KR100259695B1 - Method of managing lan gateway - Google Patents

Abstract

PURPOSE: A method for operating a LAN gateway of a satellite Internet network is provided to be connected to a LAN through IP packet changing of the LAN gateway assigned with a single IP address in a packet data transceiving process using a satellite, and to make each host not-assigned with IP addresses connect with an Internet network. CONSTITUTION: An IP(Internet Protocol) packet relating to a service request from an optional host is detected. The optional host is not assigned with an IP address in a LAN connected with a LAN gateway(20), which is assigned with an IP(Internet Protocol) address. If the IP packet is detected from the optional host, the LAN gateway(20) registers the IP packet in a map table, and changes a source IP address and a port number of the IP packet into a self IP address and a set virtual port number, then routes the changed IP address and the virtual port number to an Internet network(40). An IP packet received through a satellite(80) by being outputted from an optional server is restored to an IP packet of the registered host. The restored IP packet is transmitted to the service requesting host through the LAN.

Description

LAN Gateway Operation Method of Satellite Internet

The present invention relates to a satellite Internet communication method, and more particularly, is connected to a LAN network by changing an IP packet of a LAN gateway to which a single IP address is assigned in the transmission and reception of packet data using a satellite. The present invention relates to a LAN gateway operating method of a satellite Internet network in which a plurality of hosts, each of which is not assigned, can access an Internet network and transmit and receive IP packets.

In general, the Internet network, which is called the “sea” of information, is connected to many servers having its own IP address (internet protocol address), and various information is stored therein. In order to access the Internet network, each host must have their own IP address, so in the case of a host that does not receive an IP address assigned by a public authority, the host cannot access the Internet network. When each host is assigned an IP address, there is a problem in that a cost burden occurs.

Therefore, in the conventional Internet communication, a surrogate server is used to access the Internet network in which a plurality of hosts connected to the same LAN network using one computer connected to the Internet network do not perform additional equipment or software change. I am using (proxy sever).

The above method of implementing a surrogate server uses the SOCKS protocol, which is an Internet standard, and a socket relay method and server, in which a surrogate server gets connection information from a server on the Internet and makes it appear to be provided by its surrogate server. Application surrogate methods for preparing respective programs supporting specific application protocols (e.g. http, ftp, smtp…) are used.

In the case of the SOCKS protocol, an application using the transmission control protocol / internet protocol (TCP / IP), which is an Internet communication protocol, must support the SOCKS protocol, but there are not many applications that actually support the SOCKS protocol. If it does, the application does not need to support SOCKS, but there are few such operating systems.

In addition, in the case of the socket relay method, when a LAN network host executes an application, the corresponding socket is equally opened on the surrogate server and data to and from each other is provided to each other, which has different IP addresses. Since packet data of each server is transmitted, there is a problem in that it does not work according to the type of protocol.

In addition, in the case of the application proxy method, when a LAN network host makes a request for access to packet data to an arbitrary server on the Internet, the application proxy program accepts the request as if it is a server, and then the host designates an IP address. It sends a signal to the original server for a request to access data.

Thereafter, when the packet data requested by the host of the LAN network from the designated server is transmitted to the application agent program, the application agent program transmits the data to the host side of the LAN network that has requested access to the data according to the IP address specified in the packet data transmitted from the server.

In the case of the application proxy program as described above, a lot of overhead occurs, but the overhead can be reduced by implementing the program to reflect the characteristics of each protocol.

Especially, in case of http proxy, the http server's response to the request can be cached, so it is possible to respond quickly to the same request afterwards, but in this case, the hardware performance and capacity must be expanded. This is required and a problem arises that cannot be supported other than the programmed protocol.

