KR100377191B1 - The Method of IP Tunnel Management for IP Tunnel Reuse in Mobile IP Service - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an IP tunnel management method for reusing an IP tunnel in a mobile IP service system and a computer readable recording medium recording a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention provides an IP tunnel management method and a program for realizing the IP tunnel which can reuse the IP tunnel which can remove the generated tunnel without a user without creating several tunnels having the same path in the mobile IP service system. To provide a computer-readable recording medium for recording.

3. Summary of Solution to Invention

The present invention provides an IP tunnel management method for reusing an IP tunnel applied to a mobile Internet Protocol (IP) system, comprising: a first step of constructing an IP tunnel table for IP tunnel management; A second step of determining whether to add / delete an IP tunnel according to the movement of the mobile node; A third step of adding an IP tunnel according to the presence or absence of an IP tunnel to be searched for and added to the IP tunnel using the IP tunnel table when the tunnel is added as a result of the determination in the second step; And a fourth step of deleting the IP tunnel according to the presence or absence of the IP tunnel to search for and delete the IP tunnel using the IP tunnel table when the deletion of the tunnel is determined as the second step.

4. Important uses of the invention

The present invention is used for mobile IP service.

Description

IP Tunnel Management for IP Tunnel Management for IP Tunnel Reuse in Mobile IP Service

The present invention relates to an IP tunnel management method for reusing an IP tunnel in a mobile IP service system and a computer-readable recording medium having recorded thereon a program for realizing the method.

Tunneling between home agent and visiting agent is essential to provide mobile IP service.

When a user moves to a new network, a tunnel is created from the home network to the new network, and when several users move from the same home network to the same network, the same tunnel is created as many as the number of users. Therefore, there is a problem that the performance of the system is reduced.

In addition, even if a tunnel is created and shared, in order to remove the generated tunnel, it is necessary to remove the tunnel after all of the subscribers who visited from the same network have exited. There is a problem that system resources are wasted by using.

The present invention has been proposed to solve the above problems, and it is possible to reuse an IP tunnel that can remove the generated tunnel without a user without creating multiple tunnels having the same path in the mobile IP service system. An object of the present invention is to provide an IP tunnel management method and a computer-readable recording medium recording a program for realizing the method.

1 is a configuration diagram of an embodiment of a mobile IP service system to which the present invention is applied.

Figure 2 is an embodiment data structure diagram of an IP tunnel to which the present invention is applied.

3 is a diagram illustrating the operation of one embodiment of an IP tunnel of a mobile IP service to which the present invention is applied;

4 is a diagram illustrating an embodiment of a tunnel connection of a mobile IP service in a mobile IP service system to which the present invention is applied;

FIG. 5 is a detailed structural diagram of an embodiment of multiple tunnels of an IP tunnel of a mobile IP service to which the present invention is applied; FIG.

6a to 6b is an embodiment data structure diagram of an IP tunnel table used in the IP tunnel management method for reusing an IP tunnel according to the present invention.

7 is a flowchart illustrating an operation of an IP tunnel management method for reusing an IP tunnel according to the present invention.

8A to 8B are detailed flowcharts illustrating an embodiment of a tunnel discovery process in the IP tunnel management method for reusing an IP tunnel according to the present invention.

* Explanation of symbols for the main parts of the drawings

11: visited network 12: home network

13: corresponding node

101-1: Mobile Node 101-2: Mobile Node

102: home agent 103: external agent

According to an aspect of the present invention, there is provided an IP tunnel management method for reusing an IP tunnel applied to a mobile Internet Protocol (IP) system, comprising: a first step of constructing an IP tunnel table for IP tunnel management; A second step of determining whether to add / delete an IP tunnel according to the movement of the mobile node; A third step of adding an IP tunnel according to the presence or absence of an IP tunnel to be searched for and added to the IP tunnel using the IP tunnel table when the tunnel is added as a result of the determination in the second step; And a fourth step of deleting the IP tunnel according to the presence or absence of the IP tunnel to search for and delete the IP tunnel using the IP tunnel table in the case of deletion of the tunnel as a result of the determination of the second step. It features.

