Patents by Inventor Zhuangbo Tang

Zhuangbo Tang 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).

  • Patent number: 7948899
    Abstract: This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: May 24, 2011
    Assignee: AT&T Intellectual Property II, LP
    Inventors: Angela L. Chiu, Seyhan Civanlar, Leonard L. Lu, Zhuangbo Tang
  • Patent number: 7792054
    Abstract: This invention provides a tool for reliability evaluation and performance analysis of an IP backbone network by using the network packet loss ratio as the main measurement. A queuing model and algorithm is presented for calculating packet loss at congested interfaces or links. A reliability model is presented for considering network hardware component failures such as router failures, ATM switch failures, and physical link failures. Based on the measurement and models presented, a network reliability and performance (NetRAP) apparatus calculates IP network reliability and performance measurements. The NetRAP apparatus uses the network topology, a traffic matrix, and the reliability parameters of a network as inputs and calculates the network packet loss ratio and sigma score, and provides a list of heavily congested links under non-failure or different single failure conditions.
    Type: Grant
    Filed: May 7, 2004
    Date of Patent: September 7, 2010
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Leonard L. Lu, David A. Hoeflin, Zhuangbo Tang
  • Patent number: 7778182
    Abstract: This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
    Type: Grant
    Filed: August 26, 2005
    Date of Patent: August 17, 2010
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Angela L. Chiu, Seyhan Civanlar, Leonard L. Lu, Zhuangbo Tang
  • Publication number: 20100091656
    Abstract: This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
    Type: Application
    Filed: December 11, 2009
    Publication date: April 15, 2010
    Inventors: Angela L. Chiu, Seyhan Civanlar, Leonard L. Lu, Zhuangbo Tang
  • Patent number: 7230924
    Abstract: This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: June 12, 2007
    Assignee: AT&T Corp.
    Inventors: Angela L. Chiu, Seyhan Civanlar, Leonard L. Lu, Zhuangbo Tang
  • Patent number: 6999420
    Abstract: An architecture, design, and realization for providing Quality of Service (QoS) to Internet Protocol (IP) networks based on a three-class differentiated service scheme where the service provider uses a resource management system and a schedule optimizer to enable the optimal use of bandwidth and buffer resources at each node along the various links between the ingress and egress points in a network. The resource reservation system checks to determine whether sufficient bandwidth resources are available along the path requested by the customer for a particular class. The schedule optimizer ensures that sufficient buffer resource allocations and parameter settings are made to optimally reach the predetermined QoS criteria for each of the three classes. The system also contains a mechanism supporting resource reservations providing additional resources along alternative paths if the selected path links fail in the network.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: February 14, 2006
    Assignee: AT & T Corp.
    Inventors: Angela L. Chiu, Seyhan Civanlar, Albert Gordon Greenberg, Zhuangbo Tang
  • Publication number: 20060018256
    Abstract: This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
    Type: Application
    Filed: August 26, 2005
    Publication date: January 26, 2006
    Inventors: Angela Chiu, Seyhan Civanlar, Leonard Lu, Zhuangbo Tang
  • Patent number: 6973033
    Abstract: An architecture, design, and realization for providing Quality of Service (QoS) to Internet Protocol (IP) networks based on a three-class differentiated service scheme where the service provider uses a resource management system and a schedule optimizer to enable the optimal use of bandwidth and buffer resources at each node or router along the various links between the ingress and egress points in a network. The resource reservation system checks to determine if sufficient bandwidth resources are available along the path requested by the customer for a particular class. The schedule optimizer ensures that sufficient buffer resource allocations and parameter settings are made to optimally reach the predetermined QoS criteria for each of the three classes. The system also contains a mechanism supporting resource reservations providing additional resources along alternative paths if the selected path links fail in the network.
    Type: Grant
    Filed: March 23, 2004
    Date of Patent: December 6, 2005
    Assignee: AT&T Corp.
    Inventors: Angela L. Chiu, Seyhan Civanlar, Albert Gordon Greenberg, Zhuangbo Tang
  • Publication number: 20040208128
    Abstract: This invention provides a tool for reliability evaluation and performance analysis of an IP backbone network by using the network packet loss ratio as the main measurement. A queuing model and algorithm is presented for calculating packet loss at congested interfaces or links. A reliability model is presented for considering network hardware component failures such as router failures, ATM switch failures, and physical link failures. Based on the measurement and models presented, a network reliability and performance (NetRAP) apparatus determining the IP network reliability and performance analysis. The NetRAP apparatus uses the network topology, a traffic matrix, and the reliability parameters of a network as inputs and calculates the network packet loss ratio and sigma score, and provides a list of heavily congested links under non-failure or different single failure conditions.
    Type: Application
    Filed: May 7, 2004
    Publication date: October 21, 2004
    Inventors: Leonard L. Lu, David A. Hoeflin, Zhuangbo Tang
  • Patent number: 6754843
    Abstract: This invention provides a tool for reliability evaluation and performance analysis of an IP backbone network by using the network packet loss ratio as the main measurement. A queuing model and algorithm is presented for calculating packet loss at congested interfaces or links. A reliability model is presented for considering network hardware component failures such as router failures, ATM switch failures, and physical link failures. Based on the measurement and models presented, a network reliability and performance (NetRAP) apparatus calculates IP network reliability and performance measurements. The NetRAP apparatus uses the network topology, a traffic matrix, and the reliability parameters of a network as inputs and calculates the network packet loss ratio and sigma score, and provides a list of heavily congested links under non-failure or different single failure conditions.
    Type: Grant
    Filed: June 13, 2000
    Date of Patent: June 22, 2004
    Assignee: AT&T Corp.
    Inventors: Leonard L. Lu, David A. Hoeflin, Zhuangbo Tang
  • Patent number: 6744767
    Abstract: An architecture, design, and realization for providing Quality of Service (QoS) to Internet Protocol (IP) networks based on a three-class differentiated service scheme where the service provider uses a resource management system and a schedule optimizer to enable the optimal use of bandwidth and buffer resources at each node or router along the various links between the ingress and egress points in a network. The resource reservation system checks to determine if sufficient bandwidth resources are available along the path requested by the customer for a particular class. The schedule optimizer ensures that sufficient buffer resource allocations and parameter settings are made to optimally reach the predetermined QoS criteria for each of the three classes. The system also contains a mechanism supporting resource reservations providing additional resources along alternative paths if the selected path links fail in the network.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: June 1, 2004
    Assignee: AT&T Corp.
    Inventors: Angela L. Chiu, Seyhan Civanlar, Albert Gordon Greenberg, Zhuangbo Tang
  • Publication number: 20020186658
    Abstract: This invention provides for a technique for selectively off-loading traffic from congested sub-regions of a network to more lightly-loaded regions by making use of Multiprotocol Label Switching (MPLS). For each network element, an Interior Gateway Protocol (IGP) routing is employed to provide re-routing and to identify congested links caused by re-routed trunks for each single failure. The re-routed traffic is then analyzed and alternate Label Switched Paths (LSPs) are identified for such traffic trunks so that the traffic is directed to the alternate LSPs during the single failure event.
    Type: Application
    Filed: March 28, 2001
    Publication date: December 12, 2002
    Inventors: Angela L. Chiu, Seyhan Civanlar, Leonard L. Lu, Zhuangbo Tang