Patents by Inventor Kent K. Leung

Kent K. Leung 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).

  • Publication number: 20110007742
    Abstract: Providing a mobility key for a communication session for a mobile station includes facilitating initiation of the communication session. A master key for the communication session is established, where the master key is generated at an authentication server in response to authenticating the mobile station. A mobility key is derived from the authentication key at an access node, where the mobility key is operable to authenticate mobility signaling for the communication session.
    Type: Application
    Filed: September 20, 2010
    Publication date: January 13, 2011
    Applicant: Cisco Technology, Inc.
    Inventors: Kent K. Leung, Jayaraman R. Iyer, Viren K. Malaviya
  • Patent number: 7870389
    Abstract: Methods and apparatus for generating and transmitting dynamically generated session keys are disclosed. A key distribution center generates a session key between the key distribution center and a first mobility entity (e.g., an access point). Once the session key between the key distribution center and the access point is transmitted to the access point, the access point retrieves a shared session key between the access point and a Mobile Node from the key distribution center, which is then transmitted to the Mobile Node, enabling the Mobile Node to connect to the network. Similarly, either the Mobile Node or its Home Agent retrieves a session key between the key distribution center and the access point from the key distribution center, enabling a shared session key between the Home Agent and the Mobile Node to be obtained from the key distribution center. The Mobile Node (or Home Agent) then transmits the shared session key to the Home Agent (or Mobile Node).
    Type: Grant
    Filed: December 24, 2002
    Date of Patent: January 11, 2011
    Assignee: Cisco Technology, Inc.
    Inventors: Kent K. Leung, Srinath Gundavelli
  • Patent number: 7817664
    Abstract: In one embodiment, accounting information for a mobile node operating according to Mobile IP Protocol is updated. A network device that supports Mobile IP composes a request packet for the mobile node. The request packet identifies the mobile node and includes at least one counter associated with accounting information pertaining to the mobile node. The request packet is then sent to a server adapted for performing accounting. The server then logs the accounting information for the mobile node. The server may then send a reply packet to the network device acknowledging logging of the accounting information pertaining to the mobile node. A bill for Mobile IP services may then be generated from the accounting information.
    Type: Grant
    Filed: November 10, 2006
    Date of Patent: October 19, 2010
    Assignee: Cisco Technology, Inc.
    Inventor: Kent K. Leung
  • Patent number: 7813511
    Abstract: Providing a mobility key for a communication session for a mobile station includes facilitating initiation of the communication session. A master key for the communication session is established, where the master key is generated at an authentication server in response to authenticating the mobile station. A mobility key is derived from the authentication key at an access node, where the mobility key is operable to authenticate mobility signaling for the communication session.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: October 12, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Kent K. Leung, Jayaraman R. Iyer, Viren K. Malaviya
  • Patent number: 7787414
    Abstract: Requesting a network resource includes facilitating a communication session between a mobile node and an endpoint. A trigger event is received at a first anchor point associated with the mobile node. The trigger event indicates that reservation of a network resource is being requested for the communication session. A second anchor point associated with the endpoint is identified. Reservation of the network resources for the communication sessions is initiated over a tunnel between the first anchor point and the second anchor point.
    Type: Grant
    Filed: July 12, 2005
    Date of Patent: August 31, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Francois L. Le Faucheur, Kent K. Leung, Jayaraman R. Iyer, Viren K. Malaviya, Anand K. Oswal, David P. Lindert
  • Patent number: 7746874
    Abstract: Methods and apparatus for implementing a Home Agent supporting Mobile IP and being capable of allocating one or more networks to a mobile router which registers with the Home Agent comprise receiving a registration request packet from the mobile router, the registration request packet indicating one or more networks being requested by the mobile router from the Home Agent. The one or more networks are allocated to the mobile router corresponding to the one or more networks being requested by the mobile router from the Home Agent. A registration reply packet identifying the one or more networks allocated to the mobile router is then sent to the mobile router.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: June 29, 2010
    Assignee: Cisco Technology, Inc.
    Inventor: Kent K. Leung
  • Patent number: 7729314
    Abstract: Methods and apparatus for preventing an IP address from being assigned to a client implementing a protocol such as DHCP are disclosed. This is particularly useful in an environment such as a Mobile IP environment in which a network device (e.g., Access Point) performs proxy registration on behalf of the client. When the client transmits a detection packet to detect whether its IP address is still valid (e.g., whether it is on the same sub-network on which the IP address was allocated), a response is transmitted to the client that indicates that the client is still on its home network. This response is transmitted regardless of whether the client is still on its home network. Since the client believes it is still on its home network, a new IP address will not be assigned to the client. As a result, an existing Mobile IP session will not be interrupted.
