JPH1168850A - Control method for mobile terminal, mobile aid terminal and network system assisting movement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain communication according to either of the IPv6 and IPv4 when a mobile terminal moves from an IP network capable of communication in compliance with both the IPv4, IPv6 to an IP network where the communication is available by only the other of the IPv4, IPv6. SOLUTION: A LAN-a is a network available of communication in compliance with the IPv4, IPv6 and a LAN-b is a network available of communication in compliance with the IPv4. Upon the receipt of an IP packet from an IPv4/v6 mobile terminal 106 to an IPv6 terminal 104, a mobile destination IPv6 mobile aid terminal 109 adds an IPv4 header to the packet and sends the resulting packet to a mobile source IPv6 mobile aid terminal 107. The mobile aid terminal 107 sends the IP packet from which the IPv4 header is eliminated to the terminal 104. A destination of the IPv4 header is an IPv4 address of the mobile aid terminal 107 and a source of the IPv4 header is an IPv4 address of the mobile aid terminal 109.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IP network capable of communicating according to IP (Internet Protocol) version 4 and version 6 and an IP network capable of communicating only according to IP version 4 or to an IP network. The present invention relates to a control method for supporting the movement of a terminal between networks with an IP network capable of performing only communication according to version 6, a movement support terminal, and a network system for performing movement support.

[0002]

2. Description of the Related Art With the spread of small and lightweight terminals and the rapid development of the Internet, there is an increasing demand to take terminals out of offices and homes and use them anywhere.
However, the conventional TCP / IP (Transmission)
ion Control Protocol / Inte
rnet Protocol), when a terminal is moved to another network,
It is necessary to change settings such as an IP address, which is information for uniquely identifying a terminal in an IP network of the terminal, in accordance with a destination network environment. RFC, which is a method of automatically distributing IP addresses
(Request For Comment) 1541
DHCP (Dynamic Host Conf)
iprotocol), etc.
Even if the setting of the IP address is automatically changed, the network connection already established with another terminal cannot be maintained using the IP address used in the network before moving. was there. Therefore, a method for supporting movement of a terminal between networks has been devised. Among them, as a typical method,
OSI (Open Systems Intercon)
connection) is a protocol of the third layer (network layer) of the reference model, and is currently used for solving problems such as IP version 4 (hereinafter referred to as IPv4) widely used in the Internet and the like and address exhaustion in IPv4. For each version 6 (hereinafter referred to as IPv6) of the IP for which the specifications have been formulated, RFC
IP Mobility support described in 2002
in IPv4 (hereinafter referred to as Mobile IPv4) and IETF (Internet Engineering).
ering Task Force) Draft ('97
The latest version in February of the year is draft-ietf-mobile.
eip-ipv6-02. txt)
ty support in IPv6 (hereafter Mobi)
le IPv6).

[0003] Note that IPv4 described in the text refers to an IP address having an address length of 32 bits.
Means that the address length of the IP address is larger than 32 bits.

[0004] Mobile IPv4 and Mobile
According to IPv6, even when the user moves the terminal to another network, the user does not change the setting of the IP address or the like of the terminal or disconnect the network connection already established with the other terminal before moving. , It is possible to perform the same communication as before the movement.

[0005] The "terminal" described in the text is a PC (Pe
rSonal Computer) and WS (WorkS)
station), owns the IP address of the router, etc.
Refers to all devices that perform communication using P.

[0006]

In general, IPv4 to I
It is considered that the transition to Pv6 will be made gradually, and not all networks will use IPv6 at once. Therefore, for the time being, a network (hereinafter, referred to as an IPv4 network) including only terminals that perform communication using only IPv4 (hereinafter, referred to as an IPv4 terminal),
A terminal that communicates using only IPv6 (hereinafter referred to as IPv6)
Network (hereinafter referred to as IP)
v6 network) and a terminal that communicates using both IPv4 and IPv6 in a mixed manner (hereinafter referred to as IPv4 / IPv6 network).
There is a network (hereinafter, referred to as an IPv4 / v6 network) composed of an IPv4 terminal and an IPv4 terminal.

First, the IPv4 / v6 network is a Mob
Let us consider a case where the network supports both ile IPv4 and Mobile IPv6. Mo
In the case of the file IPv4, a Mobile IPv4 procedure is performed between a mobile terminal that moves between networks and a mobile support terminal that supports movement of a mobile terminal that performs communication using IPv4 (hereinafter referred to as an IPv4 mobile support terminal). Exchange messages. Similarly Mobil
e In IPv6, the Mobile IPv6 procedure was followed between a mobile terminal moving between networks and a mobile support terminal supporting the movement of a mobile terminal performing communication using IPv6 (hereinafter referred to as an IPv6 mobile support terminal). Exchange messages.

[0008] Mobi in IPv4 / v6 network
An IPv4 / v6 mobile terminal that supports both le IPv4 and MobileIPv6 is a different IPv4 / v6
When moving to the network, the destination IPv4 / v6
Since the network can perform communication using both IPv4 and IPv6, between the IPv4 / v6 mobile terminal and the IPv4 mobile support terminal and the IPv6 mobile support terminal,
Mobile IPv4 and Mobile IPv6
Exchange of messages according to the procedure becomes possible. Therefore, Mobile IPv4 and Mobile IPv6
Can support the movement of the IPv4 / v6 mobile terminal. As a result, the moved IPv4 / v6 mobile terminal
Continue communication without changing settings such as IP addresses and disconnecting network connections using IPv4 and IPv6 that have already been established with other IPv4 and IPv6 terminals before moving. Becomes possible. In addition, another terminal and IPv4, IPv4
6 can be performed.

[0009] Next, the IPv4 / v6 mobile terminal receives the IPv4 / v6.
Consider a case in which the mobile terminal has moved from a v6 network to an IPv4 network that can perform only communication conforming to IPv4 and supports Mobile IPv4. In this case, I
Since communication using IPv4 between the Pv4 / v6 mobile terminal and the IPv4 mobility support terminal becomes possible, Mobil
e Support for movement of a terminal by IPv4 becomes possible. Therefore, the IPv4 / v6 mobile terminal can continue to communicate without disconnecting the network connection using IPv4 that has already been established with another IPv4 terminal before moving, and newly establishes IPv4. It is also possible to use the communication.

[0010] However, since communication using IPv6 cannot be performed on an IPv4 network, IPv4 / v
M6 between the IPv6 mobile terminal and the IPv6 mobility support terminal
It becomes impossible to exchange messages according to the obey IPv6 procedure. Therefore, Mobile IPv
6 cannot support the movement of the terminal.
There is a problem that the 4 / v6 mobile terminal cannot keep the network connection using IPv6 already established before moving to another IPv6 terminal, and cannot perform communication. In addition, it becomes impossible to newly communicate with another terminal using IPv6.

Similarly, if the IPv4 / v6 mobile terminal is an IPv4
/ V6 network that can only communicate using IPv6 and supports Mobile IPv6
Consider the case of moving to a Pv6 network. Even in this case, since communication using IPv4 cannot be performed on the IPv6 network, the IPv4 / v6 mobile terminal and the IPv4
There is a problem in that it is impossible to exchange a message in accordance with the Mobile IPv4 procedure with a mobile support terminal, and it is impossible to support mobile terminal movement using Mobile IPv4.

A first object of the present invention is to enable an IPv4 / v6 mobile terminal to use an IPv4 / v6 mobile terminal without making any change to an existing IPv4 mobile support terminal or an IPv4 / v6 mobile terminal.
Even when moving from the network to the IPv4 network, the setting such as the address of the IPv4 / v6 mobile terminal is not changed, and the IPv6 between other IPv6 terminals is not changed.
It is an object of the present invention to provide a mobile terminal control method, a mobile support terminal, and a network system for performing mobile support, which enable communication using the mobile terminal.

A second object of the present invention is to provide an existing IPv4
The IPv4 / v6 mobile terminal is able to use the IPv4 / v6 mobile terminal without any change to the IPv6 / mobile support terminal or the IPv4 / v6 mobile terminal.
Even when moving from the v6 network to the IPv6 network, the setting of the address or the like of the IPv4 / v6 mobile terminal is not changed and the IP between the IPv6 terminal and another IPv4 terminal is not changed.
a control method of a mobile terminal enabling communication using v4,
An object of the present invention is to provide a movement support terminal and a network system for performing movement support.

[0014]

SUMMARY OF THE INVENTION The present invention provides a first type of IP.
And a first IP network capable of performing communication in accordance with the second type of IP and a second IP network capable of performing only communication in accordance with the first type of IP. When the mobile terminal capable of performing communication according to the above is moved from the first IP network to the second IP network, the mobile support terminal performs communication according to the second type of IP with another terminal belonging to the first IP network. A method of controlling, wherein an IP packet from another terminal to a mobile terminal according to a second type of IP belongs to the second IP network as a destination address by a first mobility support terminal belonging to the first IP network. An IP address according to the first type of IP of the second mobile support terminal is set, and the first type of I of the first mobile support terminal is set as a source address. The set of IP addresses according to 1
A method for controlling a mobile terminal, in which a second type of IP header is added and transmitted to a second mobile support terminal, and the first type of IP header is deleted by the second mobile support terminal to transmit an IP packet to the mobile terminal Features.

On the other hand, a second type of I from a mobile terminal to another terminal
For the IP packet according to P, the second mobile support terminal sets an IP address according to the first type of IP of the first mobile support terminal as a destination address and a first address of the second mobile support terminal as a source address. A first type IP header in which an IP address according to the type of IP is set is added and transmitted to the first mobile support terminal.
The kind of IP header is deleted and the IP packet is transmitted to another terminal.

[0016] In addition, in response to the second type of mobile registration request message received from the mobile terminal, the second mobile support terminal sets an IP address according to the first type of IP of the first mobile support terminal as a destination address. Then, according to the first type IP of the second mobility support terminal as the source address,
A first type IP header in which a P address is set is added and transmitted to the first mobility support terminal, and a message according to the second type IP for permitting movement is transmitted by the first mobility support terminal. An IP address according to the first type of IP of the second mobility support terminal is set as the destination address, and an IP address according to the first type of IP of the first mobility support terminal is set as the source address.
A first type IP header in which a P address is set is added and transmitted to the second mobility support terminal.

Further, the present invention is characterized by a network system for supporting the movement of a mobile terminal as described above.

Further, the present invention is characterized by a first movement support terminal and a second movement support terminal that support the movement of the mobile terminal as described above.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First, an IPv4 / v6 mobile terminal is set to IPv4
A case of moving from the / v6 network to the IPv4 network will be described.

An example of the configuration of a network system to which the present invention is applied and an example of the structure of a mobility support terminal will be described with reference to FIG. As illustrated, the network system shown in the present embodiment is a LAN (Local Area Net).
work-a100, LAN-b101, and LAN-a100 and LAN-b10 via a public line or a dedicated line.
WAN (Wide Area Network)
ork) 102. OS on LAN-a100
IPv4 that performs communication using only IPv4 as a protocol of the network layer corresponding to the third layer of the I reference model
Terminal 103, IPv6 that performs communication using only IPv6
6 terminal 104, an IPv4 movement support terminal a10 that supports movement between networks for a terminal performing communication using IPv4 according to a procedure according to Mobile IPv4
5, communicate using both IPv4 and IPv6,
When an IPv4 / v6 mobile terminal 106 that moves between networks and a terminal that performs communication using IPv4 and IPv6 and performs communication using IPv6 move to another network, There is a source IPv6 mobility support terminal 107 that provides support. Also, on the LAN-b101, an IPv4 mobility support terminal b108 and a terminal that performs communication using IPv4 and IPv6 and performs communication using IPv6 are LAN.
When moving to -b101, there is a destination IPv6 movement support terminal 109 that supports movement of the terminal.

The source IPv6 movement support terminal 107 also operates as a router that handles both packets used in IPv4 (hereinafter referred to as IPv4 packets) and packets used in IPv6 (hereinafter referred to as IPv6 packets).
-Connect between a100 and WAN102. Also IPv4
The router 110 that handles only packets connects the LAN-b 101 and the WAN 102. Therefore, both the IPv4 packet and the IPv6 packet can pass through the router to the outside network from the LAN-a100, whereas only the IPv4 packet can go outside from the LAN-b101. Becomes possible. Note that L
It is possible to transmit and receive an IPv4 packet and an IPv6 packet within the AN-a100 and the LAN-b101.

Here, a terminal that performs communication using IPv4 holds an IP address (hereinafter referred to as an IPv4 address) that is information for uniquely identifying the terminal. Similarly, a terminal that performs communication using IPv6 is an IP for IPv6.
Address (hereinafter referred to as an IPv6 address).
In the present embodiment, the IPv4 terminal 103, the IPv4 mobility support terminal a105, and the IPv4 mobility support terminal b108 each have a "10.0.0.1" as an IPv4 address.
0 "," 10.0.0.11 ", and" 20.0.0.
11 ", and the IPv6 terminal 104 holds" 11 :: 20 "as the IPv6 address.
Also, the source IPv6 mobility support terminal 107, the destination IPv6
6 mobile support terminal 109 and IPv4 / v6 mobile terminal 10
6 are “10.0.
0.30 "," 10.0.0.1 "," 20.0.0.
1, "11 :: 30" and "1" as IPv6 addresses.
1 :: 1 "and" 21 :: 1 ".