On the other hand, IP (Internet Protocol) tunnel management device having a processor for realizing the present invention, the first function for building an IP tunnel table for IP tunnel management; A second function of determining whether to add / delete an IP tunnel according to the movement of the mobile node; A third function of searching for an IP tunnel using the IP tunnel table and adding an IP tunnel according to whether or not an IP tunnel to be added is added as a result of the determination of the second function; And a fourth function of deleting an IP tunnel according to the presence or absence of an IP tunnel to search for and delete an IP tunnel using the IP tunnel table when it is determined that the tunnel is deleted. Provide a computer-readable recording medium for recording.

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 a configuration diagram of an embodiment of a mobile IP service system to which the present invention is applied.

The mobile IP service system includes a home network 12, a visited network 11, and a corresponding node (Correspondent Host or Correspondent Node) 13, and the home network 12 includes a home agent 102 and a mobile node (MN): The mobile node 101-1 and the visited network 11 include an external agent 103 and a mobile node 101-2.

Looking at the detailed operation, the mobile node 101-1 of the home network 12 receives a service from the home agent 102 of the home network 12 to which it belongs. After that, when the user moves to the new visited network 11, the mobile node 101-2 of the moved visited network 11 receives a service from the external agent 103. At this time, the mobile node 101-2 of the visited network 11 is moved by the mobile node 101-1 of the home network 12.

At this time, the provided mobile IP service is communication with the correspondent node 13 in which the mobile nodes 101-1 and 101-2 are hosts on the Internet.

In order for the mobile node 101-2 of the visited network 11 to communicate with the corresponding node 13, the packet from the mobile node 101-2 of the visited network 11 is transmitted to the external agent 103 of the visited network 11. Packet is transmitted through the home agent 102 of the home network 12 as though the mobile node is at the location of the mobile node 101-1 of the home network 12. The home agent 102 transmits it to the external agent 103 of the visited network through a tunnel connecting the home agent of the home network and the external agent of the visited network. The external agent 103 of the visited network receiving the packet removes the header for the tunnel of the packet and delivers it to the mobile node 101-2 of the visited network.

2 is a diagram illustrating an example data structure of an IP tunnel to which the present invention is applied.

Normal IP packet 21 includes user data 212 and IP header 211.

The destination IP address information of the IP header 211 is transmitted to the destination. If the mobile node to be actually received is located elsewhere, it should be delivered to the destination through tunneling.

Accordingly, the IP packet used for tunneling has an internal IP header 222, which is the original destination IP header, in addition to the external IP header 221, which is an IP header for a new destination.

Applying the structure of this IP tunnel to FIG. 1, the inner IP header 222 has the address of the mobile node 101-2 of the visited network, and the outer IP header 221 has the outer agent 103 of the visited network. The home agent 102 of the home network tunnels.

3 is a diagram illustrating an operation of an IP tunnel of a mobile IP service to which the present invention is applied.

As shown in FIG. 3, the IP tunnel of the mobile IP service to which the present invention is applied includes an IP layer 31 which is a network layer, a network matching card 32 which is a data link layer, and a tunnel device 33. do.

Looking at the operation in more detail, if there is no tunnel, IP transmission and reception directly occurs between the IP layer 31 and the network matching card 32 (303, 304).

On the other hand, if there is a tunnel, a tunnel device 33 is required at the data link layer, which is a software device located in the data link layer such as the network matching card 32, and is located outside of FIG. An encapsulation module 301 for adding the IP header 221 and a decapsulation module 302 for removing the external IP header 221 of FIG. 2.

In general, when a packet forwarded from the IP layer 31 to the network matching card 32 or a packet forwarded from the upper layer 34 to the IP layer is determined to look at routing information at the IP layer 31 and tunneled, IP of IP 305 is sent to encapsulation module 301 to make IP in IP 305 with external IP header 221 added, and IP 305 is created via network matching card 32 (304). It is passed to the network matching card, which is another data link layer.

In addition, if the packet transmitted to the IP layer 31 through the network matching card 32 is an IP tunnel, and the external IP header 221 of FIG. 2 is attached, the packet is decapsulated in the tunnel device ( In step 302, the external IP header 221 of FIG. 2 is removed and then transferred to the IP layer 31 to the conventional IP 307. The IP layer 31 refers to routing information according to the destination address of the internal IP header 222 of FIG. 2 and sends the routing information to the network matching card 32 to the outside or directly to the upper layer 34.

