KR100505139B1 - Method for mobility and transmission of mobile node in dymamic mobile IP - Google Patents

Abstract

The present invention relates to a method for ensuring mobility and data transmission of a mobile node in a dynamic mobile IP environment. According to the present invention, in accordance with the present invention, mobility guarantee of a mobile node is achieved by HA assigning its own IP address to the mobile node, and data transmission of the mobile node is a source port number included in a data packet transmitted from the mobile node. To match the current location registration information of the mobile node with the current location information, and compares the destination port number included in the response data packet transmitted to the mobile node with the current location information to know the destination of the response data packet. By making it possible. In this case, the present invention changes the source port number of the data packet transmitted from the mobile node to the target node to an arbitrary port number, and then transmits it to the target node, and the destination port of the response data packet transmitted in response to the target node It is recommended to change the number to the source port number before the change and transmit it to the mobile node.

Description

Method for mobility and transmission of mobile node in dynamic mobile IP environment {Method for mobility and transmission of mobile node in dymamic mobile IP}

The present invention relates to a wireless LAN or a wired LAN in a dynamic mobile IP environment, and in particular, to all mobile nodes regardless of IP address resources held by a home agent (hereinafter, referred to as 'HA'). The present invention relates to a method for enabling a mobile node to assign an IP address and enabling mobile node mobility and data transmission and reception using the assigned IP address.

The mobile node is a terminal capable of accessing a wireless LAN or a wired LAN, and is a host or router that changes an access point from one network or subnetwork to another.

As described in the Request for Comments (RFC) 2002 document and the IS-835.b document provided by the Internet Engineering Task Force (IETF), a general mobile IP WLAN is illustrated in FIG. mobile node (MN), each of which has a unique IP address and constitutes one subnet (n1, n2, n3, ...) and a number of foreign agents (FA) and one HA (with a unique IP address) Home Agent) is the basic configuration.

The mobile IP WLAN having such a configuration can be divided into a mobile IP environment and a dynamic mobile IP environment according to the mobile IP allocation method. Here, in the mobile IP environment, an IP address set for each mobile node is called a home address. Therefore, hereinafter, the home address and the IP address are used interchangeably depending on the context.

The mobile IP environment ensures each mobile node has its own home address at all times to ensure mobility to other subnets. That is, as shown in Figure 1, each mobile node (MN) has a unique home address that matches its own subnet address, and when moving to a different subnet by comparing its own home address and the subnet address of the current location It determines if it has moved to another subnet. If its home address is 10.10.10.5 and the address of the currently located subnet is 30.30.30.x, the mobile node determines that it is moving to another subnet and registers its current location with the HA.

Therefore, when a mobile node enters or initially connects to a subnet, the mobile node compares its home address with the subnet address of the current location (actually, the FA's IP address) and determines whether it is out of home. Then, the current location registration is performed accordingly.

However, the mobile IP environment requires IP address resources as many as the number of mobile nodes. However, since the IP address resources are limited, when the number of mobile nodes increases exponentially, there is a problem that the IP address resources become insufficient.

Accordingly, in order to solve the above problems of the mobile IP environment, a dynamic mobile IP environment is used. The dynamic mobile IP environment does not assign a unique IP address to each mobile node. Instead, when the mobile node connects to the subnet, the HA then assigns a home address to the mobile node. Therefore, the home node is not provided to the mobile node that is not used in the dynamic mobile IP environment, and the home address is assigned only to the mobile node in use, thereby making it more efficient to utilize the home address resource.

However, since the dynamic mobile IP environment provides a home address to all mobile nodes connected to one HA, the HA requires a large number of IP addresses.

The present invention has been made to solve the above-mentioned conventional problems, and enables the HA to provide IP addresses to all mobile nodes regardless of the amount of IP address resources, and the mobility and datagrams of the mobile nodes using the provided mobile IP. The purpose of this is to enable transmission and reception of a).

In the dynamic mobile IP environment according to the present invention for achieving the above technical problem, a method of guaranteeing mobility and data transmission of a mobile node does not have an IP address resource by assigning its own IP address as a mobile node's home address. It is characterized by having all mobile nodes assign a home address.

However, according to the above feature, if all HAs are assigned an IP address of HA as a home address, mobility of the nodes can be guaranteed, but all mobile nodes are given the same home address, and thus data with a target node. Transmission and reception cannot be guaranteed. Therefore, the present invention allows all mobile nodes assigned an IP address to pass through the HA when transmitting data, and ensures that the source port (HA) is included in the mobile node's data packet. port) is another feature of using a number as an identifier of a mobile node.

