KR20030014803A - The Method of IP Reverse Tunnel Routing in UMTS/GPRS Mobile IP Service - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an IP reverse tunnel routing method in a mobile IP network and a computer readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

An object of the present invention is to provide a computer-readable recording medium recording an IP reverse tunnel routing method and a program for realizing the method in a mobile IP (Internet Protocol) network supporting a reverse tunnel according to a source of a packet.

3. Summary of Solution to Invention

The present invention relates to an IP reverse tunnel routing method applied to an IP network. When a user message is reverse tunneled from a visited network to a home network, a tunnel device, which is a data link layer, receives a packet and transmits the packet. A first step of confirming whether the packet is from a reverse tunnel registered gateway; A second step of removing, by the tunnel device, an external IP header of the packet when it is determined that the packet is from a reverse tunnel registered gateway according to the checking result of the first step; And a third step of transmitting the reverse tunnel header as an external IP header of the packet if the packet from which the external IP header of the second step is removed is a packet from a host registered with the reverse tunnel. .

4. Important uses of the invention

The present invention is used in mobile IP networks and the like.

Description

The method of IP Reverse Tunnel Routing in UMTS / GPRS Mobile IP Service}

The present invention relates to an IP reverse tunnel routing method in a mobile IP network and a computer readable recording medium having recorded thereon a program for realizing the method.

Conventional patented technologies include "Scalable and efficient intra-domain tunneling mobile-IP scheme (Sun Microsystems, Inc., US Patent Registration 1994-5325362)", "Simplified method of configuring internet protocol security tunnels (IBM Corp., US patent) Registration 2000-6076168 ", and" Web-based administration of IPtunneling on internet firewalls (IBM Corp., US Patent Registration 1999-5864666) ".

First of all, the "Scalable and efficient intra-domain tunneling mobile-IP scheme (Sun Microsystems, Inc., US Patent Registration 1994-5325362)" is a method for supporting mobile IP using a tunnel, the data processing of the mobile node and MSR ( It consists of Mobility Support Router and Mobility Support Border Router (MSBR) to support mobile IP.

In addition, "Simplified method of configuring internet protocol security tunnels (IBM Corp., US Patent Registration 2000-6076168)" refers to a method for creating a tunnel and a filter for secure communication between two hosts. Create and create tunnels and filters on the other side.

In addition, "Web-based administration of IP tunneling on internet firewalls" (IBM Corp., US Patent Registration 1999-5864666) is a web-based tunnel management tool that supports graphically convenient management. For this purpose, the tunnel can be managed to the operator by using the tunnel information and graphics and windows to express it.

However, such a conventional technique has not been studied on the method of confirming the destination of a packet to be forwarded and forwarding the packet to the corresponding destination in supporting the mobile IP. In particular, there is a need for reverse tunneling of a user's message from a visited network to a home network in a mobile IP service, which has not yet been implemented for such a reverse tunnel in the existing routing method.

The present invention has been proposed in order to solve the above problems, and records the IP reverse tunnel routing method and a program for realizing the method in a mobile IP (Internet Protocol) network which performs reverse tunneling by checking the source of a packet. Its purpose is to provide a computer readable recording medium.

Particularly, the present invention checks whether a source is a GGSN in a tunnel between a GGSN of a UMTS / GPRS network and a foreign agent (FA: Forien Agent) of a UMTS / GPRS mobile IP network, and then re-tunnels the address of the GGSN. By tunneling only packets having a source as the source, we want to support more efficient reverse tunneling.

1 is a diagram illustrating an embodiment of a UMTS / GPRS 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 flow diagram of one embodiment operation of an IP routing method including a general IP in IP tunnel.

5 is a flowchart illustrating an embodiment of an IP routing method including an IP in IP reverse tunnel in an IP layer according to the present invention.

6 is a diagram illustrating a tunnel connection configuration of an embodiment of a mobile IP network according to the present invention;

7 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.

8 illustrates packet forwarding in multiple tunnels for an IP in IP reverse tunnel of a Mobile IP service according to the present invention.

