JPH10313336A - Moving terminal, movement supporting device and network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit a message used in IPv6 from an IPv4 network and to continuously hold network connection using IPv6, which is established before movement by permitting an IPv4/v6 moving terminal to add an IPv4 header to the message used in IPv6, so as to transmit it. SOLUTION: When an IPv4/v6 moving terminal 106 moves from an IPv4/v6 network to the IPv4 network, it registers movements to an IPv6 movement- supporting device 107. Thus, the terminal 106 sets the IPv4 address of the supporting device 107 in the message used in the IPv6 as a transmission destination address. The moving terminal 106 adds the IPv4 header where the IPv4 address of the moving terminal 106 that can be used in the IPv4 network being the moving destination is set as the address of a transmission source, so as to transmit it. Thus, communication using IPv6 can executed anew be.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile terminal, a mobility support device, and a network system, and more particularly, to a case where an IPv4 / v6 terminal moves from an IPv4 / v6 network to an IPv4 network, and is established before moving. Mobile terminal capable of continuously maintaining a network connection using IPv6, and capable of newly performing communication using IPv6, a mobile support device for supporting the mobile terminal to move between networks, and The present invention relates to a network system including the mobile terminal and the movement support device.

[0002]

2. Description of the Related Art With the spread of small and light-weight terminals and the rapid development of the Internet, there is an increasing tendency to take terminals out of offices and homes and use them anywhere. Therefore, a method for supporting movement of a terminal between networks has been proposed. Among them, a typical method is I
IP Mobility support for IPv4 in which the address length of the P address is 32 bits (hereinafter, referred to as Mobile IPv4) and Mobility support in IPv6 for IPv6 in which the address length of the IP address is larger than 32 bits
(Hereinafter referred to as Mobile IPv6).

The above-mentioned Mobile IPv4 is described in RFC2002.
And a movement support device (hereinafter, I) that supports movement of a mobile terminal that performs communication using IPv4.
A message used as a procedure according to Mobile IPv4 is exchanged between the mobile terminal moving between the network and a mobile terminal moving between networks using IPv4.

[0004] The Mobile IPv6 is based on IETF (Int).
ernet Enginering Task Force Draft ('97 2
The latest version of the month is described in draft-ietf-mobileip-ipv6-02.txt), and a mobile support device (hereinafter referred to as IP) that supports mobile terminals performing communication using IPv6.
A message used as a procedure in accordance with Mobile IPv6 is exchanged between the mobile terminal moving between networks by using IPv6.

[0005] In this specification, the term "terminal" refers to any device (PC, router, etc.) that owns an IP address and performs communication using IP.

[0006]

At present, a terminal that performs communication using only IPv4 (hereinafter, referred to as an IPv4 terminal)
An IPv4 network consisting only of IPv6 networks, an IPv6 network consisting only of terminals that perform communication using only IPv6 (hereinafter referred to as IPv6 terminals), and an IPv4 network consisting of only IPv6 terminals.
Terminal that performs communication using both IPv4 and IPv6 (hereinafter referred to as IPv4 / v6 terminal), IPv4 terminal and IP
There is an IPv4 / IPv6 network configured with v6 terminals.

Now, when an IPv4 / v6 terminal receives an IPv4 / v
6 supporting Mobile IPv4 from 6 networks
Consider the case of moving to a Pv4 network. IPv4
Since communication using IPv4 is possible on the network, it is possible to continue communication without disconnecting the network connection using IPv4 already established with another IPv4 terminal before moving. It is. Further, it is possible to newly perform communication using IPv4. However, since communication using IPv6 cannot be performed on the IPv4 network, it is impossible to keep the network connection using IPv6 already established before moving, and communication cannot be performed. is there. Further, there is a problem that communication using IPv6 cannot be newly performed.

Accordingly, an object of the present invention is to provide an IPv4 / v6
When the terminal moves from the IPv4 / v6 network to the IPv4 network, it is possible to keep the network connection using IPv6 already established before moving, and to newly perform communication using IPv6. It is an object of the present invention to provide a mobile terminal, a mobility support device, and a network system that can perform the above.

[0009]

According to a first aspect of the present invention, there is provided an IPv4 processing means for providing a service according to IP (Internet Protocol) v4 (IP version 4);
IP that provides services according to v6 (IP version 6)
v6 processing means and communication processing means for controlling transmission / reception of packets to / from a network, and in a mobile terminal moving between IP networks, from an IPv4 / v6 network (a network capable of communication using both IPv4 and IPv6) IPv4 network (IPv4
In order to support the movement of the mobile terminal when moving to a network capable of only communication using
The IPv4 address of the mobile support device is set as a destination address in a message used in IPv6 for registering a move with the mobile support device connected to the v6 network, and the destination I address is set as a source address.
An IPv4 header that sets an IPv4 address of a mobile terminal that can be used in a Pv4 network (I4 used in IPv4)
A mobile terminal characterized by comprising a mobile registration processing means for adding and transmitting a P header). In the mobile terminal according to the first aspect, since a message used in IPv6 is transmitted with an IPv4 header added,
A message used in IPv6 can be substantially transmitted from the v4 network, and information necessary for a network connection using IPv6 can be registered in the mobility support apparatus.

[0010] In a second aspect, the present invention provides an IPv4 processing means for providing a service according to IPv4, an IPv6 processing means for providing a service according to IPv6, and a communication processing means for controlling transmission / reception of a packet to / from a network. In a mobile terminal moving between networks, I
When moving from the Pv4 / v6 network to the IPv4 network, the IPv4 address of the movement support device is set as the destination address, and the IPv4 address of the mobile terminal usable in the destination IPv4 network is set as the source address. A packet transmission processing unit that creates an IPv4-encapsulated IPv6 packet by adding an IPv4 header to an IPv6 packet (a packet used in IPv6) to be transmitted to another terminal, and transmits the IPv4-encapsulated IPv6 packet; A mobile terminal is provided. The second
In the mobile terminal according to the viewpoint of
Since the transmission is performed with the four headers added, the IPv6 packet can be substantially transmitted from the destination IPv4 network.

According to a third aspect, the present invention provides an IPv4 processing means for providing a service according to IPv4, an IPv6 processing means for providing a service according to IPv6, and a communication processing means for controlling transmission and reception of packets to and from a network. A mobile terminal moving between networks, wherein a different IPv4 network or IPv6 is used from a network in which a mobility support device used by the mobile terminal exists.
It is characterized by comprising a movement detecting means for detecting whether the communication apparatus has moved to a network (a network capable of only communication using IPv6) or an IPv4 / v6 network, and a movement state management means for managing the detected movement state. To provide a mobile terminal. In the mobile terminal according to the third aspect, the necessity of adding an IPv4 header to a message or an IPv6 packet used in IPv6 is accurately determined in order to automatically detect a type of a network in which the mobile terminal currently exists and to perform self-management. it can.

