KR100496637B1 - A Method of IPv4 communication in IPv6 Wireless LAN - Google Patents

Abstract

The present invention relates to a method and apparatus for providing a communication method in which IPv6 and IPv4 coexist while maximizing the characteristics of a wireless LAN network by supplementing disadvantages of the conventional double stack switching method. Initialization steps in preparation for the method, resolving the IP for the domain name as requested by the application, and public IPv4 address for IPv4 communication if the destination address for the requested domain name is a public IPv4 address. The present invention relates to a method for performing an IPv6 terminal communicating dynamically with an IPv4 terminal of an external network, which includes a step of dynamically allocating and a valid period of a received public IPv4 address expired and returning the address.

According to the method proposed in the present invention, IPv6 is introduced in a wireless LAN environment, thereby solving the problem of lack of IP addresses and providing a wireless LAN environment capable of maintaining compatibility with IPv4.

Description

IPv6 communication in IPv6 wireless LAN environment {A Method of IPv4 communication in IPv6 Wireless LAN}

The present invention relates to IPv6 (Internet Protocol version 6), which is a next-generation Internet addressing method, and more particularly, to a method for communicating with an external IPv4 terminal in an IPv6 wireless LAN network.

Recently, with the rapid spread of mobile devices represented by multi-function mobile phones, the spread of wireless LAN is being actively activated. Wireless LANs have an advantage that they are much less space-constrained than conventional wired LANs. In particular, since the Internet can be freely enjoyed without being constrained by the network line, commercial services are increasing rapidly in recent years.

The introduction of IPv6, the next generation Internet addressing method, in the WLAN environment solves the problem of shortage of existing IP (IPv4) address due to the increase of subscribers. However, in such an IPv6 wireless LAN environment, there is a limitation that the connection and connection with the existing IPv4 are not seamless. Therefore, a separate translator such as an IPv4-IPv6 translator is necessary for this purpose.

Conventional techniques for interworking IPv6 and IPv4 include a method of converting two packet protocols using an IPv4-IPv6 conversion device. This method can achieve the desired purpose, but all the loads are concentrated on the conversion device, reducing the network's scalability, and application services requiring end-to-end communication such as Internet telephony and games. There are disadvantages in that the communication of the devices is impossible.

Another conventional technique for interworking IPv6 and IPv4 is to configure the protocol stack as a dual stack having both the IPv4 protocol stack and the IPv6 protocol stack, and to ensure that the IP address always has both an IPv4 address and an IPv6 address. There is a way. However, this method does not have a problem in configuring a dual stack, but there is a disadvantage in that terminals always have both a public IPv6 address and a public IPv4 address and thus cannot use a public IPv4 address efficiently.

In other words, if all terminals always have a public IPv4 address statically, there is a waste of the public IPv4 address when no IPv4 communication is performed with the outside. Therefore, a method of using dual stack but trying to improve such a problem has been proposed. This method is called Dual Stack Transition Mechanism (DSTM).

The dual stack switch method (DSTM) retains the dual stack but does not assign public IPv4 addresses from scratch. That is, initially, the network is composed of terminals having only dual stacks, but only when a request for IPv4 communication is performed on a terminal having dual stacks, the terminal is allocated a public IPv4 address from a server capable of dynamically assigning an IPv4 address. When IPv4 communication is initiated using the assigned public IPv4 address, the dual stack terminal forms an IPv4 over IPv6 tunnel to the edge router of the IPv6 network.

The IPv4 transport packet is transmitted through this tunnel and after arriving at the border router, it is transmitted to the destination using the existing IPv4 routing. This double stack switching method has the advantage of using the dual stack but solving the address shortage problem of the double stack method by applying the dynamic IPv4 address allocation technique.

However, there are additional burdens such as IPv4 over IPv6 tunneling device must exist in each dual stack terminal and border router, and the state of tunneling must be managed in border router. This additional burden is not burdened by creating and deleting tunnels when the dual stack terminals and the edge router communicate with each other through IPv4 communication. Furthermore, there is a problem in that all tunnel endpoints are one border router.