The IPv4 / v6 mobile terminal 106 is connected to another IPv4 network or an IPv4 / v6
An IPv4 movement processing unit 113 that performs processing according to Mobile IPv4 when moving to a network, and an IPv6 movement processing unit that performs processing according to Mobile IPv6 when the terminal moves to another IPv6 network or an IPv4 / v6 network. 115, IPv4 processing unit 1 that performs processing according to the service provided by IPv4
12, an IPv6 processing unit 114 that performs processing in accordance with the service provided by IPv6, and a communication processing unit 111 that performs transmission and reception control of packets to and from the LAN.

The source IPv6 mobility support terminal 107
An IPv6 mobile terminal that performs communication using Pv6 and moves between networks (not particularly shown);
Alternatively, an IPv6 movement support processing unit 117 that supports movement for the IPv4 / IPv6 mobile terminal 106, another I
A mobile terminal management table 122 for managing information of mobile terminals that have moved to a Pv6 network or an IPv4 / v6 network; an IPv4 processing unit 118 for performing processing according to services provided by IPv4;
IPv4 / v6 transferred from the v6 mobility support terminal 109
The other-terminal-directed transfer processing unit 119 that performs processing of transferring the IPv6 packet transmitted from the v6 mobile terminal 106 to the destination IPv6 terminal, the IPv6 processing unit 120 that performs processing according to the service provided by IPv6, and the other IPv6 terminal
Transfer destination IPv6 transfer support terminal transfer processing unit 12 for transferring the IPv6 packet transmitted to the v4 / v6 mobile terminal 106 to the transfer destination IPv6 movement support terminal 109
1 and a communication processing unit 116 that controls transmission and reception of packets to and from the LAN.

The destination IPv6 mobility support terminal 109
Is a network (LAN-b1) in which the IPv4 / v6 mobile terminal 106 belongs to the destination IPv6 mobility support terminal 109.
01), the destination IPv6 movement support processing unit 123 that supports movement of the mobile terminal 106,
The mobility support management table 128 for managing the information of the mobile terminal 106, and the mobility support terminal address table 1 for registering the address information of the source IPv6 mobility support terminal 107.
30, an IPv4 processing unit 124 that performs processing in accordance with a service provided by IPv4, a source IPv6 movement support terminal 1
IPv4 / v6 mobile terminal 106 transferred from 07
A mobile terminal-addressed transfer processing unit 125 that performs a process of transferring a packet addressed to the IPv4 / v6 mobile terminal 106, and an IPv6 processing unit 1 that performs a process according to a service provided by IPv6
26, a source IPv6 mobile support terminal forwarding processor 127 for performing a process of transferring an IPv6 packet transmitted from the IPv4 / v6 mobile terminal 106 to another IPv6 terminal to the source IPv6 mobile support terminal 107, and a packet to the LAN And a communication processing unit 129 that performs transmission / reception control and the like.

Here, the source IPv6 mobility support terminal 1
07, the components provided particularly in the present invention include an IPv6 movement support processing unit 117, a transfer processing unit 119 to another terminal, and a transfer processing unit 1 to the destination IPv6 movement support terminal.
21 and a mobile terminal management table 122. The invention components of the destination IPv6 movement support terminal 109 include a destination IPv6 movement support processing unit 123, a transfer processing unit 125 to the mobile terminal, a transfer processing unit 127 to the source IPv6 movement support terminal, a movement support terminal address table 130,
And a transfer support management table 128.

FIG. 2 shows the mobile terminal management table 12 described above.
2 shows an example. As shown in the figure, the mobile terminal management table 122 includes a mobile terminal IPv6 address 20, which is an IPv6 address of the mobile terminal, a destination IPv6 address 21 indicating a destination IPv6 network or an IPv6 address used by the mobile terminal in the IPv4 / v6 network. , And the destination IPv6 mobility support terminal 109
The destination IPv6 movement support terminal IPv4 address 22 indicating the IPv4 address of the destination. Here, the destination IPv6
The mobile terminal has an IP address of the mobile support terminal IPv4 address 22.
When moving to the IPv6 network or the IPv4 / v6 network, “NULL” is set. When moving to the IPv4 network, the IPv4 address of the destination IPv6 movement support terminal 109 existing in the network is set. Although FIG. 4 shows a case where entries for a plurality of mobile terminals exist, there is no entry of the mobile terminal in this table in an initial state. The update processing of this table will be described later.

FIG. 3 shows an example of the mobility support terminal address table 130 described above. As shown in the figure, the mobility support terminal address table 130 stores all the source IPv6 mobility support terminals existing in the network system (in the present embodiment, only the source IPv6 mobility support terminal 107 on the LAN-a 100 is shown). , The source IPv6 movement support terminal IPv4 address 30 and the source IPv6 movement support terminal IPv6 address 31 which are the IPv4 address and the IPv6 address of the source. This table is set by an administrator or the like.

FIG. 4 shows the movement support management table 12 described above.
8 shows an example. As illustrated, the mobility support management table 128 includes a mobile terminal IPv6 address 40, which is an IPv6 address of the IPv4 / v6 mobile terminal 106, and a source IPv6 migration existing in a source network (hereinafter referred to as a home network) of the mobile terminal. Source IPv6 movement support terminal I which is the IPv4 address of the support terminal 107
A Pv4 address 41 and a registration flag 42 indicating whether the entry is “temporary registration” or “main registration”. Although FIG. 4 shows a case where entries for a plurality of mobile terminals exist, there is no entry of the mobile terminal in this table in an initial state. The update processing of this table will be described later.

In the configuration described above, IPv4 / v6
L where the mobile terminal 106 is an IPv4 / v6 network
LAN that is an IPv4 network from AN-a100
The processing operations of the IPv4 / v6 mobile terminal 106, the source IPv6 mobility support terminal 107, and the destination IPv6 mobility support terminal 109 when moving to -b101, and the handling of the above-described tables will be described in detail below.

FIG. 5 is a flow chart showing detection of whether the IPv4 / v6 mobile terminal 106 has moved to another IPv4 network or an IPv4 / v6 network.
FIG. 11 is a flowchart illustrating an example of processing of an IPv4 movement processing unit 112 that performs various kinds of processing when moving. Note that the present IPv4 transfer processing unit 112 uses the Mobile IPv4
This is processing according to the processing procedure of No. 4. First, the IPv4 movement processing unit 112 first executes another IPv4 network or I
An IPv4 movement detection message transmission request message, which is a message for requesting transmission of an IPv4 movement detection message that is a message for detecting movement to the Pv4 / v6 network, is transmitted (step 51). The message for detecting the movement of IPv4 is an IP message.
The message is transmitted periodically or when the v4 mobility support terminal receives an IPv4 mobility detection message transmission request message. Next, the IPv4 movement processing unit 112 determines whether or not an IPv4 movement detection message has been received (step 52). If the IPv4 movement detection message has been received (step 52Y), the IPv4 movement processing unit 11
2 determines whether the message has been transferred to another network (step 53). Network address information and the like are set in the IPv4 movement detection message, and movement is detected by comparing this address information with the IPv4 address of the IPv4 / v6 mobile terminal 106 itself. As a result of the determination as to whether or not it has moved to another network, if it has moved to another network (step 53Y), the IPv4 movement processing unit 11
2 is the home network of the IPv4 / v6 mobile terminal 106 (LA in this embodiment)
It is determined whether or not N-a 100 is a home network) (step 54). In this case, the IP
The v4 movement detection message is used. As a result of the determination as to whether or not the terminal is the home network, if the terminal is not the home network (Step 54N), the IPv4 movement processing unit 112 next transmits the IPv4 packet addressed to the IPv4 / v6 mobile terminal 106 to the IPv4 movement support terminal a105. An IPv4 address of a transfer destination used for transfer to the mobile terminal moving to another network is acquired (step 55). The IPv4 / v6 mobile terminal 106 obtains the IPv4 address for the transfer destination from the address provided by the IPv4 mobility support terminal b108, or obtains the address by using DHCP for automatically distributing the address or by manual setting. Then, the IPv4 transfer processing section 112 executes the IPv4
An IPv4 movement registration request message is transmitted to the movement support terminal a105 to notify the movement and register the movement (step 56). Thereafter, the IPv4 transfer processing unit 11
2 waits until an IPv4 mobile registration permission message, which is a response to the IPv4 mobile registration request message, is received from the IPv4 mobile support terminal a105 (step 57). Thereafter, the IPv4 transfer processing unit 112 repeats the above-described processing.

FIG. 6 shows the detection of whether the IPv4 / v6 mobile terminal 106 has moved to another IPv6 network or an IPv4 / v6 network,
FIG. 9 is a flowchart illustrating an example of processing of an IPv6 movement processing unit 115 that performs various kinds of processing when moving. Note that the present IPv6 transfer processing unit 115 uses the Mobile IPv6
This is processing according to the processing procedure of No. 6. First, the IPv6 movement processing unit 115 transmits a request to another IPv6 network or I
An IPv6 movement detection message transmission request message, which is a message for requesting transmission of an IPv6 movement detection message that is a message for detecting movement to the Pv4 / v6 network, is transmitted (step 61). Note that the IPv6 movement detection message is IP
The message is transmitted periodically or when the v6 mobility support terminal receives the IPv6 movement detection message transmission request message. Next, the IPv6 movement processing unit 115 determines whether or not an IPv6 movement detection message has been received (step 62). When the IPv6 movement detection message has been received (step 62Y), the IPv6 movement processing unit 115
Determines whether or not it has moved to another network by the message (step 63). Note that network address information and the like are set in the IPv6 movement detection message, and movement is detected by comparing this address information with the IPv6 address of the IPv4 / v6 mobile terminal 106 itself. As a result of the determination as to whether or not it has moved to another network, if it has moved to another network (step 63Y), the IPv6 movement processing unit 11
5 determines whether the destination network is a home network (in this embodiment, the LAN-a 100 is the home network) (step 6).
4). Also in this determination, the IPv6 movement detection message is used. If the result of the determination as to whether or not the network is a home network is not a home network (step 64N), the IPv6 transfer processing unit 115 acquires an IPv6 address that can be used next in the transfer destination network (step 65). ). The acquisition of the IPv6 address can be performed by using DHCP for automatically distributing the address or by using the IPv6 address.
6, an automatic address generation function, which is one of the functions provided by
Alternatively, it is performed by hand setting or the like. Then, the IPv6 movement processing unit 115 transmits an IPv6 movement registration request message to notify and register the movement to the movement source IPv6 movement support terminal 107 (step 66).

FIG. 13 shows the IPv4 / v6 mobile terminal 1
IPv6 movement registration request message 130 transmitted by 06
0 shows the data configuration. As shown, the IPv6 move registration request message 1300 includes an IPv6 header 1301.
And IPv6 data 1304. IPv6 header 1
Reference numeral 301 denotes a destination IPv6 address 1302 and a source I
The destination IPv6 address 1302 includes the IPv6 address of the source IPv6 movement support terminal 107 and the source IPv6 address 1303.
Is set to the IPv6 address acquired by the IPv4 / v6 mobile terminal 106 in the destination network. Also IP
The v6 data 1304 includes the own IPv6 address 130 which is the IPv6 address of the terminal transmitting this message.
5. Newly acquired IP in the destination network
It is composed of a destination IPv6 address 1306 which is a v6 address. The destination IPv6 address 1306 includes
L where the 4 / v6 mobile terminal 106 is the home network
When returning to AN-a100, the own IPv6 address 13
Set the same address as 05.

Thereafter, the IPv6 movement processing unit 115 waits until receiving an IPv6 movement registration permission message which is a response to the IPv6 movement registration request message 1300 from the source IPv6 movement support terminal 107 (step 67).
After receiving the message (step 67Y), the process returns to the first step 61 again. Thereafter, the IPv6 transfer processing unit 115 repeats the above-described processing.

