KR100413976B1 - mobile IP service method through private IP address use in wireless communication network - Google Patents

Abstract

The present invention relates to a mobile IP (MIP) service method using a private IP address in a wireless communication network and a computer-readable recording medium recording a program for realizing the method. The present invention relates to a mobile IPv4 (MIP) service in a wireless communication network. In order to provide a mobile node with a private IP address as its home address, it is possible to effectively reuse a shortage of IPv4 public addresses. IP) adding a server function and adding an RSIP client function to the mobile node; A second step of allocating a private IP address to a home address of the mobile node located in the visited network; A third step of allocating a public IP address through RSIP to the mobile node using the private IP address as a home address; And a fourth step of communicating arbitration between the mobile node and a counterpart node of an external network based on the public IP address.

Description

Mobile IP service method through private IP address use in wireless communication network}

The present invention relates to a mobile IP (MIP) service method using a private IP (IP) address in a wireless communication network, and to a computer readable recording medium recording a program for realizing the method. Specifically, to provide IP packet services using MIP (IPv4) in wireless communication networks such as digital cellular networks, personal mobile communication networks, next-generation mobile communication networks such as IMT-2000 (International Mobile Telecommunications), UMTS (Universal Mobile Telecommunications System), and the like. In this regard, the present invention relates to an address reuse scheme that enables a private IP address to be used as a mobile node's home address.

Currently, the Internet is based on a Transmission Control Protocol / Internet Protocol (TCP / IP) network and follows the IPv4 addressing scheme (hereinafter, the IPv4 address is omitted as an address). IPv4 provides a 32-bit address space that can provide unique addresses to about 4 billion hosts. This address space, which seemed sufficient in the early days of IPv4 protocol design, is becoming increasingly depleted in the early days of the Internet due to indiscriminate address distribution, the rapid growth of the Internet, and the explosion of PCs that use it. In addition, in the 3rd generation and next generation wireless mobile communication environments, IP based MIP is expected to be used for wireless data transmission, which further exacerbates the address shortage problem.

In order to solve this address shortage problem, the Internet Engineering Task Force (IETF) proposes Classless Inter-Domain Routing (CIDR) for effective address allocation and routing, and network operators use the Dynamic Host Configuration Protocol (DHCP). We attempted to maximize the utilization of addresses by introducing dynamic address allocation methods such as), but this was only a temporary solution. As a long-term solution, the IETF has developed a new Internet protocol, IPv6. However, IPv6 will ultimately solve the address shortage problem by providing an almost infinite address space of 128 bits, but it will take a long time to be deployed in development and actual networks. Currently, in the wired Internet environment, address shortage problem is solved by using a private IP address, NAT (Network Address Translator), and RSIP (Realm-Specific IP).

The Internet Assigned Numbers Authority (IANA) has defined three IP address blocks (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16) for private networks. Such a private IP address may be duplicated in several private networks and may be used for communication between hosts existing in the same private network, but may not be routed in a public network such as the Internet. Use of Private IP Address The host is assigned a public IP address only for the duration of the communication session with the external host for communication with a host that exists outside the private network, and is used when the session no longer requires a public IP address. Release to effectively reuse public IP addresses.

NA (P) T provides a transparent address reuse scheme for hosts by assigning a public IP address (port number) in a NAT router, which is the default and edge router of a host using a private IP address, and performing address translation. RSIP is a client-server model that uses a private IP address host acts as an RSIP client, and a private edge router acts as an RSIP server. For communication with the external network, the RSIP client is assigned a public IP address from the RSIP server at the beginning of the session and establishes a tunnel between the client and server.

In conclusion, any host should use a public IPv4 address as its home address, but due to lack of IPv4 public address resources, in the current technical field, it is desired to provide an IP packet transmission service using MIP (Mobile IPv4) in a wireless communication network. At the same time, there is an urgent need for a method to effectively reuse limited IPv4 public addresses.