In order to solve the above problems, the present invention provides a communication method in which IPv6 and IPv4 coexist while maximizing the characteristics of a wireless LAN network by supplementing the disadvantages of the conventional double stack switching method described above. That is, an object of the present invention is to provide a method for naturally providing IPv4 communication in an IPv6 WLAN network without load on tunneling and state information in a boundary router serving as a tunnel endpoint.

In order to achieve the above object, the present invention, the step of obtaining the public IPv6 address and the internal IPv4 address by the IPv6 terminal located in the IPv6 WLAN subnetwork; Determining whether a destination address of a terminal to communicate using the IPv4 address is a public IPv4 address instead of an internal IPv4 address existing in the IPv6 WLAN subnetwork; And if the determination result is a public IPv4 address, dynamically assigning a public IPv4 address from a dynamic host configuration protocol server for IPv4 to an IPv6 terminal located in an IPv6 WLAN subnetwork. Provide management methods.

In order to achieve the above object, the present invention provides a public IPv6 address and an internal IPv4 address allocator for allocating a public IPv6 address and an internal IPv4 address to an IPv6 terminal located in an IPv6 WLAN subnetwork; A determination unit determining whether a destination address of a terminal to communicate using the IPv4 address is a public IPv4 address, not an internal IPv4 address existing in an IPv6 WLAN subnetwork; If the result obtained by the determination unit is a public IPv4 address, the public IPv4 address is dynamically allocated from the dynamic host configuration protocol server for IPv4 to the IPv6 terminal located in the IPv6 WLAN subnetwork to replace the internal IPv4 address. An address allocator; And a public IPv4 address return unit that dynamically returns the public IPv4 address to the dynamic host configuration protocol server for IPv4 when the assigned public IPv4 address expires. Provide the device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing the overall configuration of an IPv6 wireless LAN network of the present invention.

In the drawing, the gray rectangular objects 111 and 112 refer to terminals having both double stacks. The WLAN network of the present invention is composed of an IPv6 WLAN subnetwork 110 consisting of dual stack terminals, an external IPv4 network 120 composed of IPv4 terminals, and an external IPv6 network 130 composed of IPv6 terminals. Each network is connected to a wireless LAN core network 140 including a dual stack router 141 and an IPv4 router 142.

The dual stack terminal 1 111 belonging to the IPv6 WLAN subnetwork communicates with the external IPv4 terminal 121 through the dual stack router 141 and the IPv4 router 142. In addition, another dual stack terminal 112 belonging to the IPv6 WLAN subnetwork communicates with the IPv6 terminal 131 through an IPv6 over IPv4 tunnel 145 formed between the dual stack routers.

Terminals in an IPv6 WLAN environment have two addresses, a public IPv6 address and an internal IPv4 address during initialization, and a domain name resolution process is performed using an internal IPv4 address. As a result of resolving the domain name, if the destination address is a public IPv4 address, the public IPv4 address is dynamically obtained from the Dynamic Host Configuration Protocol (DHCPv4) server for IPv4. IPv4 addresses are dynamically replaced from internal IPv4 addresses to public IPv4 addresses.

Therefore, the IPv6 WLAN terminal has both a public IPv6 address and a public IPv4 address, so that not only communication with the IPv6 terminal but also natural communication with external IPv4 terminals are possible. The public IPv4 address is dynamically returned to the Dynamic Host Configuration Protocol (DHCPv4) server for IPv4 once all communication with the external IPv4 terminal has ended or the set time has elapsed, and the terminal again has only the public IPv6 address and the internal IPv4 address. .

2 is a diagram illustrating a method in which an IPv6 terminal communicates with an IPv4 terminal using a public IPv4 address.

An IPv4 communication method in an IPv6 WLAN environment includes an initialization step 210 in which initial IPv6 terminals prepare to perform the method, resolving IP for a domain name in response to a request of an application 220, Determining whether the destination address for the requested domain name is a public IPv4 address (230), if the determination result is a public IPv4 address (240) dynamically allocated public IPv4 address for IPv4 communication and the received public IPv4 address of The expiration date expires and a step 250 is returned to the address.

