LV12519B

LV12519B - Internet caching system

Info

Publication number: LV12519B
Application number: LVP-00-10A
Authority: LV
Inventors: Sverker Lindbo
Original assignee: Mirror Image Internet Inc
Priority date: 1997-07-24
Filing date: 2000-01-24
Publication date: 2000-11-20
Also published as: CN1269896A; NO20000317D0; PL338416A1; SE9702795D0; WO1999005584A2; SE510048C2; EE200000045A; LV12519A; BR9815556A; NO20000317L; LT2000006A; JP2001511551A; KR20010052054A; SE9702795L; EP0996879A1; HUP0002834A2; IL134195A0; AU734154B2; SI20229A; CA2297658A1

Abstract

The present invention relates to a method, a system and a server for caching Internet information content. According to the invention, there is provided a set of geographically distributed cache servers generally serving different geographical regions, wherein Internet information derived in relation to the operation of one of said cache servers is distributed to essentially all of said servers.

Description

Technical field of inventionTechnical field of invention

The present invention relates to a method, a system and a server for caching Internet Information content.The present invention relates to a method, a system, and a server for caching Internet Information content.

Background to the invention and Prior ArtBackground to the Invention and Prior Art

Over the last few years, Internet has developed into the fastest growing means of communication and is predicted to be the main system for distributing Information in the future. The Internet has become increasingly popular and the number of users is growing at a magnificent rāte. Anybody can provide any Information - text, pieturēs, audio and video - on the net where it can be retrieved by users anywhere in the world. This makes for the ineredible success of the Internet and its currently most used feature, the World Wide Web, WWW.Over the last few years, the Internet has developed into the fastest growing means of communication and is predicted to be the main system for distributing information in the future. The Internet has become increasingly popular and the number of users is growing at a magnificent level. Anybody can provide any information - text, stops, audio and video - on the net where it can be retrieved by users anywhere in the world. This makes for the ineredible success of the Internet and its currently most used feature, the World Wide Web, WWW.

However, the popularity of the Internet, and especially the use of the Internet application World Wide Web, is putting the net under enormous capacity pressure. Traffic on the Internet doubles about every three months, with no signs of slowing down. This kind of exponential growth will eventually slow down, but several factors indicate that it is stili far from any slowdown in growth.However, the popularity of the Internet, and especially the use of the Internet application on the World Wide Web, is putting the net under enormous capacity pressure. Traffic on the Internet doubles about every three months, with no signs of slowing down. This kind of exponential growth will eventually slow down, but several factors indicate that it is a style far from any slowdown in growth.

Today, only a small fraction of ali PCs have access to the Internet. It is believed that most of those who have made and will make the investment in a PC will eventually want access to the Internet. Furthermore, communication speeds between the user and the Internet infrastrueture is inereasing rapidly. Technologies such as ISDN, Cable TV modems and xDSL are emerging. Moreover, manufaetures of household electronics are launching low costs devices to give Internet World Wide Web access through television sets.Today, only a small fraction of all PCs have access to the Internet. It is believed that most of those who have made and will make the investment in a PC will eventually want to access the Internet. Furthermore, communication speeds between the user and the Internet infrastrueture are inereasing rapidly. Technologies such as ISDN, Cable TV modems and xDSL are emerging. In addition, manufaetures of household electronics are launching low cost devices to give the Internet a world wide web access through television sets.

These and other factors are ali contributing in making it increasingly difficult to access information on the Internet, since the system is basically being overloaded. In many parts of the world, the lack of suffi5 cient bandwidth is a major probiem. Also, the passing information between USA and Europe is limited by the transmission capacity of the transatlantic link. The transmission capacity is simply too small to cope vvith the exploding Internet use.These and other factors are contributing to making it increasingly difficult to access information on the Internet since the system is basically being overloaded. In many parts of the world, the lack of suffi5 cient bandwidth is a major probiem. Also, the passing information between the US and Europe is limited by the transmission capacity of the transatlantic link. The transmission capacity is simply too small to cope vvith the exploding internet use.

Basically, there exists two conventional Solutions to this probiem. A first solution is to add more bandwidth and svvitching capacity, vvhich is being done, but vvhich carries huge costs and also faces significant technical problems.Basically, there are two conventional solutions to this probiem. The first solution is to add more bandwidth and svvitching capacity, vvhich is being done, but vvhich carries huge costs and also faces significant technical problems.

A second solution is to use so called caching techniques. Caching basically means to keep track of the Internet traffic and to keep copies of the most frequently accessed World Wide Web files at a location closer to the user than the original files. This hence involve the storing of a local copy of a World Wide Web Site of interest. For example, a copy of CNN's USA-based homepage may be temporarily stored in a cache at a European proxy location, whereby European Internet users may access the CNN homepage vvithout having to use the trans25 atlantic .communication JLink, thereby both attaining quicker access and at the same time lovvering the load on the net. The total World Wide Web information content itself is getting to be unmeasurable, but only a relatively small subset of ali this information accounts for a huge proportion of what is actually vievved. Depending on the size and homogeneity of a user community, about 10-20 Gigabytes of cache storage vvill (spring 1997) reduce the traffic by 30-50% in that community.The second solution is to use so called caching techniques. Caching basically means to keep track of Internet traffic and to keep copies of the most frequently accessed World Wide Web files at a location closer to the user than the original files. This hence involves storing of a local copy of a World Wide Web Site of interest. For example, a copy of CNN's US-based homepage may be temporarily stored in a cache at a European proxy location, whereby European Internet users may access the CNN homepage by using the trans25 atlantic .communication JLink, thus both attaining quicker access and at the same time loving the load on the net. The total World Wide Web information content itself is getting to be unmeasurable, but only a relatively small subset of this information accounts for a huge proportion of what is actually consumed. Depending on size and homogeneity of a user community, about 10-20 Gigabytes of cache storage vvill (spring 1997) reduce traffic by 30-50% in that community.

Hovvever, in spite of current caching techniques, in many parts of the vvorld, such as South and East Europe, South America, India and East Asia, the bandvvidth capacity of the available communication systems are far too low to provide a desired usability of the Internet.Hovvever, in spite of current caching techniques, in many parts of the vvorld such as South and East Europe, South America, India and East Asia, the bandwidth of available communication systems is far too low to provide the desired usability of Internet.

Summary of the inventionSummary of the invention

The object of the invention to reduce the capacity constraints on the Internet by providing a caching solution which reduces access time on the Internet and which allows growth to a significantly larger amount of users and Information traffic on the Internet, especially in areas where the bandwidth capacity are low.The object of the invention is to reduce the capacity constraints on the Internet by providing a caching solution which requires access to the Internet and which allows for a significant increase in users and information traffic on the Internet, especially in areas where the bandwidth is available are low.

According to the present invention, said object is achieved by a method, a system and a server for caching Internet Information content according to the appended claims.According to the present invention, the object has been achieved by a method, a system and a server for caching Internet Information content according to the appended claims.