The present invention has been proposed to meet the above requirements, and when providing a mobile IPv4 (MIP) service in a wireless communication network, it is possible to use a private IP address as a home node of a mobile node, thereby insufficient IPv4 publicity. It is an object of the present invention to provide a mobile IP (MIP) service method capable of effectively reusing an address and a computer-readable recording medium recording a program for realizing the method.

1 is an exemplary configuration of a wireless communication network for a mobile IP (MIP) service to which the present invention is applied.

2 is a detailed flowchart illustrating a registration process of a mobile node using a private IP address as a home address in a mobile IP service (MIP) method according to the present invention.

3 is a detailed flowchart illustrating a communication process between a registered mobile node and a counterpart node located in an external network in a mobile IP service (MIP) method according to the present invention;

* Explanation of symbols for the main parts of the drawings

11 ~ 14: Mobile Node 20: Home Domain

21,22,31,32: external agent (FA) 23,33: authorization / authentication / billing (AAA) server

24,34: Address Management Server (AMS) 26,36: Domain Name System (DNS) Server

27,37: home agent (HA) 30: visited domain

25,35: Dynamic Host Configuration Protocol (DHCP) server

In order to achieve the above object, the present invention provides a mobile IP (MIP) service method in a wireless communication network, and adds a Real-Specific IP (RSIP) server function, which is an address reuse scheme of a wired network, to a home agent (HA), Adding a RSIP client function to the node; A second step of allocating a private IP address to a home address of the mobile node located in the visited network; A third step of allocating a public IP address through RSIP to the mobile node using the private IP address as a home address; And a fourth step of communicating arbitration between the mobile node and a counterpart node of an external network based on the public IP address.

Meanwhile, the present invention provides a first function of allocating a private IP address as a home address of a mobile node located in a visited network to a wireless communication network having a processor for a mobile IP service through the use of a private IP address. ; A second function of allocating a public IP address to a mobile node using a private IP address as a home address through Real-Specific IP (RSIP), an address reuse scheme of a wired network; And a computer readable recording medium having recorded thereon a program for realizing a third function of communication arbitration between the mobile node and a counterpart node of an external network based on the public IP address.

The present invention enables a mobile node of a mobile communication network using a MIP (Mobile IP) to use a home address as a private IP address, and assigns a public IP address (port) only while communicating with a partner node of an external public network. You want to share your IP address effectively.

To this end, in the present invention, the home agent (HA) has an RSIP server function, and the mobile node has an RSIP client function. The mobile node uses a private IP address as its home address, and receives a public IP address from the home agent HA only when it wants to communicate with any counterpart node existing in the external network. In addition, the public IP address is assigned and retrieved through an extended MIP (Mobile IP) registration procedure.

Accordingly, the present invention enables a private IP address to be used as a mobile node's home address in a wireless communication network using MIP (Mobile IP), and assigns a public IPv4 address and port number only when communication with an external counterpart is required. By effectively sharing the problem, the address shortage problem was solved. In addition, by interworking with a Domain Name System (DNS) server, address translation and assignment are possible dynamically, so that the other node performs communication first.

As described above, any host using the MIP should use a public IPv4 address as the home address, but in order to effectively share the insufficient IPv4 address, the present invention applies RSIP, which is an address reuse scheme in the existing wired network, to the MIP environment. . To this end, it adds Realm Specific IP (RSIP) server functionality to the home agent (HAP), RSIP client functionality to the mobile node, and extends MIP registration messages for address assignment and DNS name resolution. And, in the MIP network where DIAMETER is used to provide AAA (Authentication, Authorization, Accounting) service, the home agent (HA) can be dynamically allocated from the visited network, so the DIAMETER message is further extended. The present invention provides an effective public IP address reuse scheme in MIP networks, provides transparency to hosts and routers except mobile nodes and mobility agents, and provides authentication services in address assignment in DIAMETER-based MIP networks.

Then, look at the features according to the present invention.

First, in case of applying MIP (Mobile IP) to support IP mobility in mobile communication network, private IP address is used as mobile node's home address to efficiently utilize limited address resources.

Second, for this purpose, RSIP, which is a private IP address using method in the existing wired network, is modified and used for MIP environment.

