CN1372407A - Content delivery network system and its implementation method - Google Patents

Abstract

A content delivery network system includes a communication network, a first network node for providing user access to the Internet, a second network node for host management, and a third network node, in which the third network node connects a cache server at the bandwidth exit of the first network node for providing user access to the Internet, and sets a standard route and a virtual private network tunnel (VPN tunnel) between the first and the second network nodes, the cache server will store the information content which is requested and transmitted.

Description

Content delivery network system and its implementation method

The invention relates to a content delivery network system and method thereof. More specifically, it is related to a feature of using a virtual private network (Virtual Private Network; VPN) and Border Gateway Protocol (Border Gateway Protocol; BGP), which can accelerate the transmission speed of content in the Internet, and use the characteristics of network construction Create data collection functions. In addition, the network system of the present invention can be generally used as the construction of the general Internet to achieve the purpose of extending the independent network.

The network nodes of an independent and autonomous network must have accessible private routes. General Internet Service Providers (ISPs) will use the communication network laid by the telecommunications company as a medium to extend the network and maintain the continuity necessary for network autonomy.

At present, many important and large ISPs are mostly located in the United States. If ISPs located in other regions want to provide content from American ISPs to users, they must rent the hardware and bandwidth of the international communication network. Therefore, for many ISPs, the biggest cost is the bandwidth usage fee of the international network. The following is a simple example to illustrate this situation.

Please refer to Figure 1. Assume that there are two ISPs-ISP A and ISP B located in different regions. Among them, ISPA mainly provides Internet access services for users, while ISP B provides hosting services. The main expenditure of both is the bandwidth usage fee for connecting to the Internet. In terms of income, the main income of ISP A is to charge users, which is a fixed income. The main income of ISP B is the bandwidth cost of the hosting of the customer (ICP), that is, the more people look at the information on the customer's host, the income of ISP B will also increase accordingly.

When a user of ISP A requests a piece of information from ISP B, ISP A makes a request to ISP B, and ISPB sends the piece of information to ISP A through the international network, so that ISP A can provide this information to the user. When another user requires the same information, or the same user requests the information again, the above-mentioned requirements and transmission procedures must all be repeated. In other words, the same message may be transmitted multiple times on the international network, resulting in a waste of bandwidth usage, and the ISPA must pay again and again for each use of the bandwidth to transmit the same message.

Referring to Fig. 2 again, ISP A can set a cache server at its bandwidth outlet to store the information content once captured. When a user requests a certain piece of information, ISP A can first search for it in the cache server, and if there is, it will directly provide it to the user. If not, then submit a request to ISP B to retrieve the information, and ask ISP B to transmit the desired information content. But in this way, although ISP A can save the cost of bandwidth, it will cause the loss of ISP B, because the number of times that ISP B needs to transmit the information content of its hosting client (ICP) is significantly reduced. Therefore, this approach of ISP A can be said to be the enemy of other ISPs.

For example, an autonomous network in Taiwan can use the concept of the present invention to extend the network to the United States without having to own an international network, while maintaining its autonomy. After the network is extended, it can be added to its network policy, such as using various bandwidth-saving methods such as cache server or service priority, which can greatly save the cost of international bandwidth and speed up the response speed of the network.

An object of the present invention is to provide a content delivery network system, which can solve the problem of the continuity of the independent autonomous network, so as to achieve the purpose of extending the independent network.

Another object of the present invention is to provide a kind of content delivery network system, can solve current website approaching (site proximity; find out the method that the shortest route can reach any server when connecting to a plurality of distributed servers by the user) still A problem for which there is no best solution. Ensure that information content reaches the closest cache server by the shortest route.

The third object of the present invention is to provide a content delivery network system, so that ISPs that mainly provide users with access to the Internet can reduce the probability of using international network bandwidth, thereby reducing costs, while maintaining the service quality of providing information to users, and not It will reduce the income of ISPs that mainly focus on hosting.

The fourth object of the present invention is to provide a pricing system, which is used to calculate the cost of providing user information not via the international network so that ISPs that mainly provide users with access to the Internet and ISPs that mainly host hosting can share the bandwidth reasonably cost savings.

