KR20030061760A - Mobile IPv4 system for supporting local IP - Google Patents

Abstract

PURPOSE: A mobile IPv4(Internet Protocol version 4) system supporting a private IP is provided to support a private IP by classifying an MN(Mobile Node) using reverse tunnelling and a MAC address even in case that an existing mobile IP, based on a private network, is used. CONSTITUTION: A mobile IPv4 system consists of a CN(Corresponding Node)(200), the Internet, an HN(Home Network)(100), and an FN(Foreign Network)(300). The HN(100) comprises an NAT(Network Address Translator)(130) and an HA(Home Agent)(120). The FN(300) also comprises an NAT(320) and an FA(Foreign Agent)(310). The NAT(130) of the HN(100) previously sets up a port for the registration message transmission and reception of a mobile IP and transmits a packet, received to the port, to the HA(120) or the FA(310). The HA(120), connected with the NAT(130), manages the home address of an MN(110) and the NAT-authorized address of the present location to appoint the location of the MN(110), and creates a tunnel to the FA of another network, in which the NAT of the present location exists. The NAT(320) of the FN(300) previously sets up a port for the registration message transmission and reception of the mobile IP and transmits a packet, received to the port, to the HA(120) or the FA(310). The FA(310), connected with the NAT(320), classifies each MN on the basis of a source address, a destination address and a MAC address, contained in a packet transmitted from the HA(120), and transmits the received packet to a relevant MN.

Description

Mobile IPv4 system for supporting local IP}

The present invention relates to a Mobile IPv4 (Mobile IPv4) system that supports a private IP (IP), especially when using the existing mobile IP in the private network based reverse tunneling (reverse tunneling) and MAC address The present invention relates to a Mobile IPv4 (Mobile IPv4) system that supports a private IP (IP: Internet Protocol) to support private IP by classifying user terminals.

In general, as Internet devices become wireless and miniaturized, there is a need for an environment in which users can continuously receive Internet services while moving and functions that support them.

For this user mobility, the IETF enacted the Mobile IP standard and defines functions for these services. Based on this standard, equipment and user devices capable of supporting mobile IP are being implemented. This standard and the system implemented based on this standard prescribe the basic condition that each user uses public IP.

Currently, the mobile IP standard defined by the IETF should allow the user terminal to route IP packets to the terminal using the public IP. In addition, even when the terminal moves to another network, the IP address used by the terminal remains unchanged, and thus the existing packet can be continuously received.

1 is a diagram illustrating a general mobile IPv4 network.

A user terminal (MN: Mobile Node) 11 normally communicates with a counterpart terminal (CN: Corresponding Node) 20 in a home network (HN: Home Network) 10, and then another network (FN: Foreign Network). When moving to 30, communication between the user terminal 11 and the counterpart terminal 20 should be maintained, and the IP address used by the existing user terminal 11 in the home network 10 should not be changed.

To this end, the user terminal 11 transmits a registration message (Registration Request) indicating that it has moved to the new network 30 to the foreign agent (FA) 31.

Upon receiving this, the FA 31 transmits a registration message to the HA (Home Agent) 12 in the home network 10 of the user terminal 11 to inform that the user terminal 11 is in another network 30. .

The HA 12 receiving the registration message manages the IP address (Home Address) originally used by the user terminal 11 and the address of the FA 31 where the user terminal 11 is currently located, thereby providing a home network 10. The packets transmitted to the user terminal 11 of the 1) may be tuned back to the location where the current user terminal 11 is located. That is, the counterpart terminal 20 cannot know that the user terminal 11 has moved, and transmits a packet using the IP address of the only user terminal 11 in the IP network, so that the user terminal 11 has a different network. Even if it moves to 30, the packet transmitted from the counterpart terminal 20 continues to be transmitted to the home network 10 of the user terminal 11.

Therefore, the HA 12 forwards the packet transmitted to the home network 10 of the user terminal 11 to the network 30 where the user terminal 11 is currently located, so that the user terminal 11 may move to another network. It can continuously receive the packet received from the previous network. To this end, the HA 12 tunnels the packet coming to the IP address of the user terminal 11 to the FA 31, and the FA 31 transmits the tunneled packet back to the user terminal 11. It plays a role.

In FIG. 1, reference numeral 40 denotes the Internet.

2 is a block diagram illustrating a mobile IPv4 network for explaining packet flow when using a conventional private IP.

When the user terminal (MN: Mobile Node) 11 normally communicates with the counterpart terminal (CN: Corresponding Node) 20 in the home network (HN: Home Network) (10), the counterpart terminal 20 is a user terminal ( Instead of the private IP address of 11), it communicates with the NAT (Network Address Translator) 13 address of the home network 10. That is, the source address of the packet transmitted from the user terminal 11 to the counterpart terminal 20 is the private IP of the user terminal 11, and the destination address is the IP address of the counterpart terminal 20.

As the packet passes through the NAT 13, the source address of the packet is changed to the IP address of the NAT 13, and the NAT 13 creates a mapping table for this change.

