JP2003006087A - Information processor, its method, program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce communication traffic. SOLUTION: Contents are provided from a server 1 to a PC 3-1 which stores the provided contents. When a PC 3-2 newly requests the provision of contents to the server 1 for instance, a list of PCs 3 receiving the provision of the same contents is supplied to the PC 3-1. The PC 3-2 selects the PC 3-1 whose packet transmitting/receiving response time is shortest as a PC from which the contents are provided on the basis of the supplied list. Thereby the PC 3-1 provides the contents stored in itself to the PC 3-2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus and method, a program, and a recording medium, and in particular, it is used when data of the content is exchanged between apparatuses receiving the same content. The present invention relates to a suitable information processing device and method, a program, and a recording medium.

[0002]

2. Description of the Related Art In recent years, ISDN (Integrated Services Digi
tal Network), ADSL (Asymmetric Digital Subscriber)
Lines, CATV (Cable Television), and other services that enable high-speed data transfer using lines are becoming widespread. A constant connection service to the Internet using these lines is becoming popular. With the spread of these, data exchange, distribution of live streaming data, etc. have come to be performed by communication using a line such as the Internet between arbitrary users.

[0003]

The bit rate of a device connected to a user's network is about several hundred kbps to 1 Mbps. If packets are sent to multiple-connection clients by unicast using the device connected to these networks as a server, network traffic increases and packet throughput tends to deteriorate.In such an environment, live streaming etc. Content distribution that emphasizes the real-time nature of
There was a problem of lack of reliability in quality.

It has been proposed to deliver data by multicast in order to prevent an increase in traffic due to sending packets of the same content using unicast, but on the Internet, the same content is provided at the same time. Data reception by multicast is not popular because it is rare to receive data, and as a result, data distribution by unicast is generally used to reliably deliver data to multiple clients. .

As a method for surely delivering data to a plurality of clients by unicast, it is conceivable to construct a mechanism in which the same content can be downloaded (delivered) from any server by distributing it to a plurality of servers. However, there is a problem that the cost becomes high because the number of servers and the number of lines and bandwidths must be provided.

[0006] Video distribution on the Internet and WWW (Wo
rld Wide Web) Traffic is different from voice communication used in telephones, etc., and has a large burstiness, so it is difficult to predict the communication band, and streaming data is always distributed in the same band in real-time data distribution. To secure the bandwidth, the bandwidth control is performed at the router level, or the bandwidth is controlled by the service provider side of the Internet. However, from the user's standpoint (communication application level), these QOS (Qualit
There was a problem that it was not possible to control y Of Service).

The present invention has been made in view of such a situation, and it is possible to reduce the traffic by making it possible to exchange the data of the content between computers that are provided with the same content. The purpose is to be able to do it.

[0008]

A first information processing apparatus according to the present invention is a creation means for creating a list of management means for managing content and a list of apparatuses that are provided with content managed by the management means. And a first device that provides the list created by the creating device to the other device when the device and the other device request to provide the content managed by the managing device. As a result of performing the process using the list, when another device requests to provide the content again, the second providing means for providing the content managed by the managing means to the other device is included. It is characterized by

[0009] When the content providing request is made from another device, the creating means adds information of the other device to the list, and when the other device makes a request to stop providing the content, It is possible to delete the information of other devices from the list.

[0010] When the information of one or more devices is described in the list, a determining means for determining whether or not there is another device providing the content by the second providing means is further provided. If the determination means determines that there is no other device that is providing the content by the second provision means, the second provision means is at least one of the devices listed in the list. It is possible to start providing content to one device.

The first information processing method of the present invention includes a management step of managing content, a creation step of creating a list of devices that are provided with the content managed by the processing of the management step, and the like. When the device of 1 requests to provide the content managed by the process of the management step, the first providing step of providing the list created by the process of the creating step to the other device and the other device As a result of performing the process using the list, when another device requests to provide the content again, the second providing step of providing the content managed in the process of the managing step to the other device. It is characterized by including.

The program of the first recording medium of the present invention is
A management step that manages the content, a creation step that creates a list of devices that are provided with the content that is managed in the processing of the management step, and a content management step that other devices manage in the processing of the management step. When a request for provision is made, as a result of the first providing step of providing the list created in the process of the creating step to another device and the process using the list by another device, the other device Includes a second providing step of providing the content managed in the processing of the managing step to another device when the content is requested to be provided again.

The first program of the present invention comprises a management step of managing content, a creation step of creating a list of devices that are provided with the content managed by the processing of the management step, and another device. When the user requests the provision of the content managed in the process of the management step, the first provision step of providing the list created in the process of the creating step to another device and the list provided by the other device. As a result of carrying out the processing using, the second providing step of providing the content managed by the processing of the managing step to the other apparatus when the other apparatus requests to provide the content again To run.

