JP2012175298A - Content distribution method, relay device and content distribution system - Google Patents

Abstract

An object of the present invention is to reduce the load on a network and a distribution server by performing data distribution on behalf of a user terminal rather than a distribution server.
A content distribution method in a relay device that relays content distribution from a distribution server to a user terminal includes a step in which the relay device receives a data acquisition request from a user terminal, and a data received by the relay device. Based on the access information stored in the access information storage unit, the step of storing access information to the distribution server that is the destination of the acquisition request in an access information storage unit that stores the access information for each distribution server Acquiring content from the distribution server and storing the content in a content storage unit inside the relay device or a cache server outside the relay device.
[Selection] Figure 3

Description

  The present invention relates to a content distribution method, a relay device, and a content distribution system.

  When a user terminal views content such as video via a network, the user terminal transmits a data acquisition request to the distribution server, and the distribution server distributes the content in response to the data acquisition request. This is shown in FIG. The distribution server responds one by one to the data acquisition request from the user terminal. That is, the distribution server distributes the content to the user terminal B even if it receives the data acquisition request from the user terminal B for the same content after distributing the content in response to the data acquisition request from the user terminal A. . As shown in FIG. 1, the content is distributed to user terminals A and B via a data relay device.

  Proxy delivery by a proxy server is also possible. This is shown in FIG. The proxy server can download content from the distribution server in advance and execute a data acquisition request from the user terminal on behalf of the proxy server (see Non-Patent Document 1).

Why using a proxy server improves security http://itpro.nikkeibp.co.jp/article/COLUMN/20060825/246379/

  As described above, in the communication system as illustrated in FIG. 1, the distribution server distributes content in response to a data acquisition request from the user terminal A. Further, when a data acquisition request is received for the same content from the user terminal B under the same data relay device, the distribution server distributes the same content. In this way, the same content may flow for each data acquisition request from the user terminal. As a result, useless traffic flows through the network (data relay device-data relay device-distribution server).

  In this way, in the communication system as shown in FIG. 1, the distribution server distributes content for each data acquisition request, and thus consumes a large bandwidth on the network. Further, since the number of times the distribution server responds increases, the load on the distribution server or proxy server increases.

  In a communication system using a proxy server, the user terminals A and B must send a data acquisition request to the proxy server by setting the proxy server. As described above, it is necessary to set the proxy server for each user terminal. Furthermore, there is a possibility that useless traffic flows between the proxy server and the data relay device depending on the installation location of the proxy server.

  It is an object of the present invention to reduce the load on a network and a distribution server by performing data distribution on behalf of a device closer to a user terminal than a distribution server.

The content distribution method of the present invention includes:
A content distribution method in a relay device that relays content distribution from a distribution server to a user terminal,
The relay device receiving a data acquisition request from a user terminal;
The relay device stores the access information to the destination distribution server of the received data acquisition request in an access information storage unit that stores the access information for each distribution server;
The relay device acquires content from the distribution server based on the access information stored in the access information storage unit, and stores the content in a content storage unit inside the relay device or a cache server outside the relay device. Steps,
It is characterized by having.

The relay device of the present invention
A relay device that relays distribution of content from a distribution server to a user terminal,
A data acquisition request receiver for receiving a data acquisition request from a user terminal;
An access information storage unit for storing access information for each distribution server;
An access information analysis unit for storing access information to the delivery server of the destination of the received data acquisition request in the access information storage unit;
A content storage unit for storing content;
A content acquisition unit that acquires content from the distribution server based on the access information stored in the access information storage unit, and stores the content in the content storage unit;
It is characterized by having.

The content distribution system of the present invention includes:
A content distribution system having a relay device that relays distribution of content from a distribution server to a user terminal, and a cache server capable of storing content,
The relay device is
A data acquisition request receiver for receiving a data acquisition request from a user terminal;
An access information storage unit for storing access information for each distribution server;
An access information analysis unit for storing access information to the delivery server of the destination of the received data acquisition request in the access information storage unit;
Have
The cache server is
A content storage unit for storing content;
A content acquisition unit that acquires content from the distribution server based on the access information stored in the access information storage unit, and stores the content in the content storage unit;
It is characterized by having.