    Type: Grant
    Filed: October 24, 2005
    Date of Patent: June 1, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Waseem Siddiqi, Bruce A. McMurdo, Kent K. Leung
  • Publication number: 20100088400
    Abstract: A method is provided in one example implementation and the method includes identifying through a home bearer manager that an Internet Protocol (IP) address has been previously sent to an access terminal, the IP address being issued by a visited bearer manager as a result of the access terminal requesting registration in a visited network. The method further includes communicating the IP address to the access terminal in response to the access terminal registering in a home network. The registrations in the home and the visited network allow a plurality of packets to be communicated to the access terminal via the IP address. In more specific embodiments, the IP address serves as a care of address (CoA) address and a home IP address concurrently. The IP address can be exchanged via a mobile IP (MIP) exchange. The home and visited bearer managers are independent or interdependent.
    Type: Application
    Filed: October 3, 2008
    Publication date: April 8, 2010
    Inventors: Flemming S. Andreasen, Kent K. Leung
  • Patent number: 7684794
    Abstract: Performing management operations for a mobile node present in a foreign network includes performing an address management operation and a mobility management operation. The address management operation includes receiving an address request message at a home address server of a home network of the mobile node, assigning a fixed home address to the mobile node, and sending an address acknowledgment message communicating the fixed home address. The mobility management operation includes receiving a registration request message requesting registration for the mobile node, and registering the mobile node in response to the registration request message.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: March 23, 2010
    Assignee: Cisco Technologies, Inc.
    Inventors: Kent K. Leung, Milind M. Kulkarni, Jayaraman R. Iyer
  • Patent number: 7668174
    Abstract: The present invention provides methods and apparatus for managing an IP address assigned to a Mobile Node. In one embodiment, the Mobile Node appends an extension to the registration request that is sent to its Home Agent, which indicates that the Mobile Node requests use of the IP address previously assigned to the Mobile Node for an additional period of time. When the Home Agent receives the registration request, it indicates whether a lease on the IP address previously assigned to the Mobile Node has been granted by the Home Agent for an additional period of time. In another embodiment, the Home Agent sends a first control message to determine whether the Mobile Node continues to use the IP address. The Home Agent then determines whether a second control message has been received in order to ascertain whether the Mobile Node continues to use the IP address previously assigned to the Mobile Node.
    Type: Grant
    Filed: October 17, 2002
    Date of Patent: February 23, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Alpesh Patel, Kent K. Leung, Madhavi W. Chandra
  • Patent number: 7630352
    Abstract: Methods and apparatus for registering a mobile device such as a mobile node or mobile router with a Home Agent in an asymmetric link environment. A Foreign Agent associates each of one or more interfaces of the Foreign Agent with a different care-of address. An agent advertisement including the care-of address for the one or more interfaces of the Foreign Agent is then sent via one or more uplinks. A registration request is received via a downlink router. The registration request identifies a care-of address associated with one of the one or more interfaces of the Foreign Agent. One of the interfaces identified by the care-of address is ascertained, thereby identifying the interface to which the mobile device has roamed. The registration request is forwarded to the Home Agent. A registration reply is received from the Home Agent. The registration reply is then forwarded to the mobile device via the ascertained interface.
    Type: Grant
    Filed: December 26, 2006
    Date of Patent: December 8, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Kent K. Leung, Alpesh S. Patel
  • Publication number: 20090300217
    Abstract: The present disclosure generally provides techniques for establishing a unique, ephemeral home address (hoa)/home agent address (ha?) address pair that may be limited to use in a session having a defined lifetime. Limiting the use of this dynamic address pair to a session lifetime and by preventing a mobile node from knowing the static address of a home agent may help protect the home agent from attacks.
    Type: Application
    Filed: May 28, 2008
    Publication date: December 3, 2009
    Inventors: ALPESH S. PATEL, Kent K. Leung, Pascal Thubert
  • Patent number: 7626963
    Abstract: Methods and apparatus for dynamically generating a set of Mobile IP keys are disclosed. The set of Mobile IP keys is dynamically generated using an existing HLR/AuC authentication infrastructure. This is accomplished, in part, by obtaining an International Mobile Subscriber Identity (IMSI) that uniquely identifies a particular Mobile Node. Once a set of Mobile IP keys is generated from authentication information associated with the IMSI, the Mobile Node may register with its Home Agent using the set of Mobile IP keys.
    Type: Grant
    Filed: October 25, 2005
    Date of Patent: December 1, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Alpesh S. Patel, Kent K. Leung, Joseph A. Salowey, Yu-Cheng Shao
  • Patent number: 7599370
    Abstract: Methods and apparatus for optimizing NAT traversal in Mobile IP are disclosed. Various mechanisms may performed independently or in combination with one another. A first mechanism enables one-way keep alive messaging to the Home Agent, while a second mechanism enables two-way keep alive messaging to the Home Agent, thereby enabling an entry in a NAT translation table to be maintained. The two-way keep alive messaging requires that the Home Agent send an acknowledgement message, while the one-way keep alive messaging does not. Keep alive messaging may be performed at the Mobile Node or the Foreign Agent. A third mechanism enables a Foreign Agent to encapsulate a registration request packet with the Foreign Agent care-of address in the source IP address field rather than an egress interface of the Foreign Agent. A fourth mechanism enables a Mobile Node to force a Home Agent to perform UDP tunneling.