Accordingly, the present invention for achieving the above technical problem in the method for ensuring the mobility and data transmission of the mobile node in a dynamic mobile IP environment for the mobile node to perform a location registration event, the mobile node is a HA (Home Agent) A second step of requesting location registration, a second step of the HA assigning its IP address as a home address of the mobile node and performing location registration, and a reverse between the mobile node and the HA When the mobile node transmits the data packet to the HA, the third step of tunneling is formed, and the HA manages the source port number included in the data packet by matching the current location information of the mobile node. Transmitting the data packet to the HA; and when the response data packet is transmitted from the target node to the HA, a list of the HAs included in the response data packet A fifth step of confirming that the mobile node is the destination by matching the destination port number with the source port number of the current location information, and transmitting the response data packet to the mobile node of the destination; and the mobile node is the target node. And a sixth step of receiving the response data packet transmitted from the HA from the HA.

Preferably, the present invention changes the source port number of the data packet transmitted from the mobile node to the target node to an arbitrary port number, and then transmits the response to the target node, and transmits the response data packet in response to the target node. The destination port number may be changed to the source port number before the change and transmitted to the mobile node.

Hereinafter, a method of guaranteeing mobility and data transmission of a mobile node in a dynamic mobile IP environment according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a first embodiment of the present invention will be described with reference to FIGS. 2 and 3.

FIG. 2 is a flowchart illustrating a case where a method for guaranteeing mobility and data transmission of a mobile node in a dynamic mobile IP environment according to the first embodiment of the present invention is applied to a WLAN. The first embodiment of the present invention relates to a case where a current location is registered using an IP allocated from a DHCP server and data is transmitted and received using the source port number included in a data packet of a mobile node.

As shown in FIG. 2, the mobile node MN transmits a solicitation message to the FA 11 to determine its current position at the time of initial connection or handoff. In step S201, the FA 11 transmits an agent advertisement message that is periodically broadcasted to the mobile node MN. At this time, the agent propagation message includes the IP address of the FA 11 as the current location information (S202).

When the mobile node (MN) knows its current location as the FA 11's IP address, it compares the current location (ie, the IP address of the FA 11) with the IP address of the FA previously connected. It is determined whether a new subnet has been entered, and it is determined that the current location should be registered accordingly (S203).

Accordingly, the mobile node (MN) is assigned by requesting an IP address from the DHCP server 10 (S204, S205), and includes the assigned own IP address as a Co-located COA in the current location registration request signal and HA ( 20) (S206).

When the HA 20 receives a location registration request signal from the mobile node MN, the HA 20 matches and stores the co-located COA with the home address of the mobile node MN for location registration. However, in the dynamic IP environment, the location registration request signal received by the HA 20 does not have a home address of the mobile node MN. Accordingly, if the HA 20 does not have a home address of the mobile node MN in the location registration request signal, the HA 20 sets its own IP address as the home address of the mobile node MN to perform the current location registration of the mobile node MN. (S207). Here, the HA 20 manages the home address and the current location of each mobile node MN with a location management table, and updates the COA information recorded in the location management table for the mobile nodes registering the location. Do this.

The HA 20 performs the current location registration and simultaneously transmits the home address assigned to the mobile node MN, that is, its own IP address, to the mobile node MN by including the location registration response signal (S208). Then, the mobile node MN checks whether the location is registered with the received location registration response signal, and simultaneously extracts IP address information included in the location registration response signal and sets it as its home address (S209).

Then, the mobile node MN determines whether its home address is the same as the IP address of the HA 20, and if the mobile node MN is identical, forms a reverse tunneling to the HA 20 (S210). Forming reverse tunneling to the HA 20 by the mobile node MN means that signals to be transmitted later are transmitted to the target node via the HA 20.

Accordingly, when the mobile node MN generates a data packet to be transmitted (S211), the mobile node MN encapsulates the generated data packet and transmits it to the HA 20 (S212).

Accordingly, the HA 20 decapsulates the data packet received from the mobile node MN, identifies the target node 30 as the final destination with header information, and simultaneously the source port number (included in the data packet ( source port number) is extracted and matched to the information of the mobile node 10 of the location management table (S213). The source port number is a corresponding port number of the mobile node (MN) that transmitted the data packet. Herein, the mobile node MN arbitrarily designates a port number for transmitting the data packet, and the port number is very wide. Therefore, the source port numbers included in the data packets transmitted from the plurality of mobile nodes MN are generally not the same.

