KR100238420B1 - Control method of proxy server in tdx-10 isdn internet access switching system - Google Patents

Abstract

In order to overcome the limitation of the processing capacity of the Internet server, a proxy server is installed and operated in the existing Internet network, which has the advantage of reducing the response time of the requested information from the point of view of the Internet subscriber. The disadvantage is that traffic to the server acts as a new overhead.

In the present invention, the proxy server system is connected to the TDX-10 ISDN Internet access exchange system, which is developed for Internet traffic processing, and the proxy server is controlled by a subsystem in the Internet access exchange system to provide the information requested by the subscriber. In addition, when there is no information in the proxy server, the information is obtained from the remote server of the Internet service provider, stored in the proxy server, and provided to the subscriber. Accordingly, the present invention is more efficient in terms of speed because it uses resources of the switching system than the communication method to the proxy server through a local area network (LAN) or a modem in the existing Internet network.

Description

How to control proxy server in TDX-10 ISDN internet access exchange system

The present invention relates to a method for controlling a proxy server in a TDX-10 ISDN internet access exchange system.

Currently, the number of Internet users is exploding all over the world, and the demand of clients (Internet subscribers) accessing the Internet server is naturally increasing in the Internet network based on the client-server model. Therefore, it is necessary to expand the processing capacity of the Internet server such as bandwidth of the Internet network, processing time of the server, storage device, and the like to satisfy the increasing demand of subscribers. To solve this problem, it is necessary to expand the Internet network facilities or improve the processing capacity of the Internet server.

However, as the cost is increased, an alternative is needed to satisfy the needs of the Internet subscribers at low cost. In other words, by installing a proxy server on the Internet network and placing cache memory there, it can reduce the overall traffic on the Internet network and reduce the response time to the requests of the Internet subscribers. To be.

In general, a proxy server is a special purpose server that operates in a firewall system of an Internet network. The proxy server is a proxy server for each protocol in a client application (eg, a web browser: Netscape Navigator, MicroSoft Explorer). If specified, all subsequent requests will be processed by the proxy so that the subscriber can receive the necessary information. When a request for cached information comes from a remote server, a copy of the frequently accessed information is taken from a remote server and placed faster than disk or memory. The purpose is to increase efficiency by passing from the cache to the client. It also includes the ability to filter access to specific sites or information.

1 is a diagram illustrating a communication method between a subscriber and a proxy server in an existing Internet network.

If a proxy server is not set in an application program (eg, a web browser) on an Internet subscriber station, a request message is transmitted to the server through forwarding and routing, and a response message thereof is received. That is, the service is realized through the same procedure as the transmission process of the existing IP (Internet Protocol) datagram. If a proxy server is set, the service is realized through the following procedure.

When a request arrives 102 from the client 101, which is an Internet subscriber on the subnet, to the server management module in the proxy server 103, the server management module of the proxy server 103 performs a URL (Unified Resource Locator) in the request message information. The protocol specified in the key is used as a key to identify the application protocol requesting. The server management module retrieves 105 whether the requested information (generally the document) is stored in the local cache 104, and if the requested information is present, receives the 106 information of the cache and makes a request. The subscriber 101 transmits the message through the response message 107.

If the requested information does not exist, the remote server 108 corresponding to the application protocol requests the information 109, and the remote server 108 transmits the requested information to the proxy server 103 in response 110. do. The proxy server 103 receives information from the remote server 108 and stores 105 in the local cache 104, while transmitting it via a response message 107 to the client 101, the subscriber.

The above procedure describes only basic processing procedures. In addition, the proxy server function includes cache management functions such as maintaining the consistency of cache information and deleting cache information.

The pros and cons of using a proxy server are as follows.

The advantage is that response time for requests is significantly reduced because accessing information cached in the local proxy server is not routed directly to the remote server that is the destination of the incoming call. The overall Internet network load and Internet server load are reduced compared to the case where the route to the remote server is to be routed, and the client can obtain cached information even when the remote Internet server is not running.

Disadvantages include the addition of a new device called a proxy server system in addition to the existing system, and its management problems are raised, and cache operation problems (cache content matching, cache deletion problems, etc.) occur.

Therefore, the following technical issues on how to install a proxy server and operate a cache have been studied.

1) Keeping cache information consistent

There is a substantial difficulty in ensuring complete correspondence between the cache information of the proxy server and the cache information of the remote server. The information consistency maintenance problem of updating the cache information of the proxy server immediately by reflecting the change of information of the remote server can be realized by the following method.