The invention is based upon the insight that a linguistically and culturally homogenous geographical area often differ in size and shape from the economically and technically optimal region to be served by a single cache server. Therefore, such an area is served by a set of geographically distributed servers. However, the invention is further based upon the insight that, under the assumption that users in such a linguistically and culturally homogenous geographical area will have homogenous preferences regarding visited Information sites, Information cached in one such server due to a user request should also be cached in the other servers within said area, the basie principle being that if one user is interested in a certain piece of Information, it is likely that so will other persons within the same linguistically and culturally homogenous geographical area. The larger the end user community, the larger the probability that someone else within the community has requested any given file.The invention is based upon the insight that a linguistically and culturally homogeneous geographical area often differs in size and shape from the economically and technically optimal region to be served by a single cache server. Therefore, such an area is served by a set of geographically distributed servers. However, the invention is further based upon the insight that, under the assumption that users in such a linguistically and culturally homogeneous geographical area will have homogeneous preferences regarding visited information sites, Information cached in one such server due to a user request should also be cached in the other servers within the said area, the basic principle being that one user is interested in a certain piece of information, it is likely that other persons within the same linguistically and culturally homogenous geographical area. The larger the end user community, the greater the probability that someone else within the community has requested any given file.

Hence, according to the invention, a set of geographically distributed cache servers serving different geographical reģions but having a common relation, such as the relation of serving a culturally and/or linguisti4 cally defined user group or area, is updated with essentially the same information whenever one of said cache servers retrieves information due to an information request from an end user or the like.Hence, according to the invention, a set of geographically distributed cache servers serving a different geographical region, but having a common relation such as the culturally and / or linguisti4 cally defined user group or area, is updated with substantially the same information whenever one of said cache servers retrieves information due to an information request from an end user or the like.

Such cultural and linguistical homogeneity may be defined by the boundaries of a nation, the boundaries of a specific language, the boundaries of a specific religion, the boundaries of a certain Ievel of technology or development, the boundaries of a certain economical area, as well as combinations thereof, or the like.Such cultural and linguistic homogeneity may be defined by the boundaries of a nation, the boundaries of a specific language, the boundaries of a particular religion, the boundaries of a particular economical area, as well as combinations paragraph, or the like.

Hence, according to an embodiment of the invention, said set of geographically distributed cache servers are distributed within a linguistically and culturally defined global geographical area or a geographically defined community. Furthermore, each of said cache servers is preferably arranged to serve a respective local region within said geographical area or community.Hence, according to an embodiment of the invention, said set of geographically distributed cache servers are distributed within a linguistically and culturally defined global geographical area or a geographically defined community. Additionally, each of the cache servers is preferably arranged to serve the corresponding local region within the geographical area or community.

For example, the German speaking parts of Germany, Austria, Switzerland and Italy may be seen as defining a cultural and linguistically homogenous global area. Therefore a set of cache servers operating according to the invention is distributed within this area. Among this set of servers, provided within the global area defined above, one (or more) may is for example arranged to serve a first region covering the northern part of Germany, a second one (or more) to serve a second region covering the eastern part of Germany, a third one (or more) to serve a third region covering the central part of Germany, a fourth one (or more) to serve a fourth region covering Switzerland and the northern part of Italy, and finally a fifth one (or more) to serve a fifth region covering Austria.For example, the German speaking parts of Germany, Austria, Switzerland and Italy may be seen as defining a cultural and linguistically homogenous global area. Therefore, a set of cache servers operating according to the invention is distributed within this area. Among this set of servers provided within the global area defined above, one (or more) may be provided to serve the first region covering the northern part of Germany, the second one (or more) to serve the second region covering the eastern part of Germany, the third one (or more) to serve the third region covering the central part of Germany, the fourth one (or more) to serve the fourth region covering Switzerland, and finally the fifth one (or more) to serve a fifth region covering Austria.

Note that a defined geographical area according to the invention does not necessarily imply a homogenous, continuos area encompassed by a closed boundary, but may just as well mean a set of geographically separated sub5 areas together defining an area according to the invention .Note that a defined geographical area according to the invention is not necessarily imply a homogeneous, continuos area encompassed by a closed boundary, but may just mean a set of geographically separated sub5 areas together defining an area according to the invention.

According to estimations made by the inventor, in some parts of the world, such as India and South America, the bandwidth capacity of the telecommunication network is so small, that it is actually more efficient to distribute a specific package of information to ali cache servers within the defined global area based upon just one information request to the net from one single user, than to have another user search the net for the same package of information a second time. However, rules for determining when to perform distributed caching according to the invention or not, may be set in different ways depending on the actual application environment, as will be discussed below.According to estimations made by the inventory, in some parts of the world, such as India and South America, the bandwidth capacity of the telecommunication network is so small that it is actually more efficient to distribute a specific package of information to the ali cache servers within a defined global area based on just one information request to the net from one single user than to another user searching the net for the same package of information in a second time. However, the rules for determining when to perform distributed caching according to the invention or not may be set in different ways depending on the actual application environment, as will be discussed below.

The distribution of information to the set of cache servers according to the invention may be performed in many different ways. According to one aspect, the Internet itself could be used. However this would put event more strain on the transfer capacity of the net. Therefore, according to a preferred embodiment of the invention, the information is distributed to said set of cache servers using multicast communication, preferably using dedicated data channels separated from the Internet communication itself.The distribution of information to the set of cache servers according to the invention may be accomplished in many different ways. According to one aspect, the Internet itself could be used. However, this would put the event more strain on the transfer capacity of the net. Therefore, according to the preferred embodiment of the invention, the information is distributed to the set of cache servers using multicast communication, preferably using dedicated data channels separated from the Internet communication itself.

According to a preferred embodiment, said information is distributed to said set of cache servers using a satellite link. Each of the servers then preferably have access to an uplink for sending said information, and ali servers receives a downlink which provides information sent from any one of the servers. The hardware and software for handling such disrriburion may be provided in association to the cache server itself, of may be provided by for example an Internet Service Provider or an Satellite Communication Link Provider. Similarly, the software for controlling the information flow and for performing decisions within the system may be provided at the cache servers, at the Internet Service Providers or wherever convenient, as will be clear for a person skilled in the art. If a satellite system is used, the satellite link may also be used for transferring or relaying request to other parts of the globe, for example from Europe to USA and vice vērsa.According to a preferred embodiment, the information is distributed to a set of cache servers using a satellite link. Each of the servers then preferably has access to an uplink for sending the information, and the ali servers receive a downlink that provides information from any one of the servers. The hardware and software for handling such disabling attributes may be provided in association with the cache server itself, for example, by an Internet Service Provider or a Satellite Communication Link Provider. Similarly, the software for controlling the flow of information and for executing decisions within the system may be provided at the cache servers, at the Internet Service Providers or wherever convenient, as will be clear for the person skilled in the art. If a satellite system is used, the satellite link may also be used for transferring or relaying a request to other parts of the globe, for example from Europe to the US and vice drone.

