Patents by Inventor Atsushi Tachikawa

Atsushi Tachikawa 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: 7830886
    Abstract: A boundary node router determines whether a received packet includes a SIP message and a REGISTER message, and, if so, adds its router identifier to a REGISTER message which includes a user identifier and a user terminal identifier, sent from a user terminal, and sends the message to a SIP server. The SIP server has a user management table which stores the user terminal identifier, the router identifier of a router which serves the user terminal, and a predetermined Quality of Service type, in association with each user identifier. The SIP server extracts a user identifier, a user terminal identifier, and a router identifier from a received REGISTER message, and updates the user terminal identifier and the router identifier corresponding to the extracted user identifier, to the extracted user terminal identifier and the extracted router identifier.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: November 9, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Hiroaki Nakazawa, Atsushi Tachikawa
  • Patent number: 7609717
    Abstract: A packet transfer apparatus having a plurality of protocol processing units 10 and a switch 20 for switching IP packets among the protocol processing units, wherein a protocol processing unit connected to an IPv4 network includes: input-side address translator CNv6 (I) for translating the address of an input packet to an IPv6 address; output-side address translator CNv4 (O) for translating, when an IPv6 packet is received from the switch, the address to an IPv4 address and transferring the resultant packet to the IPv4 network; and an operation mode controller for omitting address translation by the input-side address translator.
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: October 27, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Hiroaki Miyata, Atsushi Tachikawa
  • Publication number: 20080095158
    Abstract: A boundary node router determines whether a received packet includes a SIP message and a REGISTER message, and, if so, adds its router identifier to a REGISTER message which includes a user identifier and a user terminal identifier, sent from a user terminal, and sends the message to a SIP server. The SIP server has a user management table which stores the user terminal identifier, the router identifier of a router which serves the user terminal, and a predetermined Quality of Service type, in association with each user identifier. The SIP server extracts a user identifier, a user terminal identifier, and a router identifier from a received REGISTER message, and updates the user terminal identifier and the router identifier corresponding to the extracted user identifier, to the extracted user terminal identifier and the extracted router identifier.
    Type: Application
    Filed: December 6, 2007
    Publication date: April 24, 2008
    Inventors: Hiroaki Nakazawa, Atsushi Tachikawa
  • Patent number: 7330470
    Abstract: A boundary node router determines whether a received packet includes a SIP message and a REGISTER message, and, if so, adds its router identifier to a REGISTER message which includes a user identifier and a user terminal identifier, sent from a user terminal, and sends the message to a SIP server. The SIP server has a user management table which stores the user terminal identifier, the router identifier of a router which serves the user terminal, and a predetermined Quality of Service type, in association with each user identifier. The SIP server extracts a user identifier, a user terminal identifier, and a router identifier from a received REGISTER message, and updates the user terminal identifier and the router identifier corresponding to the extracted user identifier, to the extracted user terminal identifier and the extracted router identifier.
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: February 12, 2008
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Hiroaki Nakazawa, Atsushi Tachikawa
  • Publication number: 20050213591
    Abstract: A boundary node router determines whether a received packet includes a SIP message and a REGISTER message, and, if so, adds its router identifier to a REGISTER message which includes a user identifier and a user terminal identifier, sent from a user terminal, and sends the message to a SIP server. The SIP server has a user management table which stores the user terminal identifier, the router identifier of a router which serves the user terminal, and a predetermined Quality of Service type, in association with each user identifier. The SIP server extracts a user identifier, a user terminal identifier, and a router identifier from a received REGISTER message, and updates the user terminal identifier and the router identifier corresponding to the extracted user identifier, to the extracted user terminal identifier and the extracted router identifier.
    Type: Application
    Filed: January 12, 2005
    Publication date: September 29, 2005
    Inventors: Hiroaki Nakazawa, Atsushi Tachikawa
  • Publication number: 20030219023
    Abstract: A packet transfer apparatus having a plurality of protocol processing units 10 and a switch 20 for switching IP packets among the protocol processing units, wherein a protocol processing unit connected to an IPv4 network includes: input-side address translator CNv6(I) for translating the address of an input packet to an IPv6 address; output-side address translator CNv4(O) for translating, when an IPv6 packet is received from the switch, the address to an IPv4 address and transferring the resultant packet to the IPv4 network; and an operation mode controller for omitting address translation by the input-side address translator.
    Type: Application
    Filed: January 17, 2003
    Publication date: November 27, 2003
    Inventors: Hiroaki Miyata, Atsushi Tachikawa