9 is a flowchart illustrating an embodiment of an IP routing method including an IP in IP reverse tunnel in a tunnel device of a data link layer according to the present invention;

* Explanation of symbols for the main parts of the drawings

11: home network 12: visiting network

13 correspondence node 14 UMTS / GPRS network

15-1: Mobile Node 15-2: Mobile Node

101: Home Agent 102: External Agent

103: GGSN

The present invention for achieving the above object, in the IP reverse tunnel routing method applied to the IP (Internet Protocol) network, when the reverse tunneling the user message from the visited network to the home network, tunnel device which is a data link layer A first step of receiving a packet and confirming whether the packet is from a reverse tunnel registered gateway; A second step of removing, by the tunnel device, an external IP header of the packet when it is determined that the packet is from a reverse tunnel registered gateway according to the checking result of the first step; And a third step of transmitting the reverse tunnel header as an external IP header of the packet if the packet from which the external IP header of the second step is removed is a packet from a host registered with the reverse tunnel. Characterized in that made.

On the other hand, the present invention, when the reverse IP tunneling the user message from the visited network to the home network in the mobile IP system having a processor, the tunnel device, which is a data link layer receives the packet and the packet from the reverse tunnel registered gateway A first function of checking whether or not it is; A second function of removing, by the tunnel device, an external IP header of the packet when it is determined that the packet is from a reverse tunnel registered gateway according to a result of checking the first function; And if the packet from which the external IP header of the second function has been removed is a packet from a host registered with a reverse tunnel, forwarding the reverse tunnel to the reverse tunnel device to transmit the reverse tunnel header as an external IP header of the packet. A computer readable recording medium having recorded thereon a program is provided.

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.

Hereinafter, the present invention will be described using a Universal Mobile Telecommunications System (UMTS) / General Packet Radio Service (GPRS) mobile IP network as an example.

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

A home network 11, a visited network 12, a correspondent node (Correspondent Host, or CorrespondentNode) 13, and a UMTS / GPRS network 14, and mobile nodes (MN: Mobile Node, 15-1, 2) The service is provided from the home agent 101 of the home network 11 to which it belongs.

Subsequently, when the user moves, the mobile nodes 15-1 and 2 transfer foreign agents (FAs) of the visited network 12 through the gateway GPRS support node (GGSN) 103 of the UMTS / GPRS network 14. Through 102, a service is provided from a home agent (HA) 101 of the home network 11.

At this time, the provided mobile IP service is a communication service with a corresponding node (Correspondent Host or Correspondent Node) 13 for the mobile nodes 15-1, 2.

In order for the mobile node 15-2 of the visited network 12 to communicate with a corresponding host (Correspondent Host or Correspondent Node) 13, packets from the mobile node 15-2 are sent to the external agent of the visited network 12. Packets from Correspondent Host or Correspondent Node 13, though passed through 102, are transmitted to the home agent 101 of the home network 11 as if the mobile node 15-2 is in the position of 15-1. And the home agent 101 delivers it through the tunnel with the external agent 102 of the visited network 12.

The foreign agent 102 removes the header from the home agent 101 having the tunnel information of this packet to the external agent 102 and adds the header from the foreign agent 102 to the GGSN 103 to the GGSN 103. To pass. The GGSN 103 removes the header from the foreign agent 102 to the GGSN 103 and forwards it to the mobile node 15-2.

On the other hand, the packet from the external agent 102 to the corresponding node (Correspondent Host or Correspondent Node) 13 is usually delivered directly, but if the home agent 101 requests a reverse tunnel, the home agent 101 of the home network 11 In particular, the connection between the foreign agent 102 and the home agent 101 is transmitted using IP tunneling.

The foreign agent 102 communicates with the GGSN 103 of the UMTS / GPRS network to communicate with the mobile node 15-2 of the UMTS / GPRS network 14. In fact, the UMTS / GPRS network 14 is delivered to the mobile node 15-2 via various nodes in addition to the GGSN 103.