According to an alternative embodiment, ali cache servers within the system are connected via data channels to a Central control unit. Such a Central control unit may for example control the decisions as to weather or not Information should be cached and as to how it is to be distributed and so on.According to an alternative implementation, the cache servers are connected via the data channels to a central control unit. Such a central control unit may for example control decisions to weather or not Information should be cached and as to how it is distributed and so on.

Depending on the size of the community, the capacity of the cache servers, the available communication capacity of the net, the objects of the cache provider, and so on, the distributed caching technique according to the invention may be arranged to distribute, or not distribute, Information based on different rules. According to a preferred embodiment of the invention, only requests or frames referring to a specific communication format or application, corresponding to the type of Information Service provided on the local storing means, is cached. Eor example, only so called TCP-queries to the WWW port. According to another example, the cache server provider may decide only to cache from specific addresses (e.g. only .com or .org addresses), only after a certain number of requests has been made within the system (e.g. after three separate requests), or the like.Depending on the size of the community, the capacity of the cache servers, the available communication capacity of the net, the objects of the cache provider, and so on, the distributed caching technique according to the invention may be arranged to distribute, or not distribute, Information based on different rules. According to the preferred embodiment of the invention, only requests or frames referring to a specific communication format or application corresponding to the type of information service provided are local cached. Eor example, only so called TCP-queries to the WWW port. According to another example, the cache server provider can only decide to cache from specific addresses (eg .com or .org addresses), only after a certain number of requests have been made within the system (eg after three separate requests), or the like.

The processing means necessary for performing such decisions may be arranged at each cache server, at a Central control unit as mentioned above, at an Internet Service Provider or similar location working in association with the cache servers, or the like.The processing means necessary for executing such decisions may be arranged at each cache server, at a central control unit as mentioned above, at an Internet Service Provider or similar location working in association with the cache servers, or the like.

Also request relating to an Information Content Provider located in a region served by one of the cache servers in said set of cache servers may be handled in different ways according to different embodiments of the invention, as will be discussed in the follovving.Also request related to an Information Content Provider located in a region served by one of the cache servers in said set of cache servers may be handled in different ways according to different embodiments of the invention, as will be discussed in the follovving.

According to two first embodiments thereof, it is assumed that a local information request from an end user to an Internet content provider, both being located vvithin the same region, only is of local concern. Therefore the information shall: a) not be cached at ali, since a local user vvill always have easy access to a local Internet Content Provider; or b) only be cached in the local cache server and not be distributed to the entire set of geographically distributed cache servers, since the request probably only is of local concern. Hence, in this context, the term local refers to features residing vvithin one of said reģions.According to the first two embodiments of the section, it is assumed that a local information request is from an end user to an Internet content provider, both being located in the same region, only being of local concern. Therefore, the information shall: a) not be cached at all since a local user has always easy access to a local Internet Content Provider; or b) only be cached in the local cache server and not be distributed to the entire set of geographically distributed cache servers since the request is probably only of local concern. Hence, in this context, the term local refers to features residing in one of the said region.

According to a second embodiment, it is assumed that an information request from an end user to an Internet content provider located vvithin one of said reģions shall not be cached in the cache server serving that region, but shall instead only be distributed to ali other cache servers vvithin the system, since a local user vvill always have easy access to a local Internet Content Provider (hence no need for local caching) but a user outside the region vvill not have the same easy access to the local Internet Content Provider (hence the need for caching outside the region).According to a second embodiment, it is assumed that an information request from an end user to an Internet content provider is located in one of the said region. servers vvithin the system since a local user vvill always have easy access to a local internet content provider (hence no need for local caching) but a user outside the region vvill not have the same easy access to a local internet content provider (hence the need for caching outside the region).

According to another embodiment, it is assumed that the cache server capacity is large enough to handle ali request, therefore there is no need for handling information relating to local Internet Content Providers different than other information and, consequently, the caching of information in one cache server vvithin the system shall result in the caching of the same information in ali cache servers vvithin the system.According to another embodiment, it is assumed that the cache server capacity is large enough to handle the ali request, therefore there is no need for handling information related to the local Internet Content Providers different from other information and, consequently, the caching of information in one cache server vvithin the system shall result in caching of the same information in ali cache servers vvithin the system.

According to yet another embodiment of the invention, depending on the choice of rules for decisions vvithin the system, there is provided a list of Internet Content Provider addresses to be excluded from caching.According to yet another embodiment of the invention, depending on the choice of rules for decisions, the system has been provided with a list of Internet Content Provider addresses to be excluded from caching.

Hence, each cache is arranged to check incoming information requests against said list to see whether or not the request shall lead to caching.Hence, each cache is arranged to check incoming information requests against your list to see if or not the request will lead to caching.

Depending on the desired utility, the cache servers will be arranged to store information for a given amount of time. For example, the caches may operate on the principle of first-in-first-out. According to another example, certain kind of information may be provided with update requirements, which will define the longest time interval that the copied information may be used to ensure that the information is stili correct. Of course, regarding this and other aspects, the invention may be combined with different types of conventional caching techniques, as is understood by one skilled in the art.Depending on the desired utility, the cache servers will be arranged to store information for a given amount of time. For example, the caches may operate on a first-in-first-out basis. According to another example, some kind of information may be provided with update requirements, which will define the longest time interval that copied information may be used to ensure that the information is style correct. Of course, with respect to this and other aspects, the invention may be combined with different types of conventional caching techniques, as is understood by one skilled in the art.

Furthermore, each of said cache servers may be constituted by several sub-servers connected, preferabiy via high speed switching means, to a cache manager controlling the operation thereof. Further, there is no limit to the number of cache servers that may be used. Also, each server may be used by more than one Internet Service Provider.Additionally, each of the said cache servers may be constituted by several sub-servers connected, preferentially via high speed switching means, to the cache manager controlling the operation clause. Further, there is no limit to the number of cache servers that may be used. Also, each server may be used by more than one Internet Service Provider.

In the event of a failure of one of said cache servers, it can rapidly be bypassed by the system to restore some Service while the cache server is being repaired or replaced. The cache functionality may then be provided form another server in another region within the system. An advantage of the invention is that the auxiliary cache server then provides the same stored content as the bypassed serves, thus making sure that the cached information is stili relevant to the end users in the region of the bypassed server.In the event of a failure of one of said cache servers, it can be quickly bypassed by the system to restore some Service while the cache server is being repaired or replaced. The cache functionality can then be provided by another server in another region within the system. An advantage of the invention is that the auxiliary cache server then provides the same stored content as the bypassed server, thus making sure that the cached information is style relevant to the end users in the region of the bypassed server.

Although the description of the invention has been made with respect to the Internet communication system, it is understood by those skilled in the art that the invention also may be used in other similar types of global information communication systems which may be found in the future and which may show similar kinds of communication problems. The invention is therefore of course not limited to the Internet application.Although the description of the invention has been made with respect to the Internet communication system, it is understood by those skilled in the art that the invention may have been used in other similar types of global information systems which may be found in the future and which may show similar kinds of communication problems. The invention is therefore limited to the Internet application.

