Patents by Inventor Stefano Previdi

Stefano Previdi 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: 11677657
    Abstract: A method and an apparatus for obtaining information about a forwarding path of a data packet in segment routing (SR) include, when a first path indicated by a plurality of path identifiers in initial information is a unique shortest path from a start node on the first path to an end node on the first path, the first path is indicated using a node-segment identifier (SID) of the end node on the first path instead of the path identifiers.
    Type: Grant
    Filed: January 11, 2021
    Date of Patent: June 13, 2023
    Assignee: HUAWEI TECHNOLOGIES CO., LTD.
    Inventors: Cheng Li, Stefano Previdi, Guoyi Chen
  • Publication number: 20210135979
    Abstract: A method and an apparatus for obtaining information about a forwarding path of a data packet in segment routing (SR) include, when a first path indicated by a plurality of path identifiers in initial information is a unique shortest path from a start node on the first path to an end node on the first path, the first path is indicated using a node-segment identifier (SID) of the end node on the first path instead of the path identifiers.
    Type: Application
    Filed: January 11, 2021
    Publication date: May 6, 2021
    Inventors: Cheng Li, Stefano Previdi, Guoyi Chen
  • Patent number: 9515916
    Abstract: In one embodiment, a first network device may receive a request for an identifier of at least one target to service a client. The first network device may obtain an identifier of each of two or more targets. The first network device may then determine whether to redirect the request. The first network device may redirect the request to a second network device according to a result of the determining step, where the first network device is in a first autonomous system and the second network device is in a second autonomous system.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: December 6, 2016
    Assignee: CISCO TECHNOLOGY, INC.
    Inventors: Zhunian Zhang, Steven V. Luong, Manish Bhardwaj, Stefano Previdi
  • Patent number: 9419845
    Abstract: In one embodiment, a client device queries a location server using a client-selected interface for content retrieval from a content distribution network (CDN), and receives a location attribute from the location server based on a location of the client device. The client device then presents the location attribute to a CDN selector within a first content retrieval request, and may receive a redirection from the CDN selector to a selected content source based on the location attribute. As such, the client device may then initiate a second content retrieval request to the selected content source. In another embodiment, a CDN selector receives a content retrieval request from a client device, and determines that the content retrieval request contains a location attribute indicating a location of the client device. Based on the location attribute, the CDN selector selects a content source, and redirects the client device to the selected content source.
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: August 16, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Warren Scott Wainner, Aeneas Dodd-Noble, Mahesh Vittal Viveganandhan, Stefano Previdi
  • Patent number: 9300564
    Abstract: In one embodiment, a stateful path computation element (PCE) in a computer network determines a need to route at least a threshold number of tunnels, and in response, triggers a routing update from a determined set of routers. Having updated the routing information and available network resources for the set of routers, the stateful PCE may then compute the tunnels based on the update.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: March 29, 2016
    Assignee: Cisco Technology, Inc.
    Inventors: Stefano Previdi, Jean-Philippe Vasseur, David Ward
  • Patent number: 9225640
    Abstract: In one embodiment, a method includes receiving, by a first autonomous system border router (ASBR) of a first autonomous system (AS), a first plurality of provider-provisioned media access control (B-MAC) addresses via Interior Border Gateway Protocol (I-BGP). Each of first plurality of B-MAC addresses is associated with a provider edge (PE) device of the first AS. The first ASBR sends the first plurality of B-MAC addresses to a second ASBR of a second AS using Exterior Border Gateway Protocol (E-BGP). The first ASBR also receives via E-BGP a second plurality of B-MAC addresses each of which is associated with a PE device of the second AS. The first ASBR then distributes the second plurality of B-MAC addresses to each of the PE devices of the first AS using I-BGP.
