KR19990001579A - Hybrid Gateway Structure and Its Operation Method - Google Patents

Abstract

The present invention relates to a hybrid gateway structure and a method of operating the hybrid gateway structure for enabling a network that can be used by mixing a public Internet address and a private Internet address. The hybrid gateway is located in the middle of the Internet and a newly constructed network, and newly constructed. The network can be constructed by assigning it to users using a public Internet address and a private Internet address, and the Internet can easily provide various types of network configurations to Internet access service providers under a structure that can be used without changing the currently operating systems. By constructing a hybrid gateway that enables a network configuration that can meet all types of user needs, it is not only possible to construct a network using a private Internet address or a public Internet address but also a public and public network. It is possible to build a mixed network using all private Internet addresses without additional equipment, and all hosts connected to the internal network can connect to each other without restriction of Internet address types such as public and private networks. It has an effect that can be provided.

Description

Hybrid Gateway Structure and Its Operation Method

The present invention relates to a hybrid gateway structure and a method of operating the same to enable a network capable of mixing a public Internet address and a private Internet address.

Due to the popularization of the Internet, many users want to use the Internet.

However, the current Internet based on IPv4 cannot allocate public Internet addresses to newly requesting users due to the exhaustion of public addresses.

As a result, the service provider providing the Internet access service uses a method of allocating a small number of public Internet addresses and dynamically assigning them to users who require the Internet, but this is based on the number of public Internet addresses allocated. Bring constraints on

Another solution is to use a private Internet address and to use a private Internet address internally, and to provide a service by converting to a public Internet address when accessing the Internet.

This places a lot of restrictions on the service because users under this addressing system cannot use public Internet addresses.

The above-mentioned solutions are based on whether to use a public Internet address or a private Internet address when constructing a new network.

It is best to construct a network using public Internet addresses, but it is already difficult to obtain as many public Internet addresses as necessary due to the exhaustion of public Internet addresses.

In addition, the network can be configured using only a private Internet address, but there is no problem in internal communication, but there is a limitation of a provided service when accessing the Internet.

When using a small number of public Internet addresses or a network using only private Internet addresses, it is difficult to provide various kinds of services to users.

Under the current Internet environment, a way to provide various kinds of services is to build a network by mixing public and private Internet addresses.

However, there is a problem in that there are no commercially available network equipment to mix and use these two different networks.

In order to solve the above problems, the present invention provides a structure and a processing method for a hybrid gateway system that enables the construction of a network that accommodates both a user using a public Internet address and a user using a private Internet address. The purpose.

1 is a system configuration to which the present invention is applied.

2 is a functional block diagram of the hybrid gateway of FIG. 1 according to the present invention;

3 is a process flow diagram of the hybrid gateway of FIG. 1 in accordance with the present invention;

4 is a related protocol header structure diagram in accordance with the present invention;

5 is a diagram illustrating packet transmission from the internal network to the Internet according to the present invention;

6 is an exemplary packet transmission from the Internet to the internal network in accordance with the present invention.

Explanation of symbols on the main parts of the drawing

110: central Internet connection station 111: hybrid gateway

112: email server 113: web server

114, 117, 121: Router 115: Communication Server

116, 132: Modem 120: Network using public Internet address

122, 131: terminal 130: network using a private Internet address

140: Internet 150: public network

In order to achieve the above object, the present invention includes an Internet connection providing center for establishing a network providing an Internet connection, a public Internet address using network using the public Internet address, and a private network using the private Internet address. Characterized in that.

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

1 is a system configuration to which the present invention is applied, and includes an Internet access providing central station 110, a public Internet address using network 120 using a public Internet address, and a private Internet address to construct a network providing Internet access. It consists of a private network 130 to be used.

The central station 110 for providing Internet access includes routers 114 and 117 for connecting to the Internet 140 or for connecting the internal network, an e-mail server 112 for providing a mail service, and a web server 113 for providing a web service. , A communication server 115 for users who want to access the Internet 140 through the public network 150 using modems 116 and 132, and a network using both public and private Internet addresses. It is composed of a hybrid gateway 111.

The public Internet address using network 120 may be composed of a plurality of terminals 122 having a public Internet address, and the router of the central station 110 providing the Internet access for the Internet 140 through a dedicated line as well as its own interconnection. (114).

The network 130 using the private Internet address may use a public Internet address, or may use a private Internet address, and may be connected to the communication server 116 of the heartland through the public network 150 using a modem 131. May connect to the Internet 140.

FIG. 2 is a functional block diagram of the hybrid gateway of FIG. 1 according to the present invention, showing functional blocks for processing a public Internet address and a private Internet address.

