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Peter Ashwood-Smith, Hull CA

Peter Ashwood-Smith, Hull CA

Patent application numberDescriptionPublished
20090046719Method and Apparatus for Implementing Multiple Portals into an RBRIDGE Network - Shortest-path spanning trees are created outward from each portal on a Rbridge network with nodes on the network being assigned to the spanning trees. For those nodes equidistant to two portals, an election process is used to determine which tree the node should join. To enable routes associated with nodes on the Rbridge network to be distinguished from routes external to the Rbridge network, messages may be transmitted between the portals. The messages enable portals to identify routing updates received from the external network as containing internal routes, so that traffic that is required to pass between nodes on different trees may pass over the Rbridge network rather than over the external network.02-19-2009
20100074101Distributed Connection Establishment and Restoration - Connection constraints are flooded using an extension to a routing protocol being used to control forwarding on network. Nodes maintain topology and connection database and calculate routes for connections based on the constraints. If a node is on a calculated route for a connection it will install forwarding state for the connection. Since each node has a consistent view of the network topology and has been provided with the constraints associated with the connection, each node on the network will calculate the same route for the connection. When a failure occurs, the nodes will calculate restoration paths for the connections on a network-wide priority basis to enable restoration paths to be created for the affected connections without requiring the restoration paths to be signaled. Time-stamps are used to allow events to be applied by nodes in a consistent order regardless of the order in which they arrive.03-25-2010
20100172270Distributed Storage of Routing Information In a Link State Protocol Controlled Network - A distributed hash table is implemented to store routing information on a network. Node IDs exchanged in connection with implementation of a link state routing protocol are used as keys in the distributed hash table, and routes are stored at one or more nodes on the network. When a route is learned, the route is processed against the set of keys to determine which nodes should store the route. When a route is needed, the route is processed against the set of keys to determine which nodes should have the route information. The manner in which the route is processed against the set of keys is the same in both instances, so that the DHT may be used to store and retrieve route information on the network. The DHT may be implemented to store MAC addresses, IP addresses, MPLS labels, or other information of interest to enable routes to be stored and learned by network elements on the network.07-08-2010
20100271936Pre-Computing Alternate Forwarding State in a Routed Ethernet Mesh Network - A set of critical nodes or links is identified on the network and alternate forwarding state is pre-computed and disseminated within a node such that, upon failure of one of the critical nodes/links, a minimal trigger will cause the alternate forwarding state to be used to forward traffic on the routed Ethernet mesh network. In one embodiment rather than storing full tables of alternate forwarding state, only the changes to the forwarding state required by an identified failure is stored by the network nodes. Upon occurrence of a failure on the network, the identified failure is used to select the alternate forwarding state.10-28-2010
20100322263Method and Apparatus for Implementing Control of Multiple Physically Dual Homed Devices - A ring control protocol is used to establish a separate control plane for a plurality of physically dual homed devices to enable collections of dual homed devices to be represented by a single pair of addresses into the attached routed Ethernet network. The gateway devices analyze the passing ring control packets to create direct mappings for data packets to the routed Ethernet network. Thus, although the dual homed devices are treated as a ring from a control perspective, the data path is implemented to be direct so that data packets continue to flow directly from the dual homed devices to each of the attached gateway devices. In one embodiment, each of the gateway devices implements a virtual switch and advertises the MAC address of the virtual switch into the routed Ethernet network rather than the MAC addresses of each of the attached Ethernet Switch Units.12-23-2010
20110032936MULTICAST IMPLEMENTATION IN A LINK STATE PROTOCOL CONTROLLED ETHERNET NETWORK - Forwarding state may be installed for sparse multicast trees in a link state protocol controlled Ethernet network by enabling intermediate nodes to install state for one or more physical multicast trees, each of which may have multiple logical multicast trees mapped to it. By mapping multiple logical multicasts to a particular physical multicast, and installing state for the physical multicast, fewer FIB entries are required to implement the multiple multicasts to reduce the amount of forwarding state in forwarding tables at the intermediate nodes. Mapping may be performed by destination nodes before advertising membership in the physical multicast, or may be performed by the intermediate nodes before installing state when a destination node advertises membership in a logical multicast. Intermediate nodes will install state for the physical multicast tree if they are on a shortest path between a source and at least one destination of one of the logical multicasts that has been mapped to the physical multicast.02-10-2011