According to one aspect of the present invention, a content delivery network system includes a communication network, a first network node mainly used to provide users with online access, a second network node mainly used for host hosting, and a third network node, The third network node sets standard routing and virtual private network (VPN) tunnels between the first and second network nodes, and connects a cache server at the bandwidth exit of the first network node that mainly provides users with access to the Internet cache server, the cache server will store the information content that has been requested and sent, when the user requests a piece of information, it will first look for it from the cache server, if there is such information, it will be quickly The retrieval server directly provides it to the user. If there is no such information, the cache server makes a request to the second network node to retrieve the information through the VPN tunnel, and obtains the information through a standard route and sends it to the user. And through the cache server, the data of the host computer that transmits the information is recorded, so as to provide a second network node, so as to charge the client of the host hosting.

According to another aspect of the present invention, a method for delivering content via a network includes establishing a communication network; establishing a first network node for providing user access to the Internet; establishing a second network node for providing content from a network content provider. Information; set standard routing and virtual private network (VPN) tunnels through the communication network between the first and second network nodes, and set a cache server at the communication entrance and exit of the first network node for storage The content of the information transmitted from the second network node; when the user of the first network node requests a specific piece of information, it first goes to the cache server to search, and if there is such a piece of information, it is directly provided to the user; if there is no such piece of information , then submit a request to the second network node to retrieve the information through the VPN tunnel; after the second network node returns the information through the standard route, the cache server will store it and provide it to the user, the first The third network node records the data content of the information transmitted by the cache server, and provides the second network node to charge the client of its hosting.

According to the third aspect of the present invention, a method for building a content delivery network system includes the steps of, between the first network node mainly used to provide users with access to the Internet and the second network node mainly used for host hosting Establish a basic communication network between; set the route between the first network node and the second network node, including standard routing and virtual private network (VPN) tunnel; set up iBGP exchange between the first network node and the second network node; Set up a cache server at the first network node; implement redirection (redirection), forcing all communication content of the first network node to pass through the cache server; and replace by the cache server to the second network node The host of the tube obtains the required information content and stores it for use.

According to the fourth aspect of the present invention, in the network system of the present invention, the cache server is provided with a pricing system, wherein the cache server records the data of the transmission information, including the amount of information transmitted by each customer and the cost time, to calculate the average bandwidth usage, add the information volume of all customers, and compare the sum with the actual maximum bandwidth to calculate a factor value, and multiply the average transmitted information volume of each customer by the factor value It is the maximum bandwidth usage within a certain period of time.

The advantages, features and objectives of the present invention will be apparent through the detailed description of the present invention below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram schematically showing a traditional network system for transmitting information;

2 is a schematic diagram schematically showing another traditional network system for transmitting information;

FIG. 3 is a schematic diagram schematically showing a content delivery network system according to the present invention; and

FIG. 4 is a schematic diagram showing the structure of the content delivery network system according to the present invention.

Embodiments of the present invention will now be described in detail with reference to the drawings shown.

Please refer to FIG. 3 , the content delivery system according to the present invention is shown in the figure. The system of the present invention includes: a communication network 10, which can be the Internet; ISPA, a network service provider mainly to provide information to users, which provides Internet service for users 30; a network service provider mainly based on host hosting ISP B, which hosts the content provided by a plurality of Internet content providers (ICP) 20; and ISP C, which sets a cache server 40 for network services mainly providing information to users Provider ISP A's bandwidth egress.

ISP C sets up a virtual private network tunnel (VPN tunnel) 50 between ISP A and ISP B for ISP A to request information from ISP B. And ISP B should request that the return information is implemented through the standard route 60 through the communication network 10.

The cache server 40 stores and manages the requested and transmitted information. When ISP A receives the user 30's request for a specific information, ISP A first searches in the cache server 40. If there is the information in the cache server 40, the ISP A directly transmits the information to the user 30 from the cache server 40. If the information does not exist in the cache server 40, then ISP A makes a request to ISP B through the VPN tunnel 50. ISP B then responds to the request, and transmits the specific information to the cache server 40 through the standard route 60 so as to be transmitted to the user 30 and stored and managed. In this way, when another user 30' requests the specific information later on, or when the same user 30 requests the information again, ISP A can provide it to the user from the cache server 40, without requiring the ISP to B requests the transmission of the information.

It should be noted that the VPN tunnel 50 can be any technology that achieves the effect of a virtual private network.

For the sake of clarity, the above example can be simplified to a single ISP A that mainly provides information to users, and a single ISP B that mainly provides hosting. However, there may be multiple ISP A's as well as multiple ISP B's.