Looking at the function of each functional block, the interface (210, 211) represents the contacts of different networks connected to the hybrid gateway, the hardware driver (212, 213) controls the physical medium.

The link layer processing unit 214 or 215 performs a function of processing a frame transmitted and received through a physical medium, generates an IP packet using a frame upon reception, and converts the IP packet into a frame suitable for the physical medium upon transmission. .

The interfaces 210 and 211, the hardware drivers 212 and 213, and the link layer processor may vary according to characteristics of two networks to which they are connected.

The Internet protocol processing unit 216 receives the IP packet to the processing units 217 and 219 which perform its role according to the type of the IP packet, and receives and processes the IP packet from each processing unit 217 and 219.

The address translation determination unit 217 determines whether to perform address translation using the source Internet address or the destination address in the IP packet, and in the case of the IP packet to perform the address translation, the IP address to the address translation unit 218. Deliver the packet.

The address conversion unit 218 performs internet address translation using the address conversion table 221.

The routing processor 219 uses the routing table 220 to control a path to which an IP packet should be transmitted.

The operation concept of each functional block is largely divided into processing of packets transmitted from the internal networks 120 and 130 to the Internet and packets transmitted from the Internet 140 to the internal networks 120 and 130.

First, a processing procedure of a packet transmitted from the internal network 120 or 130 to the Internet 140 will be described. The packet to be transmitted to the Internet 140 may be connected to the link layer processor 215 through a physical hardware interface board 211. Transmits the received frame.

The link layer processor 215 analyzes the received frame, generates a complete IP packet, and sends it to the Internet protocol processor 216.

The internet protocol processor 216 transmits the received IP packet to the routing processor 219 to determine whether the packet is to be transmitted to the Internet 140.

The routing processor 219 analyzes the destination address of the received IP packet and determines whether the packet should be transmitted to the Internet 140 by referring to the routing table 220 and notifies the Internet protocol processor 216 of the result. .

If the result of the notification is a packet to be transmitted to the Internet 140, the Internet protocol processing unit 216 sends an IP packet to the address translation determination unit 217, and the address translation determination unit 217 analyzes the source Internet address, If the Internet address is a public Internet address, it is transmitted back to the Internet protocol processor 216 to be transmitted to the Internet 140.

If the source Internet address is a private Internet address, it is sent to the address conversion unit 218 for network address translation.

The address conversion unit 218 changes the source Internet address of the received Internet IP packet to its own public Internet address, finds an empty port among its own ports, changes the port number to this value, and then changes the information. And the change information are recorded in the address conversion table 221.

After the address translation is completed, the IP packet is also transmitted to the Internet protocol processor 216 to be transmitted to the Internet 140.

Looking at the processing procedure of the packet transmitted from the Internet 140 to the internal network (120, 130), the packet to be transmitted to the internal network (120, 130) through the physical layer interface board 210 is connected to the link layer processing unit ( 214 analyzes the received frame, generates a complete IP packet, and sends it to the Internet protocol processor 216.

The internet protocol processor 216 transmits the received IP packet to the routing processor 219 to determine whether the packet is to be transmitted to the internal networks 120 and 130.

The routing processor 219 analyzes the destination address of the received IP packet to determine whether the packet is to be transmitted to the internal network 120 or 130 with reference to the routing table 220, and then the result is the Internet protocol processor 216. Notify by.

If the result of the notification is a packet to be transmitted to the internal network 120 or 130, the Internet protocol processor 216 sends an IP packet to the address translation determination unit 217, and the address translation determination unit 217 sends the destination Internet address. If the destination Internet address is its own Internet address, it is sent to the address conversion unit 218.

The address translator 218 finds the destination Internet address of the received IP packet in the address translation table 221, changes the IP address to a corresponding private Internet address, and transmits the IP packet to the Internet protocol processor 218 to transmit the internal network 120. 130).

If the destination address is a public Internet address, the address is transmitted to the Internet protocol processor 216 and transmitted to the internal networks 120 and 130 without performing address translation.

3 is a flow chart of the hybrid gateway of FIG. 1 according to the present invention, which shows an IP packet processing flow according to the type of an Internet address.

The processing of IP packets is divided into processing for IP packets transmitted from the internal networks 120 and 130 to the Internet 140 and processing for IP packets transmitted from the Internet 140 to the internal networks 120 and 130. .

First, the processing of the IP packet transmitted from the internal network 120 or 130 to the Internet 140 is received, and a frame is received from the connected network (S1), and a complete IP packet is extracted from the received frame (S2).