-Time To Live (TTL) setting function

If the TTL value of the information stored in the proxy server's cache is valid for a certain time and the client's request for the information is expired, the information is sent back to the remote server. It's a way to come. Proper setting of the TTL value is an important issue. This method can be effectively applied to information that is updated at regular intervals, such as articles from newspapers or broadcasting stations. It is also the most widely used method because it is easy to implement.

-Client polling function

The client polls the remote server periodically to check whether the information stored in the proxy server's cache is valid. This method also matters how to set the polling period.

Invalidation protocol

Whenever the remote server changes its information, the proxy server notifies the proxy server that the cache information of the proxy server is invalid. Therefore, the remote server must know which proxy server has a copy of the information it provides.

2) Delete cache information

The proxy server's cache has a finite size, and when a request for information that does not exist in the cache comes from the client, the proxy server receives the information from the remote server, deletes one or more of the existing cache information, and sends a new one. You should save the information you received. In this case, it is a matter of what information to delete. First-In First-Out (FIFO), which deletes the oldest information first, Least-Recently Used (LRU), which first deletes the most recently used information, and LFU (Least, a deletion policy based on frequency of use). Policies such as Frequently Used are used.

In addition, the issue of when to execute such deletion policy should be solved. When deleting new information when it is received from a remote server, deleting it at regular intervals, or using a combination of both methods. Etc.

3) Multiple proxy server function

As the number of clients requesting information from the proxy server increases, bottlenecks arise in the connection to the proxy server. To solve this problem, there is a need to have several proxy servers and to link them together to share information with each other. However, the method of having multiple proxy servers includes multicasting functions, so that additional functions and procedures are increased, which may be inefficient.

As such, when a large number of Internet subscribers use a proxy server, the traffic volume to the proxy server increases, which causes problems in the overall efficiency of the Internet network. Because of the fast response time, the technology used could become a bottleneck.

In the present invention, instead of communication to a proxy server via a local area network (LAN) or a modem in an existing Internet network, an Internet subsystem developed to process Internet traffic in a public network switching system is used for controlling a proxy server. By doing so, the problem described above is solved.

The present invention connects a system to be operated as a proxy server to a TDX-10 ISDN internet access exchange system and performs a point-to-point protocol (PPP) connection procedure between the proxy server and a subscriber interface processor in the internet access exchange system to establish an internet call connection. In one state, the Internet access exchange system controls the proxy server to provide the subscriber with the desired information.

The subscriber interface processor establishes a call with the subscriber and the proxy server by a call setup procedure, requests information from the proxy server when the subscriber requests the information, and transmits the obtained information to the subscriber, and there is no information requested in the proxy server. In the city, by performing a call setup procedure with a remote server of the Internet service provider, obtaining the information from the remote server, storing it in the cache of the proxy server, and transmitting the newly stored information to the subscriber. Will be.

1 is a communication method between a subscriber and a proxy server in an existing Internet network

2 is a block diagram of a TDX-10 ISDN Internet access exchange system according to the present invention

3 is a block diagram of a proxy server control procedure in the TDX-10 ISDN Internet access exchange system according to the present invention;

4 is an exemplary diagram of a cache table managed by a proxy server according to the present invention.

<Explanation of symbols for main parts of drawing>

201: subscriber 202: proxy server

300: Internet Subsystem in TDX-10 ISDN Switching System

301: time switch 302: time switch processor

303: subscriber interface board 304: subscriber interface processor

305: interprocessor communication network 306: access signal processor

307: large-capacity communication network 308: trunk / routing interface board

309: Trunk / Routing Interface Processor

401: Internet Service Provider Router

402: remote server

2 is a block diagram of a TDX-10 ISDN Internet access exchange system.

The Internet subscriber processing subsystem (Internet subsystem) 300 receives an Internet service call connection request from an Integrated Service Digital Network (ISDN) subscriber 201 registered in the Internet data access service of the public network switching system. Perform call processing procedure to establish data transmission path between ISP (Internet Service Provider: ISP) 401 and assign IP address to calling subscriber by using Point-to-Point Protocol (PPP). Internet Protocol) Controls the transmission of datagrams. In the TDX-10 ISDN public network switching system, the Internet subsystem 300 for processing Internet traffic is mounted as one subsystem, and main components (processor and internal communication network) are as follows.