FIG. 7 shows the source IPv6 mobility support terminal 10
7 is a flowchart illustrating an example of a process of an IPv6 movement support processing unit 117 that performs an inter-network movement support process for an IPv6 mobile terminal (not particularly illustrated) or the IPv4 / v6 mobile terminal 106 in FIG. is there. IP
First, the v6 movement support processing unit 117 determines whether or not an IPv6 movement detection message transmission request message has been received (step 701). As a result of the determination, if the message has been received (step 701Y), the IPv6 movement support processing unit 117 transmits an IPv6 movement detection message (step 702). Then, the IPv6 movement support processing unit 117 sends the IPv6 movement registration request message 1
300 is determined (step 70).
3). If the result of the determination is that the message has been received (step 703Y), the IPv6 movement support processing unit 117
Determines whether the transfer registration request can be accepted (step 704). If the result of the determination is that the request is not acceptable (step 704N), the IPv6 movement support processing unit 11
7 is an IPv6 mobile registration request message 13 addressed to the mobile terminal
IPv4 which is a message for rejection of registration of 00
6. Send a move registration rejection message (step 70)
5). If acceptable (step 704Y), the IP
Next, the v6 movement support processing unit 117 sends the
Pv6 address 1305 and destination IPv6 address 13
06 (step 706). As a result of the comparison, the own IPv6 address 1305 and the destination IPv6 address 1
306 is the same address (step 706)
Y), the IPv6 movement support processing unit 117 determines that the mobile terminal has returned to the home network, and deletes the information of the corresponding mobile terminal in the mobile terminal management table 122 (Step 707). And the IPv6 movement support processing unit 1
17 transmits an IPv6 mobile registration permission message, which is a message for permitting response of registration of the IPv6 mobile registration request message 1300, to the mobile terminal (step 71).
1). As a result of the comparison, if the own IPv6 address 1305 and the movement destination IPv6 address 1306 are different addresses (step 706N), the IPv6 movement support processing unit 1
17 further judges whether or not the received IPv6 movement registration request message 1300 has been transferred by adding a IPv4 header (hereinafter referred to as IPv4 encapsulation) by the movement destination IPv6 movement support terminal 109 (step 708). ). The destination IPv6 mobility support terminal 10
I of IPv6 mobile registration request message 1300 according to I.9
The Pv4 encapsulation is performed by the destination IPv6 movement support processing unit 123 in the destination IPv6 movement support terminal 109 described later. Also, the source IPv6 mobility support terminal 107
Receives the IPv4-encapsulated IPv6 move registration request message 1300, the IPv4 processing unit 118 in its own removes the IPv4 header (hereinafter referred to as IPv4).
4 decapsulation), IPv6 mobility support processing unit 11
Passed to 7. The IP in the IPv4 processing unit 118
v4 decapsulation is one of the services provided by the existing IPv4.

As a result of the determination as to whether or not the packet has been transferred by encapsulating IPv4, if the packet has not been transferred (step 708N), the IPv6 movement support processing unit 117
If the mobile terminal is on another IPv6 network or IPv4
It is determined that the mobile terminal has moved to the 4 / v6 network, and information of the mobile terminal is set in the mobile terminal management table 122. At this time, the value of the destination IPv6 address 1306 in the received IPv6 migration registration request message 1300 is stored in the destination IPv6 address 21 in the mobile terminal management table 122, and the destination IPv6 mobility support terminal IPv4 address 22
Is set to "NULL" (step 709). Then, the IPv6 movement support processing unit 117 sends the IP address to the mobile terminal.
Transmit v6 move registration permission message (step 71)
1). If the result of the determination is that the packet is IPv4 encapsulated and transferred (step 708Y), the IPv6
The movement support processing unit 117 determines that the mobile terminal has moved to the IPv4 network, and
The information of the mobile terminal is set in (Step 710). At this time, the destination IPv6 in the mobile terminal management table 122
The destination IPv6 address 130 in the transferred IPv6 migration registration request message 1300 is stored in the address 21.
The value of 5 is set in the destination IPv6 mobility support terminal IPv4 address 22 as the value of the source IPv4 address in the IPv4 header added to the transferred IPv6 mobility registration request message 1300. Then, the IPv6 movement support processing unit 117 sends the response to the mobile terminal,
The v6 move registration permission message is encapsulated in IPv4 and transmitted (step 712).

At this time, the IPv4 encapsulated IPv4
FIG. 14 shows the configuration of the 6-movement registration permission message 1400. As shown in the figure, the message has a configuration in which an IPv4 header 1401 is added to an IPv6 movement registration permission message 1404. The destination IPv4 address 1402 in the IPv4 header 1401 has a destination IPv6 mobility support terminal IPv registered in the mobile terminal management table 122.
4 address 22 and the source IPv4 address 14
03 is the IP address of the source IPv6 mobility support terminal 107 itself.
Set the v4 address.

The IPv6 movement support processing section 117 completes the above processing, and thereafter repeatedly executes the above-described processing.

FIG. 8 shows a destination IPv6 mobility support terminal 10
9 is a flowchart illustrating an example of processing of a destination IPv6 movement support processing unit 123 that performs support processing for movement between networks for the IPv4 / v6 mobile terminal 106 in FIG. The destination IPv6 movement support processing unit 123 first
It is determined whether or not the v6 movement detection message transmission request message has been received (step 801). As a result of the judgment,
If the message has been received (step 801)
Y), the destination IPv6 movement support processing unit 123
6. Transmit a movement detection message (step 80)
2). Then, the destination IPv6 movement support processing unit 123
Determines whether the IPv6 mobile registration request message 1300 has been received (step 803). As a result of the judgment,
If the message has been received (step 803)
Y), the IPv6 movement support processing section 123 temporarily registers the information of the mobile terminal in the movement support management table 128 (step 804). At this time, the received IPv6 address is stored in the mobile terminal IPv6 address 40 in the mobility support management table 128.
The value of the own IPv6 address 1305 in the movement registration request message 1300 is changed to the source IPv6 movement support terminal IPv
4 address 41, the mobile support terminal address table 1
30, the IPv6 mobile registration request message 130
The value of the source IPv6 mobility support terminal IPv4 address 30 corresponding to the destination IPv6 address 1302 in 0 is
"Temporary registration" is set in the registration flag. And destination I
The Pv6 movement support processing unit 123 encapsulates the received IPv6 movement registration request message 1300 into IPv4 and transfers it to the source IPv6 movement support terminal 107 (Step 805).

At this time, the IPv4 encapsulated IPv4
FIG. 15 shows the configuration of the 6 move registration request message 1300. As shown in the figure, the message 1500 is an IP6 mobile registration request message 1300 shown in FIG.
It has a configuration to which a v4 header 1401 is added. IPv4
The source IPv4 address 1402 in the header 1401 contains the source IP address registered in the mobility support management table 128.
The IPv4 address 41 of the v6 movement support terminal 107 is set, and the destination IPv4 address 1403 is set as the destination IPv4 address.
6 Set the IPv4 address of the mobility support terminal 109 itself.

After moving, the IPv4 / v6 mobile terminal 106 always once transmits a packet to the destination IPv6 movement support terminal 109 in accordance with the Mobile IPv6 processing procedure. Therefore, the destination IPv6 mobility support terminal 10
9 is IPv6 addressed to the source IPv6 mobility support terminal 107
The mobile registration request message 1300 can be received.

The destination IPv6 movement support processing unit 12
3 sets a timer (step 806),
IPv6 which is a response to the 6 mobile registration request message 1300
6. Wait for a certain period of time for a move registration permission message 1404 (steps 807 and 810). The IPv6 transfer registration permission message 1404 is, as described above, the transfer source IPv4.
6 The IPv4 encapsulation is transferred by the mobility support terminal 107 and transferred.

When the IPv6 transfer registration permission message 1404 is received within a predetermined time (step 807Y), the transfer destination IPv6 transfer support processing unit 123 registers the registration flag 42 corresponding to the mobile terminal provisionally registered in the transfer support management table 128. Is updated to "official registration" (step 80)
8). Further, the destination IPv6 movement support processing unit 123
The IPv4 header added to the received IPv6 move registration permission message 1404 is removed (hereinafter referred to as IPv4
Decapsulation), IPv4 / v6 mobile terminal 106
(Step 809). IP within a certain time
If the v6 movement registration permission message 1404 has not been received (step 810Y), the movement destination IPv6 movement support processing unit 123 deletes information on the mobile terminal from the movement support management table 128 (step 811). The movement destination IPv6 movement support processing unit 123 is completed as described above, and thereafter repeats the above-described processing.

FIG. 9 shows the source IPv6 mobility support terminal 10
7, the IPv6 terminal transmitted by another IPv6 terminal to the IPv6 mobile terminal or the IPv4 / v6 mobile terminal 106
Destination IPv6 mobile support terminal transfer processing unit 12 for performing a process of transferring the six packets to the destination IPv6 mobile support terminal 109 existing in the destination network of the mobile terminal
FIG. 4 is a flowchart illustrating an example of a process 1; Destination IPv
First, the transfer processing unit 121 destined for the 6th mobile support terminal, among the IPv6 packets transmitted by the IPv6 terminal 104 or another IPv6 terminal (not particularly shown in the drawing), is transmitted to the mobile terminal registered in the mobile terminal management table 122. It is determined whether or not the IPv6 packet has been received (step 901).
As a result of the determination, if the corresponding packet has been received, the transfer destination unit for destination IPv6 mobility support terminal 121 adds a new IPv6 header to the packet (Step 902, hereinafter referred to as IPv6 encapsulation). .

At this time, the IPv6 encapsulated IPv
FIG. 16 shows the configuration of six packets. As shown, the packet is a new IPv6 header added to the IPv6 packet.
301 is added. IPv6 header 130
1, the corresponding destination IPv6 address 21 in the mobility support management table 122 is set as the destination IPv6 address 1302, and the source IPv6 address of the source IPv6 mobility support terminal 107 itself is set as the source IPv6 address 1303.

The destination IPv6 transfer support terminal forwarding processor 121 then determines whether or not the transfer destination IPv6 transfer support terminal IPv4 address 22 of the corresponding mobile terminal in the mobile terminal management table 122 is “NULL”. (Step 903). As a result of the determination, if the destination IPv6 movement support terminal IPv4 address 22 is “NULL” (step 903N), the transfer processing unit 121 for the destination IPv6 movement support terminal sends the mobile terminal to the IPv6 network or the IPv4 / v6 network. It is determined that it is moving, and the above-mentioned IPv6-encapsulated IPv6 packet 1600 is transmitted as it is (step 905). The procedure for transmitting the IPv6 packet after encapsulating the IPv6 packet is a procedure in accordance with the normal Mobile IPv6.

As a result of the determination, when the destination IPv6 movement support terminal IPv4 address 22 is other than "NULL" (step 903Y), the transfer destination IPv6 movement support terminal destination transfer processing unit 121 determines that the mobile terminal is moving to the IPv4 network. And the IP encapsulated in IPv6
Further IPv4 encapsulation for v6 packets,
The data is transmitted to the destination IPv6 mobility support terminal 109 (step 904).

FIG. 17 shows the structure of the packet encapsulated in IPv4 at this time. As shown in the drawing, the packet has a configuration in which an IPv4 header 1401 is newly added to the IPv6 encapsulated IPv6 packet 1600 shown in FIG. A destination IPv4 address 1402 in the IPv4 header 1401 has a corresponding destination IPv6 mobility support terminal IPv in the mobile terminal management table 122.
4 value of the address 22 and the source IPv4 address 140
3 is the IPv6 of the source IPv6 mobility support terminal 107 itself.
Set 4 addresses.

The transfer processing unit 121 for the destination IPv6 movement support terminal is completed as described above, and thereafter repeats the above-described processing.

FIG. 10 shows the source IPv6 mobility support terminal 1
In step 07, the IPv6 packet transmitted from the IPv4 / v6 mobile terminal 106 to another IPv6 terminal on the destination IPv4 network is transmitted to the destination IPv6 movement support terminal 1.
09, when it is encapsulated in IPv4 and transferred
FIG. 13 is a flowchart illustrating an example of a process of another terminal-directed transfer processing unit 119 that performs a process of transferring the packet to a destination IPv6 terminal. The transfer processing unit 119 to the other terminal firstly transmits
It is determined whether an IPv4 packet addressed to the Pv6 mobility support terminal 107 itself has been received (step 1001). As a result of the determination, if the message has been received (step 1001
Y), the other-terminal-directed transfer processing unit 119 sends the next received packet to the destination IPv6
It is determined whether the packet is an IPv6 packet that has been encapsulated and transferred (step 1002). The transfer of the IPv6 packet by the destination IPv6 movement support terminal 109 is performed by the destination IPv6 movement support terminal 10 described later.
9 is performed by the source IPv6 mobility support terminal transfer processing unit 127 in the source device 9. If the result of the determination is that the packet is not a forwarded IPv6 packet (step 1002N), the transfer processing unit 119 for another terminal discards the packet (step 1).
005). When the packet is the transferred IPv6 packet (step 1002Y), the transfer processing unit 119 for another terminal is sent.
Determines whether the source terminal of the IPv6 packet is a mobile terminal registered in the mobile terminal management table 122 (step 1003). If the result of the determination is that the packet has not been registered (step 1003N), the transfer processing unit 119 for another terminal discards the packet (step 1003).
5). If the packet has been registered (step 1003Y), the transfer processing unit 119 for another terminal decapsulates the packet in IPv4 and transmits the packet to the destination IPv6 terminal (step 1004).