After extracting the IP packet, it is determined whether the source Internet address in the IP packet is a public Internet address used by the internal network (S3). If the source Internet address is a public Internet address, the destination Internet of the corresponding IP packet is determined using a routing table (S4). The routing is determined according to the address (S5), and the IP packet is transmitted to the corresponding host on the Internet (S6).

After the determination, if the source Internet address is not the internal network Internet address, it is determined whether the source Internet address is a private Internet address (S7) and if the private Internet address is changed to the public Internet address of the hybrid gateway itself (S7); S8), the change result is recorded in the address conversion table (S9).

After recording, routing is determined according to the destination Internet address of the corresponding IP packet using the routing table S4 (S5), and the IP packet is transmitted to the corresponding host on the Internet (S6).

In the processing of the IP packet transmitted from the Internet 140 to the internal network 120 or 130, after receiving the frame (S1), the IP packet is extracted (S2), and the destination Internet address in the IP packet is set to the hybrid gateway 111 itself. It is determined whether the address (S10).

After the determination, if it is the address of the hybrid gateway 111, the address of the hybrid gateway 111 is converted into the corresponding private Internet address recorded in the address translation table S9 (S11), and the routing table S4 is used. After determining the routing according to the destination Internet address of the IP packet (S12), and transmits the IP packet to the corresponding terminal of the internal network (S13).

After the routing is determined according to the destination Internet address of the IP packet using the routing table S4 without performing the destination Internet address translation (S12), the IP packet is transmitted to the corresponding terminal of the internal network (S13).

4 is a diagram of a related protocol header structure according to the present invention, which shows a structure of related protocol headers required for a hybrid gateway to process.

The packets processed by the hybrid gateway 111 are the IP packet 310, the TCP packet 330, the UDP packet 320, and the ICMP packet 340.

Among the headers of the IP packet 310, the hybrid gateway processes the source internet address 311, the destination internet address 312, the protocol 313, and the IP header checksum 314.

The Internet addresses 311 and 312 are used for actual Internet address translation, and the Protocol 313 is used to manage the sessions for each protocol after classifying the TCP, UDP and ICMP protocols.

The IP header checksum 314 portion is used to reset the checksum value of the IP header changed due to the changed Internet address.

Among the packets transmitted from the internal networks 120 and 130 to the Internet 140, the packet using the private Internet address is changed from the source Internet address 311 to the hybrid gateway 111 Internet address, and the changed information is converted into an address translation table ( 221).

If the destination Internet address 312 is the address of the hybrid gateway 111 among the packets transmitted from the Internet 140 to the internal networks 120 and 130, the packet is changed to the corresponding private Internet address recorded in the address translation table 221. do.

The portion of the header of the TCP packet 330 or the UDP packet 320 that is processed by the hybrid gateway 111 is a source port number 321, 331, a destination port number 322, 323, and a checksum 323 of each header. , 324).

The packet using the private Internet address among the packets transmitted from the internal network 120 and 130 to the Internet 140 is changed from the source port number 321 and 331 to the port number available at the hybrid gateway 111, and the changed information. Is recorded in the address translation table 221.

When the destination Internet address 312 is the address of the hybrid gateway 111 among the packets transmitted from the Internet 140 to the internal networks 120 and 130, the destination Internet address 312 may be recorded in the address translation table 221 when the Internet 140 is transmitted to the Internet 140. Changed to the port number.

The checksums 323 and 324 of the TCP or UDP header are used to rewrite the checksum value of the TCP header generated by the changed port number.

The parts processed by the hybrid gateway 111 in the header of the ICMP packet 340 are the message type 341 and the checksum 342 part indicating the message type of the ICMP.

The checksum 342 of the ICMP header is used to rewrite the checksum value of the ICMP header which is changed according to the ICMP message type.

FIG. 5 is a diagram illustrating packet transmission from the internal network to the Internet according to the present invention, and illustrates a process of processing an Internet address for each main subsystem when a terminal using a private Internet address using a hybrid gateway performs internet access.

When a terminal 410 using a private Internet address 10. 100. 100. 100 is allocated and requests a service to a server 414 using an Internet address of 129.254.235.154 on the Internet 417, The terminal 410 connects to the communication server 411 of the central station through the public network 416 using the modem 415.

The source Internet address in the transmitted IP packet is 10.100.100.100, and the destination Internet address is 129.254.235.154.

The communication server 411 transmits the received IP packet to the hybrid gateway 412.

The hybrid gateway 412 analyzes the source address in the header in the received IP packet and changes the private Internet address of 10. 100. 100. 100 to its public Internet address of 111. 111. 100. 1 and then the router ( 413).