A plurality of subscribers 201 and a proxy server 202 are controlled by a time switch processor (TSP) 302 of the TDX-10 ISDN Internet subsystem 300, which is an Internet subscriber processing subsystem. 301, the time switch 301 is connected to a Subscriber Interface Board (SIF) 303 which is controlled by a Subscriber Interface Processor (SIP) 304, and the subscriber interface thereof. Board 303 is a trunk / under the control of the Trunk / Routing Interface Processor (TIP) (309) through a high-capacity inter-processor communication network (HIPCN) (307) It is connected to a Trunk / Rounting Interface Board (TIF) 308, the Time Switch Interface Processor (TSP) 302, the Subscriber Interface Processor (SIP) 304 and a phase. The trunk / routing interface processor (TIP) 309 is connected to an Inter-Processor Communication Network (IPCN) 305, and the Inter-Processor Network (IPCN) 305 is an Internet Call Processing Matched Switch Processor (ASP_INT). Access Switch Processor for Internet (306), the trunk / routing interface board 308 is connected to the router 401 of the external Internet service provider (ISP), the router 401 of the Internet service provider It is configured to connect to the remote server 402 through.

Here, the matched switch processor (ASP_INT) 306 for processing an internet call is a processor for processing an internet service call connection request and is responsible for setting up a call between an originating subscriber and an ISP through an ITU-T Q.931 signaling procedure. . Operation is initiated by an internet call attempt signal from the number translation block of the digital subscriber processing subsystem and becomes a counterpart of the originating subscriber call control block to perform a function corresponding to the called party call control block. It performs the function of allocating switch system switch information for the Internet subscriber interface and notifying the Internet subscriber interface processor. It is also the main processor in charge of overall control functions such as releasing switch resources of the switching system when a call is released.

In addition, the subscriber interface processor (SIP) 304 manages the switch information and the Internet address information for each Internet subscriber for the subscriber interface for the Internet service, and performs the function of substantially transmitting the IP datagram. Point-to-point (PPP) protocol, which is a two-layer protocol, is responsible for assigning Internet addresses to outgoing subscribers through access. After that, it transmits the IP datagram transmitted from the calling subscriber through the communication between the large processors.

The trunk / routing interface processor (TIP) 309 also connects to a trunk line (T1 / E1) management function connected to an Internet service provider (ISP) 401 and a large interprocessor communication network for transmitting IP datagrams. It is a processor that performs. Early in the implementation, the connection from the switching system to the router 401 of the Internet Service Provider (ISP) is connected to the line termination device (RS) via an RS-232C or V.35 cable via the switching system's serial interface. Service Unit: It is connected to DSU / HSM / CSU, and in line terminator, it is connected to line terminator and router of ISP side through dedicated line (4-wire cable).

In addition, the high-capacity interprocessor communication network (HIPCN) 307 is an interprocessor communication network having a high speed (400 Mbps) transmission rate, which is insufficient for processing Internet traffic with an inter_processor communication network (IPCN) of an existing public network switching system. Therefore, it is an interprocessor communication network for transmitting data, audio, video and the like at high speed by increasing the transmission speed.

In the present invention configured as described above, the proxy server 202 establishes a point-to-point (PPP) connection under the control of the subscriber interface processor 304 of the Internet subsystem 300, and after the call setup of the subscriber 201 is made, By requesting the information of the subscriber 201, the proxy server 202 establishes a transmission path with the proxy server 202 through the time switch 301 so that the proxy server 202 provides the information desired by the subscriber 201.

On the other hand, if the proxy server 202 does not have the desired information, it connects to the router 401 of the Internet service provider (ISP) through the large interprocessor communication network 307 and the trunk / routing interface board 308, and the Internet service. The subscriber 201 that obtains the desired information by setting a transmission path with the remote server 402 set up in the provider 401, the proxy server 202 stores itself, and requests the corresponding information again through the subscriber interface processor 304. Will be sent to.

3 is a block diagram of a proxy server control procedure in the TDX-10 ISDN Internet access exchange system.

First, connect the system that will act as a proxy server to the TDX-10 ISDN Internet Access Exchange system. The same procedure is used for connecting an Internet subscriber to a switching system. This means that proxy servers can also act as Internet subscribers. However, it is common to configure the Internet server so that only the server functions.

[1] After the physical connection between the proxy server 202 and the switching system is finished, the proxy server 202 is connected to the Internet subsystem 300 in the TDX-10 ISDN Internet Access Switching System via ITU-T Q.931 signaling. Set up the connection. The call connection request is sent from the subscriber via the ISDN digital link (64 Kbps) to the matching switch processor 306 (ASP), and the number translation processor (NTP) performs the number translation of the called party. As a result of the number translation, the Internet name is found. A time switch processor (TSP) 302 and a space switch processor (SSP) allocate time and space switch resources inside the TDX-10 ISDN switched system.