The present invention has been made in view of the above-mentioned general problems. First of all, when packet transmission and reception occurs between a server connected to the Internet network and any host connected to the LAN network, an IP packet requesting access to an arbitrary server on the Internet network from any host is transferred to the default gateway ( It is applied to LAN gateway set as default gateway. Second, the source IP address of the IP packet of the host is converted into a single IP address assigned to the LAN gateway, and the source port of the IP packet is converted into a new port number that the LAN gateway can utilize. Sent to the server. Third, the source IP address and source port number of any host are set in a table in the LAN gateway when converted and sent. Fourth, the packet sent to the server is processed, and the resulting packet corresponding to the request is sent via satellite. Packets sent to the satellite are sent to the ground via the satellite. Fifth, all packets received by the terrestrial receivers are compared and analyzed with the host IP packet address set in the map table of the LAN gateway, and when the IP packet of the host requesting data access is detected, the IP address and port number of the received IP packet are serviced. It restores the IP packet of the host requesting connection and transmits it to the host through LAN. This way, hosts on the LAN can access the Internet without changing the host's hardware or software. You can also rule out protocol dependencies, which are problems with the surrogate server.

In addition, the present invention allows the IP packet for data access of a host connected to the LAN network and not assigned an IP address to be changed from a ISP to a single IP address of a LAN gateway to which a single address is assigned, thereby allowing the server to be used without registration. This allows the use of dedicated address spaces in RFC 1597 Recommendations that specify zones so that each host connected to the LAN can be assigned an IP address without the need for an ISP.

1 is a diagram illustrating a configuration of an internet communication network and a transmission flow of an IP packet according to the present invention;

FIG. 2 is a schematic diagram of a LAN gateway of the present invention in FIG.

3 is a schematic diagram illustrating management of an IP packet of a routing module in the LAN gateway of FIG.

4 (a) to (d) is an example of a packet configuration showing the transmission and reception of the IP packet through a single IP address allocation of the LAN gateway.

According to the present invention for achieving the above object, any host that is connected to the same LAN as a LAN gateway to which an IP address is assigned from an ISP, and that any host whose IP address is not assigned from an ISP, accesses a service from a server on the Internet network. Is required, the host may receive the requested packet from the corresponding server by transmitting the packet through the IP address change and restoration of the LAN gateway.

The present invention also provides a method of detecting an IP packet for a service request from an arbitrary host that has not been assigned an IP address to a LAN to which a LAN gateway to which an IP address has been assigned is connected;

When an IP packet is detected from any host, the LAN gateway registers the detected IP packet in the map table, and then changes the source IP address and port number of the IP packet to its own IP address and a set virtual port number. Routing to the Internet;

And restoring the IP packet outputted from any server designated through the routing to the IP packet of the registered host, and then transmitting the received IP packet to the host requesting a service through a LAN.

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

As can be seen in Figure 1, the configuration of the Internet communication network according to the present invention, a plurality of hosts (10a-10n), LAN gateway 20, router 30 (60), Internet network 40, a plurality of Server 50a-50n, uplink site 70, and satellite 80, where a plurality of hosts 10a-10n are connected to the same LAN and are not assigned an IP address from an ISP, When its own IP address is assigned and a packet access is desired from any server connected to the Internet, a packet service request is executed using its own IP address.

The LAN gateway 20 has a single IP address assigned to access the Internet network from an ISP and detects an IP packet for accessing an arbitrary server 50a-50n from an arbitrary host 10a-10n. In this case, the IP packet of the host 10a-10n is changed into its own IP packet, and the server 50a-50n designated by the host is connected to the server, and the port number corresponding to the connection request of the server is stored.

In addition, all IP packets received from the satellite 80 are compared with the IP address and port number set in the map table, and then the IP address and port number of the host corresponding to the destination IP address of the received IP packet are detected. When the received IP packet is restored to the IP packet of the detected host 10a-10n and transmitted to the corresponding host 10a-10n through the LAN.

The router 30 analyzes the destination IP address specified in the header of the IP packet authorized by the LAN gateway 20, and then transmits the IP packet applied to the router side of the designated path, and the router 60 sends an arbitrary server 50a-. 50n) analyzes the destination IP address specified in the header of the IP packet received through the Internet, and then transmits the authorized IP packet to the designated path.