Router 413 sends the received IP packet to server 414 on the Internet 417.

The source Internet address of the IP packet arriving at the server 414 is 111.111.100.1.

That is, from the server's point of view, the corresponding IP packet is not a packet transmitted from the terminal 410 using an address of 10. 100. 100. 100 but a hybrid gateway 412 using an address of 111. 111. 100. 1. It is recognized as a packet sent by.

6 is a diagram illustrating packet transmission from the Internet to the internal network according to the present invention. When the Internet server attempts to transmit data requested to a terminal using a private Internet address using a hybrid gateway, an Internet address of each major subsystem is included. Indicates the process.

The server 514 on the Internet receives and processes the packets sent from the hybrid gateway 512 and sends the result to the Internet 515 using the public Internet address of 111.111.100.1 as the destination Internet address. do.

Routers on the Internet transmit the packet to the router 513 connectable to the internal network.

The router 513 analyzes the received packet and transmits it to the hybrid gateway 512.

The hybrid gateway 512 analyzes the destination Internet address in the received packet header and, if the destination Internet address matches its own address, searches the address translation table and returns the corresponding private Internet address 10. 100. 100. 100. After replacing, the packet is transmitted to the communication server 511 to transmit to the terminal.

The communication server 511 transmits the packet to the terminal 510 through the public network 517 using the modem 516 to transmit a packet to the terminal 510 using a private Internet address of 10. 100. 100. 100. .

As described above, the present invention enables the construction of a network using only a private Internet address or a network using only a public Internet address by using a hybrid gateway, as well as a mixed type of network using both public and private Internet addresses. Deployment is possible without additional equipment.

In addition, all hosts connected to the internal network can be connected to each other without restriction of Internet address types such as public and private, thereby providing various types of Internet services.

Claims (4)

In a hybrid gateway structure that allows the construction of a network that can be used by mixing a public Internet address and a private Internet address, An internet access providing center for constructing a network providing internet access; A public internet address use network using the public internet address; And a private internet address using network using the private internet address. The central office of claim 1, wherein A router necessary for internet access or connection of an internal network; An e-mail server for providing a mail service; A web server for providing a web service; A communication server for users who want to access the Internet through a public network using a modem; A hybrid gateway structure comprising a hybrid gateway capable of accessing both a network using a public Internet address and a private Internet address. 3. The hybrid gateway of claim 2, wherein the hybrid gateway is An interface representing a contact point of different networks connected to the hybrid gateway; A hardware driver for controlling the physical medium; A frame layer processing unit for generating and transmitting an IP packet using the received frame and changing the IP packet into a frame suitable for the physical medium when the frame is transmitted and received through the physical medium; An Internet protocol processor for receiving the IP packet and performing its role according to each packet type; An address translation determination unit for determining an address translation using an originating Internet address or a destination Internet address in the IP packet and delivering the corresponding IP packet; An address conversion unit for performing an Internet address conversion using an address conversion table; And a routing processing unit which controls a route to which an IP packet should be transmitted using a routing table. Located in the middle of the Internet and the newly constructed network, the newly constructed network is allocated to the user by using the public Internet address and the private Internet address, and the Internet is provided without changing the operating systems. In the operating method of the hybrid gateway to provide a variety of network configuration to the user easily, and to enable a network configuration that can meet various types of user needs, Receiving a frame from a connected network and extracting a complete IP packet from the received frame; After extracting the IP packet, if the source Internet address in the IP packet is a public Internet address used by the internal network, the routing table is used to determine routing according to the destination Internet address of the corresponding IP packet, and the IP packet is transmitted to the corresponding host on the Internet. Performing a second step; After the determination, if the source internet address is not the internal network internet address, if the source internet address is the private internet address, changing the private internet address to the public internet address of the hybrid gateway itself and recording the result of the change in the address translation table. With three steps; A fourth step of determining routing according to a destination Internet address of the corresponding IP packet using a routing table after recording, and then transmitting the IP packet to a corresponding host on the Internet; A fifth step of extracting an IP packet by receiving the frame and determining whether a destination Internet address in the IP packet is an address of the hybrid gateway itself; After the determination, if the address of the hybrid gateway, converts the address of the hybrid gateway into a corresponding private Internet address recorded in the address translation table; A seventh step of determining the routing according to the destination Internet address of the corresponding IP packet using the routing table after the conversion, and then transmitting the IP packet to the corresponding terminal of the internal network; And a eighth step of determining routing according to a destination internet address of the corresponding IP packet using a routing table without performing a destination internet address translation, and then transmitting the IP packet to a corresponding terminal of an internal network. How to operate.