Patent application number | Description | Published |
20080219156 | Communication Network Protection Systems - A communication network protection system made up of interconnected networks, at least one of which has an automatic control plane (for example ASTN) among which are terminal interconnecting nodes. With the terminal interconnection nodes, termed primary nodes, are associated corresponding secondary terminal nodes wherein a secondary terminal node is used to realize a protection circuit in case of failure of the associated primary node. | 09-11-2008 |
20090003192 | Protection Mechanisms for a Communications Network - A method of path protection for a connection-oriented packet switched communications network is described using a protection hub in communication with a worker hub via a core protection path. Both the worker hub and the protection hub communicate with at least one provider edge device via a respective worker and protection paths. The method detects a failure in the communications network, indicates the failure to the at least one of the provider edge device, the worker hub, and the protection hub. The method then employs the core protection path if a failure occurs along a worker path is detected, or a worker path and a protection path in parallel if a failure occurs along the core protection path. | 01-01-2009 |
20090034972 | Optical Path Routing in an Optical Communications Network - Routing method for paths in an optical network that includes nodes having limited conversion and/or regeneration capability and in which a routing algorithm based on considerations of cost of the links is employed and in which with the nodes is associated cost information that includes conversion and/or regeneration costs. Such conversion and/or regeneration cost information is considered in the routing algorithm together with the other cost information for calculation of the routings. | 02-05-2009 |
20100214909 | P2MP TRAFFIC PROTECTION IN MPLS-TP RING TOPOLOGY - In a connection-oriented network a point-to-multipoint working path is established between a source node and a plurality of destination nodes using a number of working path intermediate nodes. A point-to-multipoint protection path is established for possible points of failure in the working path. Each protection path connects a first working path intermediate node upstream of a point of failure and destination nodes of the working path downstream of the first working path intermediate node. The point-to-multipoint protection path only connects to destination nodes of the working path and working path intermediate nodes which must be transited to reach the destination nodes of the working path. | 08-26-2010 |
20110004455 | Designing a Network - A method of designing a network given a set of network nodes, a set of adjacencies defining which nodes can be connected together directly and so are topologically adjacent and a traffic matrix comprising a plurality of entries each indicating a source node, a destination node and a number being the number of connections from the source node to the destination node that are to be present in the network; the method comprising the steps of: simulating the network nodes and the adjacencies thereof to generate a simulated network; simulating applying the traffic matrix entry by entry, each application of an entry causing a number of links consistent with the entry to be simulated between the source and destination nodes indicated in the entry, via a chain of topologically adjacent nodes; simulating the effect of at least one failure on the simulated network, including simulating the re-routing of the links onto a replacement chain where the chain is broken; determining the number of links between each pair of topologically adjacent nodes; repeating these steps for a plurality of iterations, the order in which the entries in the traffic matrix and the faults are applied being different in different iterations; for each iteration and for each topologically adjacent pair of nodes, determining an average number of links between the pair of nodes for all iterations so far; for each iteration and for each pair of topologically adjacent pair of nodes, determining a variance in the average number of links for all iterations so far; for each iteration, determining an average variance in the average number of links for all iterations so far, the average being taken across the entire network; for each iteration, determining a variance in the variances in the average number of links for all iterations so far, the variance being taken across the entire network; determining when to cease iterating based upon the variance in the variances in the average number of links. | 01-06-2011 |
20110038628 | ROUTING IN MULTILAYER OPTICAL NETWORKS - A method, system and network for routing a multiplexed signal through an optical network ( | 02-17-2011 |