4 is a diagram illustrating an embodiment of a tunnel connection of a mobile IP service in a mobile IP service system to which the present invention is applied.

As shown in FIG. 4, the mobile IP service system to which the present invention is applied includes a home network 42, a visited network 41, and a corresponding node 43.

When several mobile nodes 401 and 402 of one home network connect to one visited network 41, each mobile node establishes a tunnel between the home agent 404 of the home network and the foreign agent 403 of the visited network. Unlike the conventional method of generating for 401 and 402, the present invention uses one tunnel initially created by the mobile nodes that have subsequently visited.

That is, in the conventional method, as many tunnels are created as the number of mobile nodes visited, and in the present invention, one tunnel is reused. Accordingly, the conventional method deletes the corresponding tunnel whenever each mobile node leaves the current visit network, but in the present invention, the tunnel is deleted when all the mobile nodes have left.

FIG. 5 is a detailed structural diagram of an embodiment of multiple tunnels of an IP tunnel of a mobile IP service to which the present invention is applied.

As shown in FIG. 5, the tunnel device according to the present invention is a multiple tunnel device having a plurality of tunnel devices regenerated therein.

Each tunnel device has an entry indicating the start of the tunnel, an exit indicating the end point of the tunnel, and an attribute indicating the attribute information of the tunnel.

In more detail, when there are many mobile nodes using tunnels connecting one visited network and one home network, the present invention reuses one tunnel. Thus, there is a multiple tunnel structure that forms multiple tunnel devices with the same entry and exit values corresponding to each mobile node in one tunnel device.

6a to 6b is an embodiment data structure diagram of an IP tunnel table used in the IP tunnel management method for reusing an IP tunnel according to the present invention.

As shown in FIG. 6A, an IP tunnel table used in an IP tunnel management method for reusing an IP tunnel according to the present invention, when using an index or a hash index (61), of an entire tunnel element included in the table. A count 611 indicating the number and as many tunnel elements 612 as the count number. At this time, each layer of the tunnel table 61 is occupied by one tunnel element 612.

At this time, each tunnel element 612 includes an entry 613 indicating the start of the tunnel, an exit 614 indicating the end point of the tunnel, and a usage value indicating the number of mobile nodes using the tunnel. usage) 615 and the name 616 of the tunnel.

In addition, as shown in Figure 6b, the IP tunnel table used in the IP tunnel management method for the reuse of the IP tunnel according to the present invention, when using a hash pointer (62), of the entire tunnel element included in the table A count 621 indicating the number and as many tunnel elements 622 as the count number. In this case, unlike the case of using the index or the hash index, each layer of the tunnel table 62 is not one tunnel element 622 but several tunnel elements 622 are located in one layer. The number of tunnel elements 622 located in each floor is different.

Each of the tunnel elements 622 includes an entry 623 indicating the start of the tunnel, an exit 624 indicating the end of the tunnel, and a usage value indicating the number of mobile nodes using the tunnel. usage 625, name 626 of the tunnel and next 627 indicating whether there is a tunnel element in parallel. Here, the tunnel element 622 in parallel means another tunnel element 622 located on one floor of the tunnel table 62.

Comparing the configuration of the tunnel connection of the mobile IP service of FIG. 4 with the tunnel element of FIG. 6, the entries 613 and 623 are the starting addresses of the tunnels. Become a home agent 404. Exits 614 and 624 are endpoints of the tunnel and are foreign agents 403 in FIG. 4.

On the other hand, with respect to the external agent 403, the entries 613, 623 are the external agent 403, and the exits 614, 624 are the home agent 404.

In FIG. 4, when two mobile nodes 401 and 402 are connected through the visited network 41, and only one tunnel is created for their home network 42 by the tunnel reuse, the visited node for the tunnel The number 2 is recorded as the usage values 615 and 625 of the tunnel elements 612 and 622 of FIG. 6, and the names of the tunnels are described in the names 616 and 626.

7 is a flowchart illustrating an operation of an IP tunnel management method for reusing an IP tunnel according to the present invention.