Also, even though the description further has been made mainly with respect to the World Wide Web application, it is to be understood that the invention may as well be used for many other kinds of net applications and is not limited thereto.Also, even though the description has been made mainly with respect to the World Wide Web application, it is to be understood that the invention may well be used for many other types of net applications and is not limited thereto.

Brief description of the drawingsBrief description of the drawings

Further aspects, features and advantages of the invention will become clear from the following description of preferred exemplifying embodiments with reference to the accompanying drawings, in which:Further aspects, features, and advantages of the invention will become clear from the following description of preferred exemplifying embodiments, with reference to the accompanying drawings, in which:

Fig 1 schematically shows an embodiment of an internet caching system according to the present invention;Fig. 1 schematically shows an embodiment of an internet caching system according to the present invention;

Fig 2 schematically shows a cache server arrangement forming a part of the system shown in Fig 1;Fig. 2 schematically shows a cache server arrangement forming a part of the system shown in Fig. 1;

Fig 3 schematically shows an alternative cache server arrangement;Fig. 3 schematically shows an alternative cache server arrangement;

Fig 4 schematically shows yet another alternative cache server arrangement;Fig. 4 schematically shows another alternative cache server arrangement;

Fig 5 schematically shows a flow chart of the operation performed by the cache server in Fig 4;Fig. 5 schematically shows a flow chart of the operation performed by the cache server in Fig. 4;

Fig 6 schematically shows a flow chart of the operation performed by the interceptor in Fig 3;Fig. 6 schematically shows a flow chart of the operation performed by the interceptor in Fig. 3;

Fig 7 schematically shows another embodiment of an internet caching system according to the present invention; andFig. 7 schematically shows another embodiment of an internet caching system according to the present invention; and

Fig 8 schematically shows yet another embodiment of an internet caching system according to the present invention.Fig. 8 schematically shows another embodiment of an internet caching system according to the present invention.

Detailed description of preferred embodimentsA detailed description of preferred embodiments

A first embodiment of an internet caching system according to the invention will now be described with reference to Fig 1. In Fig 1, a preferably linguistically and/or culturally defined geographical area 200 is shown encompassing four geographical reģions Α, B, C and D. For example, the area 200 could be the British islands, and the reģions Α, B, C and D could then be Ireland; Wales; Scotland and Northern England; and Southern England, respectively.The first embodiment of an internet caching system according to the invention will now be described with reference to Figure 1. In Figure 1, a preferred linguistically and / or culturally defined geographical area 200 is shown encompassing four geographical regions Α, B, C and D For example, the area 200 could be the British Isles, and the region Α, B, C and D could then be Ireland; Wales; Scotland and Northern England; and Southern England, respectively.

In each of the reģions Α, B, C, and D, there is at least one Internet Service Provider 110a, 110b, 110c, and HOd, respectively, providing the respective region with access to the Internet 100. Each service provider 110a, 110b, 110c, HOd, hence provides Internet connection to a number of end users 120a, 120b, 120c, and 120d, respectively, and a number of Internet content providers 130a, 130b, 130c, and 130d, respectively. It is understood that, even though the end users 120 and content providers 130 are shown in Fig 1 as being separate features, an end user may be a content provider as well.In each of the regions B, B, C, and D, there is at least one Internet Service Provider 110a, 110b, 110c, and HOd, respectively, providing the respective region with access to the Internet 100. Each service provider 110a, 110b , 110c, HOd, hence provides Internet connection to a number of end users 120a, 120b, 120c, and 120d, respectively, and a number of Internet content providers 130a, 130b, 130c, and 130d, respectively. It is understood that even though end users 120 and content providers 130 are shown in Fig. 1 as being separate features, an end user may be a content provider as well.

Each service provider is connected to at least one Internet cache server 140a, 140b, 140c, 140d, respectively. Each cache server 140 hence provides cache functionality to the end users 120 within the respective region. Also, each cache server 140a, 140b, 140c, 140d, has a connection to a satellite disc 150a, 150b, 150c, and 150d, respectively, and may broadcast information to ali other cache servers within the area 200 using a satellite 160.Each service provider is connected to at least one Internet cache server 140a, 140b, 140c, 140d, respectively. Each cache server 140 thus provides cache functionality to the end users 120 within the respective region. Also, each cache server 140a, 140b, 140c, 140d has a connection to a satellite disc 150a, 150b, 150c, and 150d, respectively, and may broadcast information to other cache servers within the area 200 using a satellite 160.

An example of the operation of the system shown in Fig 1 will now be described. When, for example, a service provider 110a in region A receives an information request from an end user 120 relating to information provided by a content provider 130e located in a region E, which in this case lies outside the area 200 (for example, the region E resemble North America), the service provider 110a checks its associated cache server 140a to see if an updated copy if the requested information is stored therein. If so, the requested information is derived from the cache server 140a and is then delivered to the end user. If, however, no copy of the reguested information is stored in the cache server 140a, the service provider 110a relays the request to the original content provider 130e via the Internet 100. When the requested Information is returned from the content provider 130e via the Internet 100, the service provider 110a delivers the Information to the end user and updates the cache server 140a with the received Information. As a part of the updating operation, the updated Information is sent via the satellite disc 150e and the satellite 160 to the cache servers 140b, 140c, 140d in the other reģions B, C, and D, thereby updating ali servers with the same Information. After this updating has been made, no user 120 within the area 200 need to access the original content provider 130e via the Internet, but can instead use the copy stored in the respective cache server. If any cache server is already full when updating, the Information having been stored the longest period of time (since last accessed by an end user) will be deleted from said server. Also each server will use on of several methods to ensure that the Information stored in each cache server are accurate and up to datē, hence providing reliable copies of the original sites.An example of the operation of the system shown in Fig. 1 will now be described. When, for example, a service provider 110a in region A receives an information request from an end user 120 related to information provided by a content provider 130e located in region E, which in this case lies outside area 200 (for example, the region E resemble North America), the service provider 110a checks its associated cache server 140a to see if the requested information is stored therein. If so, the requested information is derived from the cache server 140a and is then delivered to the end user. If, however, no copy of the reguested information is stored in the cache server 140a, the service provider 110a relays the request to the original content provider 130e via the Internet 100. When the requested information is returned from the content provider 130e via the Internet 100, the service provider 110a delivers the information to the end user and updates the cache server 140a with the received information. As part of the updating operation, the updated information is sent via the satellite disc 150e and the satellite 160 to the cache servers 140b, 140c, 140d in the other region B, C, and D, thus updating the servers with the same information. . After this updating has been made, no user 120 within the area 200 need to access the original content provider 130e via the Internet, but can instead use the copy stored in the appropriate cache server. If any cache server is already full when updating, the Information having been stored for the longest period of time (since last accessed by an end user) will be deleted from said server. Also, each server will use several methods to ensure that the information stored in each cache server is accurate and up to date, thus providing reliable copies of the original sites.