  According to the present invention, it is possible to reduce the load on the network and the distribution server.

Diagram showing data flow in communication system The figure which shows the flow of the data in the communication system using a proxy server Schematic diagram of a communication system according to an embodiment of the present invention. 1 is a functional block diagram of a data relay device according to a first embodiment of the present invention. The figure which shows the example of the information stored in an access information storage part The flowchart of the data delivery method based on 1st Example of this invention. Functional block diagram of data relay device and cache server according to second embodiment of the present invention

  Examples of the present invention will be described in detail below.

  FIG. 3 is a schematic diagram of a communication system according to an embodiment of the present invention.

  The user terminals A and B are devices used by users or devices installed in the user's house, such as mobile terminals or personal computers.

  The distribution server is a server in which content is stored. The distribution server may be an HTTP (HyperText Transfer Protocol) server, an FTP (File Transfer Protocol) server, or the like. The content indicates data stored in a distribution server such as an image or a video.

  The data relay apparatus 10 is an apparatus constituting an IP (Internet Protocol) network, an ATM (Asynchronous Transfer Mode) network, an STM (Synchronous Transfer Mode), a telephone network, and the like. The data relay apparatus 10 may be a relay apparatus on an IP network such as a router or a switch. The data relay device 10 relays the distribution of content from the distribution server to the user terminals A and B.

  In the embodiment of the present invention, the data relay device 10 collects access information from the user terminals A and B to the distribution server, and stores the content in the content storage unit 11 based on the collected access information. For example, content that is frequently accessed and content that requires a large bandwidth are stored in the content storage unit 11 in advance.

  When the user terminal A transmits a data acquisition request to the distribution server, the distribution server distributes content in response to the data acquisition request. The data acquisition request is analyzed by the data relay device 10, and content with a high access frequency or content requiring a large bandwidth is stored in the content storage unit 11. The content storage unit 11 may exist inside the data relay device 10 or may exist in a cache server connected to the outside of the data relay device 10. When the user terminal B transmits a data acquisition request for the same content, the data relay device 10 can distribute the content from the content storage unit 11 to the user terminal B by proxy.

<First embodiment>
Next, a case where the data storage unit exists inside the data relay device will be described.

  FIG. 4 is a functional block diagram of the data relay apparatus 10 according to the first embodiment of the present invention. The data relay apparatus 10 includes a data acquisition request receiving unit 101, an access information storage unit 103, an access information analysis unit 105, a content acquisition unit 107, a content distribution unit 109, and a content storage unit 111.

  The data acquisition request receiving unit 101 receives a data acquisition request for requesting distribution of content stored in the distribution server from the user terminal. From the destination of the data acquisition request, the host name or IP address of the distribution server, the content path or URI (Uniform Resource Identifier) can be known. By combining the host name (or IP address) and the content path (or URI), it is possible to know where the content exists. The combination of the host name and the content path may be expressed as a URL (Uniform Resource Locator).

  The access information storage unit 103 stores access information for each distribution server. FIG. 5 shows an example of access information stored in the access information storage unit 103. For example, the access information storage unit 103 stores the destination of the data acquisition request (host name or IP address of the distribution server, content path or URI, etc.), the number of transmission source terminals of the data acquisition request (number of IP addresses or MAC addresses), A traffic band that communicates with the data relay apparatus 10 and the number of packets per second (PPS (Packet Per Second)) are stored.

  In addition, the access information storage unit 103 acquires the content in the content storage unit 111 in the order (Rank) when sorting in the order of the number of transmission source terminals (or the order of decreasing) or the order of the bandwidth (or the order of decreasing). A download flag indicating whether or not the content is stored, and an update date and time indicating the date and time when the content is acquired in the content storage unit 111 may be stored.

  Note that FIG. 5 shows an example of access information stored in the access information storage unit 103. Some information may not be stored, and other information may be stored. For example, any one of the band and the PPS may be stored as the information regarding the band. Further, as information indicating whether or not the content exists in the content storage unit 111, either a download flag or an update date / time may be stored.

