KR20020073359A - Remote access router - Google Patents

Abstract

PURPOSE: A remote access router is provided to connect to a device in a local network through the Internet, assign a global fixed IP(Internet Protocol) address or floating IP address in the local network, route a packet transmitted from the outside to a desired device among a plurality of devices in the local network. CONSTITUTION: A processor(301) performs an entire operation. A recording medium(303) records programs for executing an entire operation. A memory(305) memorizes data generated during the entire operation. A computer connection port driver(307) records and changes internal setting data by an external computer(203). A global LAN(Local Area Network) driver(309) transmits and receives an Internet protocol signal with a global router. A local LAN driver(311) transmits and receives the Internet protocol signal with a local network router.

Description

Remote Access Router

The present invention relates to Internet address translation (NAT), and more particularly to a router that accesses a particular device within a local network with reference to a global or local IP address.

1 is a block diagram illustrating a communication environment including a conventional local network.

The communication environment shown in FIG. 1 uses the Internet network 101. The remote computer 103 and the local network 107 are connected to the Internet 101. One or more computers 105 are connected to the local network 107. The computer 105 in the local network 107 is provided with means capable of processing information according to the Internet protocol. Such means may be a LAN connection card that can be mounted on a computer or the like, or a LAN connection device built in a computer.

The local network 107 is provided with a router 100. The router 100 is connected to a connection connected to the Internet, for example, the T-1 line. A remote computer 103 accessible to the Internet 101 may access the computer 105 in the local network 107 via a router 100 in accordance with the present invention.

According to the internet protocol, the communication environment shown in FIG. 1 uses an internet protocol address (IP address) for identifying numerous computers and other devices connected with the internet 101. An IP address is specified by a 32-bit host address and is typically represented by four layers of decimal numbers separated by dots. Since it is a 32-bit address method, the upper limit of the IP address that can be specified for all devices connected to the Internet is 2 ³² . Thus, Internet Information Providers (ISPs) typically assign single or few IP addresses to organizations such as businesses or schools, and allow users of businesses or schools to share addresses. In Fig. 1, the local network is assigned a single or few IP addresses, the assigned IP address is registered with the IP address management authority of the Internet, and the computers 105 in the local network share the IP address assigned to the local network. do.

When a user in the local network 107 transmits an E-mail using the Internet, transfers a file using FTP, accesses a WWW server, or telnets, configure data to be transmitted. In this packet, the source and destination IP addresses must be specified correctly. Accordingly, the packet itself contains the source and IP addresses of the destination and is automatically routed from the source to the destination based thereon.

Router 100 of local network 107 typically performs a network address translation (NAT) or network address port translation (NAPT) function. By the NAT function, devices in the local network use addresses that are not registered as IP addresses within the local network, and outside the local network, use addresses registered as IP addresses to identify the local network. In the present specification, an address registered as an IP address on the Internet is referred to as a global IP address, and an address not registered as an IP address on the Internet is referred to as a local IP address.

It is an object of the present invention to provide a device for connecting to a device in a local network via the Internet.

Another object of the present invention is to provide a device capable of assigning a single global fixed IP address or a floating IP to a local network and routing packets transmitted from outside to a specific desired device among a plurality of devices in the local network. .

According to one aspect of the invention, a network address translation apparatus in a router of a local network is provided. The apparatus according to the invention comprises means for receiving from the Internet a datagram whose destination is specified by a global address comprising an Internet Protocol (IP) address and a port number, the IP address and port number of the datagram in the local network. Means for translating to a unique local address in C, and means for routing the received datagram to the local address.

1 is a block diagram illustrating a communication environment incorporating a conventional local network.

2 is a block diagram illustrating an environment to which a remote access router 200 according to the present invention is applied.

3 is a block diagram illustrating in more detail the configuration of a remote access router 200 in accordance with the present invention.

4 is a time series diagram illustrating the operation of a remote access router 200 according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

101: the Internet

103: remote computer

100b: global router

205a, 205b: computer

205c, 205d: Devices other than computers

100a: local network router

2 is a block diagram illustrating an environment to which the remote access router 200 according to the present invention is applied. The same configuration as that shown in FIG. 1 of the communication environment shown in FIG. 2 uses the same reference numerals.