Therefore, when the terminal is moved from the home network 10 to another network 30, when viewed from the other terminal 20, the source address of the packet received in the existing connection is NAT (home) of the home network 10 of the user terminal 11 ( 13) It is not the address but the NAT (32) address of the moved network (30). Accordingly, the counterpart terminal 20 may not maintain an existing connection with the user terminal 11.

That is, in an environment using a private IP, the user terminal uses a private IP instead of a public IP, and a NAT (Network Address Translator) must be used to access an external network such as the Internet. That is, in the external network, routing cannot be directly designated individually, and a packet can be transmitted to a corresponding terminal by using an address translated by NAT. In this case, since there is no IP address capable of routing to the corresponding terminal, it is impossible to provide mobility using the existing mobile IP when the terminal moves to another network.

In addition, in an environment using a private IP, the private IP address used in the network to which the terminal is moved may be already used by another terminal in the network. Therefore, a method for solving a routing problem of a mobile terminal using a private IP and identifying a specific terminal due to the use of a duplicate private IP address should be presented.

Accordingly, the present invention is proposed to solve the routing problem of a mobile terminal using the conventional private IP as described above, and to distinguish a specific terminal even when using a duplicate private IP address.

An object of the present invention is to provide a private IP (IP: Internet Protocol) to support private IP by distinguishing user terminals using reverse tunneling and MAC addresses even when using an existing mobile IP based on a private network. It is to provide a supported Mobile IPv4 system.

Reverse tunneling is a method of transmitting a packet for an existing connection through the HA of the mobile IP even if the user terminal moves from the mobile IP to another network. By using this method, the counterpart terminal can always receive the packet transmitted from the HA even if the corresponding terminal moves to another network, so that the corresponding terminal can be recognized as not moving. Also, this method can apply mobile IP in private IP environment by communicating with outside using HA and NAT addresses in the original network when transmitting and receiving packets through NAT in private IP environment.

In addition, the user terminal identification method using the MAC address uses that the interface card of each user has a unique MAC address. That is, since all network interface cards have a unique MAC address, the terminal can be distinguished using the same MAC address, and the packets can be transmitted to the terminal, even if there is a terminal having the same private IP address.

1 is a general mobile IPv4 network configuration diagram,

2 is a diagram illustrating a mobile IPv4 network for explaining packet flow when using a conventional private IP.

3 is a configuration diagram of a mobile IPv4 system supporting private IP according to the present invention;

4 is a configuration diagram of an embodiment of a mobile IPv4 FA of FIG. 3;

FIG. 5 is a diagram illustrating an embodiment of a mobile IPv4 MN of FIG. 3.

<Explanation of symbols for the main parts of the drawings>

100 ..... Home Network (HN)

110 ..... User terminal (MN)

120 ..... Home Agent (HA)

130, 320 ..... NAT

310 ..... FA Agent

312 ..... Address Management Table

313 ..... Tunnel Management Department

314 ..... Packet Transmitter

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above.

HA, FA, MN are needed as a function for mobile IP, and NAT is required for external internet access in a private network environment. NAT is not an additional component for Mobile IP for Existing Private IP and is assumed to be used in Existing Equipment or Existing Environment.

The functional elements and operation of HA and MN among the functional elements of the mobile IP network for applying the present invention are the same as the operation of HA and MN in the existing mobile IP. In addition, HA and MN must provide reverse tunneling function, which is defined in Mobile IP. The FA must additionally provide MAC address and IP address management to distinguish terminals having the same IP address from the existing mobile IP.

Referring to the accompanying drawings, preferred embodiments in consideration of the concept of the present invention as described above in detail as follows.

3 is a configuration diagram of a mobile IPv4 system supporting private IP according to the present invention.

The other terminal 200 should receive a packet having the source IP address of the NAT 130 address of the home network 100 of the user terminal 110, which is the original address. To this end, even if the user terminal 110 moves to another network (FN) 300, the home network 100 transmits a packet transmitted by the user terminal 110 using a reverse tunneling method between the FA 310 and the HA 120. By transmitting through the NAT 130, the other terminal 200 continues to receive a packet having the same IP address (NAT address of the home network) to maintain the connection.

To this end, the NAT 130 and 320 of the home network 100 and the other network 300 transmit the 434 port of the NAT 130 and 320 to the HA for the mobile IP in order to transmit and receive a registration message of the mobile IP. Or preset to send to FA. That is, the NAT 130 and 320 set to transmit all packets received on the port 434 to the HA 120 or the FA 310.

In addition, the HA 120 manages the NAT address of the current location of the user terminal 110 in order to designate the current location of the user terminal 110. That is, in the existing mobile IP, in order to designate the current location of the user terminal 110, the HA 120 manages the CoA of the FA 310 or the CoA of the user terminal 110, but the HA 120 of the present invention. In order to manage the NAT address of the current location of the user terminal (110).