In the IP tunnel management for reusing an IP tunnel according to the present invention, first, the movement of a mobile node is determined to determine whether to add or delete a tunnel (700). When the mobile node visits and adds an IP tunnel (700), first, the IP tunnel to be added is searched using the IP tunnel table (701), and if the IP tunnel already exists (703), The usage of the tunnel elements is increased by 1 (704) and the corresponding IP tunnel is used. On the other hand, if there is no corresponding IP tunnel (703), a new IP tunnel is added (705), and the usage value (usage) of the tunnel elements of the added IP tunnel is increased by 1 (704) and the corresponding IP tunnel is used.

If the mobile node is in the process of deleting an IP tunnel leaving the network (700), it first searches whether there is an IP tunnel to be deleted using the IP tunnel table (702).

As a result of the discovery (702), if there is no IP tunnel to be deleted (706), it is treated as an error (710), and if there is an IP tunnel to be deleted (706), the usage value of the tunnel element is decreased by one and terminated (707). . At this time, if the usage value of the reduced IP tunnel is 0 (708), that is, if no mobile node uses the tunnel, the IP tunnel is deleted (709) and terminates.

8A to 8B are detailed flowcharts illustrating a tunnel discovery process in the IP tunnel management method for reusing an IP tunnel according to the present invention.

First, to find an IP tunnel, it is determined whether the IP tunnel is based on a hash index or a hash pointer (801). In the determination result 801, when the hash index is used, the hash function is called with the entry value and the exit value of the corresponding IP tunnel, and the result is input to the i and j values (802).

If it is determined that the i-th tunnel element of the IP tunnel table is 0 (803), if it is 0, it is regarded that there is no such thing and the process fails to search (816).

On the other hand, if the i th tunnel element of the IP tunnel table is not 0 (803), it is compared with the corresponding IP tunnel (804), and if it is the same, the i th tunnel element of the IP tunnel table is output as a search result (815).

On the other hand, if the i-th tunnel element of the IP tunnel table is equal to the corresponding IP tunnel (804), if it is not equal, the value of i is changed within the entire range of the hash function (805 to 808), so that the tunnel of the IP tunnel table is the same as the corresponding IP tunnel. If an element is found and the same tunnel element is found (804), the tunnel element of the found IP tunnel table is output as a search result (815).

In addition, in order to find an IP tunnel, the IP tunnel is determined by a hash index or a hash pointer (801). When the hash pointer is used, the hash function is called with the entry value and the exit value of the corresponding IP tunnel as variables. The result is input to the value i (809).

If it is determined that the i-th tunnel element of the IP tunnel table is 0 (810), if it is 0, it is regarded as the same thing, and the search fails to process (816).

On the other hand, if the i th tunnel element of the IP tunnel table is not 0 (810), the i th tunnel element of the IP tunnel table is employed as the hash pointer p (811). Comparing whether the hash pointer (p) is the same as the corresponding IP tunnel to be searched for (812), if it is equal, outputting the hash pointer p as a search result (815), and if different, checking whether there is a next value among the tunnel elements of the hash pointer (813). If there is a tunnel element indicated by the next value as a hash pointer (814), the process compares whether the IP tunnel is equal to the corresponding IP tunnel (step 812). Quit.

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

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 apparent to those of ordinary knowledge.

As described above, the present invention has an effect of efficiently managing resource of a system by avoiding generation of multiple tunnels for supporting two or more subscribers visiting from the same network.

In addition, the present invention, by presenting the tunnel table and the tunnel element, it is possible to manage the generated tunnel to delete the tunnel when there is no user so that the system does not consume unnecessary resources.

