Patents by Inventor Mark A. W. Stewart
Mark A. W. Stewart has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7324452Abstract: A system for managing data transmission from a number of queues employs a regular credit count and a history credit count for each queue. Generally, the regular credit count is used in arbitration. The count is decreased when data is transmitted from the queue and increased at given intervals if the queue is facing no transmission-blocking backpressure. The history credit count is increased in lieu of the regular credit count when transmission from the queue is blocked. Thus, the history credit count keeps track of potential transmission opportunities that would be lost due to the blocking of transmission from the queue. The history credit counts are periodically polled instead of the regular credit counts to give each queue an opportunity to catch up in its use of transmission opportunities.Type: GrantFiled: January 14, 2002Date of Patent: January 29, 2008Assignee: Fujitsu LimitedInventors: Hong Xu, Mark A. W. Stewart
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Patent number: 7042839Abstract: A scalable protection method for connection oriented networks includes a source, a destination, and primary nodes interconnected by working path segments between the source and destination. A point-to-multipoint connection with multiple destinations and additional primary nodes is also supported. Each of a number of backup nodes is interconnected with an associated primary node by pre-provisioned shunt segments, and the backup nodes are interconnected among themselves by pre-provisioned protection path segments. Upon occurrence of a failure, the primary node upstream of the failure directs input traffic to a shunt segment, and the backup node associated with the upstream primary node directs traffic from the shunt segment to an output protection segment. Downstream of the failure, a backup node directs traffic from an input protection segment to a shunt segment, and the primary node associated with the backup node directs the traffic from the shunt segment to a downstream working segment.Type: GrantFiled: February 7, 2002Date of Patent: May 9, 2006Assignee: Fujitsu LimitedInventors: Mark A. W. Stewart, David Peck
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Patent number: 7042850Abstract: A network router generates node state advertisements identifying network links about which the router node desires to receive link state information. The node state advertisements are flooded to other routers, each of which determines whether it lies along the shortest path between the link and the originating router. Each router that lies along the shortest path maintains an association between the link and the originating router, the association indicating that link state advertisements concerning the link are to be forwarded along the path toward the originating router. Upon a change of the state of the link, each router forwards a corresponding link state advertisement to an adjacent node along the path, whereby the originating router ultimately receives the link-state advertisement.Type: GrantFiled: November 9, 2001Date of Patent: May 9, 2006Assignee: Fujitsu LimitedInventor: Mark A. W. Stewart
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Patent number: 6862288Abstract: A highly available communications system capable of circuit reestablishment and tear-down without manual intervention. The communications system includes a plurality of nodes interconnected by a plurality of communications paths to form at least one communications network. The nodes forward control packets on the network by way of a signaling protocol employing an out-of-band control technique. At least a portion of the nodes comprises a software configuration including a topology manager and a protocol manager. The protocol manager is operative to determine whether a control path is operational and whether a data transmission channel along a corresponding data path is established. In the event the control path is not operational, the protocol manager maintains the data transmission channel along the data path so long as the channel is established.Type: GrantFiled: January 16, 2001Date of Patent: March 1, 2005Assignee: Fujitsu Network Communications, Inc.Inventors: Shantnu Sharma, Peter W. Bretschneider, Robert H. Constantin, Mark A. W. Stewart, Sajin R. Valoth, Mashood Illikkal
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Patent number: 6801545Abstract: A method and system for forwarding packets within containers in a data communication network. Each container may include packets or additional containers. Packets/containers are stored within containers in a predetermined format that includes a Type field, a Length field and a Value field. The Type field includes an indication whether the respective packet/container is the last packet/container in the respective sequence. The Length field specifies the Length of the following Value field and the Value field comprises the payload, which may comprise additional packets or containers. A header, such as an MPLS shim header, is applied to containers to be transmitted over the network. Containers are closed and scheduled for transmission once when it is determined that the addition of a packet/container to the overall container would exceed a predetermined maximum container size or when a timer measures a predetermined time period from the arrival of the first packet within the container.Type: GrantFiled: February 4, 2002Date of Patent: October 5, 2004Assignee: Fujitsu Network Communications, Inc.Inventor: Mark A. W. Stewart