    Type: Grant
    Filed: September 6, 2013
    Date of Patent: December 29, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Ali Sajassi, Keyur Patel, Chandrashekhar Appanna, Stefano Previdi
  • Patent number: 9197508
    Abstract: In one embodiment, a path computation element (PCE) in a computer network receives one or more path computation requests (PCReqs), and records a time of each PCReq and the corresponding requested bandwidth. Based on this information, the PCE may determine a traffic profile of the computer network, and may augment a traffic engineering database (TED) with requested bandwidth according to time based on the traffic profile. As such, prior to a particular time, the PCE may determine placement of tunnels within the traffic profile for the particular time.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: November 24, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Stefano Previdi, Clarence Filsfils, George Swallow
  • Patent number: 9185022
    Abstract: In one embodiment, a device (e.g., a path computation element, PCE) monitors a tunnel set-up failure rate within a computer network, and determines whether to adjust an accuracy of routing information based on the tunnel set-up failure rate. For instance, the tunnel set-up failure rate being above a first threshold indicates a need for greater accuracy. In response to the tunnel set-up failure rate being above the first threshold, the device may then instruct one or more routers to shorten their routing update interval in the computer network.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: November 10, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Stefano Previdi, Clarence Filsfils
  • Patent number: 9178796
    Abstract: In one embodiment, a stateful computing entity in a computer network determines underlying network information (physical and/or optical) for the computer network, and also determines topologies (Internet Protocol (IP) and/or Multiprotocol Label Switching (MPLS)) for the computer network and associated resource information. Further, the stateful computing entity determines label switched path (LSP) state information for the computer network. The stateful computing entity may then build network state knowledge by aggregating the underlying network information, the topologies and associated resource information, and the LSP state information, and establishes communication within a dynamic network of other stateful computing entities sharing network state knowledge for parallel computation performance. Accordingly, the stateful computing entity may perform network computation based on the network state knowledge.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: November 3, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Stefano Previdi, Jean-Philippe Vasseur, Jan Medved, David Ward, Clarence Filsfils, Christopher Metz
  • Patent number: 9130863
    Abstract: In one embodiment, a particular field area router (FAR), in a local computer network (e.g., a mesh network) having a plurality of FARs, advertises a common subnet prefix assigned to the local computer network into a global computer network. Each of the plurality of FARs of the local computer network is configured to accept any traffic destined to the local computer network, and a tunnel overlay is built among the plurality of FARs. Upon receiving a packet at the particular FAR destined to a particular device in the local computer network, and in response to the particular FAR not having a host route to the particular device, it forwards the packet on the tunnel overlay to another of the plurality of FARs of the local computer network.
    Type: Grant
    Filed: June 23, 2014
    Date of Patent: September 8, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Jonathan W. Hui, Stefano Previdi, Shmuel Shaffer
  • Patent number: 9077615
    Abstract: In one embodiment, a router initiates reroutes of one or more tunnels at the router as part of optimization of a plurality of tunnels in a computer network, and stores an original state of the one or more tunnels at the router prior to the optimization. By detecting whether path computation element (PCE) failure occurs prior to completion of the optimization, the router may revert to the original state of the one or more tunnels in response to PCE failure prior to completion of the optimization.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: July 7, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Stefano Previdi, David Ward, George Swallow
  • Patent number: 9065750
    Abstract: In one embodiment, once activation of use of a backup tunnel is detected for a primary tunnel, then a level of congestion of the path of the backup tunnel may be determined. In response to the level being greater than a threshold, a head-end node of the primary tunnel is triggered to reroute the primary tunnel (e.g., requesting to a path computation element). Conversely, in response to the level not being greater than the threshold, the backup tunnel is allowed to remain activated.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: June 23, 2015
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Stefano Previdi, Clarence Filsfils
  • Publication number: 20150006615
    Abstract: In one embodiment, a client device queries a location server using a client-selected interface for content retrieval from a content distribution network (CDN), and receives a location attribute from the location server based on a location of the client device. The client device then presents the location attribute to a CDN selector within a first content retrieval request, and may receive a redirection from the CDN selector to a selected content source based on the location attribute. As such, the client device may then initiate a second content retrieval request to the selected content source. In another embodiment, a CDN selector receives a content retrieval request from a client device, and determines that the content retrieval request contains a location attribute indicating a location of the client device. Based on the location attribute, the CDN selector selects a content source, and redirects the client device to the selected content source.
    Type: Application
    Filed: June 27, 2013
    Publication date: January 1, 2015
    Inventors: Warren Scott Wainner, Aeneas Dodd-Noble, Mahesh Vittal, Stefano Previdi
  • Publication number: 20150003283
    Abstract: In one embodiment, a stateful computing entity in a computer network determines underlying network information (physical and/or optical) for the computer network, and also determines topologies (Internet Protocol (IP) and/or Multiprotocol Label Switching (MPLS)) for the computer network and associated resource information. Further, the stateful computing entity determines label switched path (LSP) state information for the computer network. The stateful computing entity may then build network state knowledge by aggregating the underlying network information, the topologies and associated resource information, and the LSP state information, and establishes communication within a dynamic network of other stateful computing entities sharing network state knowledge for parallel computation performance. Accordingly, the stateful computing entity may perform network computation based on the network state knowledge.