  The access information analysis unit 105 analyzes access information to the destination distribution server of the received data acquisition request. The access information analysis unit 105 collects access frequency information of a distribution server having a high access frequency, and stores the access information in the access information storage unit 103. This access frequency information is collected for each host name (or IP address) of the distribution server or for each combination of the host name (or IP address) of the distribution server and the content path (or URI). Specifically, when the data acquisition request receiving unit 101 receives the data acquisition request, the access information analyzing unit 105 in the access information storage unit 103 receives the destination of the distribution server of the data acquisition request (host name and content path). ) Is increased by one. When acquiring a data acquisition request to the distribution server for the first time, since no access information exists in the access information storage unit 103, a new entry is added in the access information storage unit 103. Next, the access information analysis unit 105 sorts the access information stored in the access information storage unit 103 in order of access frequency, and assigns an order (Rank). And the access information analysis part 105 extracts the content of a predetermined number of delivery servers in order with high access frequency. For example, the access information analysis unit 105 extracts the content of a predetermined number of distribution servers in descending order of the number of transmission source terminals.

  Alternatively, the access information analysis unit 105 measures the bandwidth required for distributing the content and stores the access information in the access information storage unit 103. Specifically, the access information analysis unit 105 extracts response traffic to the data acquisition request from the address and port number of the distribution server. For the extracted traffic, the bytes per second, bits per second, or packets per second of the traffic communicating with the data relay apparatus 10 are measured and stored in the access information storage unit 103. This measurement of traffic may be measured for the first certain time when content is transmitted in response to a data acquisition request, or may be measured periodically. The measured bandwidth or PPS is stored in the access information storage unit 103. Next, the access information analysis unit 105 sorts the access information stored in the access information storage unit 103 in descending order of bandwidth (or in ascending order), and extracts a predetermined number of distribution server contents in descending order of bandwidth.

  The content acquisition unit 107 stores the content in the content storage unit 111 based on the access information stored in the access information storage unit 103. For example, the content acquisition unit 107 stores content of a distribution server with a high access frequency or content of a distribution server with a large necessary bandwidth in the content storage unit 111. The content may be stored in the content storage unit 111 in advance by analyzing the access frequency at an arbitrary timing, or may be stored when the content is transmitted (downloaded) from the distribution server to the user terminal. When the content is stored, the download flag or the update date / time is changed in the access information storage unit 103.

  When the content in response to the data acquisition request is stored in the content storage unit 111, the content distribution unit 109 distributes the content in response to the data acquisition request from the content storage unit 111 instead of the distribution server. Whether or not the content corresponding to the data acquisition request is stored in the content storage unit 111 can be recognized by referring to the download flag or the update date and time stored in the access information storage unit 103. When the content distribution unit 109 distributes content instead of the distribution server, the data acquisition request is discarded by the data relay device 10 (for example, the data acquisition request reception unit 101) and does not need to be transmitted to the distribution server. Further, since the data acquisition request does not need to be transmitted to the distribution server, the domain name resolution message may be discarded by the data relay device 10 when the domain name resolution message of the distribution server is generated from the user terminal.

  FIG. 6 is a flowchart of the data distribution method according to the first embodiment of the present invention.

  First, the data acquisition request receiving unit 101 receives a data acquisition request (S101). The content distribution unit 109 extracts the host name and the content path that are the destination of the data acquisition request, and whether or not a download flag is set for the content for the data acquisition request (or whether an update date and time is set). Is confirmed (S103).

  When the download flag is not set, the data acquisition request receiving unit 101 does not discard the data acquisition request. That is, a data acquisition request is transmitted to the distribution server, and the distribution server distributes the content (S105).

  On the other hand, when the download flag is set, the data acquisition request receiving unit 101 discards the data acquisition request. In response to the discarded data acquisition request, the content distribution unit 109 distributes the content corresponding to the data distribution request from the content storage unit 111 to the user terminal (S107).

