KR20020038015A - Method and apparatus for automatically converting Proxy server IP address in PPP server - Google Patents

Abstract

PURPOSE: An automatic conversion method and a device for a proxy server IP address on a PPP(Point-to-Point Protocol) server are provided to receive a service by automatically connecting to a remote server without inputting an IP address and an HTTP(HyperText Transfer Protocol) port number of a proxy server to a browser. CONSTITUTION: The method comprises steps of a PPP subscriber(10) requesting a connection to the PPP server(20), requesting the HTTP including an URL(Uniform Resource Locator) address of the corresponding server after realizing the connection of a PPP subscriber, transmitting the data to the proxy server(30) after converting a destination IP address of an IP packet into the IP address of the proxy server, receiving the requested data by connecting to the corresponding server according to the transmitted data and transmitting the data to the PPP subscriber by receiving the data received from the server from the proxy server after converting the source IP address part into the remote server(40) IP address.

Description

Method and apparatus for automatically converting proxy server IP address in PPP server

The present invention relates to a proxy server IP address automatic translation system in a PPP server. More particularly, the PPP server automatically converts an IP (Internet Protocol) address and a Transmission Control Protocol (TCP) port number of a proxy server automatically. The present invention relates to a method and apparatus for automatically converting a proxy server IP address in a PPP server in which a subscriber does not need to input the proxy server's IP address and HTTP (HyperText Transfer Protocol) port number in communication.

In general, a proxy server is a special purpose server that operates on a firewall system of an Internet network. For each protocol in a client browser, for example, a web browser such as Netscape Navigator or Microsoft Explorer. If a proxy is specified, all subsequent requests will be processed by the proxy so that the subscriber can receive the necessary information.

More specifically, to describe a proxy server, a proxy server is a network server provided to allow users of a private network to indirectly access a public network. Private communication users can access or store public network information through a surrogate server to limit access to the public telecommunication network. There are two cases of using a proxy server. First, access control between an in-house network and the Internet is set so that only a user authorized in the company can use an Internet-specific service. The other is a cache function used to reduce traffic between the corporate network and the Internet.

The concept of the proxy server is that when a PPP server assigns a private IP to a PPP subscriber, the PPP subscriber connects to the PPP server and accesses a remote server through an Internet network, and the subscriber must designate a proxy server in a browser to receive the service. Only in this case.

In this case, the PPP server assigns a private IP to the PPP subscriber. In order for the PPP subscriber to access the PPP server and receive the Internet service, the presence of a proxy server is necessary. The PPP subscriber must use the browser's IP address. And the HTTP port number.

In more detail, as shown in FIG. 1, the PPP subscriber 10 accesses the PPP server 20 and is assigned a private IP address (S1), and the information about the proxy server 30 from the PPP server 20 is shown. When the IP address and HTTP port number of the proxy server are transmitted to the PPP subscriber 10 (S2), the PPP subscriber 10 inputs the proxy server's IP address and HTTP port number according to the transmitted proxy server information. After that, the URL (Uniform Resource Locater) of the remote server 40 to be visited is input (for example, http://www.mbc.co.kr) (S3), and the PPP server 20 sets a destination IP address. If the destination IP address is a proxy server, the data is transmitted to the proxy server 30 (S4).

The proxy server 30 connects to the remote server 40 requested by the subscriber (S5), receives the corresponding data, and the remote server 40 transmits the corresponding data to the proxy server 30 (S6).

The data transmitted to the proxy server 30 is again transmitted to the PPP server 20 (S7) and finally transmitted to the PPP subscriber 10 (S8).

The conventional method as described above has a problem in that the subscriber has to enter an IP address of a different proxy server every time a PPP connection is made.

Accordingly, an object of the present invention is to provide a method for automatically converting a proxy server IP address in a PPP server, which enables a PPP subscriber to automatically access a remote server without receiving the IP address and HTTP port number of the proxy server in a browser. There is this.

1 is a block diagram of a procedure until a conventional PPP subscriber is connected to a remote server;

2 is a block diagram of a procedure for automatically converting to a proxy IP address and accessing a remote server in a PPP server according to the present invention;

3 is a structural diagram of a data stream converted to a proxy IP address in a PPP server according to the present invention;

4 is a structural diagram of a proxy IP data stream transmitted from a PPP server to a PPP subscriber in accordance with the present invention.

