorithm executed by the controller, wherein the routing algorithm utilizes the start and end points, the associated bandwidth, and the longevity parameter to determine the path; and provisioning the path through a plurality of switches along the route.

Methods and apparatus for determining a path in a communications network

The invention relates to enabling differential forwarding in address-based carrier networks such as Ethernet networks. There is described a method of and connection controller for establishing connections () in a frame-based communications network comprising nodes (-and) such as Ethernet switches. The connections are established by configuring, in various of the nodes, mappings for forwarding data frames, such as Ethernet frames. The mappings are from a combination of a) a destination (or source) address corresponding to a destination (or source) node () of the connection and b) an identifier, such as a VLAN tag. The mappings are to selected output ports of the various nodes. By using the combination of destination (or source) address AND identifier, the mappings enable data frames belonging to different connections () to be forwarded differentially (ie forwarded on different output ports) at a node () despite the different connections having the same destination node. This enables flexibility in routing connections and the ability to perform traffic engineering.

Differential forwarding in address-based carrier networks

Typically paths are provisioned in a network with a margin which allows for component variations and failures in the network and so on. By providing more information about the requirements of the link in a path request, it is possible to more efficiently calculate a route for the path through the network. The efficiency gain allows greater network utilization which in turn saves costs for the network service provider.

An Ethernet virtual switched sub-network (VSS) is implemented as a virtual hub and spoke architecture overlaid on hub and spoke connectivity built of a combination of Provider Backbone Transport (spokes) and a provider backbone bridged sub-network (hub). Multiple VSS instances are multiplexed over top of the PBT/PBB infrastructure. A loop free resilient Ethernet carrier network is provided by interconnecting Provider Edge nodes through access sub-networks to Provider Tandems to form Provider Backbone Transports spokes with a distributed switch architecture of the Provider Backbone Bridged hub sub-network. Provider Backbone transport protection groups may be formed from the Provider Edge to diversely homed Provider Tandems by defining working and protection trunks through the access sub-network. The Provider Backbone Transport trunks are Media Access Control (MAC) addressable by the associated Provider Edge address or by a unique address associated with the protection group in the Provider Backbone Bridged network domain.

Provider backbone bridging&#x2014;provider backbone transport internetworking

A node comprises a first communications interface to a customer network element, where the first communications interface is part of a group of communications interfaces to the customer network element to provide failover support. The node further includes a network interface to communicate over a trunk group to other nodes, where the trunk group includes a primary trunk and a secondary trunk. Just one of the primary and secondary trunks is active for communicating data units.

Communicating data units in a communications network that provides failure protection

A shared (proxy) OAM session is performed in a packet-based network on behalf of a plurality of connections. First and second connections are each routed between respective nodes of the network for carrying data traffic. The second connection shares a portion of the routing of the first connection. The shared OAM session is performed along a path which is co-routed with at least part of the shared portion of the routing of the first connection and the second connection. Failure notification signalling is propagated to an endpoint node of each of the first and second connections when the shared OAM session indicates a failure has occurred. The use of a shared OAM session reduces processing at nodes and reduces OAM traffic. Each connection can be a trunk, such as a PBT/PBB-TE trunk, or a service carried within a trunk.

Scaling OAM for point-to-point trunking

An Ethernet network comprises nodes which support a plurality of different forwarding modes. A range of VLAN Identifiers (VIDs) are allocated to each of the forwarding modes. Connections are configured between a source node and a destination node of the network using different forwarding modes. Packets carrying data traffic are sent to the destination node by selectively setting a VID in a packet to a first value, to transfer a packet via a first connection and a first forwarding mode, and a second value to transfer a packet via the second connection and the second forwarding mode. Packets received from both of the connections and sent on to an end user. VLAN Identifiers can be allocated to different releases of functionality at nodes (e.g. software releases) such that packets are forwarded via a set of nodes supporting a first release, or via a set of nodes supporting a second release.

Evolution of ethernet networks

A method is provided of planning routes and allocating route identifiers in a managed frame-forwarding network. The network comprises a plurality of nodes interconnected by links, with each node being arranged to forward data frames according to a combination of an identifier and a network address carried by a received data frame and forwarding instructions stored at the node. A first step of the method identifies a sub-set of nodes which are core nodes of the network. The remaining nodes are termed outlying nodes. A spanning tree is then built off each of the identified core nodes, with the spanning tree stopping one link short of any other core node. Each spanning tree defines a loop-free path between a core node at the root of the spanning tree and a set of outlying nodes. Connections are planned between roots of the spanning trees and a different identifier is allocated to each planned connection between a pair of spanning trees.

Planning routes and allocating identifiers to routes in a managed frame-forwarding network

Growing community of inventors

Harlow, United Kingdom

Robert Friskney