With the above, the transfer processing to the other terminal is completed, and thereafter the above-mentioned processing is repeatedly executed.

FIG. 11 shows a destination IPv6 mobility support terminal 1.
09, an example of the processing of the transfer processing unit 127 to the source IPv6 mobile support terminal 107 that performs a process of transferring the IPv6 packet transmitted by the IPv4 / IPv6 mobile terminal 106 to another IPv6 terminal to the source IPv6 mobile support terminal 107 It is the flowchart shown. The transfer processing unit 127 for the source IPv6 mobile support terminal firstly stores the mobile support management table 1
It is determined whether an IPv6 packet transmitted by the IPv4 / IPv6 mobile terminal 106 registered in 28 has been received (step 1101). If the result of the determination is that the corresponding packet has been received, the transfer processing unit 127 for the source IPv6 mobile support terminal next sets the registration flag 42 of the relevant mobile terminal in the mobile terminal management table 128 to “main registration”. It is determined whether or not it is (step 1102). As a result of the judgment,
In the case of “main registration” (step 1102Y), the transfer processing unit 127 for the source IPv6
IPv6 encapsulation of Pv6 packet and source IP
Transmit to the v6 movement support terminal 107 (step 110)
3).

At this time, the IPv4 encapsulated IPv4
FIG. 18 shows the configuration of six packets. As illustrated, the packet 1800 has a configuration in which an IPv4 header 1401 is newly added to an IPv6 packet 1801. IP
Destination IPv4 address 140 in v4 header 1401
2 is set to the value of the corresponding source IPv6 movement support terminal IPv4 address 41 in the movement support management table 128, and the source IPv4 address 1403 is set to the IPv4 address of the destination IPv6 movement support terminal 109 itself.

As a result of the determination, the registration flag 42 is set to “main registration”.
If not (step 1102N), the transfer processing unit 127 for the source IPv6 movement support terminal discards the packet (step 1104). The transfer processing unit 127 for the source IPv6 mobility support terminal is thus completed, and thereafter repeats the above-described processing.

FIG. 12 shows a destination IPv6 movement support terminal 1
In step 09, when the source IPv6 mobility support terminal 107 encapsulates an IPv6 packet transmitted by another IPv6 terminal to the IPv4 / v6 mobile terminal 106 after IPv6 encapsulation, the packet is further encapsulated in IPv4 and transferred. FIG. 9 is a flowchart illustrating an example of processing of a mobile terminal-addressed transfer processing unit 125 that performs processing of transferring data to an IPv4 / v6 mobile terminal 106. Mobile terminal destination transfer processing unit 12
5 first determines whether or not an IPv4 packet addressed to the destination IPv6 movement support terminal 109 itself has been received (step 1201). As a result of the determination, if it has been received (step 1201Y), the transfer processing unit 125 for the mobile terminal
Determines whether the next received packet is an IPv6 packet that has been IPv4 encapsulated and transferred by the source IPv6 mobility support terminal 107 (step 1202). The source IPv6 mobility support terminal 10
The transfer of the IPv6 packet according to the above-described destination IP
This is performed by the v6 movement support terminal processing unit 121. If the result of the determination is that the packet is not a forwarded IPv6 packet (step 1202N), the transfer processing unit 125 for the mobile terminal discards the packet (step 1205). If the packet is the transferred IPv6 packet (step 1202
Y), the transfer processing unit 125 for the mobile terminal further
The destination terminal of the six packets is the movement support management table 12
Then, it is determined whether or not the mobile terminal has been permanently registered in step 8 (step 1203). The IPv6 address of the destination terminal is
This is the address of the destination terminal included in the IPv6 packet 1601. If the result of the determination is that the registration is not permanent (step 1203N), the transfer processing unit 125 for the mobile terminal discards the packet (step 1205). If the packet is permanently registered (Y in Step 1203), the mobile terminal transfer processing unit 125 decapsulates the packet into IPv4 and then transfers the packet to the IPv4 / v6 mobile terminal 106 (Step 1204).

With the above, the transfer processing unit 125 for the mobile terminal is completed, and thereafter the above-mentioned processing is repeatedly executed.

Here, the flow of processing from FIG. 5 to FIG. 12 will be described with reference to the network system shown in FIG. 1. If the IPv4 / v6 mobile terminal 106 exists on the LAN-a 100 which is the home network,
/ V6 mobile terminal 106 is IPv4 mobility support terminal a10
In order to receive the IPv4 movement detection message and the IPv6 movement detection message transmitted from the source IPv6 movement support terminal 107 and the movement source IPv6 movement support terminal 107, it is determined that the user has not moved. Also, the IPv4 / v6 mobile terminal 106 is the LAN-b1
01, the IPv4 / v6 mobile terminal 10
6 is the IPv4 mobility support terminal b108 and the destination IPv4
In order to receive the IPv4 movement detection message and the IPv6 movement detection message transmitted by the 6 movement support terminal 109, it is determined that the mobile terminal has moved to another network. Then, the IPv4 / v6 mobile terminal 106 sends the IPv4 / IPv6 mobile terminal 106
An IPv4 movement registration request message and an IPv6 movement registration request message 1300 are transmitted to the IPv4 movement support terminal a 105 and the source IPv6 movement support terminal 107, respectively.

The IPv6 move registration request message 13
00 is “1” as the destination IPv6 address 1302.
1 :: 1 ”(source IPv6 mobility support terminal 107)
“21 :: 3” as the source IPv6 address 1302
0 "(in this embodiment, the IPv4 / v6 mobile terminal 1
06 is an IPv6 address newly used in the LAN-b 101. ) Is its own IPv6 address 1305
"11 :: 30" (IPv4 / v6 mobile terminal 10
6) is “2” as the destination IPv6 address 1306.
1 :: 30 "is set.

In this embodiment, as described above, L
Although it is impossible for an AN-b101 to send an IPv6 packet over a router to an external network, it is possible to transmit and receive an IPv6 packet within the LAN-b101. Therefore, the IPv4 / v6 mobile terminal 106 can receive the IPv6 movement detection message transmitted from the movement destination IPv6 movement support terminal 109, and the IPv6 movement registration request message 130
0 can be transmitted on the LAN-b 101.

The IPv6 movement registration request message 13
00 is temporarily received by the destination IPv6 mobility support terminal 109. The destination IPv6 mobility support terminal 109 is
The destination IPv6 movement support processing unit 123 sets “10.0.0.1” as the transmission destination IPv4 address 1402 for the message (the source IPv6 movement support terminal 1).
07) is set as “2” as the source IPv4 address 1403.
0.0.0.1 "(destination IPv6 mobility support terminal 10
An IPv4 header 1401 in which 9) is set is added, and the packet is transferred to the source IPv6 mobility support terminal 107. Thereafter, the message is received by the source IPv6 mobility support terminal 107. The source IPv6 mobility support terminal 107 is
After receiving the message, the IPv6 movement support processing unit 117 responds to the IPv6 movement registration permission message 1404 as “20.0.
0.1 ”(the destination IPv6 mobility support terminal 109) as“ 10.0.0.
1 "(the source IPv6 mobility support terminal 107) is added to the IPv4 header 1401 and transmitted to the destination IPv6 mobility assistance terminal 109. After the message is decapsulated in IPv4 by the support processing unit 123, the message is transmitted to the IPv4 / v6 mobile terminal 106.

As described above, the IPv4 / v6 mobile terminal 106
Registration of the movement to the movement source IPv6 movement support terminal 107 is completed. At this time, I
As information on the Pv4 / v6 mobile terminal 106, the mobile terminal I
“11 :: 30” in the Pv6 address 20 is the destination IP
“21 :: 30” in the v6 address 21 is the destination IPv4
6 "20.0.
0.1 ”is set. The mobility support management table 12
8, the mobile terminal IPv6 address 40 has "11 :: 3"
"0" is set to "10.0.0.1" in the source IPv6 mobility support terminal IPv4 address 41.

Thereafter, the source IPv6 mobility support terminal 107
Means that the IPv6 terminal 104 is the IPv4 / v6 mobile terminal 106
When the IPv6 packet transmitted to the destination is received, the destination I
The Pv6 mobility support terminal addressed transfer processing unit 121 assigns “2” to the destination IPv6 address 1302 for the packet.
1 :: 30 "and an IPv6 header 1301 in which" 11 :: 1 "is set to the source IPv6 address 1303, and then" 20.0.0.1 "is further added to the destination IPv4 address 1402. IPv4 address 14
03 is added to the IPv4 header 1401 in which “10.0.0.1” is set, and the destination IPv6 mobility support terminal 10 is added.
Transfer to 9 The packet 1700 is the destination IP
Received by the v6 movement support terminal 109. Then, the destination IPv6 mobility support terminal 109 decapsulates the packet by the mobile terminal destination transfer processing unit 125 and then transmits the packet to the IPv4 / v6 mobile terminal 106. IP
The v4 / v6 mobile terminal 106 converts the packet into a normal Mo
receive and process as an IPv6 packet in accordance with the procedure of file IPv6.

Conversely, the destination IPv6 mobility support terminal 109
Is that the IPv4 / v6 mobile terminal 106 is the IPv6 terminal 10
When the IPv6 packet transmitted to the destination IPv4 is received, the transfer processing unit 127 for the source IPv6 mobility support terminal sends “1” to the destination IPv4 address 1402 for the packet.
0.0.0.1 "(source IPv6 mobility support terminal 10
7) is added to the source IPv4 address 1403 as “20.
0.01 "(movement destination IPv6 mobility support terminal 109) with an IPv4 header 1401 added thereto,
It is transmitted to the Pv6 movement support terminal 107. Its IPv4
The encapsulated packet 1800 is the source IPv6
It is received by the movement support terminal 107. And the source IP
The v6 movement support terminal 107 includes a transfer processing unit 119 for other terminals.
After the packet is decapsulated in IPv4, the packet is transmitted to the destination IPv6 terminal 104. IPv6 terminal 1
At 04, the packet is received and processed as a normal IPv6 packet.

As described above, according to the present invention, IPv4 / v
6 mobile terminal 106 is switched from LAN-a100, which is an IPv4 / v6 network, to LA, which is an IPv4 network.
Even when moving to N-b101, IPv4 / v
6 mobile terminal 106, the IPv6 terminal 104
It becomes possible to receive the IPv6 packet transmitted to the v6 mobile terminal 106, and conversely, the existing IPv6 terminal 104
Is that the IPv4 / v6 mobile terminal 106 is the IPv6 terminal 10
4 can be received.

In addition, the existing method Mobile I
IPv4 mobility support terminal a105 supporting Pv4,
With the support of the movement of the terminal by IPv4 by the IPv4 movement support terminal b108, the communication using the IPv4 between the other terminal and the IPv4 / v6 mobile terminal 106 becomes possible.

Note that the IPv4 / v6 mobile terminal 106 has the LA
When returning from N-b101 to LAN-a100, IP
The v4 / v6 mobile terminal 106 detects that it has returned to the home network by the above-described IPv6 mobility processing unit 115. Then, the IPv4 / v6 mobile terminal 106 sends “11:30” to the source IPv6 address 1305 for the source IPv6 mobility support terminal 107 and “1:30” for the destination IPv6 address 1306, which is the same as the own IPv6 address 1305.
1: IPv6 mobile registration request message 1300 in which “1 :: 30” is set.
07 is the own IPv6 address 1305 in the message.
And the destination IPv6 address 1306 are the same, it is determined that the IPv4 / v6 mobile terminal 106 has returned to the LAN-a 100 which is the home network, and the information for the mobile terminal in the mobile terminal management table 122 is deleted. I do. As a result, the IPv4 / v6 mobile terminal 106 can perform communication using normal IPv6. Similarly, the IPv4 / v6 mobile terminal 106 is Mo
According to the process procedure of the file IPv4, the IPv4 movement support terminal a105 is also notified of the return to the LAN-a100 by the IPv4 movement registration request message, so that communication using normal IPv4 is also possible.

In the above-described embodiment, an IPv4 movement detection message or an IP4 movement detection message is used for detecting movement between networks.
The automatic detection is performed by using the message for detecting the movement of the IPv4 movement. However, the user of the terminal instructs the movement processing unit 113 and the movement processing unit 115 of the IPv4 movement to change the movement of the IPv4 movement support terminal. And IPv
6 It may be configured to notify the movement support terminal.

Next, the IPv4 / v6 mobile terminal transmits the IPv4 / v6
A case of moving from a v6 network to an IPv6 network will be described.

An example of the configuration of a network system to which the present invention is applied and an example of the structure of a mobility support terminal will be described with reference to FIG.