The communication environment shown in FIG. 2 uses the Internet network 101. The internet 101 is directly connected to a remote computer 103 or a router 100b for connecting a local network to the Internet. The router 100b is connected to a connection, for example, a T-1 line, connected to the Internet. The router 100b may be assigned a global fixed IP or a floating IP address. According to an embodiment of the present invention, only the global fixed IP may be assigned to the router 100b. As a function similar to the router 100b shown in FIG. 2, there may be a CSU, a router in a conventional sense, a hub, or an ADSL modem. For example, if router 100b is an ADSL modem, the dynamic IP assigned to router 100b is assigned by an ADSL base station installed in the telephone station.

In the present specification, the router 100b connected to a connection connected to the Internet 101 is called a global router. In addition, a fixed or dynamic IP assigned to the global router 100b is called a global IP. According to a preferred embodiment of the present invention, the external remote computer 103 can access the local network 107 with reference to the global IP assigned to the global router 100b.

The computers 205a and 205b and devices 205c and 205d other than the computer are connected to the local network 107. Devices other than computers may be printers 205c, faxes 205d, telephones, and various home appliances. In addition, when the present invention is applied to remote control of an industrial device connected to the local network 103, a second industrial device, control measurement equipment, a work terminal, and automation that can be connected via the Internet with a device other than a computer. Device and the like. As an example of such a device, a digital analog input / output device manufactured by Advantech Technologies, Inc. is ADAM, a video client module connection device using a dynamic IP product named e-Camera, and a TCP / IP connector application product named eI / O. , Alarm system using TCP / IP connector with product name e-Security, Door access controller with product name e-Access, Lighting and home appliance control device using power line with product name e-PLC, Product name with e-Sign There is a display device.

Computers 205a and 205b and other devices 205c and 205d in the local network 107 are provided with means capable of processing information according to the Internet protocol. Such means may include a LAN connection card that can be attached to a computer, a LAN connection device embedded in a home appliance, a TCP / IP connector manufactured by Advantech Technologies, Inc., and the like.

In addition, the router 100a is provided in the local network 107. The router 100a provided in the local network 107 is referred to herein as a local network hub. The local network hub 100a refers to all kinds of hubs for interconnecting computers and non-computer devices within the local network.

The remote access router 200 according to the present invention is connected with the global router 100b and the local network hub 100a. In addition, the remote access router 200 according to the present invention is provided with a port to which the computer 203 can be connected. Address setting of the remote access router 200 may be performed through the computer 203. According to another embodiment of the present invention, the functions of the global router 100b and the local network hub 100a may both be included in the remote access router according to the present invention.

The remote access router 200 according to the present invention performs a function of address translation of external data transmitted through the router 100b to a specific device in a local network. According to one embodiment of the invention, such external data may be in the form of packets, and such data is generally referred to herein as datagrams. Such a remote access router 200 is a network address translation (NAT) routing service. And remote access (RA) routing services according to the present invention. In the following description, network address translation routing is referred to as NAT routing, and remote access routing according to the present invention is referred to as RA routing. In addition, the remote access router 200 according to the present invention may support TCP / IP, UDP, DHCP, PPPoE, and fixed IP.

The datagrams addressed by the remote access router 200 are transmitted via the local network hub 100a to specific devices in the local network.

According to the present invention, the remote access router 200 can assign a plurality of local IP addresses to devices in the local network. For example, the remote access router 200 allocates up to 253 local IP addresses of 127 IP addresses by NAT routing and 126 IP addresses by RA routing to devices in the local network.

According to a preferred embodiment of the present invention, a remote access router 200 capable of supporting both NAT routing and RA routing may provide a device with a NAT routing address, for example, 192.168.128.128 to provide access by NAT routing. To 192.168.128.254. In addition, a device to provide remote access by RA routing according to the present invention is assigned a remote access routing address distinct from a NAT routing address, for example, 192.168.128.2 to 192.168.128.127.

Devices in the network can treat the local IP address assigned to them as a global IP address. In addition, the remote computer 103 outside the local network can also directly access the devices in the local network using the global IP address and the local IP address assigned to the devices in the local network.