20110255443VIRTUAL ROUTERS FOR GMPLS NETWORKS - Virtual routers that abstract photonic sub-domains are provided for GMPLS networks. A virtual router uses a link viability matrix to keep track of the set of viable connections between inputs and outputs of a photonic sub-domain. A virtual router may receive RSVP-TE signaling messages and either allocate a working input to output link pair or, if explicitly signaled, verify that the requested link is currently viable. A virtual router also advertises, in its link state updates, the current set of possible outputs for any input link. Shortest path computations can be implemented utilizing virtual routers by modifying a topology graph in accordance with the link viability matrix of the virtual router.10-20-2011
20110273980Distributed Failure Recovery in a Routed Etherent Network - Link identifiers such as VIDs, selected from a defined range of values, are locally assigned by each node on a link state protocol controlled Ethernet network to each of its links or adjacencies. The link identifiers are assigned by the nodes such that each link or adjacency at the node is uniquely identified by a different link identifier. A link state protocol adjacency notification mechanism or other flooding mechanism is used to disseminate the locally assigned link identifiers to other nodes on the link state protocol controlled Ethernet network. The link identifiers are added by the nodes to their topology databases to enable detour routes to be locally calculated by the nodes on the network in a distributed manner. Upon occurrence of a failure, the link identifiers are used to source route traffic around the failure so that traffic may continue to traverse the link state protocol controlled Ethernet network.11-10-2011
20120134357MULTICAST IMPLEMENTATION IN A LINK STATE PROTOCOL CONTROLLED ETHERNET NETWORK - Forwarding state is installed for sparse multicast trees in a link state protocol controlled Ethernet network by enabling intermediate nodes to install state for one or more physical multicast trees, each of which may have multiple logical multicast trees mapped to it. By mapping multiple logical multicasts to a particular physical multicast, and installing state for the physical multicast, fewer FIB entries are required to implement the multiple multicasts. Mapping may be performed by destination nodes before advertising membership in the physical multicast, or may be performed by the intermediate nodes before installing state when a destination node advertises membership in a logical multicast. Intermediate nodes will install state for the physical multicast tree if they are on a shortest path between a source and at least one destination of one of the logical multicasts that has been mapped to the physical multicast.05-31-2012
20120147752METHOD AND APPARATUS FOR INDICATING CONGESTION IN A SOURCE ROUTED NETWORK - A packet header in a source routed network is augmented to include, with each hop identifier, at least one bit for indicating congestion at the particular hop. As the packet traverses from the source to the destination, when congestion is detected at a hop, a congestion bit associated with the hop is set in the header. At the destination, when another packet is forwarded from the destination to the source on the same path, the congestion bits are reflected back to the source. When the source receives the congestion bits, it has the option of re-routing subsequent communications between the source and destination nodes by generating a new hop list, which routes around one or more of the congested hops.06-14-2012
20120207061Distributed Storage of Routing Information in a Link State Protocol Controlled Network - A distributed hash table is implemented to store routing information on a network. Node IDs exchanged in connection with implementation of a link state routing protocol are used as keys in the distributed hash table, and routes are stored at one or more nodes on the network. When a route is learned, the route is processed against the set of keys to determine which nodes should store the route. When a route is needed, the route is processed against the set of keys to determine which nodes should have the route information. The manner in which the route is processed against the set of keys is the same in both instances, so that the DHT may be used to store and retrieve route information on the network.08-16-2012
20120218916Method and Apparatus for Establishing Forwarding State Using Path State Advertisements - Paths may be advertised on a network implementing a link state routing protocol by using Path State Advertisements (PSAs) that are distributed in the same manner as link state advertisements. The path state advertisements contain path entries, each of which includes a globally unique path ID and path information such as a series of nodes or links that defines the path through the network. When a PSA is received by a network element, the network element will evaluate the path entries in the PSA to determine if the PSA is relevant and, if necessary, install forwarding state for the relevant path entries. PSAS not relevant to a network element are not used to affect forwarding state on the network element. Label based forwarding may be used by the network elements to forward data along the path, in which the globally unique path ID is used as the label.08-30-2012
20120230183METHOD AND APPARATUS FOR IMPLEMENTING CONTROL OF MULTIPLE PHYSICALLY DUAL HOMED DEVICES - A ring control protocol is used to establish a separate control plane for a plurality of physically dual homed devices to enable collections of dual homed devices to be represented by a single pair of addresses into the attached routed Ethernet network. The gateway devices analyze the passing ring control packets to create direct mappings for data packets to the routed Ethernet network. Thus, although the dual homed devices are treated as a ring from a control perspective, the data path is implemented to be direct so that data packets continue to flow directly from the dual homed devices to each of the attached gateway devices. In one embodiment, each of the gateway devices implements a virtual switch and advertises the MAC address of the virtual switch into the routed Ethernet network rather than the MAC addresses of each of the attached Ethernet Switch Units.09-13-2012