    Type: Application
    Filed: June 28, 2013
    Publication date: January 1, 2015
    Inventors: Stefano Previdi, Jean-Philippe Vasseur, Jan Medved, David Ward, Clarence Filsfils, Christopher Metz
  • Patent number: 8879429
    Abstract: Various techniques for exchanging control messages in order to gracefully reroute multicast traffic are disclosed. For example, one method involves sending a join message for a multicast group towards a root of a new multicast tree and forwarding multicast traffic, addressed to the multicast group, on a current multicast tree until an acknowledgment corresponding to the join message is received. The new multicast tree can be identified in response to detection of a topology change within the network. Until the acknowledgment is received, multicast traffic that is received via the new multicast tree can be dropped.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: November 4, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Stefano Previdi, Dino Farinacci, Ijsbrand Wijnands, Arjen Boers
  • Publication number: 20140304427
    Abstract: In one embodiment, a particular field area router (FAR), in a local computer network (e.g., a mesh network) having a plurality of FARs, advertises a common subnet prefix assigned to the local computer network into a global computer network. Each of the plurality of FARs of the local computer network is configured to accept any traffic destined to the local computer network, and a tunnel overlay is built among the plurality of FARs. Upon receiving a packet at the particular FAR destined to a particular device in the local computer network, and in response to the particular FAR not having a host route to the particular device, it forwards the packet on the tunnel overlay to another of the plurality of FARs of the local computer network.
    Type: Application
    Filed: June 23, 2014
    Publication date: October 9, 2014
    Applicant: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Jonathan W. Hui, Stefano Previdi, Shmuel Shaffer
  • Patent number: 8855014
    Abstract: In one embodiment, a particular device in a computer network maintains a locally owned tunnel-state table, and joins a distributed hash table (DHT) ring. In addition, the locally owned tunnel-state table is shared with other devices of the DHT ring to establish a DHT-owned tunnel-state table. The particular device (and other devices) determines ownership of link-state advertisements (LSAs) for a specific portion of a traffic engineering database (TED) according to the DHT ring. As such, when the particular device (or any device) computes a path for a tunnel using a local TED, the particular device may request permission to use resources along the computed path that were advertised in particular LSAs from owners of those particular LSAs when not owned by the particular device.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: October 7, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Stefano Previdi, Jean-Philippe Vasseur, Jan Medved, David Ward
  • Patent number: 8817591
    Abstract: In one embodiment, a router in a non-originating domain receives a signal to establish a tunnel, the signal having an identification (ID) of an originating path computation element (PCE) of an originating domain from where the signal to establish the tunnel originated. In response to determining that establishment of the tunnel fails, the router may signal the failure of the establishment to a local PCE of the non-originating domain, the signaling indicating the ID of the originating PCE to cause the local PCE to provide updated routing information of the non-originating domain to the originating PCE.
    Type: Grant
    Filed: June 15, 2012
    Date of Patent: August 26, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Stefano Previdi
  • Patent number: 8799510
    Abstract: In one embodiment, a particular field area router (FAR), in a local computer network (e.g., a mesh network) having a plurality of FARs, advertises a common subnet prefix assigned to the local computer network into a global computer network. Each of the plurality of FARs of the local computer network is configured to accept any traffic destined to the local computer network, and a tunnel overlay is built among the plurality of FARs. Upon receiving a packet at the particular FAR destined to a particular device in the local computer network, and in response to the particular FAR not having a host route to the particular device, it forwards the packet on the tunnel overlay to another of the plurality of FARs of the local computer network.
    Type: Grant
    Filed: July 5, 2011
    Date of Patent: August 5, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Jean-Philippe Vasseur, Jonathan W. Hui, Stefano Previdi, Shmuel Shaffer
  • Publication number: 20140010232
    Abstract: In one embodiment, a method includes receiving, by a first autonomous system border router (ASBR) of a first autonomous system (AS), a first plurality of provider-provisioned media access control (B-MAC) addresses via Interior Border Gateway Protocol (I-BGP). Each of first plurality of B-MAC addresses is associated with a provider edge (PE) device of the first AS. The first ASBR sends the first plurality of B-MAC addresses to a second ASBR of a second AS using Exterior Border Gateway Protocol (E-BGP). The first ASBR also receives via E-BGP a second plurality of B-MAC addresses each of which is associated with a PE device of the second AS. The first ASBR then distributes the second plurality of B-MAC addresses to each of the PE devices of the first AS using I-BGP.
    Type: Application
    Filed: September 6, 2013
    Publication date: January 9, 2014
    Inventors: Ali Sajassi, Keyur Patel, Chandrashekhar Appanna, Stefano Previdi