In a fourth aspect, the present invention provides an IPv4 processing means for providing a service according to IPv4, an IPv6 processing means for providing a service according to IPv6, and a communication processing means for controlling transmission and reception of packets to and from a network. In a mobility support apparatus that supports movement of a terminal that performs communication using IPv6, registration of movement transmitted by the mobile terminal that has moved to the IPv4 network to the movement support apparatus, to which an IPv4 header has been added, Of a mobile terminal that can be used in a destination IPv4 network when a message used in IPv6 for performing
a mobile terminal management means for managing a v4 address, and a destination IP address as a destination address in a message used in IPv6 for permitting the mobile terminal to register the mobile terminal.
mobility support processing means for setting an IPv4 address of a mobile terminal usable in a v4 network and adding an IPv4 header in which an IPv4 address of a mobility support device is set as a source address and transmitting the mobile terminal; Provide a support device. In the mobility support apparatus according to the fourth aspect, the message used in IPv6 is
Since a header is added and transmitted, a message used in IPv6 can be substantially transmitted to a mobile terminal that is moving to an IPv4 network.

According to a fifth aspect, the present invention provides an IPv4 processing means for providing a service according to IPv4, an IPv6 processing means for providing a service according to IPv6, and a communication processing means for controlling transmission / reception of a packet to / from a network. In a mobility support apparatus that supports movement of a terminal performing communication using IPv6, when receiving an IPv4-encapsulated IPv6 packet transmitted by a mobile terminal, the IPv4 header is removed, and the extracted IPv6
There is provided a mobility support device comprising a transfer processing means for transmitting a packet to a network again to another terminal. In the mobility support apparatus according to the fifth aspect, the IPv4
To extract and transmit only the IPv6 packet from the encapsulated IPv6 packet, the mobile terminal moving to the IPv4 network transmits the IPv6 packet to the terminal on the IPv6 network or the IPv4 / IPv6 network.
The packet can be substantially transmitted.

In a sixth aspect, the present invention provides an IPv4 processing means for providing a service according to IPv4, an IPv6 processing means for providing a service according to IPv6, and a communication processing means for controlling transmission and reception of packets to and from a network. In a mobility support apparatus for supporting movement of a terminal performing communication using IPv6, a mobile terminal moving to an IPv4 network transmits an I
An IPv4 header in which, when a Pv6 packet is received, the IPv4 address of the destination mobile terminal usable in the destination IPv4 network is set as the destination IPv4 address, and the IPv4 address of the mobile support device is set as the source IPv4 address. Is added to a received IPv6 packet, an IPv4 encapsulated IPv6 packet is created, and a mobile terminal destination transfer processing unit for transmitting the IPv4 encapsulated IPv6 packet is provided. In the mobility support apparatus according to the sixth aspect, the IPv4 packet is
In order to add the header and transmit, from a terminal on the IPv6 network or the IPv4 / IPv6 network,
IPv6 to mobile terminal moving to IPv4 network
The packet can be substantially transmitted.

[0015] In a seventh aspect, the present invention is directed to a connection device, or a connection device and a third network, which are connected to an IP.
In a network system in which a v4 / v6 network and an IPv4 network are connected,
Or the mobile support device according to the sixth aspect is provided on an IPv4 / v6 network, and the mobile terminal according to the first, second or third aspect is connected to an IPv4 / v6 network or an IPv4 network.
The present invention provides a network system characterized by having the network system on four networks. In the network system according to the seventh aspect, the IPv4 / v6 terminal uses the IPv4 / v
When moving from the 6 network to the IPv4 network, it is possible to keep the network connection using IPv6 already established before moving, and to newly perform communication using IPv6. .

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram illustrating a network system according to an embodiment of the present invention. The network system 1 includes a LAN-a 100 that uses both IPv4 and IPv6,
It comprises a LAN-b 101 using only v4, and a WAN 102 connecting the LAN-a 100 and the LAN-b 101 by a public line or a dedicated line.

On the LAN-a 100, an IPv4 terminal 1
03, an IPv6 terminal 104, an IPv4 mobility support device a105 for supporting inter-network migration for a terminal performing communication using IPv4 by a procedure according to Mobile IPv4, an IPv4 / v6 mobile terminal 106,
Communication using v4 and IPv6 and IPv6
There is an IPv6 mobility support device 107 that supports the movement between networks for a terminal that performs communication using the IPv6. I
The Pv6 movement support device 107 also operates as a router,
The LAN-a 100 and the WAN 102 are connected.

On the LAN-b 101, an IPv4 mobility support device b 108 and a router 109 exist. The router 109 connects between the LAN-b 101 and the WAN 102.

In the present embodiment, the IP address is an IPv4 address, an IPv6 address, LAN-a100 “10.0.0.0” “:: 11.0.0.0”, an IPv4 terminal 103 “10.0.0.10”, an IPv6 terminal 104 “:: 11.0.0.30”. IPv4 / v6 mobile terminal 106 “10.0.0.1” “:: 11.0.0.1” IPv4 mobility support device a105 “10.0.0.11” IPv6 mobility support device 107 “10.0.0.20” “:: 11.0.0.20” LAN-b101 “20.0” .0.0 "IPv4 mobility support device b108" 20.0.0.11 "respectively.

The IPv4 / v6 mobile terminal 106 performs various processing when moving to another network.
6 movement processing unit 114, a movement detection processing unit 115 that performs processing for detecting movement to another network, and movement for notifying the movement to another IPv4 network or IPv4 / v6 network to the IPv4 movement support apparatus a105. IPv4 transfer registration processing unit 11 that performs notification processing
6 and another IPv6 network or IPv4 / v6
The fact that the user has moved to the network is indicated by the IPv6 mobility support device 1
07, an IPv6 move registration processing unit 117 for performing a movement notification process for notifying to the IPv7 network, an IPv4only movement registration processing unit 118 for performing a movement notification process for notifying the IPv6 movement support apparatus 107 that the mobile device has moved to another IPv4 network, and Moving state management table 119 to be managed and IPv4
An IPv4 processing unit 111 that performs processing according to the service provided by IPv6, an IPv6 processing unit 112 that performs processing according to the service provided by IPv6, an IPv6 packet transmission processing unit 113 that performs transmission processing of the IPv6 packet, and LA
A communication processing unit 110 for controlling transmission / reception of packets to / from N
Is provided. The IPv4 / v6 mobile terminal 106
Among the constituent elements of the present invention, those particularly provided in the present invention include a movement detection processing unit 114 and an IPv4only movement registration processing unit 1.
18, the IPv6 packet transmission processing unit 113, and the movement state management table 119.