Claims (9)

In the IP tunnel management method for reusing an IP tunnel applied to a mobile IP (Internet Protocol) system, A first step of constructing an IP tunnel table for IP tunnel management; A second step of determining whether to add / delete an IP tunnel according to the movement of the mobile node; A third step of adding an IP tunnel according to the presence or absence of an IP tunnel to be searched for and added to the IP tunnel using the IP tunnel table when the tunnel is added as a result of the determination in the second step; And As a result of the determination of the second step, in the case of deletion of the tunnel, the fourth step of deleting the IP tunnel according to the existence of the IP tunnel to search for and delete the IP tunnel using the IP tunnel table; IP tunnel management method for the reuse of the IP tunnel comprising a. The method of claim 1, The IP tunnel table is, When building using an index or hash index, A count field indicating a total number of tunnel elements included in the IP tunnel table; And As many IP tunnel element fields as the number of counts, one at each layer of the IP tunnel table IP tunnel management method for the reuse of the IP tunnel comprising a. The method of claim 2, The IP tunnel element, An entry field indicating the start of the IP tunnel, an exit field indicating the end point of the IP tunnel, a usage field indicating the number of mobile nodes using the IP tunnel, and a name of the IP tunnel IP tunnel management method that can reuse the IP tunnel, characterized in that it comprises a (name) field. The method of claim 1, The IP tunnel table is, When building with a hash pointer, A count field indicating a total number of tunnel elements included in the IP tunnel table; And IP tunnel element fields as many as the count, located in parallel in each layer of the IP tunnel table. IP tunnel management method for the reuse of the IP tunnel comprising a. The method of claim 4, wherein The IP tunnel element is, An entry field indicating the start of the IP tunnel, an exit field indicating the end point of the IP tunnel, a usage field indicating the number of mobile nodes using the IP tunnel, the name of the IP tunnel and a next field indicating whether there is another tunnel element located in one layer of the tunnel table. The method according to any one of claims 1 to 5, The third step, A fifth step of searching for an IP tunnel using the IP tunnel table when the tunnel is added as a result of the determination in the second step; A sixth step of checking whether the IP tunnel to be added exists according to the search result of the fifth step, if not, adding the IP tunnel to be added and initializing a usage value of the tunnel element; And A seventh step of checking whether the IP tunnel to be added exists according to the search result of the fifth step and increasing the usage value of the tunnel element of the IP tunnel to be added IP tunnel management method for the reuse of the IP tunnel comprising a. The method according to any one of claims 1 to 5, The fourth step, A fifth step of searching for an IP tunnel using the IP tunnel table when it is determined that the tunnel is deleted; A sixth step of checking whether an IP tunnel to be deleted exists according to the search result of the fifth step and outputting an error message if it does not exist; A seventh step of checking whether an IP tunnel to be deleted exists according to the search result of the fifth step and if so, reducing the use value of the tunnel element of the IP tunnel to be deleted; And An eighth step of confirming that there is no mobile node using the corresponding IP tunnel through the use value reduced in the seventh step to delete the IP tunnel; IP tunnel management method for the reuse of the IP tunnel comprising a. The method according to any one of claims 1 to 5, The discovery process of the IP tunnel, A fifth step of determining whether the IP tunnel is based on a hash index or a hash pointer; A sixth step of executing a hash function using the entry value and the exit value of the tunnel elements of the IP tunnel as variables as a result of the determination of the fifth step, and storing the result value; A seventh step of finding and outputting an IP tunnel matching the tunnel element to be found in the entire tunnel table using the result value of the sixth step; As a result of the determination of the fifth step, in the case of the hash pointer, an eighth step of executing a hash function using the entry value and the exit value among the tunnel elements of the IP tunnel as variables and setting the hash pointer using the result value accordingly; ; A ninth step of outputting the hash pointer if the hash pointer matches the tunnel element to be searched for, and checking whether a next value of the hash pointer exists if the hash pointer does not match; And A tenth step of resetting the tunnel element indicated by the next value to the hash pointer if the next value exists in the ninth step and proceeding to the ninth step, and outputting a discovery failure message if the next value does not exist IP tunnel management method for the reuse of IP tunnel comprising a. In an IP (Internet Protocol) tunnel management device having a processor, A first function of establishing an IP tunnel table for IP tunnel management; A second function of determining whether to add / delete an IP tunnel according to the movement of the mobile node; A third function of searching for an IP tunnel using the IP tunnel table and adding an IP tunnel according to whether or not an IP tunnel to be added is added as a result of the determination of the second function; And A fourth function of deleting an IP tunnel according to the presence or absence of an IP tunnel to search for and delete an IP tunnel using the IP tunnel table in the case of deleting the tunnel as a result of the determination of the second function; A computer-readable recording medium having recorded thereon a program for realizing this.