As shown, the network system shown in this embodiment is a LAN-c1900, a LAN-d19.
01, and a LAN-c 190 by a public line or a dedicated line.
0 and LAN-d1901. An IPv4 terminal 1903 that communicates using only IPv4 on the LAN-c 1900 and an IPv6 terminal
IPv6 terminal 1904 that communicates using only
an IPv4 / v6 mobile terminal 106 that communicates using both v4 and IPv6 and moves between networks;
Perform communication using IPv4 and IPv6, and
Source IPv4 mobility support terminal 1906 for supporting inter-network movement for a terminal performing communication using IPv4, and IPv6 by a procedure according to Mobile IPv6.
There is an IPv6 movement support terminal c1907 that supports movement between networks for a terminal that performs communication using the Internet. Also, IPv4, IPv6 on LAN-d1901
When a terminal performing communication using IPv4 and performing communication using IPv4 moves to the LAN-d1901, there are a destination IPv4 movement support terminal 1908 and an IPv6 movement support terminal d1909 that support movement of the terminal. I do. Here, the IPv4 / v6 mobile terminal 106 is the same as that shown in FIG.

Note that the IPv6 mobility support terminal c1907 is
It operates as a router that handles both IPv4 packets and IPv6 packets, and has a LAN-c 1900 and a WAN 1902.
Connect between. IPv6 mobility support terminal d1909
Operates as a router that handles only IPv6 packets,
The LAN-d 1901 and the WAN 1902 are connected. Therefore, both the IPv4 packet and the IPv6 packet can go out of the router to the external network from the LAN-c 1900, whereas the LAN-c 1900 can
From d1901, only IPv6 packets can go outside. Note that LAN-c 1900 and L
IPv4 packet and IPv6 in AN-d1901
It is possible to send and receive packets themselves.

Here, in the present embodiment, the IPv4 terminal 19
03 is “10.0.0.10” as the IPv4 address
It is assumed that the IPv6 terminal 1904 holds “11 :: 20” as the IPv6 address. Also, the IPv4 / v6 mobile terminal 106, the source IPv4 mobile support terminal 1906, and the destination IPv4 mobile support terminal 19
08 are “10.0.
0.30 "," 10.0.0.1 "," 20.0.0.
1, "11 :: 30" and "1" as IPv6 addresses.
1 :: 1 "and" 21 :: 1 ".

The source IPv4 mobility support terminal 1906 is
An IPv4 mobile terminal (not shown in the figure) that performs communication using IPv4 and moves between networks, or an IPv4 mobile support processing unit 191 that supports movement of the IPv4 / IPv6 mobile terminal 106.
6, another IPv4 network or IPv4 / v
6, a mobile terminal management table 1917 for managing information on mobile terminals that have moved to the network, an IPv4 processing unit 191 for performing processing according to services provided by IPv4.
8. Other IPv4 terminal is IPv4 / v6 mobile terminal 106
A transfer unit 1919 for forwarding the IPv4 packet transmitted to the destination to the destination IPv4 mobility support terminal 1908, an IPv6 processing unit 1920 for performing a process according to the service provided by the IPv6,
A transfer processing unit 1921 for another terminal that performs processing for transferring an IPv4 packet transmitted from the IPv4 / v6 mobile terminal 106 transferred from the destination IPv4 movement support terminal 1908 to the destination IPv4 terminal, and transmission / reception control of the packet to / from the LAN. And a communication processing unit 1915 for performing such operations.

Also, the destination IPv4 mobility support terminal 1908
Means that the IPv4 / v6 mobile terminal 106 belongs to the network (LAN-d
1901), the destination IPv4 movement support processing unit 1923 that supports movement for the mobile terminal.
Mobility support management table 19 for managing information of the mobile terminal;
29, the mobility support terminal address table 19 for registering the address information of the source IPv4 mobility support terminal 1906
28, an IPv4 processing unit 1924 for performing a process according to a service provided by the IPv4, the IPv4 / v6 mobile terminal 10
6, a transfer processing unit 1925 for transferring an IPv4 packet transmitted to another IPv4 terminal to the source IPv4 movement support terminal 1906, and an IPv6 processing unit 19 for performing processing according to a service provided by IPv6.
26. A mobile terminal-destined transfer processor 1927 that performs processing for transferring a packet addressed to the IPv4 / v6 mobile terminal 106 transferred from the source IPv4 mobility support terminal 1906 to the IPv4 / v6 mobile terminal 106, and a packet to the LAN. The communication processing unit 1922 performs transmission / reception control and the like.

Here, the source IPv4 mobility support terminal 1
Among the components 906, those particularly provided in the present invention include an IPv4 movement support processing unit 1916, a mobile terminal management table 1917, a transfer processing unit 1919 to the destination IPv4 movement support terminal, and a transfer processing unit 1921 to another terminal. is there. The invention element in the destination IPv4 movement support terminal 1908 includes a destination IPv4 movement support processing unit 192.
3, the mobility support terminal address table 1928, the mobility support management table 1929, the source IPv4 mobility support terminal destination transfer processing unit 1925, and the mobile terminal destination transfer processing unit 192
7

FIG. 20 shows the mobile terminal management table 1 described above.
917 is shown. As illustrated, the mobile terminal management table 1917 indicates that the mobile terminal IPv4 address 2000, which is the IPv4 address of the mobile terminal, and the mobile terminal whose source IPv4 mobility support terminal 1906 is moving to another IPv4 network or IPv4 / v6 network. When an IPv4 packet addressed to the mobile terminal is transferred, the transfer destination IP address indicating the IPv4 address of the transfer destination
A IPv4 address 2001 and a destination IPv4 mobility support terminal IPv6 address 2002 indicating the IPv6 address of the destination IPv4 support terminal. Here the destination IP
If the mobile terminal is moving to the IPv4 network or the IPv4 / v6 network, “NULL” is added to the IPv4 address of the IPv4 movement support terminal IPv6 2002.
When moving to the network, the IPv6 of the destination IPv4 movement support terminal 1908 existing in the network
Address is set. Although FIG. 2 shows a case where entries for a plurality of mobile terminals exist, there is no entry of the mobile terminal in the table in the initial state. The update processing of this table will be described later.

FIG. 21 shows an example of the mobility support terminal address table 1928 described above. As shown in the figure, the mobility support terminal address table 1928 stores all the source IPv4 mobility support terminals existing in the network system (in the present embodiment, only the source IPv4 mobility support terminal 1906 on the LAN-c1900 is shown). Source IPv4, which is the IPv6 address and IPv4 address of
Mobility support terminal IPv6 address 2100 and source I
It is composed of a Pv4 mobility support terminal IPv4 address 2101. This table is set by an administrator or the like.

FIG. 22 shows the movement support management table 1 described above.
929 is shown. As illustrated, the mobility support management table 1929 stores the I / O of the IPv4 / v6 mobile terminal 106.
Mobile terminal IPv4 address 220 which is a Pv4 address
0, the source IPv4 mobility support terminal IPv6 address 220 which is the IPv6 address of the source IPv4 mobility support terminal 1906 existing in the home network of the mobile terminal
1 and the entry is “temporary registration” or “main registration”
, And a registration flag 2202 indicating whether the Although FIG. 4 shows a case where entries for a plurality of mobile terminals exist, there is no entry of the mobile terminal in this table in an initial state. The update processing of this table will be described later.

In the configuration described above, IPv4 / v6
L where the mobile terminal 106 is an IPv4 / v6 network
LA that is an IPv6 network from AN-c1900
IPv4 / v6 when moving to N-d1901
Mobile terminal 106, source IPv4 mobility support terminal 190
6, and the processing operation of the destination IPv4 mobility support terminal 1908 and the handling of each of the above tables will be described in detail below.

FIG. 23 shows that the source IPv4 / v6 mobility support terminal 1906 is an IPv4 mobile terminal (not particularly shown) or an IPv4 / v6 mobile terminal 106.
IPv4 that performs inter-network movement support processing for
It is the flowchart which showed an example of the process of the movement assistance processing part 1916. First, the IPv4 movement support processing unit 1916
It is determined whether or not the v4 movement detection message transmission request message has been received (step 2301). If the message is received as a result of the determination (step 230
1Y), the IPv4 movement support processing unit 1916 transmits an IPv4 movement detection message (step 2302).
Then, the IPv4 movement support processing unit 1916 checks the IPv4
It is determined whether or not a 4 move registration request message has been received (step 2303). Here, FIG. 29 shows the configuration of the present IPv4 migration registration request message 2900. As shown, the IPv4 migration registration request message 2900 is
It comprises a Pv4 header 1401 and IPv4 data 2901. The IPv4 header 1401 includes a destination IPv4 address 1402 and a source IPv4 address 1403, and the source IPv4 address 1402 includes a source IPv4 address.
The IPv4 address of the 4 mobile support terminal 1906 is set, and the IPv4 address of the IPv4 / v6 mobile terminal 106 is set as the source IPv4 address 1403. Also, the IPv4 data 2901 contains the I of the terminal transmitting this message.
It is composed of its own IPv4 address 2902 which is a Pv4 address, and a transfer destination IPv4 address 2903 which is a transfer destination address when transferring an IPv4 packet addressed to this mobile terminal. The transfer destination IPv4 address 2903 includes an IPv4
/ V6 mobile terminal 106 is home network LA
When returning to N-c1900, the own IPv4 address 29
Set the same address as 02. It should be noted that this message corresponds to the I / O in the IPv4 / v6
It is transmitted by the Pv4 movement processing unit 113.

As a result of the judgment, if IPv4 mobile registration request message 2900 has been received (step 2303)
Y), the IPv4 movement support processing unit 1916 further determines whether or not the movement registration request is acceptable (step 2).
304). If the result of the determination is that the IPv4 mobile registration is not acceptable (step 2304N), the IPv4 mobility support processing unit 1916 sends an IPv4 mobile registration rejection message, which is a registration rejection response message to the IPv4 mobile registration request message 2900, to the mobile terminal (step 2305). ). If it is acceptable (step 2304Y), the IPv4 movement support processing 2300 then proceeds to the own IPv4 in the message.
The address 2902 is compared with the transfer destination IPv4 address 2903 (step 2306). As a result of comparison, own IP
v4 address 2902 and transfer destination IPv4 address 290
3 is the same address (step 2306)
Y), the IPv4 movement support processing unit 1916 determines that the mobile terminal has returned to the home network, and deletes the information of the corresponding mobile terminal from the mobile terminal management table 1917 (step 2307). Then, the IPv4 movement support processing unit 1916 sends the IPv4 movement registration request message 290
An IPv4 mobile registration permission message, which is a registration permission response message of registration 0, is transmitted to the mobile terminal (step 2).
311). As a result of the comparison, if the own IPv4 address 2902 and the transfer destination IPv4 address 2903 are different addresses (step 2306N), the IPv4 movement support processing unit 1916 further transmits the received IPv4 movement registration request message 2900 to the movement destination IPv4 movement support terminal. 19
08, an IPv6 header is added (hereinafter referred to as IPv6 encapsulation), and it is determined whether or not the packet has been transferred (step 2308). The IPv6 encapsulation of the IPv4 move registration request message 2900 by the move destination IPv4 movement support terminal 1908 is performed by the move destination I
This is performed by the destination IPv4 movement support processing unit 1923 in the Pv4 movement support terminal 1908. Source IPv4
When the mobility support terminal 1906 receives the IPv6 encapsulated IPv4 mobility registration request message 2900, the IPv6 processing unit 1920 in the mobile support terminal 1906 removes the IPv6 header (hereinafter referred to as IPv6 decapsulation).
It is passed to the Pv4 movement support processing unit 1916. This IPv
The IPv6 decapsulation in the 6 processing unit 1920 is one of the services provided by the existing IPv6.

As a result of the determination as to whether or not the packet has been transferred by encapsulating IPv6, if the packet has not been transferred (N in step 2308), the IPv4 movement support processing unit 1916
Indicates that the mobile terminal is on another IPv4 network or IP
It is determined that the mobile terminal has moved to the v4 / v6 network, and information on the mobile terminal is set in the mobile terminal management table 1917 (step 2309). At this time, the value of the transfer destination IPv4 address 2903 in the received IPv4 transfer registration request message 2900 is set in the transfer destination IPv4 address 2001 in the mobile terminal management table 1917, and “NULL” is set in the transfer destination IPv4 movement support terminal IPv6 address 2002.
Set. Then, the IPv4 movement support processing unit 1916 transmits an IPv4 movement registration permission message to the mobile terminal (step 2311). If the result of the determination is that the packet has been transferred after being encapsulated in IPv6 (step 2
308Y), the IPv4 movement support processing unit 1916 determines that the mobile terminal has moved to the IPv6 network, and sets information on the mobile terminal in the mobile terminal management table 1917 (step 2310). At this time, the transferred IPv4 move registration request message 2900 is transferred to the transfer destination IPv4 address 2001 in the mobile terminal management table 1917.
The value of the transfer destination IPv4 address 2903 in the
In the IPv4 mobility support terminal IPv6 address 2002, the value of the source IPv6 address in the IPv6 header added to the transferred IPv4 mobility registration request message 2900 is set. And IPv4 movement support processing unit 1
916 encapsulates an IPv4 move registration permission message, which is a response to the mobile terminal, into an IPv6 encapsulated message and transmits the message (step 2312).