The second information processing apparatus of the present invention receives, from another device, the information and the content of the other device, and the transmitting means for transmitting the request for providing the content to the other device. The receiving means for receiving a list composed of information of the devices, the judging means for judging the device having the shortest response time among the devices listed in the list received by the receiving means, and the judging means. Instructing means for instructing the device determined to have the shortest response time to start providing the content, and processing means for receiving the content provided by the device according to the instruction from the instructing means and processing the content. It is characterized by including.

The determining means transmits a request packet to the devices listed in the table, receives an echo packet corresponding to the request packet, and transmits the request packet from the time when the request packet is transmitted until the echo packet is received. By measuring the time, the device with the shortest response time can be determined.

Measuring means for measuring the delay time of the content received from the device, and second for judging whether or not the delay time measured by the measuring means is equal to or more than a predetermined threshold value.
When the second judgment means judges that the delay time has become equal to or longer than the predetermined threshold value, the judgment means can make the judgment again.

A second information processing method according to the present invention includes a transmission control step for controlling transmission of a request to provide content to another device, and receiving information and content from another device from the other device. The reception control step that controls the reception of the list that includes the information of the devices that are present, and the determination that determines the device with the shortest response time among the devices that are listed in the list that was received in the processing of the reception control step. Step, and an instruction step for instructing a device whose response time is determined to be the shortest in the processing of the determination step to start providing content, and receiving the content provided by the device according to the instruction of the processing of the instruction step And a processing step of processing the content.

The program of the second recording medium of the present invention is
A transmission control step of controlling transmission of a request to provide content to another device, and control of reception of a list including information of the other device and information of the device receiving the content from the other device. Of the reception control step and the device listed in the list received in the process of the reception control step, the determination step of determining the device with the shortest response time, and the shortest response time in the process of the determination step. An instruction step for instructing the determined device to start providing the content; and a processing step for receiving the content provided by the device according to the instruction of the processing of the instructing step and processing the content. Characterize.

A second program of the present invention is a transmission control step for controlling transmission of a request for providing content to another device, and a device receiving information and content of another device from the other device. A reception control step for controlling reception of a list composed of information of the information, and a determination step for determining a device having the shortest response time among the devices described in the list received in the process of the reception control step. , An instruction step for instructing the device, which is determined to have the shortest response time in the process of the determination step, to start providing the content, and the content provided by the device according to the instruction by the process of the instruction step, And causing the computer to perform the processing steps for processing the content.

A first information processing apparatus and method of the present invention,
In addition, in the program, a list of devices that are provided with the content is created, and when the other device requests to provide the content, the created list is provided to the other device, and the other device is provided. As a result of performing the processing using the list, the content is provided when another device requests to provide the content again.

A second information processing apparatus and method of the present invention,
In addition, the program receives a list including information of the other device and information of the device for which the content is provided from the other device, and receives the most response from the devices described in the list. A device with a short time is judged,
The device determined to have the shortest response time is instructed to start providing the content.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of an embodiment of an information processing system to which the present invention is applied. The server 1 is connected to a personal computer (hereinafter abbreviated as PC) 3-1 via a router 2-1 via a network such as the Internet or a LAN (Local Area Network).

PCs 3-2 to 3-5 (hereinafter PC3-1
If there is no need to distinguish 3 to 5 individually, simply use P
Described as C3. The same applies to other devices)
Are also connected to the routers 2-2 to 2-5, respectively, and can exchange data with the server 1 and other PCs 3.

FIG. 2 is a diagram showing an internal configuration example of the server 1. CPU (Central Processing Unit) 1 of server 1
1 executes various processes according to a program stored in a ROM (Read Only Memory) 12. RAM
The (Random Access Memory) 13 appropriately stores data and programs necessary for the CPU 11 to execute various processes. The input / output interface 15 is
An input unit 16 including a keyboard and a mouse is connected, and a signal input to the input unit 16 is output to the CPU 11. Further, the input / output interface 15 is also connected to an output unit 17 including a display and a speaker.

Further, the input / output interface 15 includes
A storage unit 18 including a hard disk and a communication unit 19 for exchanging data with another device (PC3) via a network such as the Internet are also connected. The drive 20 is used when reading data from or writing data to a recording medium such as a magnetic disk 31, an optical disk 32, a magneto-optical disk 33, and a semiconductor memory 34.

The PC 3 has basically the same configuration as the server 1, and the description thereof will be omitted.