[0021] The IPv6 mobility support apparatus 107 is an IPv4
/ IPv6 mobile terminal 106 or an IPv6 mobile terminal (not shown) that performs communication using IPv6 and moves between networks (not shown) receives a movement notification (notification of movement to an IPv6 network or an IPv4 / v6 network) and provides assistance. IPv6 movement support processing unit 121 to be performed
A mobile terminal management table 126 that manages the mobile state information of the mobile terminal; an IPv4 processing unit 122 that performs processing according to the service provided by the IPv4; and a packet transmitted from the IPv4 / v6 mobile terminal 106 to the IPv6 terminal 104. Other terminal-directed transfer processing unit 123 that performs transfer, and IPv6 processing unit 1 that performs processing according to the service provided by IPv6
24, a transfer processing unit 125 for transferring a packet transmitted from the IPv6 terminal 104 to the IPv4 / v6 mobile terminal 106, and a communication processing unit 120 for controlling transmission / reception of the packet to / from the LAN. . IPv6 above
Among the components of the mobility support device 107, those particularly provided in the present invention include an IPv6 mobility support processing unit 121, a transfer processing unit for other terminals 123, and a transfer processing unit for mobile terminals 12.
5 and the mobile terminal management table 126.

FIG. 2 shows a configuration example of the movement state management table 119. The moving state management table 119 has the following fields. -Own IPv4 address 200: This is the IPv4 address of the IPv4 / v6 mobile terminal 106 on the LAN-a 100 where the IPv6 mobility support device 107 supporting the movement of the IPv4 / v6 mobile terminal 106 exists. -Own IPv4 network address 201: IPv4 /
This is the IPv4 network address of the LAN-a 100 where the IPv6 mobility support device 107 that supports the movement of the v6 mobile terminal 106 exists. -Own IPv6 address 202: The IPv6 address of the IPv4 / v6 mobile terminal 106 on the LAN-a 100 where the IPv6 mobility support device 107 that supports the movement of the IPv4 / v6 mobile terminal 106 exists. -Own IPv6 network address 203: IPv4 /
This is the IPv6 network address of the LAN-a 100 where the IPv6 mobility support device 107 that supports the movement of the v6 mobile terminal 106 exists.

IPv4 mobility support apparatus IPv4 address 204: LAN-a in which an IPv4 mobility support apparatus a105 for supporting the movement of the IPv4 / v6 mobile terminal 106 exists.
100 is the IPv4 address of the IPv4 mobility support apparatus a105 on the network 100. -IPv6 mobility support device IPv4 address 205: IP
An IP address on the LAN-a 100 where an IPv6 mobility support device 107 that supports the movement of the v4 / v6 mobile terminal 106 exists.
This is the IPv4 address of the v6 movement support device 107. -IPv6 mobility support device IPv6 address 206: IP
An IP address on the LAN-a 100 where an IPv6 mobility support device 107 that supports the movement of the v4 / v6 mobile terminal 106 exists.
This is the IPv6 address of the v6 movement support device 107.

• IPv4 network address 2 after moving
07: IPv4 network address of the network where the IPv4 / v6 mobile terminal 106 currently exists. -IPv4 network address 208 before movement: IPv4
The IPv4 network address of the network before the 4 / v6 mobile terminal 106 moves. -IPv6 network address 209 after movement: IPv4
The IPv6 network address of the network where the 4 / v6 mobile terminal 106 currently exists. If the currently existing network is an IPv4 network, “NULL” is set. -IPv6 network address before movement 210: IPv
This is the IPv6 network address of the network before the 4 / v6 mobile terminal 106 moves. If the network before moving is an IPv4 network, “NULL” is set. In addition, at the time of initialization,
In each of the fields of the Pv4 network address 207, the pre-move IPv4 network address 208, the post-move IPv6 network address 209, and the pre-move IPv6 network address 210, there is an IPv6 movement support apparatus 107 that supports the movement of the IPv4 / v6 mobile terminal 106. The network address of the LAN-a 100 is set.

FIG. 3 shows a configuration example of the mobile terminal management table 126. The mobile terminal management table 126 has the following entries. Mobile terminal IPv6 address 30: The IPv6 address of a mobile terminal that the IPv6 mobility support apparatus 107 supports to move. Move destination IPv6 address 31: This is the IPv6 address on the network where the mobile terminal currently exists.
If the currently existing network is an IPv4 network, “NULL” is set. Move destination IPv4 address 32: The IPv4 address on the network where the mobile terminal currently exists.
If the currently existing network is the IPv6 network, “NULL” is set. At the initial stage, there is no entry of the mobile terminal in the mobile terminal management table 126.

FIG. 4 shows an IPv4 / v6 transfer processing unit 114.
It is a flowchart which shows the IPv4 / v6 transfer processing 40 which is performed by. In step 41, the moving state management table 11
9 is initialized. In step 50, the movement detection processing section 115 is caused to repeatedly execute the movement detection processing 50.

FIG. 5 is a flowchart showing the movement detection processing 50 executed by the movement detection processing unit 115. Step 51
Now, IPv4 movement, which is a message for requesting transmission of an IPv4 movement detection message and an IPv6 movement detection message, which is a message for detecting movement to another IPv4 network, an IPv6 network, or an IPv4 / v6 network. A detection message transmission request message and an IPv6 movement detection message transmission request message are transmitted. This IP
v4 movement detection message transmission request message and I
The IPv4 movement support device and the IPv6 movement support device that have received the Pv6 movement detection message transmission request message transmit the IPv4 movement detection message and the IPv6 movement detection message. In addition, the IPv4 movement support device and the IPv6 movement support device periodically
The v4 movement detection message and the IPv6 movement detection message are transmitted.

In step 52, a timer is set. In step 53, if an IPv4 movement detection message has been received, the process proceeds to step 54; otherwise, the process proceeds to step 55. In step 54, the received IPv4
The network address of the network to which the IPv4 movement support device that transmitted the 4 movement detection message belongs is compared with the moved IPv4 network address 207 in the movement state management table 119, and if the same network address, the process proceeds to step 55; Proceed to step 60.

In step 55, if an IPv6 movement detection message has been received, the process proceeds to step 56, and if not, the process proceeds to step 57. In step 56, the network address of the network to which the received IPv6 movement detection message belongs is compared with the post-move IPv6 network address 209 in the movement state management table 119 to which the IPv6 movement support device belongs. Go to step 70 if the network address is different.

In step 57, if it is not time-out, the flow returns to step 53, and if it is time-out, the flow proceeds to step 58. In step 58, the post-move IPv4 network address 207 in the movement state management table 119
And the IPv4 network address 208 before moving are different addresses, and the IPv6 network address 209 after moving and the IPv6 network address 21 before moving
It is determined whether 0 is the same network address. If the determination result is Yes, the process proceeds to Step 80, and if No, the process ends.