After recording the source port number, the HA 20 transmits the data packet to the identified target node 30 (S214). Accordingly, the target node 30 generates a response data packet in response to the received data packet and transmits the response packet to the HA 20 according to the path information recorded in the header of the received data packet (S215). In the response packet, the source port number included in the data packet transmitted from the mobile node MN is used as the destination port number.

When the HA 20 receives the response packet from the target node 30, the HA 20 checks the destination port number included in the received response packet and applies the checked port number to the location management table to co-located COA corresponding to the port number. Search for and determine that the retrieved Co-located COA is a destination to be transmitted (216). Then, the HA 20 transmits the response data packet to the corresponding mobile node MN according to the confirmed destination information (S217). Accordingly, the mobile node MN receives the response packet transmitted from the target node 30 (S218).

Here, the current location registration process according to the first embodiment of the present invention described above uses a Co-located COA using the IP address of the DHCP server 10. However, those skilled in the art can modify the first embodiment of the present invention as follows. That is, instead of the co-located COA, a process of registering the current location of the mobile node (MN) may be performed using the COA using the FA's IP address. In this case, the mobile node (MN) obtains the FA's IP address from the FA, creates a COA using the acquired FA's IP address, and requests the current location registration from the FA through the FA. When the current position of the mobile node is registered with the COA using the IP address of the FA as described above, data between the mobile node MN and the target node 30 is made via the FA and the HA.

Hereinafter, a data transmission / reception process between the mobile node MN and the target node 30 during the operation of the first embodiment of the present invention described with reference to FIG. 2 will be described with reference to FIG. 3.

3 is an operational flowchart of a first embodiment of the present invention described on the basis of a data packet. Here, the mobile node (MN) is located in a subnet with an IP address of 20.20.20.x, and the mobile node has received an IP address from the DHCP server 10 to generate a co-located COA of 20.20.20.11. The HA 20 has an IP address of 10.10.10.10, and the target node 30 is a yahoo, which is an internet site.

Since FIG. 3 illustrates the matching of FIG. 2, the same reference numerals are assigned to the same process as that of FIG. 2.

 As shown in FIG. 3, the mobile node (MN) uses a co-located COA address of 20.20.20.11 as a source address (src), and a destination address (10.10.10.10) of an HA 20 as a source address (src). A position registration request signal of Dest) is transmitted to the HA 20 (S206). At this time, the location registration request signal has no home address of the mobile node MN.

Then, the HA 20 confirms that there is no home address of the mobile node MN in the location registration request signal. After performing S205 of FIG. 2, the HA 20 transmits its own IP address 10.10.10.10 to the source address src. The location registration response signal of the Co-located COA of 20.20.20.11 as the destination address and the IP address of 10.10.10.10 as the data field as the home address of the mobile node (MN) is the mobile node (MN). In step S208.

The format of the location registration response signal transmitted from the HA 20 to the mobile node MN will be described in detail with reference to FIG. 4. 4 is a data structure diagram of a location registration response signal according to an embodiment of the present invention.

As shown in Fig. 4, the location registration response signal is recorded with the source address f11 and the destination address f12 in the IP field f1, and the source port number f21 in the User Datagram Protocol (UDP) field f2. ) And the destination port number f22 are recorded, and the mobile IP data f31 is recorded in the data field f3.

Here, the mobile IP data f31 includes a type 1, code 2, lifetime 3, home address 4, HA 7 and identification 6 fields. Type 1 indicates the type of the signal, and '3' indicating the location registration response is recorded. The code 2 indicates the result of the location registration request, and '0' indicating registration success is recorded. The lifetime 3 represents the valid time of the signal, that is, the expiration time. The home address 4 represents the mobile node's IP address, the HA 5 represents the HA 30's IP address, and the identification 6 prevents attempts to respond to registration messages from others and matches requests and responses. It has a value corresponding to 64 bits.

Meanwhile, after the mobile node MN is assigned its home address from the HA 20, since its home address is the same as the IP address of the HA 20, reverse tunneling to the HA 20 is performed. To form. Then, after the mobile node (MN) has been assigned its home address from the HA (20), the mobile node (MN) uses 10.10.10.10 as the source address (src) and yahoo.com as a destination to connect to Yahoo, the target node 30. Create an original data packet with the address (Dest) and the source port number (Px). Then, the original data packet is encapsulated so that 20.20.20.11 becomes a source address (src) and 10.10.10.10 becomes a destination address (Dest) (S212).