Third, the mobile node implements an RSIP client and has a structure that can be mutually associated with the MIP client. The RSIP client that detects the start of communication with any partner node located in the external network uses the extended MIP registration message in cooperation with the MIP client, requests / releases the public IP address from the HA, and allocates the assigned public IP address. Create and send an IP packet using.

Fourth, the HA of the mobile node has a structure in which not only a mobility agent function but also an RSIP server is mounted. HA has a pool of public IP addresses for mobile nodes using private IP addresses as their home addresses, and manages allocation information of public IP addresses. In addition, when only the IP address is assigned for correct address resolution, the dynamic DNS update function is performed in association with the DNS server to map the name of the mobile node and the mobile node. It can also receive address assignment requests from DNS servers.

Fifth, when the DNS server receives an address resolution request for a mobile node that does not have a public IP address, the DNS server is assigned with the mobile node's public IP address instead in association with HA and sends the address to the other node as a result. Has the function to If the HA of the mobile node is allocated in the visited domain, an address assignment request is transmitted to the corresponding HA through a DIAMETER message between AAA servers. In this case, the authentication and authorization verification service provided by the AAA protocol can be provided as it is.

Sixth, in addition to the basic DIAMETER server function, the AAA server may receive a public address assignment request from a DNS server, and forward the request message to the HA of the mobile node for which public IP address assignment is requested. If the HA of the mobile node is allocated in the visited domain, the request message can be forwarded to the AAA of the visited domain.

Seventh, when a foreign agent (FA) receives a MIP registration request message to distinguish mobile nodes using the same private IP address as a home address, the MAC (MIP Application Command) address of the corresponding mobile node (MN) And HA addresses are additionally managed. The data packet destined for the mobile node is transmitted by obtaining the MAC address of the mobile node directly managed without performing the ARP function at the FA.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of a wireless communication network for a mobile IP (MIP) service to which the present invention is applied, such as a digital cellular network, a personal mobile communication network, an international mobile telecommunication (IMT-2000), a universal mobile telecommunication system (UMTS), and the like. It represents a MIP (Mobile IP) network for supporting IP mobility in a wireless communication network such as next generation mobile communication network.

The home network (i.e., Home Domain 20) and the visited network (i.e., Visited Domain 30) supporting MIP (Mobile IP) are configured on a domain basis and are connected to each other via the Internet. .

Each MIP (Mobile IP) supported home domain 20 and visited domain 30 is a home agent (HA) for supporting MIP (Mobile IP) and a mobile communication network such as a digital cellular network or a personal mobile communication network or an IMT-2000 network. : Home Agent (27,37), Foreign Agent (FA: Foreign Agent) (21,22,31,32), Authentication Authorization Accounting Server (AAA), Address Management Server (AMS) Server (24,34), Domain Name System (DNS) server (26,36), Dynamic Host Configuration Protocol (DHCP) server (25, 35) It consists of a network.

Each mobile node 11-14 has the function of a mobile host described in RFC 2002, and is an external agent (FA) 21, 22, 31, 32 of a mobile IP (MIP) network through a wireless access network. ). The mobile nodes 11 to 14 implement the RSIP client function when they have a private IP address as a home address. The MIP client and the RSIP client of the mobile nodes 11-14 operate in association with each other. The RSIP client uses a MIP registration message to request a public IP address assignment from the RSIP server (home agent (HA) 27, 37).

Foreign Agents (FA) 21,22,31,32 also have the functionality of a mobility agent as described in RFC 2002, and additionally for mobile nodes 11-14 that use a private IP address as their home address. At the time of 11 to 14 MIP registration request, the MAC and home agent addresses of the mobile nodes 11 to 14 are managed together with the visited mobile node list for routing.

The home agents (HAs) 27 and 37 also have the functions of the home agents described in RFC 2002, and have an RSIP server function for assigning public IP addresses to mobile nodes 11-14 using private IP addresses. In order to improve capacity and performance, several home agents (HAs) 27 and 37 may be arranged in one domain.

Authorization / authentication / billing (AAA) server (23, 33) has the authentication and authorization verification function of the MIP subscriber, and the billing function, each AAA server (23, 33) communicates with the DIAMETER protocol, a secure channel is formed It is.