In the initial stage, in which the initial IPv6 terminals prepare to perform the method, each terminal in the IPv6 WLAN (assuming that all terminals in the IPv6 WLAN have a double stack) has two addresses: a public IPv6 address and It will uniquely obtain an internal IPv4 address.

In the process of resolving the IP for the domain name at the request of the application, the terminal in the IPv6 WLAN uses the internal IPv4 address assigned in the initialization step to the domain name server (DNS) in the link. Send a query about At this time, if a AAAA record type domain name query is requested for a public IPv6 address, and a result is found that no AAAA type address exists for the domain name, the A record type query for the public IPv4 address is sent once more. Do this. Therefore, the public IPv6 address has the priority and obtains the IP address according to the application's request.

If the destination address for the requested domain name is a public IPv4 address and the public IPv4 address is dynamically allocated when performing communication over IPv4, the terminal in the IPv6 WLAN is configured to use a Dynamic Host Configuration Protocol (DHCPv4) client for IPv4. Triggering is dynamically assigned a public IPv4 address from a Dynamic Host Configuration Protocol (DHCPv4) server for IPv4 within the link.

In addition, when the validity period of the assigned public IPv4 address expires and the address is returned, when all communication with the external IPv4 terminal is terminated or a predetermined time elapses, the dynamic IPv4 address for the IPv4 server is dynamically returned to the Dynamic Host Configuration Protocol (DHCPv4) server for IPv4. Return address. Thus, the terminal again has a public IPv6 address and an internal IPv4 address.

A process for the dual stack terminal to perform external IPv4 communication will be described with reference to FIGS. 3, 4, 5, and 6.

3 is a diagram illustrating an initialization step in which an IPv6 terminal prepares to perform the present method.

When the dual stack terminal 311 in the IPv6 WLAN enters the IPv6 WLAN subnetwork 310, the dual stack terminal 311 performs an operation for obtaining its IPv6 address and IPv4 address. The dual stack terminal 311 receives a Router Advertisement Message, which is periodically scattered by the dual stack router 320, to obtain a public IPv6 address (330).

In order to obtain an internal IPv4 address, a private IPv4 address may be allocated from another dynamic host configuration protocol (DHCPv4) server 340 for other IPv4 in the link (350) or link-local without receiving information. Local) IPv4 address can be created and used. When an internal IPv4 address is obtained through a private IPv4 address or a link local IPv4 address, the IPv6 WLAN terminal can communicate with the outside through IPv6 and with the terminals inside the WLAN subnetwork link through IPv4. You have the ability to

FIG. 4 is a diagram showing the types of two addresses (IPv4, IPv6) assigned in the initial process and the setting state of the terminal in the initialization step on the IPv6 WLAN terminal of the present invention.

That is, an IPv6 terminal address is assigned a public IPv6 address by a router advertisement message, a default router address is obtained by a router advertisement message, and a domain name server (DNS) address is not necessary and thus is not assigned.

The IPv4 terminal address is assigned by the internal address assignment method, the default router address is statically preassigned, and the domain name server (DNS) address is also statically preset.

5 is a diagram illustrating a process of resolving an IP for a domain name and communicating with an external IPv4 host according to a request of an application program.

The IPv6 WLAN terminal 510 sends a query for the domain name to the domain name server 520 in the link (521). In this case, a domain name query with an AAAA record type that first asks for a public IPv6 address is sent first, and if an AAAA type address is not returned for that domain name, then an A record type query for the public IPv4 address is sent once more. Repeat the process. Therefore, the priority of the public IPv4 address in the public IPv6 address to obtain IP values at the request of the application. The domain name server 520 queries the upper domain name server (DNS) 530 along the connection of the domain name server (DNS) (522) (523).