Therefore, the encapsulated data packet transmitted from the mobile node MN is received by the HA 20 according to the header information.

After checking the mobile node MN that transmitted the data packet, the HA 20 decapsulates the encapsulated data packet and transmits the original data packet to the target node 30 (214).

Then, the target node 30 receives the original packet transmitted from the mobile node (MN), in response to yahoo.com as the source address (src) and 10.10.10.10 as the destination address (Dest), A response original data packet is generated and transmitted using the source port number Px of the mobile node MN included in the received original packet as the destination port number Px (S215).

The response original data packet is sent to the HA 20 because the destination address Dest is 10.10.10.10, and the HA 20 sets the received response original data packet to 10.10.10.10 as the source address src and 20.20.20.11. Encapsulates the destination address (Dest) and transmits it to the mobile node (MN) (S217).

Accordingly, the mobile node MN receives the encapsulated response original data packet, decapsulates it, and checks the response original data packet transmitted from the target node 30.

Herein, when the present invention is applied to a case in which the mobile node MN uses a COA created using the IP address of the FA, which is not a co-located COA, the encapsulation and decapsulation performed by the mobile node MN is performed by the FA. Same as the description with reference to FIG. 2 and FIG. 3 except that FA is added to the data transmission path to be performed.

Hereinafter, a method of guaranteeing mobility and data transmission of a mobile node in a dynamic mobile IP environment according to a second embodiment of the present invention will be described with reference to FIG. 5.

FIG. 5 is a flowchart illustrating a method of ensuring mobility and data transmission of a mobile node in a WLAN of a dynamic mobile IP environment according to a second embodiment of the present invention. FIG. 5 is a data packet of a mobile node in the same environment as that of the first embodiment. This is for data transmission and reception by arbitrarily changing the source port number included in the.

As described above, since the second embodiment of the present invention operates in the same environment as the first embodiment, the process of the mobile node MN grasping the current position from the DHCP server 10 is the same as that of the first embodiment. Therefore, hereinafter, the process of the mobile node MN grasps the current position is omitted.

As shown in FIG. 5, the mobile node MN includes an IP address allocated from the DHCP 10, that is, a co-located COA, in a location registration request signal and transmits the same to the HA 20 (S501). Then, when the HA 20 confirms that the received location registration request signal lacks the mobile node MN's home address, it sets its IP address as the mobile node MN's home address, and receives the received location registration. After updating the location management table that matches the co-located COA included in the request signal with the home address of the mobile node, the current location registration is performed, and then its own IP address of 10.10.10.10 is transferred to the home of the mobile node MN. The location registration response signal including the content allocated to the address is transmitted to the mobile node MN (S502).

Accordingly, the mobile node MN checks whether the location is registered by using the received location registration response signal, and simultaneously sets the IP address of the HA 20 included in the location registration response signal as its home address (S503).

Then, since the mobile node MN has the same home address as that of the HA 20, the mobile node MN forms reverse tunneling to the HA 20 (S504). When the data packet to be transmitted is generated, the mobile node (MN) has original data including 10.10.10.10 as the source address (src), yahoo.com as the destination address (Dest), and a source port number (Px). A data packet is generated, and the original data packet is encapsulated with 20.20.20.11 as the source address (src) and 10.10.10.10 as the destination address, and transmitted to the HA 20 (S505).

Accordingly, the HA 20 checks the header information of the data packet received from the mobile node MN, identifies the target node 30 as the final destination, and simultaneously decapsulates the encapsulated original data packet. After that, the source port number Px included in the original data packet is changed to an arbitrary source port number Py (S506).

Then, the HA 20 matches and records the changed source port number Py and the source port number Px before the change with the mobile node 10 information of the location management table, and then writes them to an arbitrary source port number Py. The modified original data packet is transmitted to the target node 30 (S507).

When the target node 30 receives the original data packet from the HA 20, the target node 30 transmits the original response data packet to the HA 20 in response thereto (S508).

Then, the HA 20 checks the destination port number Py included in the received response original data packet and applies the same to the location management table to inform the destination where the original response data packet was transmitted and the co-located COA before the change. Check the source port number (Px). Then, the HA 20 changes the destination port number of the original response data packet from Py to the Px (S509), and sets the packet to 20.20.20.11, which is a co-located COA, as the destination address (Dest), and 10.10.10.10. Encapsulation is performed using the source address src and transmitted to the mobile node MN (S510).