In step 60, the IPv4 transfer registration processing section 116 is caused to execute the IPv4 transfer registration processing 60. In step 70, the IPv6 transfer registration processing unit 117
The v6 movement registration processing 70 is executed. In step 80, the IPv4only transfer registration processing unit 118
The transfer registration processing 80 is executed.

More specifically, the movement detection processing 50 will be described.
a4, the IPv4 / v6 mobile terminal 1
06 is the IPv4 mobility support apparatus a105 and IPv6
It receives the IPv4 movement detection message and the IPv6 movement detection message transmitted by the movement support apparatus 107. Then, the LAN-a10 to which the IPv4 movement support apparatus a105 that has transmitted the IPv4 movement detection message belongs.
Since the network address of “0” (= “10.0.0.0”) and the post-migration IPv4 network address 207 (= “10.0.0.0”) of the movement state table 119 are the same address, another IPv4 network or IPv4 / IPv4
6 is not moved to the network, the process proceeds from step 54 to step 55, and step 60 (IPv4
Do not execute move registration processing). Also, the network address (= “:: 11.0.0.0”) to which the IPv6 movement support device 107 that transmitted the IPv6 movement detection message belongs, and the moved IPv6 network address 209 (= “:: 11.0.0.0”) in the movement state table 119. ) Is the same address, so another IPv6 network or I
It is determined that the user has not moved to the Pv4 / IPv6 network, and the process proceeds from step 56 to step 57, where step 70 (IPv6 move registration processing) is not executed.

Next, if the IPv4 / v6 mobile terminal 106 is currently moving to the LAN-b 101,
/ V6 mobile terminal 106 is an IPv4 mobility support device b10
8 receives the IPv4 movement detection message transmitted. Then, the LAN-b10 to which the IPv4 movement support apparatus b108 that has transmitted the IPv4 movement detection message belongs.
Since the network address 1 (= “20.0.0.0”) is different from the post-migration IPv4 network address 207 (= “10.0.0.0”) in the movement state table 119, the user has moved to another IPv4 network or IPv4 / v6 network. It is understood that Step 54 to Step 6
The process proceeds to 0, and the IPv4 transfer registration process 60 is executed. FIG.
As described later with reference to the above, the IPv4 pre-migration network address 208 of the movement state table 119 is updated to “10.0.0.0” in the IPv4 move registration process 60,
After moving, the IPv4 network address 207 is "20.0.
0.0 "). On the other hand, I-
Since there is no Pv6 movement support device, no IPv6 movement detection message is received.
The process proceeds from Step 5 to Step 57, and Steps 56 and 70 (IPv6 transfer registration processing) are not executed. Then, after the timeout, the moved IPv4 network address 207 (= “20.0.0.
0 ") and the IPv4 network address 208 before movement
(= “10.0.0.0”) and the IPv6 after moving
The network address 209 (= “:: 11.0.0.0”) and the pre-migration IPv6 network address 210 (= “::
11.0.0.0 ”) is the same address,
4 and moves to step 80 from step 58, and the IPv4only move registration processing 80
Execute

Note that the IPv4 / v6 mobile terminal 106
When moving to another IPv4 / v6 network such as LAN-a100, since both the IPv4 movement detection message and the IPv6 movement detection message are received, both the IPv4 movement registration processing 60 and the IPv6 movement registration processing 70 are executed. Is done. On the other hand, the post-move IPv4 network address 207 in the movement state table 119
と な り Before moving to IPv4 network address 208,
Further, since the IPv6 network address 209 after the movement becomes the IPv6 network address 210 before the movement,
Do not proceed from step 58 to step 80.
The ly movement registration processing 80 is not executed.

FIG. 6 is a flowchart showing an example of the IPv4 mobile registration processing executed by the IPv4 mobile registration processing unit 116. The IPv4 transfer registration process 60 is performed by
e This is processing according to the processing procedure of IPv4. Step 6
In step 1, the own IPv4 network address 201 in the movement state management table 119 is compared with the network address of the network to which the IPv4 movement support device that transmitted the IPv4 movement detection message belongs. If the network addresses are not the same, it is determined that the network has been moved to another network, and the process proceeds to step 62. On the other hand, if the network addresses are the same, IPv4 / v6
The process returns to the LAN-a 100 where the IPv6 mobility support device 107 that supports the movement of the mobile terminal 106 is found, and the process proceeds to step 63. In step 62, IPv4
/ V6 Acquires the IPv4 address on the destination network that can be used by the mobile terminal 106. The acquisition of the IPv4 address is performed by using DHCP for automatically distributing the address, by manual setting, or the like.

At step 63, the IPv4 movement support device IPv4 address 204 of the movement state management table 119
Transmits an IPv4 movement registration request message to the IPv4 movement support device registered in the. In step 64,
The process waits until an IPv4 move registration permission message, which is a response to the IPv4 move registration request message, is received from the IPv4 movement support apparatus. In step 65, the post-move IPv4 network address 207 of the movement state management table 119 is substituted for the pre-move IPv4 network address 208, and then the network address of the network to which the IPv4 movement support device that transmitted the IPv4 movement detection message belongs is moved. After that, it is assigned to the IPv4 network address 207.

The IPv4 mobile registration process 60 will be described in detail.
If it has moved from a100 to the LAN-b101, it proceeds from step 61 to step 62, and further proceeds to step 63, and transmits an IPv4 movement registration request message to the IPv4 movement support apparatus a105. Then, after receiving the IPv4 movement registration permission message from the IPv4 movement support apparatus a105, the process proceeds from step 64 to step 65, where the pre-movement I
“10.0.0.0” is set to the Pv4 network address 208, and “20.0.0.0” is set to the IPv4 network address 207 after moving.

FIG. 7 is a flowchart showing an example of the IPv6 move registration processing executed by the IPv6 move registration processing unit 117. Note that this IPv6 transfer registration processing 70
e This is processing according to the processing procedure of IPv6. Step 7
In step 1, the own IPv6 network address 203 in the movement state management table 119 is compared with the network address of the network to which the IPv6 movement support device that transmitted the IPv6 movement detection message belongs. If the network addresses are not the same, it is determined that the network has been moved to another network, and the process proceeds to step 72. On the other hand, if the network addresses are the same, IPv4 / v6
The process returns to the LAN-a 100 where the IPv6 mobility support device 107 that supports the movement of the mobile terminal 106 is found, and the process proceeds to step 73. In step 72, IPv4
/ V6 Acquires the IPv6 address on the destination network that can be used by the mobile terminal 106. The acquisition of the IPv6 address is performed by using DHCP for automatically distributing the address, by manual setting, or the like.