At this time, the IPv6 encapsulated IPv
FIG. 3 shows the data structure of the 4 move registration permission message 3001
0 is shown. As shown, the message 3000 is I
It has a configuration in which an IPv6 header 1301 is added to the Pv4 move registration permission message 3001. IPv6 header 1
The destination IPv6 address 1302 in 301 is set to the destination IPv4 mobility support terminal IPv6 address 2002 registered in the mobile terminal management table 1917, and the source IPv6 address 1303 is set to the IPv6 address of the source IPv4 mobility support terminal 1906 itself. Set.

The IPv4 movement support processing section 1916 is completed as described above, and thereafter repeats the above-described processing.

FIG. 24 shows a destination IPv4 mobility support terminal 1
In 908, the destination IPv4 for performing the inter-network movement support processing for the IPv4 / v6 mobile terminal 106
It is the flowchart which showed an example of the process of the movement assistance processing part 1923. The movement destination IPv4 movement support processing unit 1923 first determines whether or not an IPv4 movement detection message transmission request message has been received (step 2401). As a result of the determination, if the message has been received (step 2
401Y), the movement destination IPv4 movement support processing unit 1923 transmits an IPv4 movement detection message (step 2).
402). Then, the destination IPv4 movement support processing unit 1
The 923 determines whether or not the IPv4 movement registration request message 2900 has been received (step 2403). As a result of the determination, if the message has been received (step 2
403Y), destination IPv4 movement support processing unit 1923
Temporarily registers the information of the mobile terminal in the mobility support management table 1929 (step 2404). At this time, the mobile terminal IPv4 address 2 in the mobile terminal management table 1929
200 is the received IPv4 mobile registration request message 2
The value of the own IPv4 address 2902 in 900 is added to the source IPv4 movement support terminal IPv6 address 2201.
Referring to the mobility support terminal address table 1928, the IP
Destination IPv4 in v4 move registration request message 2900
The value of the source IPv4 movement support terminal IPv6 address 2100 corresponding to the IP address 4
In 02, “temporary registration” is set. And destination IPv4
The mobility support processing unit 1923 encapsulates the received IPv4 mobility registration request message 2900 in IPv6 and transfers it to the source IPv4 mobility support terminal 1906 (step 2405).

At this time, the IPv6 encapsulated IPv
FIG. 31 shows the configuration of the 4 move registration request message 2900. As shown in the figure, the message 3100 is added to the IPv4 move registration permission message 2900 shown in FIG.
It has a configuration to which a v6 header 1301 is added. IPv6
The source IPv6 address 1302 in the header 1301 has the source I registered in the mobility support management table 1929 as the source IPv6 address.
A Pv4 mobility support terminal IPv6 address 2201 is set, and the source IPv6 address 1303 is set to the destination IPv6 address.
4 Set the IPv6 address of the mobile support terminal 1908 itself.

After moving, the IPv4 / v6 mobile terminal 106 always transmits a packet to the destination IPv4 movement support terminal 1908 in accordance with the processing procedure of Mobile IPv4. Therefore, the destination IPv4 mobility support terminal 1908
Can receive the IPv4 mobile registration request message 2900.

Then, the destination IPv4 movement support processing section 19
23 sets a timer (step 2406),
I which is a response to the Pv4 move registration request message 2900
It waits for a Pv4 move registration permission message 3001 for a certain period of time (steps 2407 and 2410). As described above, the IPv4 transfer registration permission message 3001 is encapsulated in the IPv6 by the transfer source IPv4 transfer support terminal 1906 and transferred.

If IPv4 mobile registration permission message 3001 is received within a predetermined time (step 2407Y),
The movement destination IPv4 movement support processing unit 1923 updates the registration flag 2202 corresponding to the mobile terminal temporarily registered in the movement support management table 1929 to “main registration” (step 2408). Further, the destination IPv4 movement support processing unit 1
923 is the received IPv4 movement registration permission message 3
The IPv6 header 1301 added to the IPv4 / 001 is removed (hereinafter referred to as IPv6 decapsulation).
Transfer to the v6 mobile terminal 106 (step 2409).
It should be noted that the IPv4 movement registration permission message 30
If no 01 has been received (step 2410Y), the movement destination IPv4 movement support processing unit 1923 deletes information on the mobile terminal from the movement support management table 1929 (step 2411).

The destination IPv4 movement support processing unit 1923 completes the above processing, and thereafter repeatedly executes the above processing.

FIG. 25 shows the source IPv4 mobility support terminal 1
At 906, a destination IPv4 mobility support terminal existing in the destination network of the mobile terminal, the other IPv4 terminal transmitting an IPv4 packet transmitted to the IPv4 mobile terminal (not particularly shown) or the IPv4 / v6 mobile terminal 106 Destination IPv4 that performs transfer to 1908
It is the flowchart which showed an example of the process of the transfer processing part 1919 to a mobility assistance terminal. The transfer processing unit 1919 destined for the destination IPv4 movement support terminal first receives the IPv4 terminal 104 or another IP address.
IP transmitted by a v4 terminal (not particularly shown)
It is determined whether an IPv4 packet addressed to the mobile terminal registered in the mobile terminal management table 1917 has been received from the v4 packets (step 2501). As a result of the determination, if the corresponding packet has been received (step 2501)
Y), transfer processing section 191 for destination IPv4 mobility support terminal
No. 9 then determines whether the destination IPv4 mobility support terminal IPv6 address 2002 of the mobile terminal in the mobile terminal management table 1917 is "NULL" (step 2502). As a result of the determination, if the destination IPv4 movement support terminal IPv6 address 2002 is “NULL” (step 2502N), the transfer processing unit 1919 for the destination IPv4 movement support terminal sends the mobile terminal to the IPv4 network or the IPv4 / v6 network. It is determined that it is moving, and the received IPv4 packet is encapsulated in IPv4 and transmitted (step 250).
4). The procedure for transmitting the IPv4 packet after encapsulating the IPv4 packet is the same as that of the normal Mobile IPv4.
This is the procedure according to No. 4.

As a result of the determination, if the destination IPv4 movement support terminal IPv6 address 2002 is other than “NULL” (step 2502Y), the transfer destination IPv4 movement support terminal destination transfer processing unit 1919 determines that the mobile terminal is moving to the IPv6 network. Is determined, the received IPv4 packet is encapsulated in IPv6, and the destination IPv4 packet is encapsulated.
The message is transmitted to the movement support terminal 1908 (step 250).
3).

At this time, the IPv6 encapsulated IPv
FIG. 32 shows the configuration of four packets. As shown, the packet is newly added to the IPv4 packet 3201 by I.
The configuration is such that a Pv6 header 1301 is added. IPv6
The destination IPv6 address 1302 in the header 1301 has a corresponding destination I in the mobile terminal management table 1917.
The value of the Pv4 mobility support terminal IPv6 address 2002 is
The source IPv6 address 1303 sets the IPv6 address of the source IPv4 movement support terminal 1906 itself.

The transfer processing unit 1919 for the destination IPv4 mobility support terminal completes the above processing, and thereafter repeats the above-described processing.

FIG. 26 shows the source IPv4 mobility support terminal 1
In 906, when an IPv4 packet transmitted from the IPv4 / v6 mobile terminal 106 to another IPv4 terminal on the destination IPv6 network is encapsulated and transferred by the destination IPv4 mobility support terminal 1908, the packet is sent to the destination. FIG. 21 is a flowchart showing an example of processing of another terminal-directed transfer processing unit 1921 that performs processing of transferring to another IPv4 terminal. First, the transfer processing unit 1921 destined for the other terminal firstly transmits the IPv6 to
It is determined whether a packet has been received (step 260).
1). As a result of the determination, if it has been received (step 260
1Y), the transfer-to-other-terminal processing unit 1921 determines whether or not the next received packet is an IPv4 packet that has been IPv6 encapsulated and transferred by the destination IPv4 movement support terminal 1908 (step 2602). The IP address of the destination IPv4 mobility support terminal 1908
The transfer of the v4 packet is performed by a source IPv4 movement support terminal transfer processing unit 1925 in the movement destination IPv4 movement support terminal 1908 described later. If the result of the determination is that the packet is not a forwarded IPv4 packet (step 2602)
N), the transfer processing unit for other terminal 1921 discards the packet (step 2605). If the received IPv4 packet is a forwarded IPv4 packet (step 2602Y), the other-terminal-destined forwarding processor 1921 further determines whether or not the source terminal of the IPv4 packet is a mobile terminal registered in the mobile terminal management table 1917. (Step 2603).
If the result of the determination is that the information has not been registered (step 2603)
N), the transfer processing unit for other terminal 1921 discards the packet (step 2605). If the packet is registered (Y in step 2603), the transfer processing unit for other terminal 1921 decapsulates the packet into IPv6 and transmits it to the destination IPv4 terminal (step 2604).

Thus, the transfer processing section 1921 for the other terminal completes the processing, and thereafter repeats the above-described processing.

FIG. 27 shows a destination IPv4 mobility support terminal 1
At 908, the IPv4 / IPv6 mobile terminal 106 transmits the IPv4 packet transmitted to the other IPv4 terminal to the source I
It is the flowchart which showed an example of the process of the transfer process part 1925 to the source IPv4 movement support terminal which performs the process of transferring to the Pv4 movement support terminal 1906. The source IPv4 mobile support terminal destination transfer processing unit 1925 first checks the IPv4 / v6 mobile terminal 106 registered in the mobile support management table 1929.
It is determined whether the received IPv4 packet has been received (step 2701). As a result of the determination, if the corresponding packet has been received (step 2701Y), the transfer source unit 1925 for the source IPv4 movement support terminal next sets the registration flag 2202 of the corresponding mobile terminal in the mobile terminal management table 1929 to “ It is determined whether or not “registration” (step 2702). If the result of the determination is “main registration” (step 2702Y), the transfer processing unit 1925 destined for the source IPv4 movement support terminal encapsulates the received IPv4 packet in IPv6 and transmits it to the source IPv4 movement support terminal 1906 (step 2702Y). Step 2703).

At this time, the IPv6 encapsulated IPv
The four packets have the same configuration as that already shown in FIG. The destination IPv6 address 1302 in the IPv6 header 1301 has a corresponding source IPv4 mobility support terminal IPv6 address 2 in the mobility support management table 1929.
The value of 201 is set as the source IPv6 address 1303 with the IPv6 address of the destination IPv4 movement support terminal 1908 itself.

As a result of the determination, if the registration flag 2202 is not “main registration” (step 2702N), the source IPv4
4 The transfer processing unit 1925 addressed to the mobile support terminal discards the packet (step 2704). The transfer processing unit 1925 for the destination IPv4 mobility support terminal completes the above processing, and thereafter repeats the above-described processing.

FIG. 28 shows a destination IPv4 mobility support terminal 1
At 908, the source IPv4 mobility support terminal 1906
Allows other IPv4 terminals to be IPv4 / v6 mobile terminals 10
6 is a flowchart illustrating an example of processing of a mobile terminal transfer processing unit 1927 that performs processing of transferring the IPv4 packet transmitted to the IPv6 packet to the IPv4 / v6 mobile terminal 106 when the packet is transferred after being encapsulated in the IPv6. is there. The transfer processing unit 1927 to the mobile terminal first determines whether or not an IPv6 packet addressed to the destination IPv4 movement support terminal 1908 itself has been received (step 2801). As a result of the determination, if the packet has been received (step 2801Y), the mobile terminal-addressed transfer processing unit 1927 performs the IPv6 encapsulation on the next received packet by the source IPv4 mobility support terminal 1906, and uses the transferred IPv4 packet. It is determined whether or not there is (Step 2802). The transfer of the IPv4 packet by the source IPv4 movement support terminal 1906 is performed by the destination IPv4 movement support terminal processing unit 1919 described above. If the result of the determination is that the packet is not a forwarded IPv4 packet (step 280)
2N), the transfer processing unit for mobile terminal 1927 discards the packet (step 2805). IPv4 forwarded
If the packet is four packets (Y in step 2802), the transfer processing unit 1927 to the mobile terminal further determines whether or not the destination terminal of the IPv4 packet is a mobile terminal that is permanently registered in the mobility support management table 1929 (step S2802). 28
03). If the result of the determination is that the registration is not permanent (step 2803N), the transfer processing unit for mobile terminal 1927 discards the packet (step 2805). When the packet is permanently registered (Y in step 2803), the transfer processing unit for mobile terminal 1927 decapsulates the packet into IPv6 and then transfers the packet to the IPv4 / v6 mobile terminal 106 (step 2804).

Thus, the transfer processing to the other terminal is completed, and thereafter the above-described processing is repeatedly executed.