According to an embodiment of the present invention, the remote access router 200 assigns a private IP using a port number to devices in a local network provided with RA routing, and extracts an IP address from a packet transmitted from the remote computer 103. From this, a specific private IP number in the local network is decrypted. Then send to the device with the decrypted private IP. In addition, the remote access router 200 may provide a conventional NAT routing service for devices provided with NAT routing.

3 is a block diagram showing in more detail the configuration of a remote access router 200 according to the present invention. As shown in FIG. 2, the remote access router 200 according to the present invention includes a processor 301 for performing an overall operation, a recording medium 303 in which a program for performing an overall operation, and the like are recorded. Memory 305 for storing the generated data, Computer connection port driver 307 for recording and changing the internal setting data by an external computer 203, and Global for transmitting and receiving Internet protocol signals with the global router 100b. Side LAN driver 309, and a local side LAN driver 311 for transmitting and receiving the Internet protocol signal with the local network router 100a.

The processor 301 for performing the overall operation is preferably a general purpose processor. According to one embodiment of the present invention, a 32-bit processor of Hyper Stone is used as a general purpose processor.

In the recording medium 303 in which a program or the like is recorded, a program for execution by the processor 301 is recorded. The recording medium 303 also records setting data necessary for the overall operation. According to a preferred embodiment of the present invention, a port number and a local IP address allocated for a device connected to a local network are recorded for each device. According to one embodiment of the present invention, as a recording medium 303, a ROM capable of recording again, for example, a flash ROM may be used. EEPROM may be used as the recording medium 303 in which a program or the like is recorded, and typically, an EEPROM having a product name of 28F001 may be used.

The computer connection port driver 307 is a port driver capable of transmitting and receiving data with an external computer. According to one embodiment of the present invention, an RS-232 driver capable of data transmission with a serial port of a computer is used. An RS-232 driver can be used as a part number 16C550.

The global LAN driver 309 and the local LAN driver 311 are drivers for transmitting and receiving data with the global router 100b and the local network hub 100a, respectively. According to one embodiment of the invention, a conventional LAN driver is used.

4 is a time series diagram illustrating the operation of the remote access router 200 according to an embodiment of the present invention. Referring to Fig. 4, the operation of the remote access router 200 will be described. According to one embodiment of the present invention, the following operation is preferably executed by the processor 301 after the program recorded in the recording medium 303 is uploaded to the memory 305.

Initial setting

The remote access router 200 performs an initial setup process (401).

The global fixed IP address is assigned to the remote access router 200. In the example shown in FIG. 4, the case where a fixed IP address of 211.205.85.230 is assigned to the remote access router will be described as an example. In order to access the local network 107 from the outside, the external computer 103 may refer to the static IP address 211.205.85.230 assigned to the remote access router 200. For example, the external remote computer 103 may determine whether the remote access router 200 can be accessed through the Internet through the command ping 211.205.85.230.

The remote access router 200 has information of a pre-assigned local network IP for each device connected to the local network. The local network IP address is uniquely assigned to each device in the local network. Local network IP address assignment information may be recorded to the remote access router 200 via the computer connection port driver 307 using the external computer 203.

According to a preferred embodiment of the present invention, the remote access router 200 may support both network address translation (NAT) and remote access (RA) in accordance with the present invention within the local network. In this case, a device to provide access by NAT is assigned a predetermined NAT routing address, for example, 192.168.128.128 to 192.168.128.254, and NAT routing to a device to provide remote access according to the present invention. Assign a remote access routing address that is distinct from the address, for example 192.168.128.2 to 192.168.128.127. According to an embodiment of the present invention, a device to provide access by NAT may automatically assign a NAT routing address by the DHCP protocol.

2, NAT routing is provided to the first computer 205a and the second computer 205b, 192.168.128.128 and 192.168.128.129 are assigned, and the printer 205c and the fax 205d are assigned. An example is provided where remote access routing is provided and 192.168.128.2 and 192.168.128.3 are assigned.

According to a preferred embodiment of the present invention, the remote access router 200 specifies a port number for an IP address assigned to a local network. For example, for a global network IP address with a local network IP address of 192.168.128.2, the local network IP address can be identified using the port number of the global IP.