The server 50a-50n is connected to the Internet network 30 with its IP address and various information. When the packet data is required to be accessed, the server 50a-50n reads the data, forms it as an IP packet, and transmits it to the router of the designated path. do.

The uplink site 70 converts an IP packet applied from the server 50a-50n through the relay of the router 60 into a digital video broadcast (DVB) packet of the TCP / IP protocol required for satellite communication. It transmits at the frequency of band.

As shown in FIG. 2, the LAN gateway 20 includes a satellite reception card 23 for receiving all packets received from the satellite 70 through the TCP / IP protocol through the antenna ANT2, and The IP address and port number set in the header of the received packet are analyzed with the IP address of the host set in the map table to detect the host's IP address and port number, and then to the IP address and port number of the host requesting packet access. A routing module 22 for restoring, and a LAN card 83 for processing the restored IP packet in a predetermined state and then outputting the packet to a corresponding host through a LAN.

As shown in FIG. 3, the management system of the IP packet of the routing module 22 is a network device layer connected to the LAN network, the Internet network, and the satellite reception card 23 to drive IP packets transmitted and received in a designated path. And an IP address processing layer for analyzing and processing an IP address specified in a header of an IP packet to be transmitted and received, a map table management layer for managing IP addresses and port numbers of each of the processed hosts, and an IP address of each of the processed hosts. And a map table that stores port numbers and information needed for management.

In the present invention having the functions described above, packet communication operations of a host and a server not assigned an IP address from an ISP will be described as follows.

For example, the LAN gateway 20, which is assigned a single IP address of "200, 200, 200, 1" from an ISP, is connected to the same LAN network to which it is connected, and has not been assigned an IP address from the ISP. A case in which an arbitrary host 10a having an IP address is intended to receive a service from an arbitrary server 50a having an IP address of "100, 100, 100, 100", for example, will be described below.

As shown in (a) of FIG. 4 of the server 50a in order for the host 10a to receive a service from the server 50a connected to the Internet network 40, the source IP address is " 200,200,200,200 ", source port number" 2000 ", destination IP address" 100,100,100,100 ", and destination port number" 80 "are formed and outputted, the default gateway (default gateway) output from the host 10a is a LAN gateway ( 20, the above IP packet is transmitted to the LAN gateway 20 side.

In the above, it is assumed that the port number of the host 10a is "2000".

At this time, the LAN gateway 20 having a single IP address assigned from the ISP can recognize the IP packet authorized from the host 10a through the LAN network in FIG. 4B through the routing module 22. As shown, the source IP address of "200,200,200,200" and the source port number of "2000" are changed to "200,200,200,1", which is the IP address of the LAN gateway 20, and the source port number is "3000". After changing to, the changed contents are stored in the map table through the map table management layer of FIG. 3.

It is assumed that the source port number which is not used among the port numbers set in the LAN gateway 20 is "3000".

In addition, since the header information of the IP packet for the server request has been changed, the network device layer and the IP address processing layer of FIG. 3 recalculate " checksum " of the IP packet header, and then calculate the calculated result as a packet " checksum " The IP packet is transmitted to the internet network 40 through the router 30 of the network.

As described above, the IP packet shown in FIG. 4B output from the LAN gateway 20 through the designation of the router 30 and the Internet network 40 is a server 50a designated by the host 10a at the time of service request. Is sent to the side.

At this time, the server 50a analyzes the received IP packet and then forms and transmits the result of the packet according to the requested service. Since the formed packet is in a state where the transceiver is changed, the server 50a may be configured as shown in FIG. As can be seen from c), the source IP address is set to "100, 100, 100, 100" which is the IP address of the server 50a, the port number of the source is set to "80" which is the port number of the server 50a, and the destination IP address is set. When a packet having the IP address "200, 200, 200, 1" of the LAN gateway 20 and a destination port number of "3000" is formed and outputted on the Internet network 40, the output packet is transmitted through the router 60. It is routed to the uplink site 70 side.