If the destination address obtained for the requested domain name is a public IPv4 address and performs IPv4 communication, it is detected by a dynamic host configuration protocol (DHCPv4) trigger program for IPv4 in the WLAN terminal, and the dynamic host configuration protocol for IPv4 ( DHCPv4) triggers the client to request a dynamic host configuration protocol (DHCPv4) server 540 for IPv4 to assign a public IPv4 address (541).

The Dynamic Host Configuration Protocol (DHCPv4) server for IPv4 sends a response to the WLAN terminal with information about one public IPv4 address in the IPv4 address pool and the IPv4 default router address for connecting to the outside world. . The Dynamic Host Configuration Protocol (DHCPv4) trigger program for IPv4 running on the WLAN terminal receives this response and assigns this public IPv4 address to the interface instead of the internal IPv4 address currently assigned to the WLAN terminal. Then, when an application program operating in the WLAN terminal communicates with an external IPv4 terminal from now on, it communicates with the newly assigned public IPv4 address.

6 is a diagram illustrating the type and configuration of the IPv4 address and the IPv6 address after dynamically obtaining the public IPv4 address in the IPv6 WLAN environment of the present invention.

In this way, the public IPv4 address is allocated and used only when an application communicates with an IPv4 terminal of an external network, thereby providing IPv6 communication in a wireless LAN network and efficiently using an important resource, the public IPv4 address.

7 is a diagram illustrating an IPv4 address management apparatus in an IPv6 wireless LAN environment in which an IPv6 terminal communicates with an IPv4 terminal using a public IPv4 address.

The communication apparatus includes a public IPv6 address and an internal IPv4 address allocator 710, a determination unit 720, a public IPv4 address allocator 730, and a public IPv4 address return unit 740.

The public IPv6 address and internal IPv4 address allocating unit 710 performs a function of allocating a public IPv6 address and an internal IPv4 address to an IPv6 terminal located in an IPv6 WLAN subnetwork.

The determination unit 720 performs a function of determining whether the destination address of the terminal to communicate using the IPv4 address is a public IPv4 address, not an internal IPv4 address existing in the IPv6 WLAN subnetwork.

If the result obtained by the determining unit is a public IPv4 address, the public IPv4 address allocator 730 dynamically receives a public IPv4 address from an IPv4 dynamic host configuration protocol server for an IPv6 terminal located in the IPv6 WLAN subnetwork. It performs a function of replacing the internal IPv4 address.

The public IPv4 address return unit 740 dynamically returns the public IPv4 address to the IPv4 dynamic host configuration protocol server when the assigned public IPv4 address expires.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium.

The computer-readable recording medium may be a magnetic storage medium (for example, a ROM, a floppy disk, a hard disk, etc.), an optical reading medium (for example, a CD-ROM, DVD, etc.) and a carrier wave (for example, the Internet). Storage medium).

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

As described above, the present invention has the effect of providing a wireless LAN environment that can solve the shortage of IP addresses by introducing IPv6 in a wireless LAN environment and maintain compatibility with IPv4.

As described above, the wireless LAN market has been exploding in recent years. As a result, the current shortage of public IPv4 address space will accelerate. Therefore, the introduction of IPv6, which is the fundamental answer to the address shortage problem, is urgently needed. It is expected that the introduction will increase in the wireless LAN network rather than the wired network. However, not all networks can be set up with IPv6 right away, and will require coexistence with IPv4 during the transition.

All the services currently available by the method proposed in the present invention are IPv6, but when there is a case of communicating with IPv4, the public IPv4 address is dynamically received and used to effectively communicate with existing IPv4 terminals. have.

1 is a view showing the overall configuration of an IPv6 wireless LAN network of the present invention.

2 illustrates a method in which an IPv6 terminal communicates with an IPv4 terminal using a public IPv4 address.

3 is a diagram illustrating an initialization step in which an IPv6 terminal prepares to perform the present method.

Figure 4 is a diagram showing the configuration state of the terminal of the IPv4 address and the type of IPv6 address and the initialization stage given to the initial process on the IPv6 WLAN terminal of the present invention.