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Patent number: 6687651Abstract: An apparatus and method for generating via integer calculations a metric for estimating link utilization within a network device having at least one output port. The metric is determined by calculating at least three data rate link parameters for a given sampling period. The data rate link parameters include an error data rate parameter, an average data rate parameter, and a deviation data rate parameter. These parameters are determined using integer values and integer operations and may be used by a link management system for performing load balancing among a plurality of output ports and for determining whether to forward low priority data traffic via a particular output port.Type: GrantFiled: January 10, 2002Date of Patent: February 3, 2004Assignee: Fujitsu Network Communications, Inc.Inventor: Mark A. W. Stewart
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Publication number: 20030147344Abstract: A scalable protection method for connection oriented networks includes a source, a destination, and primary nodes interconnected by working path segments between the source and destination. A point-to-multipoint connection with multiple destinations and additional primary nodes is also supported. Each of a number of backup nodes is interconnected with an associated primary node by pre-provisioned shunt segments, and the backup nodes are interconnected among themselves by pre-provisioned protection path segments. Upon occurrence of a failure, the primary node upstream of the failure directs input traffic to a shunt segment, and the backup node associated with the upstream primary node directs traffic from the shunt segment to an output protection segment. Downstream of the failure, a backup node directs traffic from an input protection segment to a shunt segment, and the primary node associated with the backup node directs the traffic from the shunt segment to a downstream working segment.Type: ApplicationFiled: February 7, 2002Publication date: August 7, 2003Inventors: Mark A. W. Stewart, David Peck
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Publication number: 20030147393Abstract: A method and system for forwarding packets within containers in a data communication network. Each container may include packets or additional containers. Packets/containers are stored within containers in a predetermined format that includes a Type field, a Length field and a Value field. The Type field includes an indication whether the respective packet/container is the last packet/container in the respective sequence. The Length field specifies the Length of the following Value field and the Value field comprises the payload, which may comprise additional packets or containers. A header, such as an MPLS shim header, is applied to containers to be transmitted over the network. Containers are closed and scheduled for transmission once when it is determined that the addition of a packet/container to the overall container would exceed a predetermined maximum container size or when a timer measures a predetermined time period from the arrival of the first packet within the container.Type: ApplicationFiled: February 4, 2002Publication date: August 7, 2003Inventor: Mark A. W. Stewart
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Publication number: 20030135449Abstract: A system for managing data transmission from a number of queues employs a regular credit count and a history credit count for each queue. Generally, the regular credit count is used in arbitration. The count is decreased when data is transmitted from the queue and increased at given intervals if the queue is facing no transmission-blocking backpressure. The history credit count is increased in lieu of the regular credit count when transmission from the queue is blocked. Thus, the history credit count keeps track of potential transmission opportunities that would be lost due to the blocking of transmission from the queue. The history credit counts are periodically polled instead of the regular credit counts to give each queue an opportunity to catch up in its use of transmission opportunities.Type: ApplicationFiled: January 14, 2002Publication date: July 17, 2003Inventors: Hong Xu, Mark A. W. Stewart
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Publication number: 20020093961Abstract: A highly available communications system capable of circuit reestablishment and tear-down without manual intervention. The communications system includes a plurality of nodes interconnected by a plurality of communications paths to form at least one communications network. The nodes forward control packets on the network by way of a signaling protocol employing an out-of-band control technique. At least a portion of the nodes comprises a software configuration including a topology manager and a protocol manager. The protocol manager is operative to determine whether a control path is operational and whether a data transmission channel along a corresponding data path is established. In the event the control path is not operational, the protocol manager maintains the data transmission channel along the data path so long as the channel is established.Type: ApplicationFiled: January 16, 2001Publication date: July 18, 2002Inventors: Shantnu Sharma, Peter W. Bretschneider, Robert H. Constantin, Mark A. W. Stewart, Sajin R. Valoth, Mashood Illikkal