20120263075Method and Apparatus for Exchanging Routing Information and the Establishment of Connectivity Across Multiple Network Areas - Routes may be installed across multiple link state protocol controlled Ethernet network areas by causing ABBs to leak I-SID information advertised by BEBs in a L1 network area into an L2 network area. ABBs will only leak I-SIDs for BEBs where it is the closest ABB for that BEB. Where another ABB on the L2 network also leaks the same I-SID into the L2 network area from another L1 network area, the I-SID is of multi-area interest. ABBs will advertise I-SIDs that are common to the L1 and L2 networks back into their respective L1 network. Within each L1 and L2 network area, forwarding state will be installed between network elements advertising common interest in an ISID, so that multi-area paths may be created to span the L1/L2/L1 network areas. The L1/L2/L1 network structure may recurse an arbitrary number of times.10-18-2012
20120307625Method and Apparatus For Selecting Between Available Neighbors in a RAPID Alternate Path Calculation - A weighting process may be used to select between alternate neighbors in a RAPID calculation to enable policy and/or traffic engineering considerations to affect the selection of an alternate path through the network. The information used to weight the neighbors may static administratively assigned weighting information or dynamic weighting information such as local statistical traffic condition information. The process may take into account the amount of traffic being handled by the current primary next hop for the destination, the available capacity of the available alternate neighbors, the ability of the alternate neighbors to handle the additional traffic, and other considerations. Weighting may occur after a set of available loop free alternate neighbors has been determined. Alternatively, weighting may occur before the RAPID calculation has been performed to cause the neighbors to be ordered prior to RAPID processing. This may enable RAPID calculation to stop without considering all available neighbors.12-06-2012
20120314582METHOD AND APPARATUS FOR SIMPLIFYING THE COMPUTATION OF ALTERNATE NETWORK PATHS - An alternate path calculation process may be terminated after considering some of a source node's neighbors and without considering each of its neighbors, to reduce the amount of processing required to perform the alternate path calculations. The neighbors may be ranked according to the number of alternate paths that the neighbor has historically been able to provide on the network. The influence of historical success or failure may degrade over time so that the rankings may be adjusted to reflect changes in network topography. A given source node, when computing alternate paths through the network, may preferentially select neighbors to perform alternate path calculations on historically higher scoring nodes before performing calculations on historically lower scoring nodes. Several different criteria may be used to stop the alternate path calculation process before considering all neighbors. The neighbors may be loop free neighbors or U-turn neighbors.12-13-2012
20130073616DISTRIBUTION OF XML DOCUMENTS/MESSAGES TO XML APPLIANCES/ROUTERS - XML appliances/routers may be organized to implement one or more XML distribution rings to enable XML documents/messages to be distributed efficiently. The rings may be logical or physical. The XML distribution rings enable the XML documents/messages to be exchanged without requiring the XML appliances/routers to run a routing protocol to determine how XML documents/messages should be distributed through the network. Documents may be transmitted in one way on the ring or may be transmitted in both directions around the ring to enable the ring to tolerate failure of an XML appliance/router. Each XML appliance/router will receive all XML documents/messages and will make routing decisions for those clients that have provided the XML appliance/router with XML subscriptions. The subscriptions may be formed according to the XPath standard or in another manner.03-21-2013
20130088355THREE DIMENSIONAL RF SIGNATURES - Method and systems to detect tampering in a physical article are described herein. A method includes receiving, at a first point in time, at least two response signals from at least one RF tag in a set of RF tags associated with the physical article; forming a first response signature for the physical article based on the received response signals; receiving a second response signal from at least one other RF tag in the set of RF tags associated with the physical article at a second point in time; assessing a relative spacing between the RF tags associated with the physical article has changed from the first point in time to the second point in time; and determining tampering of the physical article as a result of the spacing assessment.04-11-2013
20130148660MULTICAST IMPLEMENTATION IN A LINK STATE PROTOCOL CONTROLLED ETHERNET NETWORK - Forwarding state is installed for sparse multicast trees in a link state protocol controlled Ethernet network by enabling intermediate nodes to install state for one or more physical multicast trees, each of which may have multiple logical multicast trees mapped to it. By mapping multiple logical multicasts to a particular physical multicast, and installing state for the physical multicast, fewer FIB entries are required to implement the multiple multicasts. Mapping may be performed by destination nodes before advertising membership in the physical multicast, or may be performed by the intermediate nodes before installing state when a destination node advertises membership in a logical multicast. Intermediate nodes will install state for the physical multicast tree if they are on a shortest path between a source and at least one destination of one of the logical multicasts that has been mapped to the physical multicast.06-13-2013
20140006514DISTRIBUTION OF XML DOCUMENTS/MESSAGES TO XML APPLIANCES/ROUTERS01-02-2014