In other words, the HA 120 manages the address of the user terminal 110 and the address of the NAT 320 to create a tunnel to the corresponding NAT 320.

In the FA 310 of another network 300, since the moved user terminal 110 uses a private IP address, there is a high possibility of using the same IP. That is, an IP address used by the home network 100 of the user terminal 110, an IP address used by another node in the current network 300, and an IP used when another user terminal moves from another network to the current network. If the addresses are all the same, the FA 310 of the existing mobile IP cannot use the method of distinguishing each terminal by the IP address.

Therefore, in order to solve this problem, each user terminal must be distinguished based on the MAC address of the user terminal 110, which is a uniquely distinguishable factor. That is, the FA 310 classifies the user terminal 110 based on a source address (HA address), a destination address, and a MAC address in the packet received from the HA 120, and receives the received packet from the corresponding user terminal 110. To send.

4 is a diagram illustrating an embodiment of a mobile IPv4 FA of FIG. 3.

As shown therein, a FA function performing unit 311 performing a FA function of the mobile IP; An address management table 312 for managing the MAC addresses of the HA / FA and the user terminal; A tunnel manager 313 for classifying user terminals and managing tunnels based on the HA / FA and MAC addresses of the user terminals; And a packet transmitter 314 for classifying the user terminal based on the HA / FA and the MAC address of the user terminal and transmitting a packet with the separated user terminal.

The operation of the FA 310 configured as described above will be described in more detail as follows.

First, the FA function performing unit 311 is connected to the NAT 320 to perform a FA function of a typical mobile IP.

Next, the address management table 312 is connected to the FA function performing unit 311, and stores and manages the address of the HA 120, the address of the FA 310, and the MAC address of the user terminal 110.

In addition, the tunnel manager 313 manages the tunnel by dividing the user terminal based on the addresses of the HA 120 and FA 310 and the MAC address of the user terminal 110, and the packet transmitter 314 also. The user terminal is classified based on the addresses of the HA 120 and the FA 310 and the MAC addresses of the user terminal 110, and the received packet is transmitted to the separated user terminal 110.

On the other hand, since the FA 310 is operated in a private network, the user terminal 110 detects a movement to an IP address when the FA 310 moves to another network from another network 300 to another network. It can't be done. Accordingly, the movement detection in the user terminal 110 is also performed based on the MAC address of the FA 310 or the HA 120.

FIG. 5 is a diagram illustrating an embodiment of a mobile IPv4 MN of FIG. 3.

As shown therein, a user terminal function performing unit 111 performing a normal user terminal function; The MAC address based movement detection unit 112 detects movement based on the MAC address of the FA or HA.

The user terminal 110 configured as described above performs the normal user terminal function in the user terminal function performing unit 111, and the MAC address of the FA 310 or the HA 120 in the MAC address-based movement detection unit 112. The movement is detected based on.

According to the present invention as described above, there is an effect to efficiently use the limited IPv4 address resources in the network that requires IP address, such as wireless LAN, home networking that is emerging.

In addition, there is an effect to efficiently use the limited IPv4 address resources without the existing network configuration and additional application development.

Claims (3)

In a mobile IPv4 system that supports private IP and consists of a counterpart terminal (CN), the Internet, a home network (HN), and another network (FN), The home network (HN), A network address translator (NAT) which previously sets a port (434 port) for transmitting and receiving a registration message of a mobile IP and transmits a packet received to the port to a home agent (HA) or an agent (FA) in the other network (FN). )Wow; Connected to the network address translator, and manages the home address of the user terminal (MN) and the NAT public address of the current location to specify the location of the current user terminal (MN), FA of the other network with the NAT of the current location A home agent (HA) that creates a tunnel The other network (FN), A network address translator (NAT) which presets a port (434 port) for transmitting and receiving a registration message of a mobile IP, and transmits a packet received to the port to a home agent (HA) or a forest agent (FA); Connected to the network address translator, the packet received by distinguishing each user terminal (MN) based on a source address (HA address), a destination address, and a MAC address included in the packet transmitted from the HA is received by the corresponding user terminal (MN). Mobile IP version 4 system that supports private IP, characterized in that configured as a FA agent to transmit to). The method of claim 1, wherein the FA, A FA function performing unit performing a FA function of Mobile IP; An address management table for managing MAC addresses of the HA (home agent) / FA (forin agent) and user terminal (MN); A tunnel manager for classifying a user terminal (MN) and managing a tunnel based on the HA / FA and the MAC address of the user terminal; Private IP characterized in that it is provided as a packet transmission unit for classifying the user terminal (MN) based on the MAC address of the HA / FA and the user terminal (MN), and transmits packets with the separated user terminal (MN) Mobile IP version 4 system that supports. The method of claim 1 or 2, wherein the user terminal (MN), A user terminal function performing unit performing a normal user terminal function; Mobile IP version 4 system supporting a private IP, characterized in that it comprises a MAC address based movement detection unit for detecting movement to the MAC address of the FA or HA.