The server 1 stores a plurality of contents in the storage unit 1.
I remember in 8. A unique identifier (such as an ID number) (hereinafter referred to as a content ID) is assigned to each of the contents, and the content ID allows the server 1 and the PC 3 to identify one content without contradiction. There is. The server 1 manages the content by the content ID and, when an access request (content provision request) is made, also manages a list (hereinafter, referred to as an access list) regarding the PC 3 requesting the access.

The operation of the information processing system shown in FIG. 1 will be described below. First, referring to the flowchart of FIG. 3, one of the PCs 3-1 to 3-5
The process when the server 3 requests the provision of the content managed by the server 1 will be described. In step S1, the PC 3 requests the server 1 to provide the content. For example, the user of the PC 3 connects the PC 3 and the server 1 via the network, and selects a desired content from the list of contents provided by the server 1 to issue a request for providing the content.

In step S1, when a request for providing content is issued to the server 1, as a corresponding process, the server 1 sends an access list corresponding to the content to the PC 3 that issued the request. In step S2, the PC 3 receives the access list in order to transmit the access list. The access list requests the provision of the same content (same content ID) at that time, and the IP (Internet P
rotocol) is a list of addresses.

In step S3, the PC 3 selects a route according to the received access list. The route selection performed in step S3 is to select a route having the shortest packet arrival time. Therefore, the server 1 or the PC 3 other than the PC 3 performing the process of FIG. 3 is selected as the route having the shortest packet arrival time.

In step S3, information is transmitted to the PC3 selected as the route having the shortest packet arrival time in step S4. Step S
The information sent in 4 is at least the IP
Address and content ID of the content to be provided
including. When the transmission of the information is completed, the content is transmitted from the server 1 or the PC 3 which has received the information. Here, PC3 that requested the content is PC3-
2, and PC3 which transmits content is PC3-1.

At step S5, the PC 3-2 sets P
By receiving and processing the content transmitted by C3-1, the content desired by the user is provided. As described above, in the present invention, the content is not always provided from the server 1 that manages the content, but is provided from another PC 3 that is provided with the same content (at that time point). , If provided from a route with optimal throughput).

As described above, by providing the content from other than the server 1, the number of mirror servers is substantially increased, and the processing performed by the server 1 itself and the traffic can be reduced. It will be possible.

In step S6, the PC 3-2 determines whether or not the user has instructed to stop providing the content. If it is determined that the user has not instructed to stop the content provision, the process proceeds to step S7. In step S7, the content is
It is determined whether or not it is provided from the server 1.

This determination includes, in the content received by the PC 3-2, a flag (hereinafter, appropriately referred to as a master flag) indicating whether or not the content is provided by the server 1 as the content information. The master flag may be referred to so that the process is performed.

In this case, since the content is provided from the PC 3-1, the content is stored in the server 1 in step S7.
Is determined not to be provided by the
Go to 8. In step S8, the delay time is measured. The delay time is measured by using the time information included in the received content packet and the clock (timer) included in the PC 3-2.

In step S9, the delay time is the threshold value τ
Is greater than or equal to. When it is determined in step S9 that the delay time is not greater than the threshold value τ, the process returns to step S5, and the subsequent processing, that is, the reception and processing of the content from the PC 3-1 is maintained.

On the other hand, in step S9, when it is determined that the delay time is larger than the threshold value τ, that is, when it is determined that the delay time is not negligible, the process returns to step S3 and the subsequent processing is repeated. Be done. That is, the route is selected again using the access list already received in step S2, and the content is received and processed based on the selection.

On the other hand, if it is determined in step S6 that the user has instructed to stop receiving the content, the process proceeds to step S10. In step S10,
Stop notification is given. This stop notification is
This is performed for the server 1 and the PC 3-1. Or PC
3-1 may be performed, and thereafter, the PC 3-1 may notify the server 1 that the PC 3-2 has instructed to stop providing the content.

While such processing is performed on the side of the PC 3 (PC 3-2 in this case) that has issued the content provision request, on the side of the server 1, the processing of the flowchart shown in FIG. 4 is executed. It That is, step S21
In step S1, the content providing request transmitted from the PC 3 in step S1 is received. In response to the request, in step S22, the server 1 adds information including the IP address of the PC 3 that has transmitted the content request to the managed access list.

In step S23, the access list is transmitted. As a result, the PC 3 receives the access list in step S2. In step S24, the reception stop notification transmitted from the PC 3 in step S10 is received.

Between the processes of steps S23 and S24, if the device provided with the shortest path to the PC 3 and capable of providing the content is selected by the process of step S3, the process of providing the content is performed. Be seen.