  At this time, the access information analysis unit 105 accumulates the access information in the access information storage unit 103 (S109). Specifically, the access information analysis unit 105 counts the number of transmission source terminals (the number of IP addresses or the number of MAC addresses) that has transmitted a data acquisition request for the extracted host name and content path, and the access information storage unit 103. Alternatively, the access information analysis unit 105 measures, for the extracted host name and the content path, the bytes per second, the bits per second, or the packets per second of the traffic through which the content corresponding to the data acquisition request communicates with the data relay device 10, and stores the access information Stored in the unit 103.

  Further, the access information analysis unit 105 sorts the counted number of transmission source terminals or measured bandwidths in ascending or descending order, and the predetermined number in descending order of content or bandwidth of a predetermined number of distribution servers in descending order of the number of transmission source terminals. The contents of the distribution server are extracted (S111).

  The content acquisition unit 107 acquires the extracted content of the distribution server from the distribution server (S113). At this time, a download flag or an update date / time is set in the access information storage unit 103. The content may be acquired in advance by analyzing access information, or may be acquired when a data acquisition request is transmitted to the distribution server in step S105 and the content is downloaded from the distribution server to the user terminal.

  Note that steps S109 to S113 may be performed simultaneously with steps S103 to S107, or may be performed before steps S103 to S107.

<Second embodiment>
Next, a case where the data storage unit exists in a cache server connected to the outside of the data relay device will be described.

  FIG. 7 is a functional block diagram of the data relay device 10 and the cache server 20 according to the second embodiment of the present invention. The data relay device 10 includes a data acquisition request receiving unit 101, an access information storage unit 103, an access information analysis unit 105, and a data acquisition request redirect unit 113. The cache server 20 includes a data acquisition request receiving unit 201, a content acquisition unit 207, a content distribution unit 209, and a content storage unit 211.

  Since the data acquisition request receiving unit 101, the access information storage unit 103, and the access information analysis unit 105 are the same as those in the first embodiment, description thereof is omitted. Also, the content acquisition unit 207 and the content storage unit 211 operate in the same manner as the content acquisition unit 107 and the content storage unit 111 in the first embodiment.

  When the content for the data acquisition request is stored in the cache server 20, the data acquisition request redirect unit 113 distributes the content for the data acquisition request from the cache server 20 instead of the distribution server. Whether the content corresponding to the data acquisition request is stored in the cache server 20 can be recognized by referring to the download flag or the update date / time stored in the access information storage unit 103.

  Specifically, the data acquisition request redirect unit 113 transmits a redirect message for the data acquisition request to the user terminal, and causes the user terminal to transmit a data acquisition request to the cache server. In this case, the user terminal that has received the redirect message accesses the cache server 20 specified by the redirect message. Alternatively, the data acquisition request redirecting unit 113 may convert the address of the distribution server included in the data acquisition request into the address of the cache server 20, and the cache server 20 may respond to the data acquisition request. In this case, the user terminal can access the cache server 20 without being aware of the address translation.

  The data acquisition request redirect unit 113 may set a VPN (Virtual Private Network) tunnel for the cache server 20. This VPN tunnel is set to forcibly direct the traffic destination to the cache server 20 by a redirect message or address translation.

  When the data acquisition request receiving unit 201 of the cache server 20 receives the redirected data acquisition request or the address-converted data acquisition request, the content distribution unit 209 transmits the content corresponding to the data acquisition request to the content storage unit instead of the distribution server. 2. Deliver from 211. When the content distribution unit 209 distributes content instead of the distribution server, the data acquisition request is discarded by the data relay device 10 (for example, the data acquisition request reception unit 101) and does not need to be transmitted to the distribution server. Further, since the data acquisition request does not need to be transmitted to the distribution server, the domain name resolution message may be discarded by the data relay device 10 when the domain name resolution message of the distribution server is generated from the user terminal. At this time, the address of the cache server 20 may be returned as a domain name resolution message.

  The flowchart of the data distribution method according to the second embodiment of the present invention is also performed in the same manner as in FIG. 6 except that the data acquisition request is transferred to the cache server and the content is distributed from the cache server.