    Type: Grant
    Filed: April 17, 2003
    Date of Patent: October 6, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Kent K. Leung, Alpesh Patel, Milind M. Kulkarni, Madhavi W. Chandra
  • Patent number: 7587498
    Abstract: In accordance with one aspect of the invention, methods and apparatus for distributing a Mobile IP registration request to one of a plurality of Home Agents are disclosed. A registration request is received from a Foreign Agent to which the Mobile Node has roamed. One of the plurality of Home Agents is selected. The registration request is then forwarded to the selected one of the plurality of Home Agents. The source IP address of the registration request is an IP address of the Foreign Agent to which the Mobile Node has roamed, thereby enabling the selected one of the plurality of Home Agents to send a Mobile IP registration reply directly to the Foreign Agent without interception by the network device.
    Type: Grant
    Filed: May 6, 2002
    Date of Patent: September 8, 2009
    Assignee: Cisco Technology, Inc.
    Inventors: Kent K. Leung, Alpesh Patel, Stefan B. Raab
  • Patent number: 7580391
    Abstract: Methods and apparatus for implementing a Home Agent supporting Mobile IP and being capable of allocating one or more networks to a mobile router which registers with the Home Agent comprise receiving a registration request packet from the mobile router, the registration request packet indicating one or more networks being requested by the mobile router from the Home Agent. The one or more networks are allocated to the mobile router corresponding to the one or more networks being requested by the mobile router from the Home Agent. A registration reply packet identifying the one or more networks allocated to the mobile router is then sent to the mobile router.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: August 25, 2009
    Assignee: Cisco Technology, Inc.
    Inventor: Kent K. Leung
  • Publication number: 20090141688
    Abstract: An invention is disclosed that enables proxy Mobile IP registration to be performed in a secure manner. Various security mechanisms may be used independently, or in combination with one another, to authenticate the identity of a node during the registration process. First, an Access Point receiving a packet from a node verifies that the source MAC address identified in the packet is in the Access Point's client association table. In addition, as a second mechanism, the Access Point ensures that a one-to-one mapping exists for the source MAC address and source IP address identified in the packet in a mapping table maintained by the Access Point. As a third mechanism, a binding is not modified in the mobility binding table maintained by the Home Agent unless there is a one-to-one mapping in the mobility binding table between the source MAC address and the source IP address.
    Type: Application
    Filed: February 9, 2009
    Publication date: June 4, 2009
    Applicant: CISCO TECHNOLOGY, INC.
    Inventors: Kent K. Leung, Gopal Dommety
  • Patent number: 7535871
    Abstract: Methods and apparatus for enabling intra-agent mobility by a mobile node are disclosed, thereby permitting a mobile node to register with a Home Agent via a Foreign Agent where the Home Agent and the Foreign Agent are provided in the same router. A method of registering a mobile node visiting a Foreign Agent with a Home Agent includes receiving a registration request packet specifying a Home Address and a care-of address. It is then determined whether the Home Address specified in the registration request packet is equivalent to a Home Agent address associated with the router. In addition, it may be determined whether the care-of address specified in the registration request packet is equivalent to a Foreign Agent address advertised by the router. Alternatively, it may be determined whether the D bit specified in the registration request packet is set and the care-of address specified in the registration request packet is a collocated care-of address.
    Type: Grant
    Filed: July 24, 2003
    Date of Patent: May 19, 2009
    Assignee: Cisco Technology, Inc.
    Inventor: Kent K. Leung
  • Publication number: 20090080370
    Abstract: In one embodiment, an apparatus receives an advertisement from each of one or more Home Agents, the advertisement including a first set of information associated with a corresponding one of the Home Agents, each advertisement being in a first protocol. The apparatus obtains the first set of information associated with a corresponding one of the Home Agents from each advertisement. The apparatus composes a router advertisement including a second set of information associated with at least one of the Home Agents, the router advertisement being in a second protocol. The apparatus then sends the router advertisement.
    Type: Application
    Filed: September 24, 2007
    Publication date: March 26, 2009
    Inventors: Alpesh S. Patel, Kent K. Leung, Gopal K. Dommety
  • Publication number: 20090080399
    Abstract: Methods and apparatus for enabling mobility of a node that does not support Mobile IP are disclosed. When an AP receives a data packet, the AP may compare the data packet (e.g., source address) with the AP information for one or more APs to determine whether to send a registration request on behalf of the node. More particularly, the AP determines from the source address whether the node is located on a subnet identical to a subnet of the AP. If the node is located on the subnet of the AP, no Mobile IP service is required on behalf of the node. However, when it is determined from the source address that the node is not located on the subnet identical to the subnet of the Access Point, the AP composes and sends a mobile IP registration request on behalf of the node. For instance, the mobile IP registration request may be composed using the gateway associated with the “home” AP (e.g., having a matching subnet) as the node's Home Agent.
    Type: Application
    Filed: November 25, 2008
    Publication date: March 26, 2009
    Applicant: Cisco Technology, Inc., A corporation of California
    Inventors: Huizhao Wang, Kent K. Leung, Waseem A. Siddiqi, Christine Andiazabal