20110122765 | Protection Against The Effect of Equipment Failure in a Communications System - A data communications system has a plurality of nodes connected by a plurality of links. A subset of the links and nodes forms a worker path for carrying worker data through the communications system, and a further subset of links and nodes provides a protection path for carrying other data in the absence of a fault in the worker path and for providing an alternative path for the worker data in the event of a fault in the worker path. The alternative path is predetermined prior to the detection of a fault in the worker path. | 05-26-2011 |
20120148240 | RESERVING A PATH USING GMPLS EXTENSIONS FOR ODU SIGNALLING - A method of requesting reservation of a label switched path (LSP) for traffic of a type compatible with ITU-T G709 amendment 3, in an optical transport network by sending a RSVP-TE path message for the reservation of the requested LSP from an ingress node of the requested path, via intermediate nodes along the path to an egress node, and sending a RSVP-TE resv message from the egress node, to cause the nodes to reserve resources for the requested path. The path message has a signal type field having values assigned to indicate traffic types specified in G.709 amendment 3 beyond those specified by G.709 pre amendment 3, without reuse of values specified by G.709 pre amendment 3. Since the nodes along the path can still distinguish in the signal type field any values of the signal type field specified by G.709 pre amendment 3, new nodes can still work with legacy messages. | 06-14-2012 |
20120155327 | OWNERSHIP TRANSFER OF A LABEL SWITCHED PATH - Control of a label switched path established in a network is transferred between a management plane and a control plane of the network. A node (e.g., node C) receives a message indicating a change in control of the label switched path, the message identifying the label switched path by a cross-connection identifier corresponding to an entry in the control data stored at the node which identifies data plane ingress and egress segments cross-connected at the node. Control data at the node is updated based on the identified label switched path. The message includes a list of cross-connection identifiers for nodes (e.g., nodes C, E, and F) along the label switched path. The cross-connection identifier can be an mplsXCIndex. | 06-21-2012 |
20120207017 | RECOVERY MECHANISM FOR POINT-TO-MULTIPOINT TRAFFIC - A connection-oriented network ( | 08-16-2012 |
20120321297 | ROUTING AND VALIDATION OF PATHS IN A WAVELENGTH SWITCHED OPTICAL NETWORK - A network comprises nodes connected by optical sections. The nodes support a plurality of traffic types. A candidate optical path having a first traffic type is selected as a routing for at least part of the connection on the basis of at least one routing metric. Pre-computed parameters are retrieved for the optical sections of the candidate optical path. The pre-computed parameters are indicative of quality of transmission along the optical section for the first traffic type. A quality of transmission is determined along the candidate optical path using the retrieved parameters. The pre-computed parameters for each of the optical sections can be used at a network planning tool and then exported to a network management system or a path computation entity at a node for creating a validation module for use in validating connections across the optical transmission network. | 12-20-2012 |
20130021908 | METHOD OF AND APPARATUS FOR CONFIGURING QUALITY OF SERVICE - The present invention relates to configuring the quality of service in a label switched network. In particular, the invention relates to configuring quality of service for the return path of a bi-directional label switched path in a label switched network. | 01-24-2013 |
20130044589 | SHARED PATH RECOVERY SCHEME - A connection-oriented network has a first working path (W | 02-21-2013 |
20130121696 | APPARATUS AND METHOD FOR PHOTONIC NETWORKS - A node for use in a photonic network comprises an optical to electrical interface for receiving a traffic signal and an electrical to optical interface for outputting a traffic signal. A processor is adapted, in response to receiving a control plane message, to reconfigure at least one feature of an optical-to-electrical-to-optical conversion process carried out in the node, according to a type of traffic signal identified by the control plane message. | 05-16-2013 |