Utilizing this system, for ISPA A, can greatly reduce the usage requirement for the bandwidth of the communication network 10, thereby significantly reducing the cost in this respect. In addition, since the repeated transmission of the same information on the communication network 10 is reduced, the waste of bandwidth usage can be avoided, so that the information transmission of the overall communication network 10 remains smooth.

However, for ISP B, revenue would be affected due to the reduced number of delivery requests for the content it hosts.

ISP C can set up a billing system on the cache server 40 to record and count the bandwidth used by each piece of information actually transmitted to the user 30, and hand over the statistical results to ISP B for reporting to its host. Managed Client (ICP) charges. In this way, it will not cause the loss of ISP B, but also can greatly reduce the cost of ISP A. Then ISP C can charge service fees from ISP A and ISP B.

For the sake of clarity, here is an example of establishing a network system between two points. It should be understood that when the number of network nodes exceeds two or more points, the steps can be repeated and adjusted according to requirements. Please refer to Figure 4.

Procedure 1: Basic network construction.

First of all, the autonomous number (AS number) of the network and the Internet protocol (IP) address that can be declared by itself are prepared; the two network nodes in two places apply for connection to the local ISP respectively, and obtain the legal IP of the other party Address and Border Gateway Protocol (BGP) exchange permission; set the interface with the local ISP connection, BGP exchange and other data. When exchanging BGP, you can choose to receive all the BGP routing data (full routing table) of the other party, or only receive part of the BGP routing data, or not receive it at all. However, if you do not obtain all BGP routing information, you must add a standard route (defaultroute) to point to the local ISP gateway (gateway). However, even if all BGP routes are received, standard routes can be established separately.

For the convenience of description, it is assumed that the networks in the two locations are respectively CDN1 and CDN2. The ISPs of the two places are ISP1 and ISP2 respectively. The connection interface between CDN1 and ISP1 is CI1. The connection interface between CDN2 and ISP2 is CI2.

After the connection is successful and the relevant routes have been established, start to set up the virtual private network tunnel (VPN tunnel). First, set the interface on the routers of CDN1 and CDN2, such as using loopback or directly using CI1 and CI2, which use the IP addresses owned by ISP1 and ISP2 (that is, announced by the autonomous numbers of ISP1 and ISP2 ), hereafter referred to as IP1 and IP2 respectively. In CDN1, IP1 is used as the source of the VPN tunnel and IP2 is used as the destination of the VPN tunnel; in CDN2, IP2 is used as the source of the VPN tunnel and IP1 is used as the destination of the VPN tunnel ( destination). In this way, the VPN tunnel has been established. It should be noted that the route to the destination cannot be through the VPN tunnel, but must be through the network of the corresponding ISP itself, otherwise there will be a loop (loop) and the establishment of the VPN tunnel cannot be completed. Therefore, it may be necessary to add a static route to specify the route.

Next, build an interior gateway protocol (IGP) or static route according to the general network construction method, so that the IP addresses allocated on the routers of CDN1 and CDN2 can specify routes for each other.

  Establish an internal BGP (iBGP) exchange between CDN1 and CDN2. It should be noted that the route of the regional address exchanged by CDN1 and CDN2 must be reached through the VPN tunnel. Static routing can be added if necessary.

Procedure 2: CDN (Content Delivery Network) network construction

Like the construction method of procedure 1. It should be noted that during iBGP exchange, there is no need to exchange routes outside the CDN network. In addition, when exchanging routes with local ISPs, choose to only announce your own IP address as much as possible, without receiving any routes from local ISPs, and establish standard routes. Moreover, it should be noted that the route lengths announced by all CDN routers to the external ISP are the same length.

In addition, use the IP address of the local ISP to set up the cache server. The cache server should be on the same subnet as the interface used by the local CDN router as far as possible. And establish the standard routing of the cache server (the gateway of the local ISP or CDN can be used).

  Set redirection:

    Parameters such as WCCP (Web Cache Coordinate Protocol), WCCP2 or any port redirection can be set on routers and cache servers;

  Can use a layer 4 switch for layer 4 redirection;

 The cache server can be directly used as the connection entrance and exit in the ISP and CDN, forcing all communication traffic to pass through the cache server. Or redirect cacheable content to the cache server by any other practicable means.