<Effect of Example>
As described above, in the embodiment of the present invention, the delivery of content takes over at a position closer to the user terminal. Specifically, the data relay device analyzes the contents of the packet and responds on behalf of the proxy, thereby reducing the number of responses to be made by the distribution server and preventing unnecessary traffic from flowing into the network. As a result, network resources and distribution server resources can be saved, and the load on the network and distribution server can be reduced.

  In the embodiment of the present invention, setting of a proxy server is not necessary.

  For convenience of explanation, the data relay device and the cache server according to the embodiment of the present invention are described using functional block diagrams. However, the data relay device and the cache server of the present invention may be hardware, software, or their It may be realized in combination. For example, each function unit of the data relay device and the cache server may be realized by software, and may be realized as a program in the data relay device and the cache server. In addition, two or more embodiments and each component of the embodiments may be used in combination as necessary.

  As mentioned above, although the Example of this invention was described, this invention is not limited to said Example, A various change and application are possible within a claim.

  It can be used when distributing data in a network in which a server and a terminal are connected by a router connected by IP or the like and HTTP, file distribution, video distribution, etc. are provided as services.

DESCRIPTION OF SYMBOLS 10 Data relay apparatus 11 Content storage part 101 Data acquisition request reception part 103 Access information storage part 105 Access information analysis part 107 Content acquisition part 109 Content distribution part 111 Content storage part 113 Data acquisition request redirect part 20 Cache server 201 Data acquisition request reception Unit 207 content acquisition unit 209 content distribution unit 211 content storage unit

Claims (9)

A content distribution method in a relay device that relays content distribution from a distribution server to a user terminal,
The relay device receiving a data acquisition request from a user terminal;
The relay device stores the access information to the destination distribution server of the received data acquisition request in an access information storage unit that stores the access information for each distribution server;
The relay device acquires content from the distribution server based on the access information stored in the access information storage unit, and stores the content in a content storage unit inside the relay device or a cache server outside the relay device. Steps,
A content distribution method comprising: The step of storing the access information counts the number of data acquisition requests to the distribution server and stores it in the access information storage unit,
The content distribution method according to claim 1, wherein the content storing step stores a predetermined number of contents in descending order of the number of data acquisition requests. The step of storing the access information measures a bandwidth required for distributing content in response to a data acquisition request, and stores the bandwidth in the access information storage unit.
The content distribution method according to claim 1, wherein the step of storing content stores a predetermined number of content in descending order of bandwidth.   The relay device further includes a step of distributing the content from the content storage unit without transmitting the data acquisition request to the distribution server when content corresponding to the data acquisition request is stored in the content storage unit. The content delivery method according to any one of claims 1 to 3.   The relay apparatus further includes a step of distributing the content to the cache server without transmitting the data acquisition request to the distribution server when the content corresponding to the data acquisition request is stored in the cache server. Item 4. The content distribution method according to any one of Items 1 to 3.   The content distribution method according to claim 5, wherein the distributing step causes the relay device to distribute the content to the cache server by transmitting a redirect message for a data acquisition request to the user terminal.   6. The distributing step according to claim 5, wherein the relay device distributes the content to the cache server by converting an address of the distribution server included in a data acquisition request into an address of the cache server. Content distribution method. A relay device that relays distribution of content from a distribution server to a user terminal,
A data acquisition request receiver for receiving a data acquisition request from a user terminal;
An access information storage unit for storing access information for each distribution server;
An access information analysis unit for storing access information to the delivery server of the destination of the received data acquisition request in the access information storage unit;
A content storage unit for storing content;
A content acquisition unit that acquires content from the distribution server based on the access information stored in the access information storage unit, and stores the content in the content storage unit;
A relay device. A content distribution system having a relay device that relays distribution of content from a distribution server to a user terminal, and a cache server capable of storing content,
The relay device is
A data acquisition request receiver for receiving a data acquisition request from a user terminal;
An access information storage unit for storing access information for each distribution server;
An access information analysis unit for storing access information to the delivery server of the destination of the received data acquisition request in the access information storage unit;
Have
The cache server is
A content storage unit for storing content;
A content acquisition unit that acquires content from the distribution server based on the access information stored in the access information storage unit, and stores the content in the content storage unit;
A content distribution system.

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