20130142508 | CONFIGURING A PATH IN AN OPTICAL COMMUNICATIONS NETWORK - A method of configuring a path between an ingress node and an egress node in an optical communications network, the path comprising a first hop and a subsequent hop. The method includes: a) selecting a candidate hop for the first hop of the path; b) obtaining a value of a signal feasibility parameter for the candidate hop; c) determining whether said value lies within an acceptable value range and if one is, accepting said candidate hop for the first hop of the path, and if one is not, repeating steps a. to c.; d) selecting a candidate hop for the subsequent hop of path; e) obtaining a value of a signal feasibility parameter for a combined path comprising the first hop and the candidate hop for the subsequent hop of the path; f) determining whether said value lies within an acceptable value range, if one is, acceptable value range accepting said candidate hop for the subsequent hop of the path, and if one is not, repeating steps d. and e.; and g) generating and transmitting a control signal for configuring the path. Each step of obtaining a value of a signal feasibility parameter comprises checking whether a measured value of the signal feasibility parameter is available, and if one is, retrieving said measured value and if one is not, calculating an estimated value of the signal feasibility parameter. | 06-06-2013 |
20130163981 | SIGNALLING IN OPTICAL TRANSMISSION NETWORKS - A connection-oriented optical network ( | 06-27-2013 |
20130198379 | LOGGING CONTROL PLANE EVENTS | 08-01-2013 |
20130301402 | MESSAGE PASSING TO ASSURE DELETION OF LABEL SWITCHED PATH - A label switched path through a network of nodes, is torn down by sending a message along the path from an ingress node. If there is a fault along the path, a path error message ( | 11-14-2013 |
20140016925 | RESIZING A PATH IN A CONNECTION-ORIENTED NETWORK - An existing path in a connection-oriented network requires resizing from a first size to a second size. Nodes exchange control plane signalling with other nodes which advertises available resources on links between nodes. A node on the existing path receives a request to establish a path capable of being resized to the second size. The node determines, using information acquired by the control plane signalling with other nodes, a new path between nodes capable of supporting the second size. The node signals to establish the new path and switches traffic from the existing path to the new path. The node causes the new path to be resized to the second size. Nodes exchange control plane signalling with other nodes which advertises whether a link supports resizing, such as OSPF-TE advertisements. | 01-16-2014 |
20140029416 | SEGMENT RECOVERY IN CONNECTION-ORIENTED NETWORK - A connection-oriented network has a working path and a segment recovery path for a segment of the working path. The working path has a branch node at an end of the segment where the segment recovery path connects to the working path. The branch node is not located at an end node of the working path. Control plane signalling is received at an end node of the working path from a node along the working path, indicating that a failure has occurred along the working path. The end node determines, from the received control plane signalling, if the failure has occurred outside the segment of the working path. When it is determined that the failure has occurred outside the segment of the working path, a notification is sent to the branch node. The notification is an instruction not to reroute to the segment recovery path. | 01-30-2014 |
20140294383 | Apparatus and Method For an Optical Network - An optical network is configured to provide an optical reroute over a backup path ( | 10-02-2014 |
20140328159 | Recovery of Split Architecture Control Plane - A method of operating a control plane having a centralised network management system ( | 11-06-2014 |
20150023157 | Protection Against the Effect of Equipment Failure in a Communications System - A data communications system has a plurality of nodes connected by a plurality of links. A subset of the links and nodes forms a worker path for carrying worker data through the communications system, and a further subset of links and nodes provides a protection path for carrying other data in the absence of a fault in the worker path and for providing an alternative path for the worker data in the event of a fault in the worker path. The alternative path is predetermined prior to the detection of a fault in the worker path. | 01-22-2015 |
20150071057 | SEGMENT RECOVERY - In a communications network, a recovery segment is used to reroute a recoverable part of a path set up along an original route along links between nodes. When a defect is detected in the original route of the path, but is undetectable by nodes within the recoverable part, a reroute message is sent (5) from outside the recoverable part to an end node (N2,N4) of the recoverable part. This prompts the rerouting of the recoverable part over the recovery segment. Thus segment recovery becomes possible for these defects which cannot be detected at nodes in the segment. This extends the applicability of benefits of segment recovery such as reduced resources devoted to recovery, and flexibility to choose which parts of paths to protect. The end node can send a notify message beforehand, to request (3) notification of the defect as the reroute message. | 03-12-2015 |