In the following figurēs, for ease of description, elements having similar functions as those described wit’n reference to Fig 1 will be designated with the same numerals.In the following figures, for ease of description, elements having similar functions to those described with reference to Fig. 1 will be designated with the same numerals.

A cache server arrangement forming part of a system of the kind shown in Fig 1 will now be described with reference to Fig 2. In Fig 2, three end user termināls or stations 120 are connected to a multiplexing unit 170, which may be a modēm pool or a LAN router depending on the type of user system. The multiplexing unit 170 is connected to an interceptor 110 arranged at an Internet Service Provider providing access to the Internet 100,The cache server arrangement forming part of the system shown in Figure 1 will now be described with reference to Figure 2. In Figure 2, three end user terminals or stations 120 are connected to a multiplexing unit 170, which may be a modem pool or a LAN router depending on the type of user system. The multiplexing unit 170 is connected to an interceptor 110 arranged at an Internet Service Provider providing access to the Internet 100,

The multiplexing unit 170 multiplexes the Communications to and from the user termināls 120.The multiplexing unit 170 multiplexes the Communications to and from the user terminal 120.

According to this arrangement, a user 120 wishing to access information provided for example as a World Wide Web homepage or site by an Internet content provider (not shown), located at a original site of publication somewhere on the Internet 100, generally sends an information request, specifically a HTTP request to the WWW-port, via the multiplexing unit 170 to the Internet service provider 110, where the request is routed out on the Internet 100 to finally reach the content provider. The content provider then answers the request, sending the requested information via the Internet 100 back to the user 120 via the service provider 110.According to this arrangement, a user 120 wishing to access information provided for an example of a World Wide Web page or site by an Internet content provider (not shown), located at the original site somewhere on the Internet 100, generally sent by information request, specifically an HTTP request to the web port, via the multiplexing unit 170 to the internet service provider 110, where the request is routed out to the internet 100 to finally reach the content provider. The content provider then answers the request, sending the requested information via the Internet 100 back to the user 120 via the service provider 110.

However, according to the arrangement shown in Fig 2, the information request from a user 120 is examined by the interceptor 110 at the service provider. The interceptor then decides whether or not the requested information, for example the information provided by said the content provider, exist in a copy or similar form on a local cache server 140 arranged in direct communication with the interceptor 110. If a copy or the like of the requested information is stored at the local server 140, the request from the user is re-routed to the server 140, which will then return the requested information to the user. In this case, the information will already exist on ali cache servers within the area 200 shown in Fig 1, and there is hence no need for distributing the information to other caches.However, according to the arrangement shown in Figure 2, the request for information from a user 120 is examined by the interceptor 110 at the service provider. The interceptor then decides whether or not the requested information is provided by the content provider, exist in a copy or similar form on a local cache server 140 arranged in direct communication with the interceptor 110. If a copy or the like of the requested information is stored at the local server 140, the request from the user is re-routed to the server 140, which will then return the requested information to the user. In this case, the information will already exist on the cache servers within the area 200 shown in Figure 1, and there is therefore no need for distributing the information to other caches.

However, if the interceptor 110 determinēs that no copy or the like of the information of interest exists on the local server 140, then the information request from the user 120 is sent on to the Internet 100 as in the conventional form of Internet communication. The interceptor will then monitor the response from the Internet 100 to the user 120 and update the cache server 140 with the requested information as it is received.However, if the interceptor 110 determines that no copy or information of interest exists on the local server 140, then the information request from the user 120 is sent to the Internet 100 as in the conventional form of Internet communication. The interceptor will then monitor the response from the Internet 100 to the user 120 and update the cache server 140 with the requested information as it is received.

The caching of new or updated information in the cache server 140 is, according to the invention, accompaLV 12519 nied by the distribution of the nevz or updated information to other cache servers within the area 200 shovzn in Fig 1. This distribution is enabled by either the cache server 140 or the interceptor 110 at the service provider, for example, and uses a satellite uplink to the satellite 160 to reach other cache servers vzithin the defined area. Similarly, when receiving information relating to nevz or updated information from other cache servers vzithin the area, the cache server 140 vzill receive such information via a dovznlink from the satellite.The caching of new or updated information in the cache server 140 is according to the invention, accompaLV 12519 nied by the distribution of the new or updated information to the other cache servers within the area 200 shovzn in Fig. 1. This distribution is enabled by either the cache server 140 or the interceptor 110 at the service provider, for example, and uses a satellite uplink to the satellite 160 to reach other cache servers vzithin the defined area. Similarly, when receiving information relating to nevz or updated information from other cache servers vzithin the area, cache server 140 vzill receive such information via a dovznlink from the satellite.

Note that the interceptor 110 in this example only intercepts communication packages of certain specific types. For example, only World Wide Web information requests from the users 120 is intercepted. Other types of communication Services, such as e-mail or the like, is left undisturbed by the interceptor 110.Note that the interceptor 110 in this example only intercepts communication packages of certain specific types. For example, only World Wide Web information requests from users 120 is intercepted. Other types of communication services such as e-mail or the like are left undisturbed by the interceptor 110.

An alternative cache server arrangement, similar to the one shovzn in Fig 2, vzill novr be described vzith reference to Fig 3. The arrangement in Fig 2 differs from the one shovzn in Fig 2 in that the interceptor 110 at the service provider is connected to not only the cache server 140, but also to a quick access cache memory 112. In comparison to the cache server 140 according to the invention, for example providing several hundred Gigabytes of storage, the quick access cache memory vzill in this case provide a much smaller storage capacity, for example a around one Gigabyte of storage. The cache memory 112 is therefore used to store essentially ali information passing the interceptor 110, but consequently, each package of information vzill only be stored a comparatively small amount of time.An alternative cache server arrangement similar to the one shovzn in Fig. 2 is described below with reference to Fig. 3. The arrangement in Fig. 2 differs from the one shovzn in Fig. 2 that the interceptor 110 is connected to the service provider. not only the cache server 140, but also to the quick access cache memory 112. In comparison to the cache server 140 according to the invention, for example providing several hundred gigabytes of storage, vzill in this case provide a lot smaller storage capacity, for example a gigabyte of storage. The cache memory 112 is therefore used to store substantially ali information passing the interceptor 110, but consequently, each packet of information is stored only in a comparatively small amount of time.