The address management server (AMS) 24,34 is provided in the AAA server 23,33 because it provides address management function only to subscribers authenticated by the AAA server 23,33, or the AAA server 23,33. It is mounted on a host connected via a secure channel. In addition, the address management servers (AMS) 24 and 34 have a function of dynamically allocating and releasing IP addresses to the mobile nodes 11 to 14 in association with the DHCP servers 25 and 35. In conjunction with 36), dynamic DNS update is performed to map the name of the mobile host and the dynamically assigned IP address.

2 and 3 illustrate a registration procedure of a mobile node using a private IP address as a home address and a communication procedure with a counterpart node located in an external network, according to an embodiment of the present invention. Indicates a message procedure. An example of a mobile node that uses a private IP address located in a home network as a home address is intuitive and thus is not discussed in the present invention.

2 illustrates a message processing procedure when a mobile node performs MIP registration by receiving a private IP address as a home address in a visited domain.

The mobile node 14 moving to the visited domain 30 performs a MIP registration procedure.

Specifically, the mobile node 14 transmits a MIP registration request message to an external agent (FA) 32 to which the mobile node 14 is currently connected through the wireless access network (201). At this time, the mobile node 14 sets the home address field of the MIP registration request message to 255.255.255.255 to indicate that the home address is a private IP address that is dynamically allocated. Then, the FA 32 analyzes the received MIP registration request message and adds the information of the mobile node to the MIP visitor list. At this time, the MAC address and home agent address information of the mobile node 14 are added in addition to the basic MIP information. Subsequently, the FA 32 generates a DIAMETER AMR message (private IP address assignment request message) using the MIP registration request message and transmits it to the AAA server 33 (202). The corresponding AMR message (private IP address assignment request message) contains a private_home_address_available flag that extends the DIAMETER MIP Application, MIP-Feature-Vector AVP to indicate that the mobile node 14 uses a private IP address. do.

Thereafter, the AAA server 33 receiving the AMR message (private IP address assignment request message) sends the corresponding AMR message (private IP address assignment request message) to the AAA server of the home domain 20 to which the mobile node 14 belongs. 23) through a secure channel established between AAAs (203). Then, after the AAA server 23 of the home domain 20 authenticates the mobile host, whether the IP address of the home domain 20 or the visited domain 30 is assigned an IP address and the private IP address. Determine whether to use. If the mobile node 14 receives a home IP address from the home domain 20, the AAA server 23 of the home domain 20 sends an address assignment request message to the AMS 24 in charge of address management. After transmitting (204) and receiving the address assignment request message, the AMS (24) is assigned a home IP address to be used by the mobile node (14) in association with the DHCP server (25). At this time, when the mobile node 14 does not specify the home agent 27 in the MIP (Mobile IP) registration request message, the AMS 24 selects an available home agent 27 and responds to the address assignment. When the message is sent (207), it is sent to the AAA server 23 with the assigned home IP address of the mobile node (14).

Next, the AAA server 23 receiving the address assignment response message sends a dynamic home agent request message to the dynamically assigned home agent 27 (208). In response, the home agent 27 generates binding information for the mobile node 14 and sends a dynamic home agent response message including the resulting MIP registration response message to the AAA server 23.

After the dynamic IP address assignment and dynamic DNS update for the mobile node 14 and the dynamic home agent assignment are normally processed, the AAA server 23 of the home domain 20 receives a DIAMETER AMA message (private IP address assignment response message). ) Is transmitted to the AAA server 33 of the visited domain 30 where the corresponding mobile node 14 is located (210).

Thereafter, the AAA server 33 receiving the AMA message (private IP address assignment response message) transmits the corresponding AMA message (private IP address assignment response message) to the FA 32 (211), and the FA 32 The MIP registration response message is extracted and transmitted to the corresponding mobile node 14 through the wireless access network (212).

3 is a detailed flowchart illustrating a communication process between a registered mobile node and a counterpart node located in an external network in a mobile IP service (MIP) method according to the present invention.

