SE522316C2 - Procedure and system for intermediate storage of information in a communication system - Google Patents

Abstract

Procedure and communications system to buffer information in a communications system, with a system design which is in accordance with, or is similar to, WWW (World Wide Web), at which a proxy server buffers information or files for further distribution to user 1, at which the information is buffered in a structured way on several levels, at which access time is reduced and that double storing of information is avoided. Communications system including computer equipment located at a user's 1, which communicates via his/her computer by an open computer network, and intends to collect information from one or more computers which are connected to the open computer network, at which the information which is collected to the own computer first is buffered in a special computer, or server, at which the buffering is done in a number of in the communications network existing servers, or computers, depending on the type of information which is collected from the open computer network.

Description

other» 10 15 20 25 30 522 316 The protocol used when WWW documents are sent over the internet is called HTTP - Hypertext Transfer Protocol.

The server program that handles document distribution is called httpd - the HTTP daemon, in UNIX parlance. The httpd program is constantly listening for HTTP requests from the network, ready to deliver documents to clients. When it receives a request for a document, it checks that the request is legitimate, that the file exists, and then sends the document to the client's IP address.

The WWW server's functions can be summarized as follows and are shown in Figure 1: 0 Retrieve and return HTML documents to client programs 0 Translate URLs to the server's file system (mapping) 1 Send information about the type, date and size of files according to MIME (typing) 0 Generate and send graphic file directories with README files 0 Send users' HTML pages via /~username/ 0 Redirect HTTP requests to other WWW servers (redirection) 0 Keep a log file with data about which computers requested which documents 0 Start external programs to retrieve data and generate dynamic documents 0 Include external files in HTML documents (server side includes, end. NCSA) 0 Act as a proxy server and cache files. 10 l5 20 25 30 Technical problem.

A WWW server that works as a so-called proxy server (usually) receives HTTP requests from clients on a local network and forwards them to the external final destination. When the documents are then delivered from the network, the proxy server receives the document, temporarily stores it in its cache and finally sends it over to the client program. This will be done for all HTTP requests for the client programs that have set up the server as their proxy server.

A proxy server is usually run on a so-called firewall computer that acts as a barrier between a local network and the Internet.

The temporary storage of documents in the server's cache has the good effect that many documents can be retrieved directly from the server's cache without the external network having to be loaded.

However, this storage methodology is not as well thought out and effective since the system is only to a limited extent adapted for simpler terminals and lower bandwidths, such as when transferring information via modem or ISDN.

Technical solution The technical solution is described in what is stated in the patent claims.

Benefits.

The present invention improves communication between a user and the open data network Internet, especially when the transmission takes place via smaller bandwidths, such as when using a modem or ISDN.

By dividing images and web pages into their components (i.e. text, audio and video) which are then stored on different proxy servers in the system, better use is made of the available storage space than with today's proxy system with only one level (equivalent to Access Proxy).

List of figures Fig. 1 shows a known principle solution for WWW.

Fig. 2 shows a part of a network architecture according to the invention. Detailed description.

To facilitate the understanding of the present invention, an explanation of the abbreviations used is given. 15 HTML HyperText Markup Language. The "language" used, and which Netscape interprets, when making a web page, for layout and links. Almost all addresses to web pages end in ".html". If you want to see what the HTML code looks like, you bring up a web page and select 20 "View Source" or "Document Source" under the "View" menu in Netscape, the code will appear. Everything inside the "<" and ">" brackets is HTML code.

) HTTP HyperText Transfer Protocol. A 25 transfer protocol used when two computers send hypertext documents (documents.html) between them. :anno 3*\ 30 IP Internet Protocol. One of the protocols on which the Internet is based. c Q n 1 Q v o on IP address, IP number A numerical address to a computer on an IP network (e.g. the Internet). IP addresses have the form 5 nnn.nnn.nnn.nnn, i.e. four groups of one to three integers, separated by periods.

Gif, .gif ) Graphical Interchange Format. An image format, or rather a way of compressing images. 10 Java ) A programming language used to enhance the interactivity of a web page. In practice, it works so that when the user enters a page with Java, the small program is downloaded 15 to his computer, and executed by the browser, that is, run by Netscape.

MIME Multipurpose Internet Mail Extension. A standard for, among other things, the transfer of attachments in e-mail. MIME also makes it possible to send Swedish/national characters (à,ä,ö) in e-mail without them being garbled.

World Wide Web. "The world wide web". The ) server system on the Internet that contains information 25 and services which are linked together using hypertext documents The invention is based on the use of proxy servers in several levels where information is cached in a structured manner 30 so that access time is shortened while double storage of information is avoided. w...- u.~» av» a-Q. .v- s >.. -.. 10 15 20 25 30 522 316 23:11; Figure 2 shows a network architecture for efficient cache in the World Wide Web according to the invention. The figure shows schematically the division of the cache into different proxy levels and the names of the different cache locations (proxy) where cached takes place and which are described in the following.

The invention is described in an embodiment where up to three proxy steps exist between client and original web server.

If a user who intends to use the Internet uses a limited number of terminals (computers), in most cases the Access Proxy and Home Proxy will be the same Server.

