Patents by Inventor Karthikeyan Ramanan

Karthikeyan Ramanan 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).

  • Method and system for preventing data packet loss in a redundant PDSN environment
    Patent number: 7756010
    Abstract: A method and apparatus are provided for preventing data-packet loss upon a switchover from an active to a standby PDSN, in a redundant PDSN environment. Data-packet loss is prevented by modifying the checking of the sequence number associated with the data-packets. The first sequence number received upon switchover is used to determine the order of the subsequent GRE frames. The standby PDSN sends keep-alive packets associated with an arbitrary sequence number to a packet control function (PCF). On receiving a response from the PCF, the arbitrary sequence number is used as a starting sequence number for sending the data-packets. Otherwise, keep-alive packets with modified numbers are sent to the PCF. In synchronized communication sessions between the PDSN and the PCF, data-packet loss can be prevented by disabling the checking of the sequence number upon a switchover. In another embodiment, data-packet loss is prevented by excluding the sequence number.
    Type: Grant
    Filed: December 21, 2005
    Date of Patent: July 13, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: Karthikeyan Ramanan, Bhaskar Bhupalam, Venkatesh Gota
  • Method and system for preventing data packet loss in a redundant PDSN environment
    Publication number: 20070140111
    Abstract: A method and apparatus are provided for preventing data-packet loss upon a switchover from an active to a standby PDSN, in a redundant PDSN environment. Data-packet loss is prevented by modifying the checking of the sequence number associated with the data-packets. The first sequence number received upon switchover is used to determine the order of the subsequent GRE frames. The standby PDSN sends keep-alive packets associated with an arbitrary sequence number to a packet control function (PCF). On receiving a response from the PCF, the arbitrary sequence number is used as a starting sequence number for sending the data-packets. Otherwise, keep-alive packets with modified numbers are sent to the PCF. In synchronized communication sessions between the PDSN and the PCF, data-packet loss can be prevented by disabling the checking of the sequence number upon a switchover. In another embodiment, data-packet loss is prevented by excluding the sequence number.
    Type: Application
    Filed: December 21, 2005
    Publication date: June 21, 2007
    Applicant: Cisco Technology, Inc.
    Inventors: Karthikeyan Ramanan, Bhaskar Bhupalam, Venkatesh Gota