[2] As the result of the translation of the number, the Internet call is found, and an Internet Call Setup message is transmitted to the Internet subsystem 300 in the TDX-10 ISDN exchange system.

[3] An incoming procedure is performed to an internet call processing matched switch processor (ASP_INT) 306, which sends an Internet call setup request message to a subscriber interface processor (SIP) 304.

[4] The subscriber interface processor (SIP) 304 in the Internet subsystem 300 receives an Internet call setup request message and then uses a Point-to-Point Protocol (PPP) connection procedure (PPP) for sending and receiving Internet Protocol (IP) datagrams. Connection). During the PPP connection procedure, the subscriber is assigned an IP address to act as an Internet host.

When the PPP connection is terminated, IP datagrams can be transmitted and received between the proxy server 202 and the Internet subsystem 300. In a later step, the procedure for receiving an Internet subscriber 201 through the proxy server 202 will be described. The same signaling and procedures as the connection of the proxy server 202 are performed.

[5] A call connection request is sent from subscriber 201 through an ISDN digital link (64 Kbps or 128 kbps) to access signaling processor (ASP) of matching switch processor 306, and the number of called party in number translation processor (NTP). The translation is performed. As a result of the number translation, the Internet name is found. The time switch processor (TSP) 301 and the space switch processor (SSP) allocate time and space switch resources inside the TDX-10 ISDN switching system.

[6] As the result of the number translation, the Internet call is found, and an Internet Call Setup message is transmitted to the Internet subsystem 300 in the TDX-10 ISDN exchange system.

[7] An incoming procedure is performed to an internet call processing matched switch processor (ASP_INT) 306, which access signal processor 306 sends an Internet call setup request message to a subscriber interface processor (SIP) 304.

[8] The subscriber interface processor (SIP) 304 in the Internet subsystem 300 receives an Internet call setup request message and then performs a point-to-point protocol (PPP) connection procedure for transmitting and receiving Internet Protocol (IP) datagrams. do. During the PPP connection procedure, the subscriber 201 is assigned an IP address to operate as an Internet host.

[9] The subscriber 201 terminal, which has been assigned an IP address and is able to operate as an Internet host, requests a connection (HTTP Request) with the proxy server 202 if a proxy is set.

Upon receiving the connection request with the proxy server 202, the subscriber interface processor (SIP) 304 establishes a physical connection to the proxy server 202 and transmits an information request message (HTTP Request).

[11] The proxy server 202 receiving the information request message checks its own cache table shown in Fig. 4 and if the requested information exists,

The information is transmitted to the Internet subscriber 201 via the subscriber interface processor (SIP) 304.

The subscriber interface processor (SIP) 304 transmits the information received from the proxy server 202 to the subscriber 201 through the type switch 301.

[14] If the requested information does not exist in its cache table, the proxy server 202 should receive the information through the information request procedure to the remote server 402. First, it is necessary to confirm which protocol the information requested from the subscriber 201 is for. The remote server 402 is connected by the protocol specified in the URL (Unified Resource Locator) of the received HTTP request message. However, even when the client connects to the remote server using a protocol other than HTTP (Hyper Text Transfer Protocol), the proxy server 202 transmits the request message in an HTTP transaction.

The proxy server 202 determines the protocol and transmits an information request message to the subscriber interface processor 304.

[0016] The subscriber interface processor 304 transmits an information request message to a trunk interface processor (TIP) 309, which is a connection point with an external network, for a request for information to the remote server 402. To be routed.

[17] The router 401 of the Internet Service Provider (ISP) that has received a request for information from the TDX-10 ISDN Internet system 300 uses a communication protocol with an existing server.

[18] Obtain the requested information from the remote server 402.

[19] Appropriate information corresponding to the request of the subscriber 201 from the remote server 402, through the Internet service provider (ISP) router 401,

[20] via a trunk / routing interface processor (TIP) 309 in the TDX-10 ISDN internet subsystem 300,

Receives up to subscriber interface processor (SIP) 304 [21].

The subscriber interface processor 304 transmits the new information received from the remote server 402 to the proxy server 202.

The proxy server 402 stores new information received from the subscriber interface processor 304 in its cache table.

The information is transmitted to the subscriber interface processor 304 for delivery to the Internet subscriber 201.

The subscriber interface processor 304 transmits the information to the internet subscriber 201. If the same information is later requested by the subscriber, the information stored in the cache table can be provided immediately.

4 is a configuration example of a cache table managed by a proxy server.