Here, FIG. 5 and FIG.
The flow of processing up to 8 will be described with reference to the network system shown in FIG. 19. When the IPv4 / v6 mobile terminal 106 exists on the LAN-c 1900 which is a home network, the IPv4 / v6 mobile terminal 106
4 mobile support terminal 1906 and IPv6 mobile support terminal c
In order to receive the IPv4 movement detection message and the IPv6 movement detection message transmitted in 1907, it is determined that they have not moved. IPv4 / v6 mobile terminal 1
06 has moved to the LAN-d 1901, the IPv6
Since the 4 / v6 mobile terminal 106 receives the IPv4 movement detection message and the IPv6 movement detection message transmitted by the destination IPv4 movement support terminal 1908 and the IPv6 movement support terminal d1909, the 4 / v6 mobile terminal 106 determines that it has moved to another network. . Then, the IPv4 / v6 mobile terminal includes the IPv4 mobile processing unit 113 and the IPv6 mobile processing unit 1
15, the IPv4 movement registration request message 290
0, and the IPv6 movement registration request message 1300, respectively,
6 to the mobile support terminal c1907.

The IPv4 movement registration request message 29
00 is “1” as the destination IPv4 address 1402.
0.0.0.1 "(source IPv4 mobility support terminal 190
6) is “1” as the source IPv4 address 1403
0.0.0.30 "(IPv4 / v6 mobile terminal 106)
However, as the own IPv4 address 2902, "10.0.
0.30 ”is“ 20.0.0.30 ”as the transfer destination IPv4 address 2903 (in this embodiment,
If the v4 / v6 mobile terminal 106 is the destination LAN-d 190
1 is set as the transfer destination IPv4 address acquired from the transfer destination IPv4 movement support terminal 1908).

In this embodiment, as described above, LA
Although it is impossible for N-d1901 to pass an IPv4 packet over a router to an external network, it is possible to transmit and receive an IPv4 packet within LAN-d1901. Accordingly, the IPv4 / v6 mobile terminal 106 can receive the IPv4 movement detection message transmitted by the movement destination IPv4 movement support terminal 1908, and the IPv4 movement registration request message 2
It is also possible to transmit 900 on the LAN-d1901.

The IPv4 move registration request message 29
00 is temporarily received by the destination IPv4 mobility support terminal 1908. Destination IPv4 mobility support terminal 1908
Is the destination IPv6 address 1 for the message 2900 by the destination IPv4 movement support processing unit 1923.
“11 :: 1” (source IPv4 mobility support terminal 1906) as 302 and “21 :: 1” (source IPv4 mobility support terminal 19) as source IPv6 address 1303
08) to which an IPv6 header 1301 having been set is added, and the packet is transferred to the source IPv4 movement support terminal 1906. Thereafter, the message is transmitted to the source IPv4 mobility support terminal 190.
6 is received. Source IPv4 mobility support terminal 1
906, after receiving the message, the IPv4 movement support processing unit 1916 causes the IPv4 movement registration permission message 3
“21 :: 1” (destination IPv4 mobility support terminal 190 as the destination IPv6 address 1302)
6) as “1” as the source IPv6 address 1303
1: 1: "(source IPv4 mobility support terminal 1908), and add an IPv6 header 1301 to the destination IP.
It transmits to the v4 movement support terminal 1908. The destination IPv4 mobility support terminal 1908 that has received the message decapsulates the message using the destination IPv4 mobility support processing unit 1923 and then transmits the message to the IPv4 / v6 mobile terminal 106.

As described above, the IPv4 / v6 mobile terminal 10
The registration of the movement to the movement source IPv4 movement support terminal 1906 of No. 6 is completed. At this time, the mobile terminal management table 1917
As information of the IPv4 / v6 mobile terminal 106, “10.0.0.3” is added to the mobile terminal IPv4 address 2000.
0 is added to the transfer destination IPv4 address 2001 as “20.
0.0.30 "is the destination IPv4 mobility support terminal IPv
"21 :: 1" is set to the 6th address 2002. In addition, the mobility support management table 1929 includes the mobile terminal IPv
"4.0.0.30" is set to the 4 address 2200, and "11 :: 1" is set to the source IPv4 movement support terminal IPv6 address 2201.

Thereafter, the source IPv4 mobility support terminal 190
6, when the IPv4 terminal 1903 receives the IPv4 packet transmitted to the IPv4 / v6 mobile terminal 106, the destination IPv6 address support processing unit 1919 transfers the packet to the destination IPv6 address 1302
"21 :: 1" (the destination IPv4 mobility support terminal 190
8) is added to the source IPv6 address 1303 as “11 ::
1 "(the source IPv4 mobility support terminal 1906) to which the IPv6 header 1301 is set, and the destination IPv4
Transfer to the mobile support terminal 1908. The IPv6-encapsulated packet is received by the destination IPv4 movement support terminal 1908. Then, the destination IPv4 movement support terminal 1908 decapsulates the packet by IPv6 using the transfer processing unit 1927 to the mobile terminal,
4 / v6. IPv4 / v6
The mobile terminal 106 transmits the packet to a normal Mobile
It receives and processes it as an IPv4 packet according to the procedure of IPv4.

Conversely, destination IPv4 mobility support terminal 1908
Means that the IPv4 / v6 mobile terminal 106 is the IPv4 terminal 19
When the IPv4 packet transmitted to the destination IPv3 is received, the transfer processing unit 1925 for the source IPv4 mobility support terminal sends “11 :: 1” to the destination IPv6 address 1302 (11 :: 1) (the source IPv4 mobility support terminal 190
6) is added to the source IPv6 address 1303 as “21 ::
1 "(movement destination IPv4 mobility support terminal 1908) to which an IPv6 header 1301 is set, and the source IPv4
It is transmitted to the mobility support terminal 1906. The IPv6-encapsulated packet is received by the source IPv4 mobility support terminal 1906. Then, the source IPv4 movement support terminal 1906 decapsulates the packet by the other terminal transfer processing unit 1921 and then transmits the packet to the destination IPv4 terminal 1903. IPv4 terminal 1
903 receives and processes the packet as a normal IPv4 packet.

As described above, according to the present invention, IPv4 / v
6 mobile terminal 106 is changed from LAN-c 1900 which is an IPv4 / v6 network to L which is an IPv6 network.
Even when moving to AN-d1901, IPv4
/ V6 mobile terminal 106 has an IPv4 terminal 1903
It becomes possible to receive the IPv4 packet transmitted to the v4 / v6 mobile terminal 106, and conversely, the existing IPv4 terminal 1
Reference numeral 903 enables reception of an IPv4 packet transmitted from the IPv4 / v6 mobile terminal 106 to the IPv4 terminal 1903.

In addition, the existing method, Mobile IP
IPv6 mobility support terminal c1907 supporting v6,
With the support of the movement of the terminal in IPv6 by the IPv6 movement support terminal d1909, communication using IPv6 between another terminal and the IPv4 / v6 mobile terminal 106 is also possible.

Note that the IPv4 / v6 mobile terminal 106 has the LA
When returning from N-d1901 to LAN-c1900,
The IPv4 / v6 mobile terminal 106 detects that it has returned to the home network by the above-described IPv4 migration processing 113. And the IPv4 / v6 mobile terminal 106
“10.0.0.30” is assigned to the source IPv4 address 2902 to the source IPv4 mobility support terminal 1906, and the transfer destination IP
An IPv4 move registration request message 2900 in which the same “10.0.0.30” as the own IPv4 address 2902 is set in the v4 address 2903 is transmitted. Source IPv4 that received the IPv4 move registration request message 2900
The mobility support terminal 1906 sends its own IPv4
Since the address 2902 and the transfer destination IPv4 address 2903 are the same address, the IPv4 / v6 mobile terminal 106 has the LAN-c 190 as the home network.
0 and returns to the mobile terminal management table 191.
7 for the mobile terminal. as a result,
The IPv4 / v6 mobile terminal 106 can perform communication using normal IPv4. Similarly, the IPv4 / v6 mobile terminal 106 also sends an L6 to the IPv6 mobility support terminal c1907 according to the Mobile IPv6 processing procedure.
In order to notify the return to the AN-c 1900 by the IPv6 movement registration request message 1300, the normal
Communication using Pv6 is also possible.

[0113]

According to the present invention, even when an IPv4 / v6 mobile terminal moves from an IPv4 / v6 network to an IPv4 network, an existing IPv6 terminal transmits an IPv4 / v6 mobile terminal to an IPv4 / v6 mobile terminal. The received IPv6 packet can be received. Conversely, the existing IPv6 terminal can receive the IPv6 packet transmitted to itself (to the IPv6 terminal) by the IPv4 / v6 mobile terminal. Therefore, the IPv4 / v6 mobile terminal does not disconnect the network connection using IPv6 already established with another terminal before moving.
It will be possible to keep it. It is also possible to newly establish a network connection using IPv6.

Further, the existing method, Mobile I
IP by IPv4 mobility support terminal supporting Pv4
With the support of the movement of the terminal in v4, the other terminal and IPv4 /
Communication using IPv4 between v6 mobile terminals will continue to be possible.

Further, according to the present invention, even when the IPv4 / v6 mobile terminal moves from the IPv4 / v6 network to the IPv6 network, the IPv4 / v6 mobile terminal transmits the existing IPv4 terminal to the IPv4 / v6 mobile terminal. The received IPv4 packet can be received.
Conversely, the existing IPv4 terminal can receive the IPv4 packet transmitted to itself (to the IPv4 terminal) by the IPv4 / v6 mobile terminal. Therefore, the IPv4 / v6 mobile terminal has the IP address already established with another terminal before moving.
The network connection using v4 can be maintained without being disconnected. In addition, I
It is also possible to establish a network connection using Pv4.

Further, the existing method, Mobile I
IP by IPv6 mobility support terminal supporting Pv6
With the support of the movement of the terminal in v6, other terminals and IPv4 /
Communication using IPv6 between v6 mobile terminals will continue to be possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a network to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a configuration example of a mobile terminal management table used in a source IPv6 mobility support terminal shown in FIG. 1;

FIG. 3 is an explanatory diagram showing a configuration example of a mobility support terminal address table used in the destination IPv6 mobility support terminal shown in FIG. 1;

FIG. 4 is an explanatory diagram showing a configuration example of a movement support management table used in the destination IPv6 movement support terminal shown in FIG. 1;

FIG. 5 is a block diagram illustrating I / O in the IPv4 / v6 mobile terminal shown in FIG. 1;
It is an operation | movement flowchart which showed an example of the Pv4 movement processing procedure.

FIG. 6 is a block diagram illustrating I / O in the IPv4 / v6 mobile terminal shown in FIG. 1;
It is an operation | movement flowchart which showed an example of the Pv6 movement processing procedure.

7 is an operation flowchart illustrating an example of an IPv6 movement support processing procedure in the source IPv6 movement support terminal illustrated in FIG. 1;

FIG. 8 is an operation flowchart showing an example of a destination IPv6 movement support processing procedure in the destination IPv6 movement support terminal shown in FIG. 1;

FIG. 9 is an operation flowchart showing an example of a transfer processing procedure for the destination IPv6 mobile support terminal in the source IPv6 mobile support terminal shown in FIG. 1;

FIG. 10 is an operation flowchart showing an example of a transfer procedure to another terminal in the source IPv6 movement support terminal shown in FIG. 1;

11 is an operation flow chart showing an example of a transfer processing procedure for a source IPv6 movement support terminal in the movement destination IPv6 movement support terminal shown in FIG. 1;

FIG. 12 is an operation flowchart showing an example of a mobile terminal transfer processing procedure in the destination IPv6 mobility support terminal shown in FIG. 1;

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

FIG. 14 shows an IPv6 transfer registration permission message in IPv4
FIG. 3 is an explanatory diagram showing a configuration example of an encapsulated packet.

FIG. 15 is a diagram showing an IPv6 movement registration request message in an IPv4
FIG. 3 is an explanatory diagram showing a configuration example of an encapsulated packet.

FIG. 16 is an explanatory diagram showing a configuration example of a packet obtained by encapsulating an IPv6 packet in IPv6.

FIG. 17 is an explanatory diagram showing a configuration example of a packet obtained by encapsulating an IPv6 packet in which the IPv6 is encapsulated;

FIG. 18 is an explanatory diagram showing a configuration example of a packet obtained by encapsulating an IPv6 packet in IPv4.

FIG. 19 is a configuration diagram showing another example of a network to which the present invention is applied.