In step S25, the PC 3 which has issued the stop notification is deleted from the access list. In step S26, the server 1 directly determines whether or not the connection is lost as a result of deleting the PC3 that has issued the stop notification from the access list in step S25, in other words, other than the PC3 that has issued the stop notification. It is determined whether or not there is the PC 3 that has provided the content.

When it is determined in step S26 that there is no connection, the process proceeds to step S27, and it is determined whether or not an IP address exists in the access list. The process in step S27 is a process of determining whether or not the PC 3 requesting the provision of the content exists. If the PC 3 does not exist, the process of the flowchart shown in FIG. 4 is terminated and a new request is made. Is put in a standby state.

On the other hand, when it is determined in step S27 that the PC 3 requesting the content provision exists, the route is selected in step S28. If the process proceeds to step S28, it means that there is a PC3 requesting the content provision, but there is no PC3 directly receiving the content provision from the server 1. This means that the PC3s are the same. It indicates that the content is only exchanged, and as a result, the subsequent part (new part) of the content is P
It means that there is a possibility that it will not be provided to the network configured by C3.

Therefore, in step S28, the server 1 selects the PC 3 located on the route closest to the server 1 by using the managed access list, and starts providing the content based on the selection result.

On the other hand, if it is determined in step S26 that a connection exists, the process proceeds to step S29, the connection is maintained, and the provision of the content is maintained.

Next, referring to the flowchart of FIG.
PC3 that is both the recipient and sender of the content
The operation of (PC 3 functioning as a mirror server) will be described. In this case, the operation is performed by the PC 3-1. The PC 3-1 receives the content provided from the server 1 and also provides the content to the PC 3-2. Here, the PC 3-1 has already
The server 1 executes the process of the flowchart shown in FIG.
The description will be given assuming that the content is being provided from the.

In step S41, in the process of step S3 in the PC 3-2, as a result of the route selection,
As a result of the information selected by the PC 3-2 being transmitted in the processing of step S4, the PC 3-1 receives the content provision request by receiving the information. In step S42, the content requested to be provided is received from the server 1, and the stored data is inspected and read.

In step S43, the read content data is packetized, and is transmitted to the PC 3-2 in step S44. When the generation of the packet and the transmission of the packet are repeated and the notification of the reception stop is received from the PC 3-2 in step S45, the stop of the packet transmission is executed in step S46.

As described above, the PC 3-1 receives the content provided from the server 1, while providing the content to the PC 3-2 by playing the role of the mirror server.

In the processing of the flow chart shown in FIG. 3 of the above-described embodiment, when it is determined in step S9 that the delay time is equal to or longer than the threshold value τ, the process returns to step S3 and the already received access list is referred to. Although a new route is selected by the above, the process may return to step S1 and the subsequent processes may be repeated.

That is, the processing is as shown in the flowchart of FIG. The processing of steps S51 to S60 is the same as the processing of steps S1 to S10 shown in FIG. 3, and therefore description thereof will be omitted. If it is determined in step S59 that the delay time is equal to or greater than the threshold value τ,
After the process of step S61, the process returns to step S51,
The subsequent processing is repeated.

The processing in step S61 is performed in step S60.
This is similar to the process of (step S10). in this way,
After the stop notification is issued, the content providing request is again issued to the server 1, the access list is newly acquired from the server 1, and the route is selected based on the acquired access list. Thus, when a problem such as a delay occurs, it becomes possible to deal with the latest information.

As in the flow chart shown in FIG. 6, the stop notification is made in step S61 by making a request for content provision again in step S51 to the server 1 so that the access list is added. This is to prevent duplicate registration. The process for preventing such a situation may be performed on the server 1 side instead of the process on the side that receives the provision of the content, that is, the process of step S61 is deleted.

The flowchart of FIG. 7 shows that the server 1 side
This includes processing for managing so that there are no PCs 3 that are redundantly registered in the access list. That is,
Step S72 in the processing of the flowchart shown in FIG.
The processing of is added. The processing of step S71 and steps S73 to S80 is the same as the processing of steps S21 to S29 shown in FIG. 4, so description thereof will be omitted.

In step S72, the PC 3 that has issued the content providing request is already registered in the access list, and if additional registration is performed, it is determined whether or not duplicated. If it is determined in step S72 that there is no duplication, in other words, if it is determined that the registration is new, the process proceeds to step S73, where the process of adding to the access list is performed, and when it is determined that there is duplication, The process of step S73 is skipped, and step S
By proceeding to 74, management is performed so that duplicate registration will not occur.

In this way, the server 1 side determines whether or not there is a duplication, so that it is possible to prevent the inconvenience that the PC 3 is duplicatively registered in the access list.