In step 73, the IPv6 movement support device IPv6 address 206 of the movement state management table 119 is used.
Transmits an IPv6 movement registration request message to the IPv6 movement support device registered in the. As shown in FIG. 13, the IPv6 move registration request message includes its own IPv6
Address 1301 and destination IPv6 address 1302
And a destination IPv4 address 1303. IP
In the v6 transfer registration process 70, the own IPv6 address 130
1 is set to the IPv6 address held in the own IPv6 address 202 of the movement state management table 119, and the destination IPv6 address 1302 is set to the IPv6 address at the destination.
6 address, and the destination IPv4 address 1303
Is set to "NULL".

In step 74, the process waits until an IPv6 move registration permission message, which is a response to the IPv6 move registration request message, is received from the IPv6 move support device.
After receiving the IPv6 movement registration permission message, step 75
Proceed to. In step 75, the moving state management table 11
9, the IPv6 network address 209 after the transfer is substituted for the IPv6 network address 210 before the move, and then the IPv6 network
The network address of the network to which the movement support device belongs is assigned to the IPv6 network address 209 after the movement.

FIG. 8 shows an IPv4only mobile registration processing unit 11.
FIG. 8 is a flowchart showing an example of an IPv4only transfer registration process executed by the No. 8; In step 81, the IPv6 movement support device IPv6 address 20 in the movement state management table 119
IPv4 to IPv6 mobility support device registered in IPv6
The encapsulated IPv6 mobile registration request message is transmitted. As shown in FIG. 14, the IPv4 encapsulated IPv6 movement registration request message includes an IPv4 header 1401 and an IPv6 movement registration request message 1300.
Consists of The IPv4 header 1401 contains the destination I
Pv4 address 1402 and source IPv4 address 1
403. The destination IPv4 address 1402
Is set to the address of the IPv6 movement support apparatus IPv4 address 205 of the movement state management table 119, and the source IPv4 address 1403 is set to the destination IPv4 address.
The IPv4 address acquired in the four networks is set. The IPv6 movement registration request message is shown in FIG.
As shown in FIG. 3, it is composed of a local IPv6 address 1301, a destination IPv6 address 1302, and a destination IPv4 address 1303. IPv4only transfer registration process 80
Then, the IPv6 address held in the own IPv6 address 202 of the movement state management table 119 is set as the own IPv6 address 1301, “NULL” is set as the destination IPv6 address 1302, and the destination IPv4 address is set.
In the address 1303, an IPv4 address at the destination is set.

In step 82, the IPv4-encapsulated IPv4 response which is a response to the IPv4-encapsulated IPv6 mobility registration request message from the IPv6 mobility support apparatus.
6 Wait until a mobile registration permission message is received,
After receiving the 4-encapsulated IPv6 movement registration permission message, the process proceeds to step 83. The received IPv4 encapsulation IPv6 transfer registration permission message is
After the IPv4 header is removed by the 4 processing unit 111 (hereinafter, referred to as IPv4 decapsulation), IPv4on
ly Transferred to the transfer registration processing unit 118. Note that this IPv4
The IPv4 decapsulation in the four processing unit 111 is one of the services provided by the existing IPv4. Step 8
3, in the post-migration IPv6 of the movement state management table 119,
The network address 209 is assigned to the pre-migration IPv6 network address 210, and then “NULL” is assigned to the post-migration IPv6 network address 209.

The IPv4 only mobile registration process 80 will be specifically described.
When moving from the Na-a 100 to the LAN-b 101, in step 81, the following IPv4 encapsulated IP
A v6 move registration permission message 1400 is created. -IPv4 header-Destination IPv4 address 1402: "10.0.0.20"
(IPv4 address of IPv6 mobility support apparatus 107) Source IPv4 address 1403: "20.0.0.1"
(IPv4 address newly used by the IPv4 / v6 mobile terminal 106 on the LAN-b 101) • IPv6 mobile registration message 1300 • own IPv6 address 1301: “:: 11.0.0.
1 ”... The destination IPv6 address 1302:“ NULL ”... The destination IPv4 address 1303:“ 20.0.0.1 ”Then, the IPv6 encapsulation IPv6 migration registration permission message 1400 is sent to the IPv6 migration support apparatus 10.
Send to 7. Next, in step 82, after receiving the IPv4-encapsulated IPv6 movement registration permission message from the IPv6 movement support apparatus 107, in step 83, ":: 11.0.
0.1 ”is set, and“ NULL ”is set in the IPv6 network address 209 after the movement.

FIG. 9 is a flowchart showing an example of the IPv6 packet transmission processing 90 executed by the IPv6 packet transmission processing unit 113 of the IPv6 processing unit 112 in the IPv4 / v6 mobile terminal 106. In step 91, the process waits for an IPv6 packet transmission request from a network application or the like.
In step 92, the post-migration IPv6 network address 209 of the movement state management table 119 is set to "NULL".
It is determined whether or not the value is "NULL". If the value is "NULL", the process proceeds to step 93;
Proceed to. In step 93, since the moving destination is the IPv4 network, the IPv6 packet is encapsulated in the IPv4 and transmitted. That is, as shown in FIG.
An IPv4 header 1401 is added to the v6 packet 1501, and a destination IPv4 address 1402 of the IPv4 header 1401 is added to the IPv6 header 1401 of the moving state management table 119.
The mobility support apparatus IPv4 address 205 is set, and the source IPv4 address 1403 is set to the IPv4 address acquired in the destination IPv4 network.
A Pv4 encapsulated IPv6 packet 1500 is created and transmitted. Then, the process returns to step 91. In step 94, the destination is an IPv6 network or I
Since it is a Pv4 / IPv6 network, an IPv6 packet is transmitted as it is. Then, the step 91
Return to

The above-described IPv6 packet transmission processing 90 will be specifically described.
When moving from the Na-a 100 to the LAN-b 101, when the transmission request of the IPv6 packet 1501 by the network application or the like is received in Step 91, in Step 92, the IPv6 packet 1501 is
“10.0.0.20” as the destination IPv4 address 1402
(IPv4 address of the IPv6 mobility support apparatus 107) is set and “2” is set as the source IPv4 address 1403.
An IPv4 header 1401 set to “0.0.0.1” is added, and the IPv4-encapsulated IPv6 packet is
It is transmitted to the Pv6 movement support device 107.

FIG. 10 is a flowchart showing an example of the IPv6 movement support processing 1000 executed by the IPv6 movement support processing unit 121 of the IPv6 movement support apparatus 107. In step 1001, it is checked whether an IPv6 movement detection message transmission request message has been received from an IPv6 mobile terminal (not shown) or the IPv4 / v6 mobile terminal 106. If not, the process proceeds to step 1003. In step 1002, an IPv6 movement detection message is transmitted to the terminal that has transmitted the IPv6 movement detection message transmission request message. In step 1003, I
It is checked whether or not the Pv6 move registration request message 1300 has been received. If it has been received, the process proceeds to step 1004, and if not, the process returns to step 1001.