20 is an explanatory diagram showing a configuration example of a mobile terminal management table used in the source IPv4 mobility support terminal shown in FIG. 19;

21 is an explanatory diagram showing a configuration example of a mobility support terminal address table used in the destination IPv4 mobility support terminal shown in FIG. 19;

FIG. 22 is an explanatory diagram showing a configuration example of a movement support management table used in the destination IPv4 movement support terminal shown in FIG. 19;

23 is an operation flowchart illustrating an example of an IPv4 movement support processing procedure in the source IPv4 movement support terminal illustrated in FIG. 19;

FIG. 24 is an operation flowchart showing an example of a destination IPv4 movement support processing procedure in the destination IPv4 movement support terminal shown in FIG. 19;

FIG. 25 is an operation flowchart showing an example of a transfer processing procedure for the destination IPv4 mobility support terminal in the source IPv4 mobility assistance terminal shown in FIG. 19;

26 is an operation flowchart showing an example of a transfer procedure to another terminal in the source IPv4 movement support terminal shown in FIG. 19;

27 is an operation flowchart illustrating an example of a transfer processing procedure for a source IPv4 mobility support terminal in the destination IPv4 mobility support terminal illustrated in FIG. 19;

FIG. 28 is an operation flowchart showing an example of a mobile terminal transfer processing procedure in the destination IPv4 mobility support terminal shown in FIG. 19;

FIG. 29 is an explanatory diagram showing a configuration example of an IPv4 move registration request message.

FIG. 30 shows an IPv4 transfer registration permission message in IPv6
FIG. 3 is an explanatory diagram showing a configuration example of an encapsulated packet.

FIG. 31 shows an IPv4 movement registration request message sent to IPv6
FIG. 3 is an explanatory diagram showing a configuration example of an encapsulated packet.

FIG. 32 is an explanatory diagram showing a configuration example of a packet obtained by encapsulating an IPv4 packet in IPv6.

[Explanation of symbols]

106: IPv4 / v6 mobile terminal, 107: source IP
v6 movement support terminal, 109: destination IPv6 movement support terminal, 112: IPv4 processing unit, 113: IPv4 movement processing unit, 114: IPv6 processing unit, 115: IPv6 movement processing unit, 117: IPv6 movement support processing unit, 118: I
Pv4 processing unit, 119: transfer processing unit for other terminals, 120:
IPv6 processing unit, 121: transfer processing unit for mobile terminal, 12
2: mobile terminal management table, 123: destination IPv6 movement support processing unit, 124: IPv4 processing unit, 125: mobile terminal transfer processing unit, 126: IPv6 processing unit, 127:
Source IPv6 transfer support terminal destination transfer processing unit, 128: transfer support management table, 130: transfer support terminal address table

Claims (12)

[Claims] 1. A first IP capable of communicating according to a first type IP (Internet Protocol) and a second type IP
In a network system in which a network and a second IP network that can only communicate according to a first type of IP are mutually connected, a mobile terminal capable of communicating according to a second type of IP is moved from the first IP network to a second terminal. A method in which the mobile terminal controls the mobile terminal to perform communication according to a second type of IP with another terminal belonging to a first IP network when the mobile terminal moves to the second IP network. To a second IP as a destination address for an IP packet conforming to the second type of IP to the first mobile support terminal belonging to the first IP network.
The first type I of the second mobility support terminal belonging to the network
P, sets an IP address according to P, adds a first type IP header in which an IP address according to the first type of IP of the first mobile support terminal is set as a source address, and transmits the IP address to the second mobile support terminal, A method for controlling a mobile terminal, wherein the first type of IP header is deleted by a second mobile support terminal and the IP packet is transmitted to the mobile terminal. 2. A first IP capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP.
In a network system in which a network and a second IP network that can only communicate according to a first type of IP are mutually connected, a mobile terminal capable of communicating according to a second type of IP is moved from the first IP network to a second terminal. A method in which the mobile terminal controls the mobile terminal to perform communication according to a second type of IP with another terminal belonging to a first IP network when the mobile terminal moves to the second IP network. For the IP packet according to the second type of IP to the first mobile support terminal belonging to the first IP network, the IP address according to the second type of IP relating to the second IP network of the mobile terminal as the destination address A second type IP header that has been set and an IP address according to the second type IP of the first mobility support terminal is set as a source address. After adding the address, an IP address according to the first type IP of the second mobility support terminal belonging to the second IP network is further set as a destination address,
The first type I of the first mobility support terminal as the source address
A first type IP header in which an IP address according to P is set is added and transmitted to the second mobility support terminal, and the first type IP header is deleted by the second mobility support terminal and the IP packet is transmitted to the second mobility support terminal. A method for controlling a mobile terminal, wherein the method is to transmit to the mobile terminal. 3. A first IP capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP.
In a network system in which a network and a second IP network that can only communicate according to a first type of IP are mutually connected, a mobile terminal capable of communicating according to a second type of IP is moved from the first IP network to a second terminal. A method in which the mobile terminal controls the mobile terminal to perform communication according to a second type of IP with another terminal belonging to the first IP network when the mobile terminal moves to the second IP network. To the first IP as a destination address for an IP packet according to the second type of IP to the second mobile support terminal belonging to the second IP network.
The first type I of the first mobility support terminal belonging to the network
P, an IP address according to P is set, and a first type IP header in which an IP address according to the first type of IP of the second mobile support terminal is set as a source address is transmitted to the first mobile support terminal, A method for controlling a mobile terminal, characterized in that the first type of IP header is deleted by a first mobility support terminal and the IP packet is transmitted to the other terminal. 4. A first IP capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP
In a network system in which a network and a second IP network that can only communicate according to a first type of IP are mutually connected, a mobile terminal capable of communicating according to a second type of IP is moved from the first IP network to a second terminal. A method in which when the mobile terminal moves to the second IP network, the mobile terminal controls the mobile terminal to perform communication according to the second type of IP with another terminal belonging to the first IP network. The second mobile support terminal belonging to the second IP network responds to the first type of mobile registration request message according to the two types of IPs as the first destination address.
Of the first mobility support terminal belonging to the IP network of the first
An IP address according to the type of IP is set, and a first type IP header in which an IP address according to the first type of IP of the second mobility support terminal is set as a source address is transmitted to the first mobility support terminal. The first mobile support terminal sets an IP address according to the first type IP of the second mobile support terminal as a destination address for the message according to the second type IP for permitting the movement, and transmits the message. A first type IP header in which an IP address according to the first type of IP of the first mobile support terminal is set as an original address is transmitted to the second mobile support terminal with the first type of IP header added thereto. A method for controlling a mobile terminal, comprising deleting one type of IP header and transmitting the message to the mobile terminal. 5. A first IP capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP
A network system in which a network and a second IP network that can only communicate according to a first type of IP are interconnected, and a mobile terminal that can communicate according to a second type of IP is connected to a first IP network. From the second IP
A network system controlled by a mobility support terminal such that when the mobile terminal moves to a network, the mobile terminal performs communication according to a second type of IP with another terminal belonging to a first IP network. For the IP packet according to the second type of IP, an IP address according to the first type of IP of the second mobility support terminal belonging to the second IP network is set as a destination address, and the first IP network is set as a source address. A first mobility support terminal that adds a first type IP header in which an IP address according to a first type of IP of the first mobility support terminal belonging to the first type is set and transmits to the second mobility support terminal; A second mobility support terminal that deletes a certain type of IP header and transmits the IP packet to the mobile terminal. Stem. 6. A first IP capable of communicating according to a first type IP (Internet Protocol) and a second type IP
A network system in which a network and a second IP network that can only communicate according to a first type of IP are interconnected, and a mobile terminal that can communicate according to a second type of IP is connected to a first IP network. From the second IP
A network system controlled by a mobility support terminal such that when the mobile terminal moves to a network, the mobile terminal performs communication according to a second type of IP with another terminal belonging to a first IP network. The second type of the mobile terminal is used as a destination address for an IP packet conforming to the second type of IP.
IP address according to a second type of IP associated with the first IP network, and an IP address according to a second type of IP of a first mobility support terminal belonging to the first IP network as a source address After adding the header, an IP address according to the first type of IP of the second mobility support terminal belonging to the second IP network is set as a destination address, and a first address of the first mobility support terminal is set as a source address. A first mobility support terminal that adds a first type IP header in which an IP address according to the type of IP is set and transmits the first type of IP header to the second mobility support terminal; and deletes the first type of IP header and generates the IP packet. And a second mobility support terminal that transmits a message to the mobile terminal. 7. A first IP capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP
A network system in which a network and a second IP network that can only communicate according to a first type of IP are interconnected, and a mobile terminal that can communicate according to a second type of IP is connected to a first IP network. From the second IP
A network system controlled by a mobility support terminal such that when the mobile terminal moves to a network, the mobile terminal communicates with another terminal belonging to a first IP network according to a second type of IP. For an IP packet according to the second type of IP, an IP address according to the first type of IP of the first mobility support terminal belonging to the first IP network is set as a destination address, and the second IP network is set as a source address. A second mobility support terminal that adds a first type IP header in which an IP address according to a first type of IP of a second mobility support terminal belonging to the first type is added and transmits to the first mobility support terminal; And a first mobility support terminal that deletes the IP header of the above and transmits the IP packet to the other terminal. Beam. 8. A first IP capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP
A network system in which a network and a second IP network that can only communicate according to a first type of IP are interconnected, and a mobile terminal that can communicate according to a second type of IP is connected to a first IP network. From the second IP
A network system controlled by a mobility support terminal such that when the mobile terminal moves to a network, the mobile terminal performs communication according to a second type of IP with another terminal belonging to a first IP network, the second type received from the mobile terminal. The first IP as the destination address for the mobile registration request message according to the IP
The first type I of the first mobility support terminal belonging to the network
A first type I that sets an IP address according to P and sets an IP address according to the first type of IP of the second mobility support terminal belonging to the second IP network as a source address
Second to add a P header and transmit to the first mobility support terminal
And an IP address according to the first type IP of the second mobile assistance terminal as a destination address for a message according to the second type IP for permitting the movement, and a source address as the source address IP according to the first type of IP of the first mobility support terminal
A second type of IP header with an address
And a first mobility support terminal for transmitting to the mobility support terminal. 9. A first IP capable of communicating according to a first type IP (Internet Protocol) and a second type IP
In a network system in which a network and a second IP network that can only communicate according to a first type of IP are interconnected, a mobile terminal that can communicate according to a second type of IP is moved from the first IP network to a second terminal. A mobile support terminal that controls the mobile terminal to perform communication according to a second type of IP with another terminal belonging to the first IP network when the mobile terminal moves to the second IP network; Sets the IP address according to the first type IP of the second mobility support terminal belonging to the second IP network as the destination address for the IP packet according to the second type IP to the mobile terminal, and the source address And adds a first type IP header in which an IP address according to the first type IP of the mobility support terminal belonging to the first IP network is set. A means for transmitting the data to a second mobile support terminal. 10. A first I which can communicate according to a first type of IP (Internet Protocol) and a second type of IP.
In a network system in which a P network and a second IP network that can only communicate according to a first type of IP are interconnected, a mobile terminal capable of communicating according to a second type of IP is connected from the first IP network. Second IP
A mobile support terminal that controls the mobile terminal to perform communication according to a second type of IP with another terminal belonging to a first IP network when the mobile terminal moves to a network; For an IP packet according to the second type of IP to the terminal, an IP address according to the first type of IP of the first mobility support terminal belonging to the first IP network is set as a destination address, and a second address as a source address is set. Characterized in that it has means for adding a first type IP header in which an IP address according to the first type IP of the mobile support terminal itself belonging to the IP network of the first type is added and transmitting the IP address to the first mobile support terminal. Support terminal. 11. A first I-type communication device capable of communicating according to a first type of IP (Internet Protocol) and a second type of IP.
In a network system in which a P network and a second IP network that can only communicate according to a first type of IP are interconnected, a mobile terminal capable of communicating according to a second type of IP is connected from the first IP network. Second IP
A mobile support terminal that controls the mobile terminal to perform communication according to a second type of IP with another terminal belonging to a first IP network when the mobile terminal moves to a network, the mobile support terminal receiving from the mobile terminal Second kind of I
For the transfer registration request message according to P, an IP address according to the first type of IP of the first mobility support terminal belonging to the first IP network is set as a destination address, and belongs to the second IP network as a source address. A mobility support terminal comprising: means for adding a first type IP header in which an IP address according to the first type of IP of the mobility support terminal itself is set and transmitting the IP header to the first mobility support terminal. 12. A first I which can perform communication according to a first type of IP (Internet Protocol) and a second type of IP.
In a network system in which a P network and a second IP network that can only communicate according to a first type of IP are interconnected, a mobile terminal capable of communicating according to a second type of IP is connected from the first IP network. Second IP
A mobile support terminal for controlling the mobile terminal to perform communication according to a second type of IP with another terminal belonging to a first IP network when the mobile terminal moves to a network. Of the second kind of I
The second as the destination address for the message according to P
Of the second mobility support terminal belonging to the first IP network
An IP address according to the type of IP is set, and an IP according to the first type of IP of the mobile support terminal itself is set as a source address.
A second type of IP header with an address
Transmitting to a mobile support terminal of the first IP
Mobility support terminal belonging to the network.