5 is a diagram illustrating a process of resolving an IP for a domain name and communicating with an external IPv4 host at the request of an application.

6 is a diagram showing the type and configuration of the IPv4 address and IPv6 address after dynamically obtaining a public IPv4 address in the IPv6 WLAN environment of the present invention.

FIG. 7 illustrates an IPv4 address management apparatus in an IPv6 wireless LAN environment in which an IPv6 terminal communicates with an IPv4 terminal using a public IPv4 address. FIG.

Claims (10)

(a) acquiring a public IPv6 address and an internal IPv4 address by an IPv6 terminal located in an IPv6 WLAN subnetwork; (b) determining whether a destination address of a terminal to communicate using the IPv4 address is a public IPv4 address, not an internal IPv4 address existing in the IPv6 WLAN subnetwork; And (c) if the determination result is a public IPv4 address, an IPv6 terminal located in an IPv6 WLAN subnetwork dynamically allocates a public IPv4 address from a dynamic host configuration protocol server for IPv4 in an IPv6 WLAN environment How to manage your address. The method of claim 1, And dynamically returning the public IPv4 address to the IPv4 dynamic host configuration protocol server when the validity period of the assigned public IPv4 address expires. The method of claim 2, After returning the public IPv4 address, the IPv6 terminal maintains the public IPv6 address and the internal IPv4 address, IPv4 address management method in an IPv6 wireless LAN environment. The method of claim 1, wherein the IPv6 terminal An IPv4 address management method in an IPv6 wireless LAN environment having a double stack structure having both an IPv4 protocol stack and an IPv6 protocol stack. The method of claim 1, wherein step (a) The public IPv6 address is transmitted from a dual stack router located at a WLAN core network boundary, and the internal IPv4 address is transmitted from the dynamic host protocol version 4 server. In the step (a) of claim 1, wherein the internal IPv4 address is An IPv6 WLAN, which is a private IPv4 address allocated from another dynamic host protocol version 4 server in a link connecting the WLAN subnetwork and the WLAN core network, or an IPv4 address for a link local created by the IPv6 terminal. How to Manage IPv4 Addresses in Your Environment. The method of claim 1, wherein step (b) (b1) the IPv6 terminal making a domain name query of an AAAA record type asking the domain name server in the link for the public IPv6 address; And (b2) if the result of the query indicates that the AAAA type address does not exist for the domain name, then performing a domain name query of the A record type asking the public name for the public IPv4 address to the domain name server. IPv4 address management method in IPv6 wireless LAN environment. The method of claim 1, wherein step (c) (c1) requesting the dynamic host configuration protocol server for IPv4 to allocate the public IPv4 address by triggering the dynamic host configuration protocol client program for IPv4 by the dynamic host configuration protocol trigger program for IPv4 installed in the IPv6 terminal; ; (c2) receiving the request, by the dynamic host configuration protocol server for IPv4, transmitting information about one public IPv4 address and an IPv4 default router address from an IPv4 address pool to the IPv6 terminal; And (c3) receiving the public IPv4 address and communicating with the IPv4 terminal to which the IPv6 terminal communicates using the public IPv4 address instead of the internal IPv4 address; How to manage your address. A non-transitory computer-readable recording medium having recorded thereon a program for executing the method of claim 1. A public IPv6 address and an internal IPv4 address allocator configured to allocate a public IPv6 address and an internal IPv4 address to an IPv6 terminal located in an IPv6 WLAN subnetwork; A determination unit determining whether a destination address of a terminal to communicate using the IPv4 address is a public IPv4 address, not an internal IPv4 address existing in an IPv6 WLAN subnetwork; If the result obtained by the determination unit is a public IPv4 address, the public IPv4 address is dynamically allocated from the dynamic host configuration protocol server for IPv4 to the IPv6 terminal located in the IPv6 WLAN subnetwork to replace the internal IPv4 address. An address allocator; And And a public IPv4 address return unit that dynamically returns the public IPv4 address to the dynamic host configuration protocol server for IPv4 when the assigned public IPv4 address expires.