In step 1004, it is checked whether or not the move registration request can be accepted. If the request cannot be accepted, the process proceeds to step 1005. If the request can be accepted, the process proceeds to step 1005.
Proceed to 6. In step 1005, the terminal that transmitted the IPv6 mobile registration request message 1300 receives the IP
Send a v6 move registration reject message. Then, the process returns to step 1001.

In step 1006, the own IPv6 address 1301 of the IPv6 move registration request message 1300
Is compared with the destination IPv6 address 1302. If the addresses are the same, the process proceeds to step 1007. If the addresses are different, the process proceeds to step 1008. In step 1007, it is determined that the mobile terminal has returned to its own network, and the information of the mobile terminal in the mobile terminal management table 126 is deleted. Then, the process proceeds to step 1011.

At step 1008, the destination IPv4 address 1 in the IPv6 migration registration request message 1300
303 is checked, and if “NULL” is set, the process proceeds to step 1009. If “NULL” is not set, the process proceeds to step 1010. Step 1009
Now, if the mobile terminal is an IPv6 network or IPv4
It is determined that the mobile terminal has moved to the / v6 network, and information of the mobile terminal is set in the mobile terminal management table 126. That is, the value of the destination IPv6 address 1302 in the received IPv6 migration registration request message 1300 is set in the destination IPv6 address 31 in the mobile terminal management table 126, and “NULL” is set in the destination IPv4 address 32.
Set. Then, the process proceeds to step 1011.

In step 1010, the mobile terminal sets the IPv4
It is determined that the mobile terminal has moved to the fourth network, and information of the mobile terminal is set in the mobile terminal management table 126. That is,
The destination IPv6 address 31 in the mobile terminal management table 126 is set to “NULL”, and the destination IPv4 address 32 is set to the value of the destination IPv4 address 1303 in the received IPv6 migration registration request message 1300. Then, the process proceeds to step 1012.

In step 1011, an IPv6 mobile registration permission message is transmitted to the mobile terminal. Then, the process returns to step 1001.

In step 1012, the mobile terminal sends the
A 4-encapsulated IPv6 mobile registration permission message is transmitted. That is, as shown in FIG. 16, the IPv4 header 1401
Is added, and the destination IPv4 of the IPv4 header 1401 is added.
The destination IPv4 address 1303 in the IPv6 migration registration request message 1300 is set as the fourth address 1402, the IPv4 address of the IPv6 movement support apparatus 107 is set as the source IPv4 address 1403, and the IPv4 address is set.
An encapsulated IPv6 movement registration permission message is created and transmitted. Then, the process returns to step 1001.

As described above, when the IPv4 / v6 mobile terminal 106 moves to the IPv4 network,
The IPv4 / v6 mobile terminal 106 transmits an IPv4-encapsulated IPv6 mobility registration request message 1300 to the IPv6 mobility support apparatus 107.
When the Pv6 movement support apparatus 107 receives the message, the IPv4 processing unit 122 performs IPv4 decapsulation of the message, extracts an IPv6 movement registration request message 1300, and passes the message to the IPv6 movement support processing unit 121.
Since this is a service provided by the existing IPv4, it is not necessary to add a new function to the IPv4 processing unit 122.

The IPv6 mobility support processing 1000 will be described in detail.
When moving from the Na-a 100 to the LAN-b 101, the process proceeds to steps 1001, 1002, 1003, and 1004. In step 1005, the destination IPv6 address 1302 (=
“NULL”) and own IPv6 address 1301
(= “:: 11.0.0.1”), so step 10
Proceed to 08. In step 1008, the destination IPv4 address 13 in the IPv6 migration registration request message 1300
Since 03 (= "20.0.0.1") is not "NULL", the process proceeds to step 1010. At step 1010, the mobile terminal management table 126 stores the IPv4 / v6 mobile terminal 106 in the mobile terminal management table 126.
Of the mobile terminal IPv6 address 30 as "::
11.0.0.1 ”is registered,“ 20.0.0.1 ”is registered as the destination IPv4 address 32, and“ NULL ”is registered as the destination IPv6 address 31. Step 1012
In the IPv6 move registration permission message 1601, “20.0.0.1” is set as the destination IPv4 address 1402 and “10.0.0.1” is set as the source IPv4 address 1403.
An IPv4 header 1401 in which “0.20” is set is added, and the packet is transmitted to the IPv4 / v6 mobile terminal 106.

FIG. 11 shows the transfer processing unit 1 for the mobile terminal of the IPv6 processing unit 124 in the IPv6 movement support apparatus 107.
25 is a flowchart illustrating an example of a mobile terminal-directed transfer process 1100 executed by the mobile terminal 25. FIG. In step 1101, IPv6
Of the IPv6 packets transmitted by the terminal 104 or another IPv6 terminal (not shown), the mobile terminal management table 126
Waits until an IPv6 packet addressed to the mobile terminal registered in. Is received, and if received, proceeds to step 1102. In step 1102, the destination IPv6 address 31 of the mobile terminal in the mobile terminal management table 126 is “NU
It is checked whether or not it is "LL". If it is "NULL", the process proceeds to step 1103, and if it is not "NULL", the process proceeds to step 1104. In step 1103, the IP
It is determined that the destination mobile terminal of the v6 packet is moving to the IPv4 network, and the IPv6 packet is sent to the IPv4 network.
Encapsulated and transmitted to the IPv4 network in which the destination mobile terminal is moving. The configuration of the IPv6 packet encapsulated in IPv4 at this time is as shown in FIG. 15, and the destination IPv4 address 1402 has the destination IPv4 of the corresponding mobile terminal in the mobile terminal management table 126.
Address 32 is set and source IPv4 address 140
In 3, the IPv4 address of the IPv6 mobility support apparatus 107 is set. Then, the process returns to step 1101.

In step 1104, the mobile terminal as the destination of the IPv6 packet is sent to the IPv6 network or the IPv6 network.
It is determined that it is moving to the 4 / v6 network,
6 packet, a new IPv6 header is added (hereinafter referred to as IPv6 encapsulation), and the destination mobile terminal is moving on the IPv6 network or IPv4 / IP.
Send to v6 network. That is, as shown in FIG. 17, the IPv6 packet 1704 contains an IPv6 header 1
701, and the mobile terminal management table 1 is added to the destination IPv6 address 1702 of the IPv6 header 1701.
26, the destination IPv6 address 3 of the corresponding mobile terminal
1 and set the source IPv6 address 1703 as IP
Set the IPv6 address of the v6 movement support device 107,
An IPv6 encapsulated IPv6 packet 1700 is created and transmitted. Then, the process returns to step 1101. Note that the processing procedure for encapsulating an IPv6 packet and transmitting it is a procedure in accordance with Mobile IPv6.