In Fig 3, the quick access cache memory, comprising a memory areas 112 and a look-up table 111 shovzing vzhich information is currently stored in said memory areas, is used as a vzorking memory of the interceptor 110. Hence, vzhen receiving an information request from a user 120, the interceptor vzill first check its guick access cache memory 111, 112 for the requested information. The cache server 140 will then be accessed only if the requested information cannot be found on the cache memory 112. The operation the follows the one described with reference to Fig 2. However, in Fig 3, ali information relating to every information request from the users 120 wilļ be temporarily stored in the quick access cache memory 112, either information received from the Internet 100 or information received from the cache server 140, whereas the cache server will only be updated when new information is received from the Internet 100. Furthermore, the cache memory may be user to cache information of other kind than the information being stored in the cache server 140. For example, in addition to storing WWW information, as the cache server 140, the cache memory may also store information relating to other types of queries. Also, information stored in the cache memory 112 will not automatically be distributed to other caches within the area 200 in Fig 1.In Fig. 3, a quick access cache memory comprising memory areas 112 and a look-up table 111 is currently stored in said memory areas, is used as a memory memory of the interceptor 110. Hence, vzhen receiving an information request from a user 120, the interceptor vzill first check its guick access cache memory 111, 112 for the requested information. The cache server 140 will then be accessible only if the requested information cannot be found on the cache memory 112. The operation follows the one described with reference to Fig. 2, however, in Fig. users 120 wil be temporarily stored in the quick access cache memory 112, either information received from the internet 100 or information received from the cache server 140, will only be updated when new information is received from the internet 100. the cache memory may be a user of the cache information other than the information being stored in the cache server 140. For example, in addition to storing the web information 140, the cache memory may also store information relating to other types of queries. Also, information stored in the cache memory 112 will not be automatically distributed to other caches within the area 200 in Fig. 1.

Another alternative cache server arrangement, also similar to the one shown in Fig 2, will now be described with reference to Fig 4. īn Fig 4, ali WWW requests will be relayed form the Service provider 110 to the cache server 140. The cache server will then answer the request, if the requested information is stored in therein, or itself handle the information retrieval from the internet 100, either using a satellite link or some other connection 141 to the Internet. When receiving the requested information, the cache server will 140 update itself, as well as other caches via the satellite 160, according to its own decisions, and deliver the information to the end user 120 via the Service provider 110.Another alternative cache server arrangement, also similar to the one shown in Fig. 2, will now be described with reference to Fig. 4, ali WWW requests will be relayed to form the Service Provider 110 to the cache server 140. The cache server will then answer the request, if the requested information is stored therein, or itself handle the information retrieval from the internet 100, either using a satellite link or some other connection 141 to the internet. When receiving the requested information, the cache server will 140 update itself, as well as other caches via the satellite 160, according to its own decisions, and deliver the information to the end user 120 via the Service Provider 110.

Note in Fig 4 that the Service provider may stili handle other type of Services, such as email or the like, on its own, without relaying such information packages via the cache server.Note in Fig. 4 that the Service Provider may style handle other type of Services, such as email or the like, on its own, without relaying such information packages via the cache server.

An example of the operations performed by the cache server 140 in Fig 4 vvill novv be described vvith reference to the flovv chart in Fig 5. After activating the operation in step Sl, the cache server receives, in step S2, an information request from an end user relating to a specific content provider. In step S3, the cache server then determinēs vvhether or not a copy of the requested information is stored therein. If so, the requested information is delivered to the end user in step S4 and the operation is ended in step S10. (Of course, the end step S10 may cause a return to the starting step Sl).An example of the operations performed by the cache server 140 in Fig. 4 is a vvith reference to the flovv chart in Fig. 5. After activating the operation in step Sl, the cache server receives, in step S2, an information request from an end user related to a specific content provider. In step S3, the cache server then determines whether or not a copy of the requested information is stored therein. If so, the requested information is delivered to the end user in step S4 and the operation is completed in step S10. (Of course, end step S10 may cause a return to starting step Sl).

Hovvever, if it is determined in step S3 that no copy of the requested information is stored in the cache server, the process continues to step S5, vvherein the cache server sends a request for said information to the designated content provider via the Internet. The cache server then receives the requested information in step S6 and delivers it to the end user in step S7. In step S8, the received information is stored in the cache server, and then, in step S9, the information is distributed to ali other cache servers vvithin the area 200 shovvn in FigHovvever, if it is determined in step S3 that no copy of the requested information is stored in the cache server, the process continues to step S5, vvherein the cache server sends a request for information to the designated content provider via the Internet. The cache server then receives the requested information in step S6 and delivers it to the end user in step S7. In step S8, the received information is stored in the cache server, and then, in step S9, the information is distributed to the other cache servers vvithin the area 200 shovvn in Fig.

1. Hence, the received nevv, previously not stored information vvill then be stored in essentially ali cache servers vvithin the area and thus be easily accessed by ali users vvithin the area.1. Hence, the received nevv, previously not stored information vvill then be stored in essentially ali cache servers vvithin the area and thus be easily accessible by ali users vvithin the area.

An example of the operations performed by the interceptor or Service provider 110 in Fig 3 vvill now be described vvith reference to the flovv chart in Fig 6. After activating the operation in step Sll, the interceptor 110 reads, in step S12, an information request from an end user directed to a specific content provider. In step S13, the interceptor 110 checks the content table 111 of the quick access cache memory 112 to see if a copy of the requested information exists therein. If so, the opera35 tion continues to step S15 described belovv. In not, the operation continues to step S14, in vvhich the interceptor sends a query to the cache server 140 to see if a copy of the requested information exists therein. If the answer is yes, the process continues to step S15, in which the request from the end user is intercepted, and to step S16, wherein the requested information is delivered, either using the cache memory 112 or the cache server 140. However, if the ansvver form the cache server in no, the process continues to step S17, wherein the interceptor determinēs not to intercept the request from the user, vvhich is instead passed on to the designated content provider via the Internet. The process then continues to step S18, in vvhich the interceptor monitors the ansvver sent from the content provider to the end user. When such information passes the interceptor on its way to the end user, the interceptor, in step S19, stores the previously unattainable information in the cache server 140 and distributes the information to ali other cache servers vvithin the area 200 in Fig 1. Hence, the received nevv, previously not stored information vvill then be stored in essentially ali cache servers vvithin the area and thus be easily accessed by ali users vvithin the area. Note that every time information is received from the cache server of from the net, a copy is preferably temporarily stored in the quick access cache server 112.An example of the operations performed by the interceptor or service provider 110 in Fig. 3 is now described as a reference to the flow diagram in Fig. 6. After activating the operation in step Sll, the interceptor 110 reads, in step S12, an information request from an end user directed to a specific content provider. In step S13, the interceptor 110 checks the content table 111 of the quick access cache memory 112 to see if a copy of the requested information exists therein. If so, opera35 tion continues to step S15 described belovv. In not, operation continues to step S14, in vvhich the interceptor sends a query to the cache server 140 to see if a copy of the requested information exists therein. If the answer is yes, the process continues to step S15, in which the request from the end user is intercepted, and to step S16, the requested information is delivered, either using the cache memory 112 or the cache server 140. However, if the ansvver form the cache server in no, the process continues to step S17, the interceptor determines not to intercept the request from the user, vvhich is instead passed to the designated content provider via the Internet. The process then continues to step S18, in vvhich the interceptor monitors the ansvver sent from the content provider to the end user. When such information passes the interceptor on its way to the end user, the interceptor, in step S19, stores the previously unattainable information in the cache server 140 and distributes the information to the other cache servers in the area 200 in Fig. 1. Hence, the received nevv, previously not stored information vvill then be stored in essentially ali cache servers vvithin the area and thus be easily accessible by ali users vvithin the area. Note that every time the information is received from the cache server from the net, the copy is preferably temporarily stored in the quick access cache server 112.