Due to the characteristics of BGP, when any ISP wants to obtain the information content on the CDN network, it will compare the routes with the same length, and choose the shortest path as the route for the information to be transmitted outward. Therefore, information will reach any node on the CDN network with the shortest path. Due to the effect of redirection, the local cache server will re-send the request to the CDN to retrieve information. The CDN sends the data retrieval request to the other party's server through the VPN tunnel. Since the IP address of the caching server that sends the request is not the IP address of its own network, the router will choose to use the standard route to send the information back to the caching server, and then the caching server will send the request to retrieve the information ISPs to supply their subscribers.

Since the VPN tunnel has an overhead, the request for transmitting and retrieving data is more acceptable because the transmitted content is less. However, it is unacceptable to return information content through the VPN tunnel, because there is a limitation of overhead. Therefore, it will choose to send via the standard route.

In addition, since the route of the returned information is not specified, the satellite system can also be used for information transmission. The system mode of the present invention has nothing to do with time, so cache servers or network system administrators can actively send or request to update information according to their own data analysis.

Procedure 3: Obtain the information content of the ICP server

A server side cache server (server side cache server) is separately established at the network node of the CDN using the IP address of the CDN, and a private domain name service (DNS) system is established through the local billing system. After pointing the DNS of the cache server on the server side to the private DNS, you can use any technology such as DNS redirection or global server switching load balancing to direct the original host request on the ISP to the server side on the cache server. In this way, ICP can use the CDN network without changing the IP address.

Procedure 4: Build a global content delivery network system

According to the above method, based on various practical considerations, a global content delivery network system can be flexibly constructed.

With the above system, most of the information provided by the Internet Content Provider (ICP) will be cached on the cache server, so that the ISP mainly hosting hosting cannot charge the ICP for the amount of data. However, according to the present invention, a billing system can be established on the cache server to record and make statistics on the amount of information actually transmitted and time and other data, and then provide the recorded and statistical data to the mainframe. Based on which the ISP charges the hosted ICP. Therefore, there will be no loss to the ISP providing the information. The builder of the delivery system of the present invention can uniformly provide cache servers to all major ISPs and establish a billing system. The bandwidth transmitted by the cache server can be recorded in detail through the billing system, and made into individual ISP bills, and handed over to the ISP to charge its hosting customers. Since the actual transmission bandwidth is shown on the bill, the customer's payment is reasonable. In fact, the ISP does not use the bandwidth of its connection to the Internet to transmit information, but uses the content delivery network system of the present invention to transmit, which can save a lot of bandwidth costs. And the builder of the content delivery network system of the present invention can charge service fees from each ISP as appropriate.

Since the construction of the above CDN network is entirely based on BGP routing, it will be very close to the physical network routing (unless other VPN tunnels exist). The various data obtained on the CDN will be far more valuable than those obtained from other networks.

It should be understood that although the content delivery network system with two network nodes is used as an example for illustration, the present invention can be extended to a system with multiple network nodes. In addition, various modifications and changes can be made without departing from the spirit and scope of the present invention.

According to the system of the present invention, it can be guaranteed that the information request will be sent to the nearest cache server without changing the writing method of the webpage hosted by the client, which is better than the traditional system that must change the webpage and use DNS interpretation to deliver the information content More convenient and faster.

The above method does not limit the construction method of the network itself, that is, it does not limit the existing structure of the network or its internal and external communication protocol exchange, or the equipment interface of the line used. Therefore, the versatility of the present invention is applicable to global network systems. At present, the site proximity on the Internet is still unsolvable, and only DNS or node calculation (hop count) can be used for proximity. However, the present invention can ensure that information arrives by the shortest route.

