Method and apparatus for translating protocol

• US 20030185236A1
• Filed: 09/05/2002
• Published: 10/02/2003
• Est. Priority Date: 03/27/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Asano, Yutaro, Tanaka, Koji, Shibata, Haruo
• Granted Patent: US 7,310,351 B2
• Time in Patent Office: Days
• US Class Current: 370/469
• CPC Class Codes: H04L 61/251 between different IP versions
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/167 Adaptation for transition between two IP versions, e.g. between IPv4 and IPv6 translation of Internet protocol [IP] addresses H04L61/2503

Abstract

A translation apparatus retains a first correlation between a Mobile IPv6 terminal'"'"'s home address and virtual IPv4 address. When the Mobile IPv6 terminal transmits a packet to said IPv6 network with a care-of address specified as the packet'"'"'s source address and a home address specified in an extension header, the translation apparatus changes the packet'"'"'s source address to a virtual IPv4 address that corresponds to the packet'"'"'s home address in accordance with the first correlation, and then transmits the packet to an IPv4 network. Mobile IPv6 terminal-to-IPv4 terminal communication can then be established between an IPv6 network to which Mobile IPv6 terminals are connected and an IPv4 network to which IPv4 terminals are connected.

Claims

1. A method for protocol translation in a network system where an IPv6 network to which a Mobile IPv6 terminal is connected is connected via a translation apparatus to an IPv4 network to which an IPv4 terminal is connected, comprising steps of:

retaining a first correlation between a home address of said Mobile IPv6 terminal and a virtual IPv4 address of the Mobile IPv6 terminal in said translation apparatus;

transmitting a packet from said Mobile Ipv6 terminal to said IPv6 network with a care-of address specified as the packet'"'"'s source address and a home address specified in an extension header; and

changing the packet'"'"'s source address to a virtual IPv4 address corresponding to the home address of the packet in accordance with said first correlation in said translation apparatus, and transmitting the packet from the translation apparatus to said IPv4 network.

2. The method for protocol translation according to claim 1, the method further comprising:

when said Mobile IPv6 terminal moves and causes a change in said care-of address, transmitting the packet from said Mobile Ipv6 terminal to said IPv6 network with the resulting new care-of address specified as the packet'"'"'s source address and the same home address as prevailing before the move specified in the extension header.

3. The method for protocol translation according to claim 1, the method further comprising:

retaining a second correlation between a home address of said Mobile IPv6 terminal and a care-of address of the Mobile IPv6 terminal in said translation apparatus;

transmitting a packet from said Mobile Ipv6 terminal to said IPv4 network with a virtual IPv4 address specified as the packet destination address; and

translating the virtual IPv4 address into a corresponding home address in accordance with the first correlation in said translation apparatus;

translating the home address into a corresponding care-of address in accordance with the second correlation in said translation apparatus;

changing the packet transmission destination address to the resulting care-of address in said translation apparatus; and

transmitting the packet from said translation apparatus to said IPv6 network.

4. A protocol translation apparatus connectable between an IPv6 network connected to a Mobile IPv6 terminal and an IPv4 network connected to an IPv4 terminal, the apparatus comprising:

a means for retaining the correlation between the home address of said Mobile IPv6 terminal and the virtual IPv4 address of the Mobile IPv6 terminal; and

a means for receiving a packet transmitted to said IPv6 network by said Mobile IPv6 terminal with a care-of address specified as the packet transmission source and a home address specified in the extension header and transmitting the packet to said IPv4 network with the packet'"'"'s source address changed to a virtual IPv4 address that corresponds to the packet'"'"'s home address in accordance with said first correlation.