Even when the server 1 determines whether or not there is a duplicate PC 3 in the access list, the content is provided to the other PC 3 that was providing the content at some timing. Notification of suspension will be issued. Alternatively, the side receiving the content should always issue a content transmission request to the side providing the content, and when the transmission request is exhausted, the side providing the content should provide the content. A mechanism for stopping may be provided.

The above-described embodiment will be described with reference to the drawings. In the following description, it is assumed that the processing is performed according to the processing of the flowcharts shown in FIGS. FIG. 8 is a diagram showing an example of a route when content is exchanged by performing the above-described processing. Here, I
The server 1 sets the P address to "10.2.2.1",
PC3-1 is set to "10.1.1.1", PC3-2 is set to "192.168.2.2", and PC3-3 is set to "17."
2.16.2.10 "and PC3-4 sets" 172.1.
6.1.10 ”, and the PC 3-5 sets“ 192.168.1.
3.3 ".

First, the PC 3-1 issues a content provision request to the server 1 (processing in step S1 of FIG. 3), so that the PC 3-1 can access the access list as shown in FIG. 9A. Is received (processing of step S2 in FIG. 3). When the PC 3-1 requests the content provision, the other PCs 3 do not request the content provision, and thus only the IP addresses of the server 1 and the PC 3-1 are registered in the access list. Therefore, PC3-
The server 1 selects the server 1 as the shortest route and receives the content provided from the server 1.

At the next time point, the PC 3-2 newly requests the server 1 to provide the content. As a result, the access list as shown in FIG. 9B is acquired. From the acquired access list, the PC 3-2 sets an IP address other than itself as a route selection candidate. As a result, the server 1 and the PC 3-1 are listed as route selection candidates. Then, as the selected route, PC3-1
As shown in FIG. 8, the PC3
-2 receives the content provided from the PC 3-1.

Further, as a result of the PC 3-4 issuing a request for providing contents to the server 1 and receiving the access list as shown in FIG. 9C, PC 3-4 is the shortest route to PC 3-4. 2 is selected, PC3-2
The provision of contents from will be started.

Here, the process when the PC 3-4 acquires the access list and selects the shortest route will be described with reference to FIG.
Will be described with reference to. The access list acquired by the PC 3-4 is as shown in FIG. Therefore, the PC3-4 selects the server 1 and the PC3- as the selection candidates.
1 and PC3-2. Request packets are transmitted to these three devices. The request packet is, for example, ICPM (Internet Control Message).
It is possible to use an echo request packet defined by the ge Protocol).

After transmitting the request packet, the PC 3-4 receives the echo packet from the server 1, PC 3-1, and PC 3-2, which has received the echo request packet. The PC 3-4 measures the time from the transmission of the request packet to the reception of the echo packet. Then, the measured time is summarized as a response time list. Then, the device having the shortest response time in the response time list, in this case, the P having the response time of 50 ms.
C3-2 is selected as the shortest path.

Although the access list is shown in FIG. 9, the access list managed by the server 1 and the access list provided to the PC 3 do not have to be the same and may be different. For example, as shown in FIG. 11, the access list managed by the server 1 manages content IDs, currently distributed sequence numbers, domain names, IP addresses, connection start times, and bandwidths.

For example, in FIG. 11, the content ID is "0.
12ABC ”, the sequence number of the content distributed at that time is“ 00100022 ”, and the IP address of the domain name“ Server 1 ”is“ 10.2.2.1 ”, The connection start time is “AM 8:00, Feb 21”, and the bandwidth is “500 kbps”.

Of such access lists, PC3
On the side, only the information necessary for selecting the route as described above may be provided as the access list. When the server 1 also manages the bandwidth as information included in the access list, the bandwidth is managed by the PC.
It may be included as information of the access list provided to the third side. When providing the bandwidth as the information of the access list, the PC 3 side may select the route based on the bandwidth.

If a route is selected based on bandwidth,
The device having the largest bandwidth may be selected as the route. However, if the device with the largest bandwidth is always selected as the route, access will be concentrated on that device, traffic will increase, and as a result, the optimal route may not be selected. . To prevent such things, for example,
The number of devices (which can provide contents) that can be connected is limited for each server 1 or PC 3, and connections can be made within the limits.

When an optimum route is selected according to such bandwidth, in a small network,
This is an effective means because it requires less processing.

When the PC 3 requests the server 1 to provide the above-described access list (contents), the PC 3 requests the server 1 or PC 3 selected as the route to provide the contents. PC3 and server 1 when you stop providing the content
FIG. 12 shows the structure of data exchanged with (another PC 3).

As shown in FIG. 12, the data includes a header portion and a footer portion, and between them, data indicating the type of request is included. The header part and the footer part comply with the transmission protocol of the network that transmits and receives this data. The header portion includes an IP address and a port number, and it is possible to duplicately include an IP address and the like.