Explanation of symbols on the main parts of the drawings

10: Point-to-Point Protocol (PPP) Subscriber

20: PPP Server

30: Proxy server

40: remote server (Content Provider)

In order to achieve the above object, the present invention includes the steps of the PPP subscriber requesting access to the PPP server; Making an access to the PPP subscriber and making an HTTP request including a URL address of the corresponding server; Transmitting data to the proxy server while converting the destination IP address of the IP packet into the IP address of the proxy server; Receiving the requested data by accessing the corresponding server according to the transmitted data; Receiving the information received from the server from the proxy server is characterized in that the step of transmitting to the PPP subscriber with the source IP address portion converted to the remote server IP address again.

In the step of transmitting data to the proxy server while converting the destination IP address of the IP packet into the IP address of the proxy server, the data of the IP packet is converted into a destination IP address portion of the IP address of the proxy server, and the destination IP address portion And a checksum data for.

In addition, in the step of receiving the information received from the corresponding server from the proxy server and converting the source IP address portion to the remote server IP address and transmitting the information to the PPP subscriber, the data of the IP packet is stored in the remote server (the corresponding IP address). Server) and configured to change the TCP head checksum and IP head checksum data.

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

2 is a block diagram of a procedure for automatically converting a PPP server to a proxy IP address and accessing a remote server according to the present invention. FIG. 3 is a data stream converted to a proxy IP address in a PPP server according to the present invention. Stream), and FIG. 4 is a schematic diagram of a proxy IP data stream transmitted from a PPP server to a PPP subscriber according to the present invention.

As shown in FIG. 2, when the PPP subscriber 10 accesses the PPP server 20 and is assigned a private IP address (S10), the PPP subscriber 10 URL (Uniform) of the remote server 40 to be visited. Resource Locater) (for example, http://www.mbc.co.kr) (S11).

At this time, the PPP server 20 converts the destination IP address into the IP address of the proxy server 30 and transmits it to the proxy server 30 (S12).

In this case, as shown in FIG. 3, the destination IP address is converted into the IP address of the proxy server 30, and a checksum of the destination IP address is checked.

When the IP packet thus converted is transmitted to the proxy server 30 (S12), the proxy server 30 requests the corresponding data from the remote server 40 (S13), and receives a response thereto (S14) to the PPP server. The transmission to 20 (S15).

The data stream thus transmitted is converted to the IP address of the remote server 40 in the source IP address portion of the IP packet in the PPP server 20 and the TCP head checksum and IP head checksum are changed as in the data stream shown in FIG. 4. do.

In this way, the finally converted IP packet and the corresponding data are transmitted to the PPP subscriber 10 (S16).

Therefore, the PPP subscriber can automatically access the remote server and receive the service without inputting the IP address and the HTTP port for the proxy server.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention described in the claims. Of course, such a change is of course within the scope of the present invention.

As described above, according to the present invention, since the PPP server converts the IP packet into the proxy server IP address from the PPP server to the proxy server, the PPP subscriber does not have to manually enter the proxy server IP address and HTTP port number in the subscriber browser. When connecting to a server that requires authentication, there is an additional effect such that surrogate authentication can be easily performed in the proxy server where the subscriber is directly authenticated, and the PPP subscriber can be restricted from accessing a specific server.

Claims (4)

Requesting a PPP subscriber to connect to the PPP server; Making an access to the PPP subscriber in the step and making an HTTP request including a URL address of the corresponding server; Transmitting data to a proxy server while converting a destination IP address of the IP packet into an IP address of a proxy server; Accessing a corresponding server according to the transmitted data and receiving requested data; Receiving information received from the corresponding server from a proxy server; Converting the source IP address portion back to the remote server IP address from the information received in the step; And transmitting to the PPP subscriber in the converted state to the remote server IP address. 2. The method of claim 1, wherein the step of transmitting data to the proxy server while converting the destination IP address of the IP packet into the IP address of the proxy server includes converting the destination IP address portion of the data of the IP packet into the IP address of the proxy server. And the checksum data for the destination IP address portion is changed. The method of claim 1, wherein the step of receiving the information received from the corresponding server from the proxy server and transmitting the source IP address portion to the remote server IP address and transmitting the information to the PPP subscriber is performed. And converting the TCP head checksum and the IP head checksum data to a part, wherein the portion is converted to the IP address of the remote server. Automatically proxy server IP address in the PPP server characterized in that the PPP server to automatically convert the IP address and HTTP port number of the remote server requested when the PPP subscriber is connected to the remote server to transmit to the PPP subscriber Converter.