Taking HiNet in Taiwan and AboveNet in the United States as two network nodes as an example, the settings are as follows:

This network: AS-9836, IP-202.143.128.0/19

AboveNet: AS-6461, IP-208.185.154.0/23

HiNet: AS-3462, IP-210.71.224.0/24

Relevant settings of the Taiwan node:

clock timezone TPE 8

ip subnet-zero

ip wccp web-cache! interface Loopback2ip address 202.143.129.253.255.255.255.255ip router isis! interface Loopback3ip address 210.71.224.5.255.255.255.255! interface Tunel1ip address 208.185.155.6.255.255.255.252ip directed-broadcastip wccp web-cache redirect outip router isistunnel source 210.71.224.5tunnel destination 208.185.154.3! interface Serial1/1description Hinet2iaspbandwidth 1544ip address 210.59.213.205.255.255.255.252no ip redirectsno ip proxy-arpencapsulation pppno ip route-cacheno ip mroute-cacherandom-detectno cdp enablehold-queue 104 router isisnet 49.0001.2021.4312.9253.00! router bgp 9836no synchronizationbgp log-neighbor-changesneighbor APEXTHINET peer-groupneighbor APEXTHINET remote-as 9836neighbor APEXTHINET update-source Loopback1neighbor APEXTHINET version 4neighbor APEXTHINET route-reflector-clientneighbor APEXTHINET next-hop-selfneighbor APEXTHINET filter-list 41 outneighbor 208.185.154.2 peer-group APEXTHINET no auto-summary! ip classless ip route 0.0.0.0 0.0.0.0 Serial1/1ip route 208.185.154.2 255.255.255.255 Tunnel 1ip route 208.185.154.3 255.255.255.255 Serial1/1ip as-path access-path acc1asmit-list 44 peress .*! ! ip prefix-list EBGP seq 5 permit 0.0.0.0/0 le 19 US node related settings clock timezone TPE 8ip subnet-zeroip wccp web-cache! interface Loopback2ip address 202.143.129.251.255.255.255.255ip router isis! interface Loopback3ip address 208.185.154.3 255.255.255.255! interface Tunnel1ip address 208.185.155.5 255.255.255.252ip directed-broadcastip wccp web-cache redirect outip router isistunnel source 208.185.154.3tunnel destination 210.71.224.5! router isisnet 49.0001.2021.4312.9251.00! router bgp 9836no synchronizationbgp log-neighbor-changesneighbor AboveNet peer-groupneighbor AboveNet remote-as 6461 neighbor AboveNet ebgp-multihop 3neighbor AboveNet update-source FastEthernet0/0neighbor AboveNet version 4neighbor AboveNet next-hop-selfneighbor AboveNet filter-list 41 outneighbor APEXTHINET peer-groupneighbor APEXTHINET remote-as 9836neighbor APEXTHINET updat e-source Loopback1neighbor APEXTHINET version 4neighbor APEXTHINET next-hop-selfneighbor APEXTHINET prefix-list US inneighbor 208.184.104.2 peer-group AboveNetneighbor 208.184.104.3 peer-group AboveNetneighobr 210.200.186.2 peer-group APEXTHINETno auto-summary ! ip classlessip route 0.0.0.0 0.0.0.0 208.184.104.1ip route 210.71.224.5 255.255.255.255 208.184.104.1ip route 210.200.186.2 255.255.255.255 Tunnel1ip as-path access-list 41 permit ^$ip as-path access-list 41 permit ^9346$ip as-path access-list 41 permit ^9747$ip as-path access-list 41 deny. ^* ! ! ip prefix-list US seq 5 permit 0.0.0.0/0 le 19 In addition, you only need to create a cache server locally, and filter the routes outside the north body network in the iBGP announcement to complete the construction of the second procedure .

The current cache server can only calculate the bandwidth used by itself, but cannot distinguish the bandwidth usage of each user. For Internet Content Providers (ICP), the meaning of bandwidth is the maximum amount of information that the network can transmit in one second, that is, network performance (performance), which is an indicator of customer (ICP) satisfaction. At present, the network management system provided by the ISP is based on the average value of 600 seconds as the billing basis. According to the network system of the present invention, the cache server is to record the client's information transmission data in detail, including transmission time, customer information (IP address), transmission data volume and time spent. The average bandwidth usage is obtained by dividing the amount of data sent by the time spent. Then add up the amount of information of all customers and compare it with the actual maximum bandwidth to calculate the factor value at that time. Since the users served by the cache server have no preference settings, it is reasonable to directly multiply the average amount of information sent by each customer by the factor value, and the result is the maximum within 600 seconds (or any custom time) bandwidth usage. The next step is to add up the bandwidth usage of network nodes in various places. The specific method adopted is that the network nodes in each region can first send the relevant data to the regional center for addition, and then each regional center will send their respective addition results to the general center for addition. This can save a lot of unnecessary information flow and make the network operation more efficient.