As the request type, as described above,
First, there is a request for an access list. The request for the access list is a request issued when the PC 3 requests the server 1 to provide the content. When the PC 3 issues an access list request to the server 1, the data includes the information of the PC 3 itself. The information included includes an IP address and bandwidth.

The content distribution request is transmitted to the selected server 1 or PC 3 as a result of the route selection, and the data includes the content ID and the sequence number. The content reception stop request is transmitted to the server 1 and the PC 3 that is actually providing the content when the content provision is stopped.

Although such data is exchanged between the server 1 and the PC 3, the part for processing such data will be described. FIG. 13 shows the server 1 or the PC 3.
FIG. 3 is a diagram showing a portion for processing data to be exchanged. While the server 1 provides contents,
It also processes the data from PC3. The PC 3 may receive the content from the server 1 or another PC 3 while providing the content to the other PC 3. Basically, the configurations of the data processing portions of the server 1 and the PC 3 are the same.

The transmission / reception buffer unit 51 temporarily stores data to be transmitted or received data. The transmission control unit 52 transmits the data to be transmitted to the transmission / reception buffer unit 5
The storage medium 56, the decoder 57, and the encoder 5 which are read from the storage medium 1 and are connected to the interface 55.
8 or network 59, interface 55
Supply by switching the physical port of. The reception control unit 53 receives the received data from the storage medium 56 and the decoder 5 connected to the interface 55.
7. From encoder 58 or network 59,
It is acquired by switching the physical port of the interface 55 and supplied to the transmission / reception buffer unit 51.

The transmission controller 52 and the reception controller 53 are shown in FIG.
1 has the function of controlling the access list, and has the function of analyzing the data having the data structure shown in FIG. 12, which is input from the network 59 through the interface 55. The reception control unit 53 is input from the network 59 through the interface 55,
For example, by analyzing the data of the access list request, the content desired by the PC3 (user of the PC3) who has issued the request is determined.

According to the judgment (according to the content ID), the reception control section 53 connects the interface 55 to the storage medium 56 and reads the access list of the content stored in the storage medium 56. The access list read by the reception control unit 53 is supplied to the transmission / reception buffer unit 51. The reception control unit 53 instructs the transmission control unit 52 to read out the access list stored in the transmission / reception buffer unit 51 and transmit it.

According to the instruction, the transmission control unit 52 reads the access list from the transmission / reception buffer unit 51, switches the physical port of the interface 55 to the network 59, and transmits the read access list.

Next, the operation in the case of receiving the data of the request for providing the content will be described. Reception control unit 53
Analyzes the content request data input from the network 59 via the interface 55 to determine the content ID desired by the requesting PC3 (user of PC3).

In accordance with the content ID, the reception control unit 53 causes the interface 55 to use the storage medium 56.
And the content data stored in the storage medium 56 is read. The data to be read is not limited to the data stored in the storage medium 56, but the data decoded by the decoder 57, the data encoded by the encoder 58, or
Data from another device connected via the network 59 may be used.

However, in this way, the content data is read from the storage medium 56, etc.
In the case where processing is performed in the server 1 and the PC 3 is the content providing side, the transmission / reception buffer unit 5
It is read from 1. Details of such a case will be described later, and here, the processing in the server 1 will be described.

The content data read by the reception control section 53 is supplied to the transmission / reception buffer section 51.
The reception control unit 53 instructs the transmission control unit 52 to read the data of the content stored in the transmission / reception buffer unit 51 and transmit it. The transmission controller 52
According to the instruction, the content data is read from the transmission / reception buffer unit 51, the physical port of the interface 55 is switched to the network 59, and the read content data is transmitted.

When it is not the server 1 but the PC 3 that provides the content data, the content data already stored in the transmission / reception buffer unit 51 by the server 1 or another PC 3 is read out. And is provided to the PC 3 that has requested the provision. The configuration of the transmission / reception buffer unit 51 will be described with reference to FIG.

Reception is controlled by the reception controller 53,
Content data from the server 1 or another PC 3 is
By controlling the write pointer, data is sequentially written in the transmission / reception buffer unit 51. The data to be written is the content body (image data, audio data, etc.)
And the information associated with the body. The information attached to the main body is a content ID, a master flag, a sequence number, a time stamp and the like.

As described above, the content ID is a unique I assigned to uniquely distinguish the content.
It is D. The master flag is a flag indicating whether or not the content data is directly supplied from the server 1, and is represented by, for example, 1 bit.

When the data of the same content with different master flags are received, in other words, when the data of the content directly provided from the server 1 and the data of the content provided from another PC 3 are mixed, the master flag However, the data indicating that the data is the content data directly supplied from the server 1 is processed with priority over other data.