The uplink site 70 multiplexes the routed packets into DVB / MPEG packets needed for transmission to the satellites and then transmits them to the satellite 80 at the protocol frequency of TCP / IP.

At this time, the satellite reception card 23 of the LAN gateway 20 receives all the packets from the satellite 80 and then compares the IP addresses of the packets with the IP addresses registered in the map table of FIG. If it is determined that the IP address is changed by the service request of (10a), as shown in (d) of FIG. 4 through the map table management layer, the source IP address and the source port number are "100,100,100,100". &Quot; " and " 80 ", restore the destination IP address and destination port number to " 200, 200, 200, 200 " and " 2000 " and then transmit it to the host 10a that requested the service through the LAN network to enable the Internet service of the host 10a. do.

In the case of receiving a packet not registered in the map table among the packets received by the satellite 80, the received packet is ignored.

As described above, in the present invention, a host that is not assigned an IP address from an ISP is connected to the same LAN, and a desired service can be provided from an Internet server for any packet through a LAN gateway assigned an IP address from an ISP. Therefore, there is no dependency on the protocol, and it can be provided with the service from the desired server by simple processing, and efficient internet service is provided because the program of the host does not involve change.

In addition, it is possible to efficiently use the limited IP address of the Internet network to provide Internet services to more users, and to reduce the burden on the user due to the allocation of IP address is provided economical to use.

Claims (9)

In the satellite Internet communication method, a LAN gateway to which a single IP address is assigned from an ISP is connected to the same LAN, and any host whose IP address is not assigned from the ISP is required to access a service from a server of the Internet network. The LAN gateway operating method of the satellite Internet network, characterized in that the host can receive the requested packet from the server by transmitting the packet through the IP address change and restoration of the LAN gateway. The LAN gateway operating method of claim 1, wherein a virtual port number corresponding to a server connection on the Internet is automatically generated from a host connected to the same LAN network and set in a map table. The LAN gateway of claim 1, wherein the LAN gateway changes a source IP address of the packet to an IP address of the LAN gateway itself when an IP packet of a host for a service request is detected from a server of an Internet network at an arbitrary host. The LAN gateway operating method of the satellite Internet network, characterized in that to change the newly assigned port number and then register the IP of the host requesting the service in the map table and route the changed packet to the Internet network. The host of claim 1, wherein the host requesting the service by restoring the IP address of the packet received through the satellite according to the packet transmitted by the IP address change of the LAN gateway to the IP address of the host registered in the map table. LAN gateway operating method of a satellite Internet network characterized in that the transmission to the side. The method according to claim 1, wherein in changing the port number of the LAN gateway, the LAN gateway operating method of the satellite Internet network automatically generates a virtual port number that has not been used yet or can be reused after an effective time. The LAN gateway operating method of claim 1, wherein a plurality of hosts connected to the same LAN can simultaneously receive services from a server of the Internet network by changing an IP address and a port of the LAN gateway. The LAN gateway operating method of claim 1, wherein an IP address is set in each host connected to the LAN network regardless of an ISP. Detecting an IP packet for a service request from an arbitrary host that has not been assigned an IP address to a LAN to which a LAN gateway assigned an IP address is connected; When an IP packet is detected from any host, the LAN gateway registers the detected IP packet in the map table, and then changes the source IP address and port number of the IP packet to its own IP address and a set virtual port number. Routing to the Internet; And restoring the IP packet outputted from any server designated through the routing to the IP packet of the registered host, and transmitting the received IP packet to the host requesting the service through the LAN. LAN gateway operation method on the Internet. The LAN gateway of claim 8, in which all packets received from the satellite are compared with data set in its map table, and when the IP packet of the host requesting service is detected, only the packet is accepted and other packets are ignored. LAN gateway operation method of a satellite internet network.