In the figure, the procedure corresponding to "300" indicates a process in which the mobile node 14 is assigned a public IP address for communication with any counterpart node located in the external network.

Specifically, the RSIP client of the mobile node 14 detects communication with the external network and, if there is no assigned public IP address, makes an address assignment request to the MIP client. The MIP client mounted on the mobile node 14 generates a MIP registration request message including a private address extension and transmits the message to the FA 32 (301). In response, the FA 32 transmits the MIP registration request message including the private address extension to the HA 27 of the external network (302).

After receiving the MIP registration request message including the private address extension, the HA 27 creates a binding entry for the corresponding mobile node 14, analyzes the private address extension, and requests a public IP address allocation request from the RSIP server. . On the other hand, the RSIP server allocates a public IP address for the mobile node 14 and a code number if necessary, and returns the result to the corresponding HA 27. Subsequently, the HA 27 performs a dynamic DNS update in association with the DNS server 26 to map the assigned address and the name of the mobile node 14 (303). Thereafter, the HA 27 generates a MIP registration response message and includes the public IP address information in the private address extension and transmits it to the FA 32 (304). In response to this, the FA 32 receiving the MIP registration request message including the corresponding private address extension (including the public IP address information) transmits it to the mobile node 14 (306).

Meanwhile, in the drawing, "310" indicates an address when a relative node located in an external network attempts to communicate with a mobile node using a private IP address as a home address through address resolution, when there is no public IP address assigned to the corresponding node. It shows the allocation process.

Specifically, the DNS server 26 that receives the DNS query message for the mobile node 14 from the counterpart node 311 sends to the AAA server 23 when the mobile node 14 does not have a public IP address. The address request message is transmitted (312). In response, the AAA server 23 transmits a Public IP Request message (PAR: Public Address Request), which is an extension of the DIAMETER MIP Application Command, to the HA 27 assigned to the mobile node 14 at the time of MIP registration (313). ). The PAR contains a Username AVP for that mobile node 14.

Thereafter, the HA 27 receiving the PAR message (public IP address request message) allocates a public IP address and performs dynamic DNS updating in association with the DNS server 26 (314). Thereafter, the DNS server 26 returns to the partner node including the public IP address allocated as a result of the DNS query (315).

On the other hand, "320" in the drawing indicates the communication process between the mobile node 14 and the counterpart node after the allocation of the public IP address is completed.

Specifically, when the mobile node 14 transmits the data packet to the counterpart node 321, the destination address of the IP packet is set to the counterpart node's address, and the source address is the public IP address assigned by the RSIP client. Or set the destination address included in the IP packet sent by the other node.

When the partner node transmits the IP packet data to the mobile node 14, the destination node is set to the source address of the IP packet transmitted by the mobile node or to the public IP address of the mobile node obtained in the address resolution process. In this case, the packet transmitted by the counterpart node is transmitted to the HA 27 through general IP routing (322). In response, the HA 27 receiving the packet acquires the private IP address of the mobile node 14 to which the destination IP address is assigned to the RSIP server. The packet is encapsulated with the private home address of the mobile node 14 and the address of the home agent. The encapsulated packet is encapsulated again to the FA 32 where the mobile node 14 is currently located with reference to the MIP binding table and transmitted to the FA 32 (323).

Thereafter, the FA 32 receiving the packet removes the MIP capsule header by performing a MIP decapsulation process, and transmits the packet to the mobile node 14 by referring to the visited mobile node list stored at the time of MIP registration. (324). In response, the mobile node 14 receiving the packet removes the RSIP capsule header encapsulated by the home agent 27 and transmits the packet to the application program.

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention enables a mobile node to use a private IP address as a home address so that when there is no communication session with an externally located counterpart, it does not use a public IP address and communicates with the externally located counterpart node. By assigning a public IP address and a port address only when this is enabled, the MIP service can be provided to more mobile nodes than the actual number of public IP addresses.

In addition, the present invention has the effect of enabling the other node to communicate with the mobile node having a private IP address as a home address through address resolution through dynamic DNS updating and public IP address assignment in conjunction with a DNS server.