The procedure for temporarily storing information is based on users authenticating themselves in order to be offered advanced and personalized services.

At the first level, the user is authenticated and connected to the respective home proxy. This is done through the functionality found in an Access Proxy. This is done either integrated with the IP network authentication (e.g. in a modem pool) or via a separate JAVA mechanism in the Access Proxy.

Once a user has authenticated via login, they can use all services and resources to which they have permission. This is ensured by the proxy servers utilizing a common database for information about users and logins.

The second-level proxy functions ensure a quality of service (QOS) level that is tailored to the user's system by reducing file sizes to the user's available bandwidth and hardware.

By distributing the files on different servers in a structured way, through the functionality found in vv.- «.-' -.w _.. u-. nu.. »- .- > uw. ~._ 10 15 20 25 30 522 316 .sauc- . 0 o n on.- homeproxy, double storage is avoided. The second level includes Home Proxy, Mime Proxy, Site Proxy and Push Tuner.

The Home Proxy is located on a physical server that the system has identified as optimal for a particular user. A user who normally connects from the same geographical location will be assigned the closest server for the Home Proxy by the system. If a user changes their access pattern (e.g. when traveling or permanently moving), the system will change the assignment of the Home Proxy for this user after a certain period of time. For most accesses, the Home Proxy will therefore be the same server as the Access Proxy.

Because each user always uses the same Home Proxy, this server's cache will often contain the requested "hit rate" for the cache function in Home web material, i.e.

Proxy gets high.

The Home Proxy chooses for each HTTP access whether the material should be retrieved directly from the original web server, retrieved via specialized MIME Proxy or Site Proxy. In this way, the Home Proxy controls other proxy levels. Similarly, designated Site Proxy provides a mechanism for efficiently storing information belonging to popular information providers, without users having to choose between so-called "mirror sites".

To further save bandwidth, Home Proxy has functionality to compress the information if it knows that the terminal is capable of decompression. Similarly, Home Proxy takes care of decompressing compressed information in formats that the terminal does not know.

Certain web material needs to be adapted for different bandwidths, different types of terminals or according to the user's wishes.

Examples of this are graphic material (e.g. MIME types 1 advertisement: image/gif and image/jpeg), whose bandwidth requirements are greatly reduced by reducing the resolution in terms of color and pixels. In the same way, presentation elements such as video are adapted to otherwise insufficient bandwidths and terminals.

Because MIME Proxy is specialized in handling specific MIME types, it is equipped with special software or hardware to adapt to this particular information type without major delays. Scalability for these MIME types is an important part of offering customized Quality of Service (QOS).

In the system, all Home Proxies know which MIME Proxies handle each MIME type.

Some places on the World Wide Web are more popular than others.

By having certain proxy servers responsible for caching information from a particular name domain (e.g. ibm.com) that is not handled by the MIME proxy, such as software or text, better storage efficiency is achieved than if all proxy servers cache this information.

A Home Proxy knows which Site Proxy handles different name domains. By knowing which proxy server(s) cache information from a particular name domain, it is possible to perform programmed updates of the material, using the so-called PUSH technique.

The third level is the public Internet. This level is used if the desired information is not in the system or if an update has been made on the original web server. Owners of popular websites can offer information channels through which updates are sent out regularly (many times per day). In this way it is avoided that a-.un v I noovuo 10 l5 20 25 30 522 316 s o o c a u a u. all readers must go to the original web server to get the most updated information. A so-called Push Tuner is used to fill a Site Proxy with updated information.

The invention is limited only to what is stated in the patent claims so that the inventive concept is applicable to all types of intermediate storage methods that are implemented in a communication network.

Claims (3)

10 15 20 25 30 522 316 70 Patent claims 1. l. Method for temporarily storing information in a communication system, with a system structure that corresponds to or resembles WWW (Word Wide Web) whereby a proxy server temporarily stores information or files for further distribution to users(l) characterised in that the information is temporarily stored in a structured manner on several levels whereby access time is reduced and double storage of information is avoided, that the temporary storage takes place in 3 levels whereby the first level handles authentication of users and connection to the intended home proxy and the second level contains proxy functions which ensure a QoS which is adapted to the user's system by reducing the information to the user's available bandwidth and hardware whereby the third level is the public Internet, that the home proxy distributes the files or information on different servers, that the information consists of web pages which are divided into their components i.e. text, image, audio and video, that the different components are stored in different proxy servers in the system. 2. Communication system comprising computer equipment located at a user(s) who communicates via his/her computer with an open data network and intends to retrieve information from one or more computers connected to the open data network, whereby the information retrieved to the user's computer is first temporarily stored in a special computer or server, characterised in that the temporary storage takes place at a number of servers or computers located in the communication network depending on the type of information retrieved from the open data network, that the information retrieved from the open data network 10 522 316 ff consists of web pages which are stored at different temporary storage locations or proxy servers depending on the type of information the web pages represent, the information on the web pages consists of the various components text, image, audio, video. 3. A communication system according to claim 2, characterized in that the servers for intermediate storage are located at three levels where the user only has direct contact with a first intermediate storage server at a first level and the server that provides information to the user located at a third level has direct contact with all servers at a second level among the intermediate storage servers.