Patents by Inventor Xiangrong Cai

Xiangrong Cai 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: 10020952
    Abstract: Techniques are described for operating a network switch device associated with a virtual layer two (L2) network instance according to a protocol independent multicast (PIM) relay mode. The PIM relay mode enables the network switch device to receive a PIM control message, i.e., a PIM join and/or prune request, for a multicast group on a downstream port of the network switch device associated with a virtual L2 network instance, determine an upstream neighbor port of the network switch device associated with the instance, and relay the PIM control message on the upstream neighbor port of the network switch device without flooding the PIM control message on all ports of the switch device associated with the instance. In the PIM relay mode, the network switch device avoids triggering join suppression in downstream PIM neighbor devices with receivers, and avoids maintaining upstream states and setting a PIM periodic message timer.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: July 10, 2018
    Assignee: Juniper Networks, Inc.
    Inventors: Xiangrong Cai, Princy T. Elizabeth, Zhaohui Zhang
  • Patent number: 8099516
    Abstract: A method and apparatus is disclosed by which IGMP Host messaging is translated to PIM messaging for the purposes of efficiently and accurately maintaining group membership data in a multicast network.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: January 17, 2012
    Assignee: Avaya Inc.
    Inventor: Xiangrong Cai
  • Patent number: 7944846
    Abstract: Described is a method for statically or dynamically enabling a DVMRP router in a DVMRP domain to perform a reverse path forwarding check for an external source. A route report is generated for each known external source and injected into the DVMRP domain. Each route report includes routing information for a respective one of the known external sources. In one embodiment, the route report is generated for each network listed in a unicast routing table maintained on a DVMRP multicast border router and each route report includes unicast routing information for each of the networks and an indicator designating that the routing information is derived from unicast routing information. In another embodiment, if it is determined that routing information for an external source of multicast traffic received at a DVMRP border router is not available, the route report is generated at that time and includes a predetermined metric value.
    Type: Grant
    Filed: August 18, 2005
    Date of Patent: May 17, 2011
    Assignee: Avaya Inc.
    Inventors: Xiangrong Cai, Haixiang He
  • Patent number: 7752670
    Abstract: To detect an attack of a network connection, detection of a message containing a sequence number that is within a valid sequence number range is performed, where the message is intended to cause reset of the network connection. The message is dropped, and a counter is incremented to track a number of occurrences of receiving the message in response to detecting that the sequence number in the message is within the valid sequence number range.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: July 6, 2010
    Inventors: Xiangrong Cai, Sasi Harpanahalli, Deepak Seth
  • Publication number: 20060072455
    Abstract: To detect an attack of a network connection, detection of a message containing a sequence number that is within a valid sequence number range is performed, where the message is intended to cause reset of the network connection. The message is dropped, and a counter is incremented to track a number of occurrences of receiving the message in response to detecting that the sequence number in the message is within the valid sequence number range.
    Type: Application
    Filed: September 23, 2004
    Publication date: April 6, 2006
    Applicant: Nortel Networks Limited
    Inventors: Xiangrong Cai, Sasi Harpanahalli, Deepak Seth
  • Patent number: 6721318
    Abstract: A router is configured with a static membership to a multicast group address and is capable of transmitting a message reporting the static membership to another router.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: April 13, 2004
    Assignee: Nortel Networks Limited
    Inventors: Xiangrong Cai, Shuching Shieh
  • Patent number: 6581175
    Abstract: An apparatus and method of requesting retransmission of at least a portion of a message (having a plurality of message segments) from a sender utilizes message units in a memory device for storing data relating to retransmit messages. In particular, each message unit in the memory has data for one message segment. To that end, a retransmit message requesting retransmission of a set of message segments to a given receiver is received from the given receiver. The given retransmit message then is parsed to determine both the identity of the given receiver, and the identity of the set of message segments requested by the given receiver. A message unit then is produced in the memory for each of the set of message segments that does not have an existing message unit in memory. Data representing the identity of the given receiver then is added to all message units for the set of message segments.
    Type: Grant
    Filed: December 27, 1999
    Date of Patent: June 17, 2003
    Assignee: Nortel Networks Limited
    Inventors: Richard Crump, Janet Doong, Xiangrong Cai