By thus prioritizing the content data, it is possible to prevent disconnection of data communication. That is, for example, when the processing is performed according to the processing of the flowcharts illustrated in FIGS. 3 to 5, a communication disconnection may occur. In such a case, the server 1 is forced to use the access list. By providing the content to at least one PC 3 of the above, and by preferentially processing the data provided directly from the server 1, it is possible to prevent a communication disconnection or the like from occurring. Can be dealt with without problems.

The sequence number is a continuous number assigned to each predetermined unit of packet or content, and is used when controlling the order of data. For example, sequence numbers are assigned in packet units,
It is advisable to easily manage the buffer unit used during transmission and reception.

When there is a request from the PC 3 to provide the content, the content data desired by the requesting PC 3 (user of the PC 3) is judged based on the content ID and the sequence number and provided. Further, the sequence number is used for estimating the position of retransmission in the case of inconvenience such as packet loss in real-time communication, or the position at the time of loss. Sequence numbers are preferably assigned to facilitate this.

The sequence number is managed by the access list as shown in FIG. Therefore, the server 1 and the PC 3 rewrite the “currently delivered sequence number” of the access list to be managed after transmitting the content packet. In this way, by constantly rewriting the “currently delivered sequence number”, the PC3 side receiving the sequence number should receive the next sequence number (when the content data is received by always issuing a transmission request, Next, it becomes possible to recognize the sequence number which issues the transmission request.

When the content is file data such as a program, all the data of the program is stored in the PC3.
The side needs to receive. Therefore, when receiving file data such as a program, it is necessary to receive from the first sequence number. Therefore, the PC 3 serving as the mirror server stores the file downloaded from the server 1 or another PC 3 in the transmission / reception buffer unit 51 and then stores it again in the storage medium 56 or the like. Then, when there is a request to provide the file, when the data of the corresponding sequence number is not stored in the transmission / reception buffer unit 51, the storage medium 56
Read the data of the file to the transmission / reception buffer unit 51,
Find and read the data of the corresponding sequence number,
Send.

By doing this, files such as
Even if the data must provide all the data, it can be surely provided.

The time stamp indicates the time when the server 1 delivers the packet or the time when the PC 3 delivers the packet to another PC 3, and is provided directly from the server 1 or via the other PC 3. The PC 3 that has received the content (packet) measures the delay of the reception time using the time stamp and its own clock. For example, if the reception of real-time data (video, etc.) content is delayed, the receiving side can skip the next sequence number and adjust the time. It is possible to maintain control.

The content data including such data is sequentially written in the transmission / reception buffer section 51 under the control of the write pointer as described above. As for the data written in the transmission / reception buffer unit 51, desired data can be arbitrarily read by the read pointer. As shown in FIG. 14, the read data is transmitted with a header part and a footer part attached.

As described above, not only the server 1 but also the PC 3 which receives the data from the server 3 functions as a mirror server, thereby maintaining the communication quality and
It is possible to reduce the traffic and keep the cost low.

The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processes is executed by software, it is possible to execute various functions by installing a computer in which the programs that make up the software are built into dedicated hardware, or by installing various programs. The recording medium is installed in a general-purpose personal computer, for example.

As shown in FIG. 2, the recording medium is a magnetic disk 31 (including a flexible disk) and an optical disk 32 on which the program is recorded, which is distributed in order to provide the program to the user separately from the personal computer. (CD-ROM (CompactDisk-Read Only Memory),
Not only is it configured by a package medium such as a DVD (including a Digital Versatile Disk), a magneto-optical disc 33 (including an MD (Mini-Disc) (registered trademark)), or a semiconductor memory 34, but is also incorporated in a computer in advance The hard disk, which is provided to the user in the stored state, includes the ROM 12 in which the program is stored and the storage unit 18, and the like.

In this specification, the steps for describing the program provided by the medium are not limited to the processing performed in time series according to the order described, but are not necessarily performed in time series and may be performed in parallel. Alternatively, it also includes processes that are individually executed.

In this specification, the system means
It represents the entire apparatus composed of a plurality of devices.

[0101]

As described above, according to the first information processing device and method and the program of the present invention, a list of devices that are provided with contents is created, and another device requests the contents to be provided. When the other device requests the provision of the content again as a result of providing the created list to another device and performing a process using the list by the other device, the content is provided. I decided to do so,
It is possible to reduce the traffic without degrading the quality.