20140105001Distributed Failure Recovery in a Routed Ethernet Network - Link identifiers such as VIDs, selected from a defined range of values, are locally assigned by each node on a link state protocol controlled Ethernet network to each of its links or adjacencies. The link identifiers are assigned by the nodes such that each link or adjacency at the node is uniquely identified by a different link identifier. A link state protocol adjacency notification mechanism or other flooding mechanism is used to disseminate the locally assigned link identifiers to other nodes on the link state protocol controlled Ethernet network. The link identifiers are added by the nodes to their topology databases to enable detour routes to be locally calculated by the nodes on the network in a distributed manner. Upon occurrence of a failure, the link identifiers are used to source route traffic around the failure so that traffic may continue to traverse the link state protocol controlled Ethernet network.04-17-2014
20140140243METHOD AND APPARATUS FOR LAYER 2 FAST RE-CONFIGURATION IN A ROUTING BRIDGE NETWORK - A method and apparatus in provided which enables fast layer 2 reconfiguration in a network that includes Routing Bridges. Each Routing Bridge stores, for each forwarding target, identifiers of a primary next Rbridge and an alternate next Rbridge. The forwarding target may be a network end node, or an Egress Rbridge associated with the network end node. In response to a trigger condition, layer 2 communications are selectively switched from a path that includes the primary next Rbridge device to a path that includes the alternate next Rbridge device.05-22-2014
20140146825IMPLEMENTING MULTIPLE PORTALS INTO AN RBRIDGE NETWORK - Shortest-path spanning trees are created outward from each portal on a Rbridge network with nodes on the network being assigned to the spanning trees. For those nodes equidistant to two portals, an election process is used to determine which tree the node should join. To enable routes associated with nodes on the Rbridge network to be distinguished from routes external to the Rbridge network, messages may be transmitted between the portals. The messages enable portals to identify routing updates received from the external network as containing internal routes, so that traffic that is required to pass between nodes on different trees may pass over the Rbridge network rather than over the external network.05-29-2014
20140153382METHOD AND APPARATUS FOR IMPLEMENTING CONTROL OF MULTIPLE PHYSICALLY DUAL HOMED DEVICES - A ring control protocol is used to establish a separate control plane for a plurality of physically dual homed devices to enable collections of dual homed devices to be represented by a single pair of addresses into the attached routed Ethernet network. The gateway devices analyze the passing ring control packets to create direct mappings for data packets to the routed Ethernet network. Thus, although the dual homed devices are treated as a ring from a control perspective, the data path is implemented to be direct so that data packets continue to flow directly from the dual homed devices to each of the attached gateway devices. In one embodiment, each of the gateway devices implements a virtual switch and advertises the MAC address of the virtual switch into the routed Ethernet network rather than the MAC addresses of each of the attached Ethernet Switch Units.06-05-2014
20140153579Distributed Storage of Routing Information in a Link State Protocol Controlled Network - A distributed hash table is implemented to store routing information on a network. Node IDs exchanged in connection with implementation of a link state routing protocol are used as keys in the distributed hash table, and routes are stored at one or more nodes on the network. When a route is learned, the route is processed against the set of keys to determine which nodes should store the route. When a route is needed, the route is processed against the set of keys to determine which nodes should have the route information. The manner in which the route is processed against the set of keys is the same in both instances, so that the DHT may be used to store and retrieve route information on the network. The DHT may be implemented to store MAC addresses, IP addresses, MPLS labels, or other information.06-05-2014
20140301244Method and Apparatus for Exchanging Routing Information and the Establishment of Connectivity Across Multiple Network Areas - Routes may be installed across multiple link state protocol controlled Ethernet network areas by causing ABBs to leak I-SID information advertised by BEBs in a L1 network area into an L2 network area. ABBs will only leak I-SIDs for BEBs where it is the closest ABB for that BEB. Where another ABB on the L2 network also leaks the same I-SID into the L2 network area from another L1 network area, the I-SID is of multi-area interest. ABBs will advertise I-SIDs that are common to the L1 and L2 networks back into their respective L1 network. Within each L1 and L2 network area, forwarding state will be installed between network elements advertising common interest in an ISID, so that multi-area paths may be created to span the L1/L2/L1 network areas. The L1/L2/L1 network structure may recurse an arbitrary number of times.10-09-2014
20140365562DISTRIBUTION OF XML DOCUMENTS/MESSAGES TO XML APPLIANCES/ROUTERS - XML appliances/routers may be organized to implement one or more XML distribution rings to enable XML documents/messages to be distributed efficiently. The rings may be logical or physical. The XML distribution rings enable the XML documents/messages to be exchanged without requiring the XML appliances/routers to run a routing protocol to determine how XML documents/messages should be distributed through the network. Documents may be transmitted in one way on the ring or may be transmitted in both directions around the ring to enable the ring to tolerate failure of an XML appliance/router. Each XML appliance/router will receive all XML documents/messages and will make routing decisions for those clients that have provided the XML appliance/router with XML subscriptions. The subscriptions may be formed according to the XPath standard or in another manner.12-11-2014

Patent applications by Peter Ashwood-Smith, Hull CA

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