More specifically, the transfer processing 1100 to the mobile terminal will be described.
In the case of moving from -a100 to LAN-b101, IPv4 / v6
Mobile terminal management table 12 as information of mobile terminal 106
In the mobile terminal IPv6 address 30 in “6: 6 :: 11.0.0.
"1" is set, "NULL" is set in the destination IPv6 address 31, and the destination IPv4 address 3 is set.
2 is set to “20.0.0.1”, the IPv6 mobility support apparatus 107 sends an I-address to the IPv4 / v6
When the Pv6 packet is received, “20.0.0.1” is added to the destination IPv4 address 1402 for the IPv6 packet.
Is set, and “10.
An IPv4 header 1401 in which “0.0.20” is set is added, and the IPv4 / v6 mobile terminal 106 of the LAN-b 101 is added.
Transfer to The IPv6-encapsulated IPv6 packet 1500 is received by the IPv4 / v6 mobile terminal 106, de-capsulated by the IPv4 processing unit 111, and processed as a normal IPv6 packet. Thus, LA, which is an IPv4 / v6 network
From the Na-a 100 to the LAN that is an IPv4 network
In the case where the mobile terminal 106 moves to b101, the IPv4 / v6 mobile terminal 106 is also the IPv6 terminal 10 of the LAN-a100.
4 can receive the IPv6 packet transmitted. FIG.
FIG. 11 is a flowchart showing an example of the other-terminal-directed transfer processing 1200 executed by the other-terminal-directed transfer processing unit 123 of the IPv4 processing unit 122 in the IPv6 mobility support apparatus 107. In step 1201, the user (IPv6 mobility support device 10
7) Wait until an IPv4 packet addressed to is received, and if received, go to step 1202. In step 1202, it is checked whether or not the received IPv4 packet is an IPv4 encapsulated IPv6 packet. If the received IPv4 packet is an IPv4 encapsulated IPv6 packet, step 1 is executed.
The process proceeds to step 203, and if the packet is not an IPv6 encapsulated IPv6 packet, the process proceeds to step 1205. Step 12
At 03, it is checked whether or not the source terminal of the IPv4-encapsulated IPv6 packet is a mobile terminal registered in the mobile terminal management table 126, and if registered, the process proceeds to step 1204, where it is not registered. In this case, the process proceeds to step 1205. In step 1204, the IPv4
The four-encapsulated IPv6 packet is decapsulated in IPv4 and transmitted to the network where the destination terminal is located.
Then, the process returns to step 1201. Step 120
In step 5, the received IPv4 packet is discarded. Then, the process returns to step 1201.

The above-described transfer processing 1200 to another terminal will be described in detail.
When moving from a100 to LAN-b101, IPv4
4 / v6 mobile terminal 106 sends IP address to IPv6 terminal 104
When a v6 packet is transmitted, the destination I
“10.0.0.20” as the Pv4 address 1402 (IPv4
6 to the mobility support device 107) and the source IPv4
IPv4 with “20.0.0.1” set as address 1403
IPv4 encapsulation with an IPv4 header 1401 and IPv6
Since the packet is transmitted to the mobility support apparatus 107, the IPv6 mobility support apparatus 107 receives it and performs steps 1201 and 120.
In step 1204, the IPv4 header 1402 of the IPv6 encapsulated IPv6 packet is passed.
1 and remove the IPv6 packet 1501
The v6 terminal 104 transmits to the LAN-a 100. The IPv6 packet is received by the IPv6 terminal 104 as a normal IPv6 packet. Thus, IPv
IP from LAN-a100 which is 4 / v6 network
Even when the mobile terminal 106 moves to the v4 network LAN-b101, the IPv4 / v6
An IPv6 packet can be transmitted to the IPv6 terminal 104 of the Na-a 100. The existing method, Mobile IP
With the support of the movement of the terminal by the IPv4 by the IPv4 movement supporting apparatus a105 and the IPv4 movement supporting apparatus b108 supporting the v4, the communication using the IPv4 between the IPv4 / v6 mobile terminal 106 and another terminal is also possible.

When the IPv4 / v6 mobile terminal 106 is connected to the LAN-
When returning from b101 to LAN-a100, IPv4
The / v6 mobile terminal 106 detects that the mobile terminal 106 has moved to the IPv6 network or the IPv4 / v6 network by the movement detection processing 50 described above. And the IP mentioned above
By the v6 move registration processing 70, it is determined that the mobile terminal has returned to the LAN-a100, and ":: 11.
0.0.1 ”and the destination IPv6 address 1302
":: 11.0.0.1" same as the own IPv6 address 1301
Is set and “NU” is set as the destination IPv4 address 1303.
IPv6 move registration request message 13 with "LL" set
00 is transmitted to the IPv6 mobility support apparatus 107. IPv
Upon receiving the IPv6 move registration request message 1300, the IPv6 move support apparatus 107 receives the IPv6 move registration request message 1300, because the own IPv6 address 1301 and the move destination IPv6 address 1302 in the IPv6 move registration request message 1300 are the same address. 106 is LAN-a
100, and the mobile terminal management table 126
The information on the IPv4 / v6 mobile terminal 106 in the IP address is deleted. As a result, the IPv4 / v6 mobile terminal 106 can perform communication using normal IPv6. In addition, IPv4
The 4 / v6 mobile terminal 106 follows the processing procedure of Mobile IPv4, and also provides the IPv4 mobility support apparatus a105 with:
Since the return to the LAN-a 100 is notified by an IPv4 move registration request message, normal communication using IPv4 is also possible.

In the above embodiment, the movement between networks is automatically detected by using the IPv4 movement detection message and the IPv6 movement detection message. It instructs the movement detection processing unit 116 to execute the IPv4 movement registration processing 60
Alternatively, the IPv6 transfer registration process 70 or the IPv4 only transfer registration process 80 may be executed.

[0061]

According to the mobile terminal, the mobility support apparatus, and the network system of the present invention, when the IPv4 / v6 terminal moves from the IPv4 / v6 network to the IPv4 network, the IP that has already been established before moving.
Network connection using v6 can be maintained continuously, and communication using IPv6 can be newly performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a network system according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a movement state management table used in the IPv4 / v6 mobile terminal shown in FIG.

FIG. 3 is a configuration diagram of a mobile terminal management table used in the IPv6 mobility support device shown in FIG. 1;

FIG. 4 is a diagram showing an I / O in an IPv4 / v6 mobile terminal shown in FIG. 1;
It is a flowchart which shows Pv4 / v6 movement processing.

FIG. 5 is a flowchart showing a movement detection process in the IPv4 / v6 mobile terminal shown in FIG. 1;

FIG. 6 is a block diagram illustrating I / O in the IPv4 / v6 mobile terminal shown in FIG. 1;
It is a flowchart which shows Pv4 movement registration processing.

FIG. 7 is a diagram illustrating an I / O in an IPv4 / v6 mobile terminal shown in FIG. 1;
It is a flowchart which shows Pv6 movement registration processing.