Another exemplifying embodiment of an internet caching system according to the present invention, similar to the one shovvn in Fig 1, vvill novv be described vvith reference to Fig 7. In Fig 7, the system differs from the one shovvn in Fig 1 in the ansvver from the content provider 130e, in this case being located in the region Eoutside the system area 200, relating to an information request originally sent by an end user 120a, vvill not be transmitted back to the user via the Internet 100. Instead, the ansvver is transmitted directly via the satellite 160 to the servers 140a, 140b, 140c, and 140e, thereby automatically updating ali cache servers 140a.Another exemplifying embodiment of an internet caching system according to the present invention, similar to the one shovvn in Fig. 1, is described in Fig. 7, the system differs from the one shovvn in Fig. 1 in the ansvver from the content provider 130e, in this case being located in the region Eoutside the system area 200 relating to an information request originally sent by an end user 120a, not being transmitted back to the user via the Internet 100. Instead, the ansvver is transmitted directly via satellite 160 to servers 140a, 140b, 140c, and 140e, thus automatically updating the cache servers 140a.

The cache server 140a and the Service provider 110a then handles the delivery of said information to the end user 120a.The cache server 140a and the service provider 110a then handles the delivery of the received information to the end user 120a.

Yet another exemplifying embodiment of an internet caching system according to the present invention, similar to the one shown in Fig 1, will now be described with reference to Fig 8. In Fig 8, the cache servers within the area 200, each serving a respective region A, B, C, and D, is connected to via data channels to a Central control unit 190. The central control unit 190Yet another exemplifying embodiment of an internet caching system according to the present invention, similar to the one shown in Fig. 1, will now be described with reference to Fig. 8. In the cache servers within the area 200, each serving a corresponding regions A, B, C, and D are connected to via data channels to a central control unit 190. The central control unit 190

Controls the decisions as to weather or not information shall be cached in the respective cache servers and as to how it is to be distributed to other caches within the area 200. In this case, information may be distributed between the different caches either using the satellite link or using the data channel connection to and via the central control unit 190.Controls the decisions as to the weather or not the information is cached in the respective cache servers and how it is distributed to the other caches within the area 200. In this case, the information may be distributed between the different caches either using the satellite link or using the data channel connection to and via the central control unit 190.

Furthermore, with reference primarily to Fig 1, 7 and 8 above, it is understood that decisions regarding how to handle the caching of information relating to local requests, i.e. for example an information request from an end user 120a relating to a content provider 130a located within the same region A, which has been discussed above in the summary of the invention, the different schemes of operation, including the needed decision25 making, may be implemented either at each of the cache servers 140, at each of the Service providers 110, or at a central control unit 190, for example.Furthermore, with reference mainly to Figures 1, 7 and 8 above, it is understood that how to handle the caching of information in relation to local requests, i.e. for example, an information request from an end user 120a related to a content provider 130a located within the same region A which has been discussed above in the summary of the invention either at each of the cache servers 140, at each of the Service Providers 110, or at a central control unit 190, for example.

It is understood that the construction and function of the elements described with reference to the drawings will become apparent for those skilled in the art.It is understood that the construction and function of the elements described with reference to the drawings will become apparent for those skilled in the art.

Even though the invention has been described with reference to specific exemplifying embodiments, many different alterations, modifications and the like will become apparent for those skilled in the art. The des35 cribed embodiments are therefore not intended to limit the scope of the invention, as defined by the appended claims.Even though the invention has been described with reference to specific exemplifying embodiments, many different alterations, modifications and the like will become apparent to those skilled in the art. The des35 cribed embodiments are therefore not intended to limit the scope of the invention as defined by the appended claims.

Claims

1. Method for caching Internet information, comprising the steps of:1. Method for caching Internet information, comprising the steps of:

deriving information sent to an end user from an Internet content provider based upon an information request from said end user; and distributing said information to a set of geographically distributed cache servers.deriving information sent to an end user from an Internet content provider based on an information request from said end user; and distributing said information to a set of geographically distributed cache servers.

2. Method as claimed in claim 1, wherein said deriving step is performed in connection with a cache server serving said end user, said end user being located in a geographical region served by said a cache server.2. The method as claimed in claim 1, wherein said step of deriving is performed in connection with a cache server serving said end user, said end user being located in a geographical region served by said cache server.

3. Method as claimed in claim 2, comprising storing said information in said a cache server.3. Method as claimed in claim 2, comprising storing said information in said cache server.

4. Method as claimed in claim 3, comprising storing said information in said a cache server only if said content provider is located outside said region.4. Method as claimed in claim 3, comprising storing said information in a cache server only if said content provider is located outside said region.

5. Method as claimed in claim 3, comprising storing said information in said a cache server only if said content provider is located inside said region.5. Method as claimed in claim 3, comprising storing said information in a cache server only if said content provider is located inside said region.

6. Method as claimed in claim 2, comprising performing said distributing step only if said content provider is located outside said region.6. Method as claimed in claim 2, comprising performing the distribution step only if the content provider is located outside the said region.

7. Method as claimed in claim 2, comprising performing said distributing step only if said content provider is located inside said region.7. Method as claimed in claim 2, comprising performing the distribution step only if the content provider is located inside the said region.

8. Method as claimed in any one of the preceding claims, comprising distributing said information to said set of geographically distributed cache servers using multicast communication.8. Method as claimed in any one of the preceding claims, comprising distributing said information to a set of geographically distributed cache servers using multicast communication.

9. Method as claimed in claim 8, comprising distributing said Information to said set of geographically distributed cache servers using a satellite link.9. A method of claiming claim 8, comprising distributing information to a set of geographically distributed cache servers using a satellite link.

10. Method as claimed in any one of the preceding claims, comprising only distributing said Information based upon the outcome of a rule determining, for each derived piece of Information, whether or not it is to be distributed to said set of geographically distributed cache servers.10. Method as claimed in any one of the preceding claims comprising only the distribution of information based on the outcome of the rule, for each derived piece of information whether or not it is distributed to a set of geographically distributed cache servers .

11. Method as claimed in any one of the preceding claims, wherein said set of geographically distributed cache servers serve different geographical reģions.11. A method as claimed in any one of the preceding claims, wherein said set of geographically distributed cache servers serve a different geographical region.

12. Method as claimed in any one of the preceding claims, wherein said set of geographically distributed cache servers are distributed within a linguistically or culturally defined area.12. The method as claimed in any one of the preceding claims, said set of geographically distributed cache servers being distributed within a linguistically or culturally defined area.

13. Method as claimed in claim 11, wherein said set of geographically distributed cache servers are distributed within a linguistically or culturally defined area encompassing said reģions.13. A method for claiming claim 11, wherein said region of the caching servers is distributed within a linguistically or culturally defined area.