Accordingly, the mobile node MN receives the encapsulated response data packet from the HA 20, decapsulates it, and checks the original response data packet transmitted from the target node 30 (S511).

On the other hand, the current location registration process according to the second embodiment of the present invention described above uses a Co-located COA using an IP address assigned from the DHCP server 10, those skilled in the art, instead of the co-located COA, The COA using the IP address may be used to register the current location of the mobile node (MN). When the current position of the mobile node is registered with the COA using the IP address of the FA as described above, data between the mobile node MN and the target node 30 is made via the FA and the HA.

As described above, the present invention has been described in the case where it is applied and used in the WLAN through the first and second embodiments. In addition, the present invention can be applied to the wired LAN. When the present invention is applied to a wired LAN, there is only a difference between whether a mobile node communicates with a network wirelessly or a wired network like the difference between a general wireless LAN and a wired LAN. Same as the first and second embodiments described above. Those skilled in the art will appreciate that the present invention can be easily applied to a wired LAN from the first and second embodiments of the present invention described above.

The technical spirit of the present invention has been described above with reference to the accompanying drawings, but this is by way of example only and not intended to limit the present invention. In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

The present invention operates by using only one address when HA assigns a mobile node's home address in a dynamic mobile IP WLAN environment, thereby assigning different home addresses for each mobile node in the conventional dynamic mobile IP WLAN environment. This has the effect of improving the waste of IP addresses.

1 is a structural diagram of a typical WLAN environment.

2 is a flowchart illustrating a method for ensuring mobility and data transmission of a mobile node in a dynamic mobile IP environment according to a first embodiment of the present invention.

3 is a flowchart of a first embodiment of the present invention described with reference to a data packet.

4 is a data structure diagram of a location registration response signal according to an embodiment of the present invention;

5 is a flowchart illustrating a method of ensuring mobility and data transmission of a mobile node in a dynamic mobile IP environment according to a second embodiment of the present invention.

Claims (8)

A method for guaranteeing mobility and data transmission of a mobile node in a WLAN of a dynamic mobile IP environment with respect to a mobile node to perform a location registration event, A first step of the mobile node requesting location registration with a home agent (HA); A second step of the HA assigning its own IP address as the home address of the mobile node and performing location registration; A third step of forming reverse tunneling between the mobile node and the HA; When the mobile node transmits the data packet to the HA, the HA manages the source port number included in the data packet by matching the current location information of the mobile node, and transmits the data packet to the target node. step; When the response data packet is transmitted from the target node to the HA, the HA matches the source port number included in the response data packet with the current location information of the stored mobile node to confirm that the mobile node is the destination, and the mobile node Transmitting a response data packet to the server; And And a sixth step of receiving, by the mobile node, a response data packet transmitted from the target node from the HA. 6. The method according to claim 1, The first step is to ensure the mobility and data transmission of the mobile node in a dynamic mobile IP environment, characterized in that the IP address assigned from the DHCP server, that is, Co-located COA included in the location registration request signal to request the location registration Way. The method according to claim 1, The first step is a method for ensuring mobility and data transmission of a mobile node in a dynamic mobile IP environment, characterized in that the location registration request by including the COA using the FA IP address in the location registration request signal. The method according to claim 2, The third step may be performed when the mobile node compares the home address allocated from the HA with the IP address of the HA, and is performed only when the allocated home address and the IP address of the HA are the same. How to ensure mobility and data transfer of mobile node in mobile IP environment. The method according to claim 4, In the fourth step, the mobile node encapsulates the data packet to be transmitted to the target node by adding header information to be transmitted to the HA, and the HA decapsulates the encapsulated data packet to the target node. A method for guaranteeing mobility and data transmission of a mobile node in a dynamic mobile IP environment, characterized by transmitting to a node. The method according to claim 5, In the fourth step, the HA changes the source port number including the decapsulated data packet to an arbitrary source port number and then transmits the source port number to the target node. And managing the source port number by matching the current location information of the mobile node with the current location information of the mobile node. The method according to claim 6, In the fifth step, if the HA changes the source port number in the fourth step, the response data packet received from the target node changes the source port number to the source port number before the change, and then the response data packet. Transmitting the data to the mobile node in a dynamic mobile IP environment. The method according to claim 5, In the fourth step, the HA manages the mobile node's mobility and data transmission in a dynamic mobile IP environment by managing the source port number including the decapsulated data packet with the current location information of the mobile node. How to guarantee.