FIG. 8 is a diagram illustrating an I / O mode in the IPv4 / v6 mobile terminal shown in FIG. 1;
It is a flowchart which shows Pv4only transfer registration processing.

FIG. 9 is a diagram illustrating an I / O in the IPv4 / v6 mobile terminal shown in FIG. 1;
It is a flowchart which shows a Pv6 packet transmission process.

FIG. 10 is a diagram showing an I in the IPv6 mobility support apparatus shown in FIG. 1;
It is a flowchart which shows Pv6 movement support processing.

FIG. 11 is a flowchart showing a transfer process to a mobile terminal in the IPv6 mobility support apparatus shown in FIG. 1;

FIG. 12 is a flowchart showing a transfer process to another terminal in the IPv6 mobility support apparatus shown in FIG. 1;

FIG. 13 is a configuration diagram of an IPv6 movement registration request message.

FIG. 14 is a configuration diagram of an IPv6 encapsulated IPv6 mobility registration request message.

FIG. 15 is a configuration diagram of an IPv4 encapsulated IPv6 packet.

FIG. 16 is a configuration diagram of an IPv6 encapsulated IPv6 transfer registration permission message.

FIG. 17 is a configuration diagram of an IPv6 encapsulated IPv6 packet.

[Explanation of symbols]

106: IPv4 / v6 mobile terminal, 110: communication processing unit, 111: IPv4 processing unit, 112: IPv6 processing unit, 113: IPv6 packet transmission processing unit, 114: I
Pv4 / v6 movement processing unit, 115: movement detection processing unit, 1
16: IPv4 move registration processing section, 117: IPv6 move registration processing section, 118: IPv4 only move registration processing section, 119: movement state management table, 107: IPv6
Mobility support device, 120: communication processing unit, 121: IPv6
Movement support processing unit, 122: IPv4 processing unit, 123: Transfer processing unit for other terminals, 124: IPv6 processing unit, 125:
Mobile terminal destination transfer processing unit, 126: Mobile terminal management table, 40: IPv4 / v6 move processing, 50: Move detection processing, 60: IPv4 move registration processing, 70: IPv6 move registration processing, 80: IPv4 only move registration processing, 9
0: IPv6 packet transmission processing, 1000: IPv6 movement support processing, 1100: transfer processing for mobile terminal, 120
0: Transfer processing to another terminal.

Claims (7)

[Claims] 1. An Internet Protocol (IP) v4 (IP
IPv4 processing means for providing services according to version 4), IPv6 processing means for providing services according to IPv6 (IP version 6), and communication processing means for controlling transmission and reception of packets to and from the network. In a moving mobile terminal, an IPv4 / v6 network (a network capable of communication using both IPv4 and IPv6)
When a mobile terminal moves to a network (a network capable of only communication using IPv4), the mobile terminal registers the movement with a mobility support device connected to an IPv4 / v6 network to support the movement of the mobile terminal. IPv
IPv4 header (IPv4 address used in IPv4) in which the IPv4 address of the mobile support device is set as the destination address and the IPv4 address of the mobile terminal that can be used in the destination IPv4 network is set as the source address in the message used in Step 6. A mobile terminal, comprising: a mobile registration processing unit for adding a header to the transmission. 2. An IPv4 service providing service in accordance with IPv4.
4 processing means and IPv6 for providing services according to IPv6
6 processing means and communication processing means for controlling transmission and reception of packets to and from a network, wherein a mobile terminal that moves between networks moves as an address of a destination when moving from an IPv4 / v6 network to an IPv4 network. An IPv4 header that sets the IPv4 address of the support device and sets the IPv4 address of a mobile terminal that can be used in the destination IPv4 network as the source address,
IPv6 packet to be transmitted to another terminal (IPv6
A mobile terminal comprising: a packet transmission processing unit that generates an IPv4 encapsulated IPv6 packet added to the packet used in (1), and transmits the IPv4 encapsulated IPv6 packet. 3. An IPv4 for providing a service according to the IPv4
4 processing means and IPv6 for providing services according to IPv6
6 processing means, and communication processing means for controlling transmission / reception of packets to / from the network, wherein a mobile terminal moving between networks is connected to another IPv4 from a network in which a mobility support device used by the mobile terminal exists. Network or IPv
It is characterized by comprising a movement detecting means for detecting whether the mobile device has moved to one of six networks (a network capable of only communication using IPv6) or an IPv4 / v6 network, and a moving state managing means for managing the detected moving state. Mobile terminal. 4. An IPv4 service providing service in accordance with IPv4
4 processing means and IPv6 for providing services according to IPv6
6 processing means, and a communication processing means for controlling transmission and reception of packets to and from the network, the mobile support apparatus supporting the movement of a terminal performing communication using IPv6, wherein the mobile terminal having moved to the IPv4 network is The IPv4 header transmitted to the mobility support device is added,
When receiving a message used in IPv6 for registering a move, a mobile terminal managing means for managing an IPv4 address of a mobile terminal usable in a destination IPv4 network, and permitting the mobile terminal to register the move. An IPv4 message in which the IPv4 address of the mobile terminal usable in the destination IPv4 network is set as the destination address and the IPv4 address of the mobility support device is set as the source address in the message used in IPv6 to be performed.
And a movement support processing means for transmitting the data with the addition of four headers. 5. An IPv4 service providing service in accordance with IPv4
4 processing means and IPv6 for providing services according to IPv6
6 processing means and communication processing means for controlling transmission / reception of packets to / from the network, and a movement support apparatus for supporting movement of a terminal performing communication using IPv6, wherein IPv4 encapsulated by the mobile terminal is encapsulated. A mobility support apparatus comprising: a transfer processing unit that removes an IPv4 header when an IPv6 packet is received, and transmits the extracted IPv6 packet to the network again. 6. An IPv4 for providing a service according to the IPv4
4 processing means and IPv6 for providing services according to IPv6
6. A mobility support device comprising: a processing unit for controlling transmission / reception of packets to / from a network, and supporting movement of a terminal performing communication using IPv6. When an IPv6 packet transmitted by another terminal is received, the IPv4 address of the destination mobile terminal usable in the destination IPv4 network is set as the destination IPv4 address, and the IPv4 address of the mobile support device is set as the source IPv4 address. An IPv4 packet is created by adding an IPv4 header in which an IPv4 address is set to a received IPv6 packet to create an IPv4-encapsulated IPv6 packet, and is provided with a mobile terminal transfer processing means for transmitting the IPv4-encapsulated IPv6 packet. Movement support device. 7. The mobility support device according to claim 4, 5 or 6, wherein the connection device or a network system in which the IPv4 / v6 network and the IPv4 network are connected by the connection device and the third network. IPv4
And the mobile terminal according to claim 1, 2 or 3 on an IPv4 / v6 network or I / V6 network.
A network system having a Pv4 network.