When the proxy server 202 receives a proxy request message (HTTP Request) from the Internet subscriber 201, the proxy server 202 refers to the cache table to check whether the requested information is stored in the cache. If the requested information exists, it is sent to the Internet subscriber 201 in response. If the requested information is not stored, the request message is routed to the remote server 402. In this case, the cache table used by the existing proxy server is used as it is.

4 is a newly proposed cache table, and the cache table may be configured and used. The contents of the cache table are used to manage the information (file) name [501], which is a key to refer to the requested information, the IP address of the remote server where the information is located [502], and the cached information. Time To Live of the information used (504), Access Frequency (505) indicating how much of the information has been accessed by Internet subscribers, and the latest access time indicating when the information was accessed. (Recent Access Time) [506]. In addition, a memory address [503], which stores information, is included to respond to the information.

In the example of the cache table of FIG. 4, a remote server having an IP address of "123.222.101.10" receives information (file) of "kif-or.html" and stores it in the cache, and this information is stored in the cache memory address address "03F0. ~ 03F5 "is stored. And the survival time of this information (file) is "3,600" second (sec), and when this time is over, this information is deleted. In addition, all of this information (file) has been accessed by "7" Internet subscribers, and the most recently accessed date is "1:25 pm on June 6, 1997."

By connecting the proxy server using the TDX-10 ISDN digital line, it can not only improve the speed over the LAN or modem connection method in the existing Internet network, but also ensure reliable transmission, and proxy through the existing LAN or modem. In the server access method, the amount of traffic acting as an overhead can be sufficiently overcome in the present invention. In addition, we presented the control method of public network switching system when accessing proxy server, so other Internet servers such as mail server, mirror server, file transfer server, etc. It can also be used to connect to a switching system.

Claims (4)

The system to be operated as a proxy server is connected to the TDX-10 ISDN Internet access exchange system in the same manner as the Internet subscriber, and the proxy server is controlled by the Internet subsystem in the Internet access exchange system to provide the information requested by the subscriber. , a) an internet call connection step in which the proxy server and the subscriber each perform a point-to-point protocol (PPP) connection procedure with a subscriber interface processor in the internet access exchange system; b) the subscriber interface processor requests information from the proxy server according to the information request message of the subscriber, and if the requested information exists in the cache of the proxy server, transmit the information to the subscriber via the subscriber interface processor. To do that, c) if there is no information requested in the cache of the proxy server, requesting the information via the subscriber interface processor to a remote server of an internet service provider; d) the subscriber interface processor transmits the information obtained from the remote server to the proxy server to store the new information in the cache of the proxy server and transmits the stored information to the subscriber via the subscriber interface processor. The control method of the proxy server in the TDX-10 ISDN Internet access exchange system, characterized in that the steps to perform. The method of claim 1, wherein step c) If the requested information does not exist in its cache table, the proxy server uses the URL (Unified Resource Locator) information of the HTTP request message received from the subscriber to determine which protocol the requested information is for. key) to distinguish the protocol, The proxy server determines the protocol and sends an information request message to the subscriber interface processor to the remote server, The subscriber interface processor transmits an information request message to a trunk / routing interface processor (TIP), which is a connection point with an external network, for requesting information to a remote server, thereby routing to the remote server through a router of an internet service provider. A method for controlling a proxy server in a TDX-10 ISDN internet access exchange system. The method of claim 1, wherein the d) step, The router of the Internet Service Provider (ISP) receiving the information request from the TDX-10 ISDN Internet system obtains the appropriate information corresponding to the subscriber's request from the remote server by using the communication protocol with the existing server. When sent to a trunk / routing interface processor (TIP) within the TDX-10 ISDN Internet subsystem, The subscriber interface processor (SIP) receives information from a remote server received via the trunk / routing interface processor (TIP), The subscriber interface processor sends the proxy server new information received from the remote server, The proxy server stores the received new information in its cache table and then sends the information to the subscriber interface processor for delivery to the subscriber, The subscriber interface processor transmits the corresponding information to the subscriber who requested the information. The control method of a proxy server in a TDX-10 ISDN internet access exchange system. The method of claim 1, wherein the proxy server, An information (file) name that becomes a key for referring to the requested information, The Internet Protocol (IP) address of the remote server, the location of the information, An information (file) location, which is a memory address where information is actually stored, to respond to the information, The survival time (TTL) of the information used to manage the cached information, The frequency of access, which indicates how much of the information was accessed by Internet subscribers, Having a cache table of the last access time indicating when the information was accessed, The proxy server manages the cache table to find out whether there is required information, updates the contents of the cache table, and stores cache table information for the new information when storing new information. Control method of proxy server in ISDN internet access exchange system.

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