Since the caching server records the bandwidth actually delivered, it is reasonable to charge colocation customers accordingly. However, the ISP does not use the bandwidth of the Internet to transmit information, but uses the content delivery system of the present invention to transmit. Therefore, ISP can charge users cheaper fees, and the builder of this system can also charge reasonable service fees to ISPs.

Claims (9)

1. A content delivery network system comprising: a communication network; The first network node is configured to provide users with Internet access services; The second network node is used to provide information from the network content provider, and it obtains the routing data of the Border Gateway Protocol (BGP) with the first network node through the Internet; A third network node, which sets standard routes, BGP route announcements and virtual private network (VPN) tunnels via the communication network between the first and second network nodes, and communicates at the communication entrance and exit of the first network node A cache server is provided for storing information transmitted from the second network node using the Internet protocol (IP) address of the third network node, and when a user of the first network node requests a certain piece of information, the first network node It will first go to the cache server to search, if there is the information, it will be directly provided to the user, if there is no information, it will propose to the second network node to retrieve the information through the VPN tunnel After the second network node sends back the information via the standard route, the cache server will provide it to the user. 2. The network system according to claim 1, wherein the cache server records the transmission data of the transmitted information in detail, and the third network node provides the record to the third network node Two network nodes so as to charge the network content provider accordingly. 3. A billing system, which can be used in the network system as claimed in claim 1 or 2, wherein the cache server records the information sent to the user, including the amount of information sent to each host hosting the client and To calculate the average bandwidth usage, add the information volume of all customers, and compare the sum with the actual maximum bandwidth to calculate a factor value, multiply the average information transmission volume of each customer by the The aforementioned factor value is the maximum bandwidth usage within a certain period of time, and billing is based on the maximum bandwidth usage. 4. A method for delivering content via a network, comprising the steps of: establish a communication network; Establishing a first network node, which is used to provide users with Internet access services; establishing a second network node for providing information from a network content provider; The first network node and the second network node mutually obtain routing data of Border Gateway Protocol (BGP) through the Internet; Set standard routing, BGP route announcement and virtual private network (VPN) tunnel between the first and second network nodes through the communication network, and set a cache server at the communication entrance and exit of the first network node , for storing information transmitted from the second network node; When the user of the first network node requests a piece of specific information, it first searches the cache server, and if there is the piece of information, it directly provides it to the user; If there is no said piece of information, requesting to retrieve said piece of information to a second network node via a VPN tunnel; Upon request, the second network node returns the pen information to the cache server via a standard route. 5. The method according to claim 4, further comprising the step of recording the transmission data of the transmitted information in detail by the cache server and providing it to the second network node, so that the second network Nodes charge network content providers accordingly. 6. A method for building a content delivery network system, comprising steps of: establishing first and second network nodes; establishing a basic communication network between the first network node and the second network node; Setting up a virtual private network (VPN) tunnel between the first network node and the second network node for sending a request to retrieve information; setting a standard route between the first network node and the second network node for transmitting information content; set up a cache server at each network node; and implement redirection, forcing all communications to pass through said cache server; The cache server obtains the information content of the host managed by its network node. 7. The method according to claim 6, wherein the step of setting the route is that the first network node and the second network node obtain each other's network address and Border Gateway Protocol (BGP) exchange permission to implement. 8. The method according to claim 6, further comprising the step of: establishing a billing system on the cache server to record the amount of information actually transmitted and time, and provide it to Network nodes in order to bill customers of their hosting. 9. A network management method for a content delivery network system comprising a plurality of network nodes, the method comprising: Set up a cache server at each network node; Setting standard routes and BGP announcements between the network nodes; Setting up a virtual private network (VPN) tunnel between the network nodes; Performing a redirection so that the communication of each network node passes through the caching server provided at said point; When a user of one of the network nodes requests a specific information content, the network node searches from its cache server, and if there is the information, it is directly provided to the user; If the written information is written, the cache server will issue a request to retrieve the content of the information; Transmitting the request for retrieving information content to a cache server of a destination network node having the information content through a VPN tunnel; The cache server of the destination network node responds to the request, and sends the information content back to the requesting cache server via standard routing; Relevant information about the information transmitted by each cache server record; Collect the data recorded by each cache server and organize them into data related to each network node; and Send the sorted data to each corresponding network node, so that each network node can charge the content service provider it hosts accordingly.

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