14. Internet caching system, comprising:14. Internet caching system, comprising:

a set of geographically distributed cache servers; means for deriving Internet Information derived in connection with the operation of one of said cache servers; and means for distributing said derived Information to essentially ali of sdid cache servers.a set of geographically distributed cache servers; means for deriving Internet Information derived from connection with operation of one of said cache servers; and means for distributing received information to essentially ali of sdid cache servers.

15. Internet caching system as claimed in claim 14, wherein said deriving means are arranged to derive said information in connection with the sending of said information from an Internet content provider to an end15. Internet caching system as claimed in claim 14, which has been arranged to derive information from the Internet content provider to an end

5 user as a result of a specific information request by said end user, said end user being located in a geographical region served by said one of said cache servers.5 user as a result of a specific information request by said end user, said end user being located in a geographical region served by one of said cache servers.

16. Internet caching system as claimed in claim 15, 10 wherein said one of said cache servers is arranged to store said information.16. An Internet caching system as claimed in claim 15, wherein one of the cache servers is arranged to store the information.

17. Internet caching system as claimed in claim 16, wherein said one of said cache servers is arranged to17. Internet caching system as claimed in claim 16, one of the caching servers being arranged to

15 store said information only if said content provider is located outside said region.15 store information only if you are located outside the said region.

18. Internet caching system as claimed in claim 16, wherein said one of said cache servers is arranged to18. An Internet caching system as claimed in claim 16, which has provided one of the caching servers is arranged to

20 store said information only if said content provider is located inside said region.20 store got information only if you got content provider is located inside said region.

19. Internet caching system as claimed in claim 15, wherein said distributing means are arranged to distri25 bute said information to said set of cache servers only if said content provider is located outside said region.19. The Internet caching system as claimed in claim 15, which has been distributed to distri25 but has received information to the cache servers only if the content provider is located outside the said region.

20. Internet caching system as claimed in claim 15, wherein said distributing means are arranged to distri30 bute said information to said set of cache servers only if said content provider is located inside said region.20. The Internet caching system as claimed in claim 15, which has been distributed to distri30 but has received information to the cache servers only if the content provider is located inside the said region.

21. Internet caching system as claimed in any one of claims 14 to 20, wherein said distributing means are21. Internet caching system as claimed in any one of claims 14 to 20, said distributed distribution means are

35 arranged to distribute said information to said set of cache servers using multicast communication.35 arranged to distribute information to a set of cache servers using multicast communication.

22. Internet caching system as claimed in claim 21, wherein said distributing means are arranged to distribute said information to said set cache servers via a satellite link.22. An Internet caching system as claimed in claim 21, which has been arranged to distribute information to a cache server via a satellite link.

23. Internet caching system as claimed in any one of claims 14 to 22, comprising processing means for determining whether or not said derived information is to be distributed to said set of cache servers.23. An Internet caching system as claimed in any one of claims 14 to 22, comprising processing means for determining whether or not received information is distributed to said set of cache servers.

24. Internet caching system as claimed in any one of claims 14 to 23, wherein said geographically distributed cache servers are arranged to serve different geographical reģions.24. An Internet caching system as claimed in any one of claims 14 to 23, said geographically distributed cache servers are arranged to serve a different geographical region.

25. Internet caching system as claimed in any one of claims 14 to 24, wherein said geographically distributed cache servers are distributed within a linguisticaliy or culturally defined geographical area.25. Internet caching system as claimed in any one of claims 14 to 24, geographically distributed cache servers are distributed within a linguistic or culturally defined geographical area.

26. Internet caching system as claimed in claims 24 to 24, wherein said geographically distributed cache servers are distributed within a linguistically or culturally defined geographical area encompassing said reģions.26. The Internet caching system as claimed in claims 24 to 24, said geographically distributed cache servers are distributed within a linguistically or culturally defined geographical area encompassing said region.

27. Internet cache server arranged in a geographical region to primarily serve users in that region, comprising:27. Internet cache server arranged in a geographical region to primarily serve users in that region, comprising:

means for deriving information sent by an Internet content provider to an end user located within said region as a result of an information reguest made by said end user; and means for distributing said information to a set of geographically distributed cache servers, said servers preferably serving different geographical reģions.means for deriving information from an Internet content provider to an end user located within a region as a result of an information reguest made by said end user; and means for distributing said information to a set of geographically distributed cache servers, said servers preferably serving a different geographical region.

28. Internet cache server as claimed in claim 27, wherein said cache servers are distributed vzithin a linguistically or culturally defined geographical area.28. Internet cache server as claimed in claim 27, said cache servers being distributed vzithin a linguistically or culturally defined geographical area.

29. Internet cache server as claimed in claim 27 cr 28, comprising processing means for determining vzhether or not a specific piece of derived information is to be cached in said server.29. Internet cache server as claimed in claim 27 cr 28, comprising processing means for determining vzhether or not specific piece of derived information is cached in said server.

30. Internet cache server as claimed in claim 27, 28 or 29, comprising processing means for determining vzhether or not a specific piece of derived information is to be distributed to said set of geographically distributed cache servers.30. An Internet cache server as claimed in claim 27, 28 or 29, comprising processing means for determining vzhether or not, a specific piece of derived information being distributed to a set of geographically distributed cache servers.

31. Internet cache server as claimed in claim 29 or 30, vzherein decisions made by said processing means is based upon vzhether or not said content provider is located vzithin said region.31. Internet cache server as claimed in claim 29 or 30, vzherein decisions made by site processing means based on vzhether or not content provider is located in vzithin said region.

32. Internet cache server as claimed in claim 29, 30 or 31, vzherein said processing means is arranged to instruct said server to not cache said information and not distribute said information to said set of geographically distributed cache servers if said end user and said Internet content provider are both located vzithin the same region as said server.32. Internet cache server as claimed in claim 29, 30 or 31, vzherein said processing means arranged to instruct site server to not cache site information and not distribute site information to site set of geographically distributed cache servers if end user and site internet content provider are both located in the same region as said server.

33. Internet cache server as claimed in claim 29, 30 or 31, vzherein said processing means is arranged to instruct said server to cache said information and to not distribute said information to said set of geographically distributed cache servers if said Internet content provider is located vzithin the same region as said server.33. Internet cache server as claimed in claim 29, 30 or 31, vzherein said processing means arranged to instruct site server to cache information and not to distribute information to site set of geographically distributed cache servers if received vzithin the same region as said server.

34. Internet cache server as claimed in claim 29, 30 or 31, vvherein said processing means is arranged to instruct said server to not cache said information but instead only distribute said information to said set of34. Internet cache server as claimed in claim 29, 30 or 31, vvherein said processing means arranged to instruct server not cache information but instead only distribute information to site set of

5 geographically distributed cache servers if said Internet content provider is located vvithin the same region as said server.5 geographically distributed cache servers if said internet content provider is located in the same region as said server.