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 internal IP header 222 has a destination address of the mobile node 15-2 of the visited network 12, and a source address of the corresponding node 13 The external IP header 221 has a destination address having the address of the external agent 102 of the visited network 12 and a source address having the address of the home agent 101, and a home agent 101 of the home network 11. ) 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 transmitted from the IP layer 31 to the network matching card 32 or a packet transmitted from the upper layer 34 to the IP layer is determined to view the routing information at the IP layer 31 and to tunnel, 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 ( 302, the external IP header 221 of FIG. 2 is removed, and then the IP address 31 is transferred to the IP layer 31 using 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 flowchart illustrating an embodiment of an IP routing method including a general IP in IP tunnel.

Referring to the conventional IP routing method including the IP in IP tunnel, when the IP layer receives the IP packet (401), the IP layer receiving the IP packet checks whether the received packet is an IP in IP tunnel packet. In step 402, if the IP in IP tunneling packet is transmitted to the tunnel device, the tunnel device removes the external IP header and delivers the IP to the IP layer (403). In addition, if it is not an IP in IP tunneling packet, it refers to the routing table and delivers it to the destination of the corresponding address (404).

5 is a flowchart illustrating an embodiment of an IP routing method including an IP in IP reverse tunnel in an IP layer according to the present invention.

The IP routing method including the IP in IP reverse tunnel in the IP layer according to the present invention first receives an IP packet in the IP layer (501).

In addition, the IP layer determines whether the received packet is an IP in IP tunnel packet (502), and if the packet is an IP in IP tunneled packet, delivers it to the tunnel device (503), and the corresponding tunnel device removes the external IP header to the IP layer. The IP layer to the destination of the packet.

In operation 502, if the packet is not an IP in IP tunneled packet, it is determined whether the packet is from a reverse tunnel registered host by referring to a reverse tunnel table (504). As a result of the check, if the packet is from the reverse tunnel registered host, the packet is forwarded to the reverse tunnel device (505), and the reverse tunnel device removes the external IP header and forwards the packet to the IP layer, and the IP layer is forwarded to the destination of the packet. Otherwise, the packet is forwarded to the routing device if it is not a normal packet (506) and forwarded to the corresponding destination according to the routing table.

In the above, processing of a packet by the reverse tunnel device means performing a constant tunneling on a packet from the reverse tunnel registered host and delivering the packet. In particular, the preferred embodiment of the present invention is such that the reverse tunnel is made from the external agent of the visited network to the home agent of the home network.

6 is a diagram illustrating a tunnel connection configuration of an embodiment of a mobile IP network according to the present invention.

15-2, 103, 102, 101, and 13 in FIG. 1 correspond to 601, 602, 603, 604, and 605, respectively.

In addition, the mobile node 601 to the GGSN 602 uses a UMTS / GPRS network through which a mobile IP signaling message and a user message are transmitted using a GPRS Tunneling Protocol (GTP).

In the present invention, the connection between the external agent 603 of the mobile IP network and the GGSN 602 of the UMTS / GPRS network should use IP in IP tunneling. In addition, the connection between the foreign agent 603 and the home agent 604 also uses IP in IP tunneling.

In the present invention, using the connection between the external agent 603 of the mobile IP network and the GGSN 602 of the UMTS / GPRS network as IP in IP tunneling is not reverse tunnel connection in the IP layer in FIG. 5. This is to perform reverse tunneling operation in the tunnel device which is the link layer. Hereinafter will be described in more detail in FIG.

7 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. 7, the tunnel device according to the present invention is a multiple tunnel device having a plurality of tunnel devices regenerated therein.

The tunnel device of 701 is the same as the tunnel device of 33 of FIG. A tunnel device including 702, 703, 704, 705, and the like in the tunnel device is referred to as a multi-tunnel device.

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

8 illustrates an example of packet forwarding in multiple tunnels for an IP in IP reverse tunnel of a mobile IP service according to the present invention. A packet forwarding operation in a multi-tunnel for an IP in IP reverse tunnel according to the present invention will be described using an operation structure diagram of an IP tunnel of a mobile IP service of FIG. 3.

A network interface card (NIC) 32 receives the packet and forwards the packet to the IP layer 31 (303). If the received packet is an IP in IP packet, the received packet is transferred to the representative tunnel 702 in the multiple tunnel structure of FIG. 7 (308).