That is, the present invention enables a private IP address to be used as a mobile node's home address in a wireless communication network using Mobile IP, and allocates a public IPv4 address and port number only when communication with an external counterpart is required, thereby effectively assigning the address. Address shortage problem can be solved by sharing, and also, it is possible to dynamically resolve address and assign by interworking with DNS server, so that the other node can perform communication first.

Claims (8)

In the mobile IP (MIP) service method in a wireless communication network, Adding a realm-specific IP (RSIP) server function, which is an address reuse scheme of a wired network, to a home agent (HA), and adding an RSIP client function to a mobile node; A second step of allocating a private IP address to a home address of the mobile node located in the visited network; A third step of allocating a public IP address through RSIP to the mobile node using the private IP address as a home address; And A fourth step of mediating communication between the mobile node and a counterpart node of an external network based on the public IP address; Mobile IP service method using a private IP address in a wireless communication network comprising a. The method of claim 1, The wireless communication network, When the mobile node makes a private IP address available as a home address and there is no communication session with an externally located counterpart, the mobile node does not use a public IP address and only when a communication session with an externally located counterpart is activated. A mobile IP service method using a private IP address in a wireless communication network, by allocating a public IP address and a port address, thereby providing mobile IP (MIP) services to a larger number of mobile nodes than actual public IP addresses. The method according to claim 1 or 2, The mobile node, A MIP client and an RSIP client are linked to each other, so that the RSIP client requests a public IP address to the MIP client for an address assignment request, and the mobile node transmits the message through an extended MIP registration request message for communication with a counterpart node of an external network. A mobile IP service method using a private IP address in a wireless communication network, characterized by requesting a public IP address to a home agent. The method of claim 3, wherein The home agent (HA), Mobile IP service method using a private IP address in a wireless communication network, characterized in that the connection with the RSIP server, analyzing the private address extension included in the MIP registration request message to request the IP address allocation and release to the RSIP server. The method of claim 4, wherein The process of the mobile node using the private IP address as a home address to communicate with the counterpart node of the external network using the public IP address allocated through the RSIP, A fifth step of performing MIP registration with a private home IP address; A sixth step of the RSIP client of the mobile node requesting a public IP address assignment through MIP registration to the RSIP server of the home agent (HA); When any counterpart node wants to communicate with the mobile node through name resolution, it communicates to the mobile node through a connection between a domain name system (DNS) server, an authorization / authentication / billing (AAA) server, and a home agent (HA). A seventh step of dynamically allocating a public IP address and transmitting the address to the counterpart node; An eighth step of transmitting IP packet data between the mobile node and the counterpart node; And A ninth step in which the mobile node releases the allocated public IP address to the home agent (HA) through an extended MIP registration request message when there is no communication with the other node; Mobile IP service method using a private IP address in a wireless communication network comprising a. The method of claim 5, When performing MIP registration with the private home IP address of the fifth step, In a wireless communication network, a foreign agent (FA) stores a mobile node's MAC (MIP Application Command) address and an HA address in addition to the MIP visited mobile node list to distinguish mobile nodes using duplicate private IP addresses. Mobile IP service method using private IP address. The method of claim 5, When transmitting the IP packet data between the mobile node and the counterpart node of the eighth step, Set the public IP address assigned to the packet transmitted by the application of the mobile node as a source address, and transmit the packet transmitted by the partner node. The external agent FA receives the packet of the counterpart node encapsulated from the home agent HA, removes the MIP capsule, and transmits the packet directly using the mobile node's MAC (MIP Application Command) address. Mobile IP service method using a private IP address in a wireless communication network. In a wireless communication network equipped with a processor for mobile IP (IP) service through the use of a private IP (IP) address, A first function of allocating a private IP address to a home address of a mobile node located in a visited network; A second function of allocating a public IP address to a mobile node using a private IP address as a home address through Real-Specific IP (RSIP), an address reuse scheme of a wired network; And A third function of communicating arbitration between the mobile node and a counterpart node of an external network based on the public IP address; A computer-readable recording medium having recorded thereon a program for realizing this.