Remote Access Routing Behavior

The remote computer 103 converts the fixed IP address assigned to the remote access router 200 and the IP of the device to be accessed in the local network into a port number and transmits it to the Internet. In the following description, the case where the remote computer 103 wants to connect to a predetermined device in the local network 107, for example, the fax 205d, will be described as an example.

At this time, the packet transmitted by the remote computer 103 includes a fixed IP address and a port number of the remote access router 200 as a destination address. For example, the remote computer 103 sends a predetermined packet with 211.205.85.230:32770 as the destination address.

The remote access router 200 receives a datagram or a packet including an IP address of a datagram or a packet transmitted from outside the local network, the IP address of which is the same as the fixed IP address previously assigned to the remote access router 200 as a destination. . The destination address, ie, port number 32770, is then referred to and translated into a local network IP address (405). According to a preferred embodiment of the present invention, both the port number and the local network IP address are selected from a finite set of numbers and addresses, both of which correspond one to one. This correspondence is recorded in the recording medium 303 or the memory 305 of the remote access router 200.

For example, if the datagram or packet sent by the remote computer 200 is set to 211.205.85.230:32770 as the destination address, the remote access router 200 replaces the destination address of the transmitted packet with the local network IP address. Convert to 192.168.128.2. According to one embodiment of the present invention, the conversion scheme converts 128 and 2 into port numbers in the manner of 128 x 256 + 2-32770 in 192.168.128.2.

Subsequently, the remote access router 200 routes the transmitted packet to the device to which the designated local network IP address is assigned through the conversion process. In the embodiment shown in Figure 2, the packet is routed to the fax 205d, which is assigned a local network IP address of 192.168.128.2.

The remote access router 200 also receives datagrams or packets sent by computers 205a and 205b or devices other than computers in the local network. The local network IP address, which is the source address of the datagram or packet, is then referred to and converted into an IP address including a global IP address and a predetermined port number. At this time, it is preferable that the predetermined port number is uniquely determined according to the local network IP address. The method of determining the port number according to the local network IP address is as described above. The remote access router 200 transmits the datagram or packet designated by the global IP address and the IP address including the predetermined port number to the destination address.

According to the present invention, it is possible to access a device in a local network via the Internet, to assign a single global fixed IP address to the local network, and to route a packet transmitted from the outside to a specific desired device among a plurality of devices in the local network. Can be. According to another embodiment of the present invention, it is also possible to assign a single global fixed IP address or dynamic IP address to the local network.

Accordingly, it is possible for a user to access a plurality of device devices in the local network by referring to only one fixed IP address using an external computer.

The present invention is particularly applicable to remote control using the Internet. That is, for a plurality of devices included in the local network, it is possible to effectively perform automation and remote management by overcoming the limitation of limited IP.

Claims (6)

Means for receiving from the Internet a datagram whose destination is specified by a global address comprising an Internet Protocol (IP) address and a port number, Means for translating the IP address and port number of the datagram into a unique local address within the local network, and Means for routing the received datagram to the local address Local access router comprising a. The method of claim 1, The local access router means for receiving from the Internet a datagram whose destination is specified by an Internet Protocol (IP) address, and Means for translating the IP address of the datagram into a unique local address within the local network Local access router, including more. The method of claim 1, The port number is one of a predetermined finite number of port numbers, the local address is one of a predetermined finite number of addresses, and the finite number of port numbers and the finite number of addresses correspond one-to-one. Local access router. The method of claim 1, And said means for converting said IP address and port number into a local address converts said address into a local address corresponding to said port number from a finite number of local addresses. Means for receiving from the local network a datagram whose destination is specified by an address comprising an Internet Protocol (IP) address and whose source is specified by a local address, Means for converting the local address of the datagram into a global address including an IP address and a port number assigned to the local network, and Means for transmitting the received datagram Local access router comprising a. The method of claim 1, The local access router Means for receiving from the local network a datagram whose destination is specified by an address comprising an Internet Protocol (IP) address and whose source is specified by a local address, and Means for converting the local address into a global address Local access router, including more.