Then, the representative tunnel 702 finds the tunnel 704 to be reverse tunnel again, removes the external IP header from the received packet, and transfers it to the tunnel 704 to be reverse tunneled (801). 704 attaches a reverse tunnel header to the received packet and forwards it to IP layer 31 (305). The IP layer 31 transmits the packet including the reverse tunnel header to the network matching card 32 so that the reverse tunnel can be reverse tunneled.

9 is a flowchart illustrating an embodiment of an IP routing method including an IP in IP reverse tunnel in a tunnel device of a data link layer according to the present invention.

When the representative tunnel 702 of FIG. 8 receives an IP in IP tunneled packet (901), it is checked whether the received packet is an IP in IP packet transmitted from a GGSN, which is a reverse tunnel registered host (902). As a result of the check, if the packet is not from the GGSN, the packet is decapsulated (903) and forwarded to the IP layer.

On the other hand, as a result of the check, if the packet is from the GGSN, the outer tunnel header is removed (904), depending on whether the reverse tunnel is registered (905) or forwarded to the corresponding reverse tunnel device (704) (906, 801), or the encapsulation of the tunnel. decapsulate (903) and forward to the IP layer.

When the packet is delivered to the reverse tunnel device (906), the reverse tunnel device attaches the reverse tunnel header to the outer header of the packet and delivers it to the IP layer.

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 reverses all packets received from an external agent by tunneling only packets having a source GGSN in a tunnel between a GGSN of a UMTS / GPRS network and an external agent of a mobile IP network in a UMTS / GPRS mobile IP network. Compared to checking whether a tunnel exists, it is effective to support more efficient reverse tunneling.

Claims (8)

In the IP reverse tunnel routing method applied to a mobile IP (Internet Protocol) network, When reverse tunneling a user message from a visited network to a home network, a first step of receiving, by the tunnel device as a data link layer, whether the packet is from a reverse tunnel registered gateway; A second step of removing, by the tunnel device, an external IP header of the packet when it is determined that the packet is from a reverse tunnel registered gateway according to the checking result of the first step; And A third step of transmitting the reverse tunnel header as an external IP header of the packet if the packet from which the external IP header of the second step is removed is a packet from a host registered with the reverse tunnel; IP reverse tunnel routing method in a mobile IP network comprising a. The method of claim 1, A fourth step of decapsulating and forwarding the packet if the packet is not a packet from the reverse tunnel registered gateway according to the result of the checking of the first step IP reverse tunnel routing method in a mobile IP network further comprising. The method of claim 2, A fifth step of decapsulating and forwarding the packet if the packet from which the external IP header of the second step is removed is not a packet from a host registered in reverse tunnel; IP reverse tunnel routing method in a mobile IP network further comprising. The method according to any one of claims 1 to 3, The reverse tunnel registered host, A method for routing IP reverse tunnels in a mobile IP network, which is a gateway GPRS support node (GGSN) of a universal mobile telecommunications system (UMTS) / general packet radio service (GPRS) network. The method according to any one of claims 1 to 3, The reverse tunnel, An IP reverse tunnel routing method in a mobile IP network, characterized by being formed between a home agent and an external agent in the mobile IP network. In a mobile IP system with a processor, When reverse tunneling a user message from a visited network to a home network, a first function of receiving a packet from a tunnel device, which is a data link layer, and confirming whether the packet is from a reverse tunnel registered gateway; A second function of removing, by the tunnel device, an external IP header of the packet when it is determined that the packet is from a reverse tunnel registered gateway according to a result of checking the first function; And A third function of forwarding the reverse tunnel header as an external IP header of the packet if the packet from which the external IP header of the second function has been removed is a packet from a host registered with the reverse tunnel; A computer-readable recording medium having recorded thereon a program for realizing this. The method of claim 6, A fourth function of decapsulating and forwarding the packet if the packet is not a packet from a reverse tunnel registered gateway according to a result of confirming the first function A computer-readable recording medium that records a program for further realization. The method of claim 7, wherein A fifth function of decapsulating and forwarding the packet if the packet from which the external IP header of the second function is removed is not a packet from a host registered in reverse tunnel; A computer-readable recording medium that records a program for further realization.