According to the second information processing apparatus and method and the program of the present invention, a list composed of information of another apparatus and information of the apparatus which is provided with the content from the other apparatus. Of the devices listed in the list, it determines the device with the shortest response time,
Since the device that was judged to have the shortest response time was instructed to start providing the content,
It is possible to reduce the traffic without degrading the quality.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of an information processing system to which the present invention has been applied.

FIG. 2 is a diagram illustrating an internal configuration example of a server 1.

FIG. 3 is a flowchart illustrating an operation of PC 3 on the side of receiving content provision.

FIG. 4 is a flowchart illustrating the operation of the server 1.

FIG. 5: Server 1 or PC on the side of providing contents
It is a flow chart explaining operation of No. 3.

FIG. 6 is a flowchart illustrating another operation of the PC 3 on the side of receiving the content provision.

FIG. 7: Server 1 or PC on the side of providing contents
6 is a flowchart illustrating another operation of No. 3;

FIG. 8 is a diagram showing an example of a selected route.

FIG. 9 is a diagram illustrating an access list.

FIG. 10 is a diagram illustrating selection of a route.

FIG. 11 is a diagram illustrating an access list.

[Fig. 12] Fig. 12 is a diagram illustrating a configuration of data to be transmitted and received.

FIG. 13 is a diagram illustrating a part of server 1 or PC 3 that performs processing relating to transmission and reception.

FIG. 14 is a diagram illustrating writing and reading with respect to the transmission / reception buffer unit 51.

[Explanation of symbols]

1 server, 2 routers, 3 PCs, 11 CPs
U, 12 ROM, 13 RAM, 14 bus,
15 input / output interface, 16 input section, 17
Output unit, 18 storage unit, 19 communication unit, 20
Drive, 51 transmission / reception buffer unit, 52 transmission control unit, 53 reception control unit, 54 timer, 55 interface, 56 storage medium, 57 decoder, 58 encoder, 59 network

Claims (12)

[Claims] 1. A managing unit for managing content, a creating unit for creating a list of devices managed by the managing unit and receiving the contents, and other devices managed by the managing unit. First providing the list created by the creating means to the other device when the content is requested to be provided.
As a result of performing the processing using the list by the other providing device,
Second providing means for providing the content managed by the managing means to the other device when the other device requests to provide the content again. Processing equipment. 2. The creating means adds information of the other device to the list when the request for providing the content is made from the other device, and provides the content from the other device. The information processing apparatus according to claim 1, wherein the information on the other apparatus is deleted from the list when a stop request is made. 3. In a state where the information of one or more devices is described in the list, it is determined whether or not the other device providing the content by the second providing means exists. When the determination unit determines that the other device providing the content by the second providing unit does not exist, the second providing unit determines the list. The information processing apparatus according to claim 1, wherein the provision of the content is started to at least one of the apparatuses described in 1. 4. A management step of managing content, a creation step of creating a list of devices managed by the processing of the management step and receiving the content, and another device When a request is made to provide the content managed in the process, a first providing step of providing the list created in the process of the creating step to the other device, and the other device As a result of performing the process using the list,
A second providing step of providing the content managed by the processing of the managing step to the other device when the other device requests to provide the content again. Information processing method. 5. A managing step of managing content, a creating step of creating a list of devices managed by the processing of the managing step and provided with the content, and another device is the managing step. When requesting the provision of the content managed in the process, a first providing step of providing the list created in the process of the creating step to the other device, and the other device As a result of performing the process using the list,
A second providing step of providing the content managed by the processing of the managing step to the other device when the other device requests to provide the content again. A recording medium on which a computer-readable program is recorded. 6. A managing step of managing content, a creating step of creating a list of devices managed by the processing of the managing step and receiving the contents, and another device When a request is made to provide the content managed in the process, a first providing step of providing the list created in the process of the creating step to the other device, and the other device As a result of performing the process using the list,
A program that causes a computer to execute a second providing step of providing the content managed by the processing of the managing step to the other device when the other device requests to provide the content again. . 7. A transmission means for transmitting a request for providing content to another device, and information of the other device and information of the device receiving the content provided from the other device. Receiving means for receiving the list, a judging means for judging the device having the shortest response time among the devices described in the list received by the receiving means, and the judging means for judging the device having the shortest response time. Instructing means for instructing a device whose response time is judged to be short to start providing the content, and receiving the content provided by the device according to the instruction of the instructing means, and processing the content. An information processing apparatus comprising: a processing unit. 8. The determination means transmits a request packet to the devices listed in the list, receives an echo packet corresponding to the request packet, and receives the echo from the time when the request packet is transmitted. The information processing apparatus according to claim 7, wherein the apparatus having the shortest response time is determined by measuring the time until the packet is received. 9. A measuring means for measuring a delay time of the content received from the device, and a second means for judging whether or not the delay time measured by the measuring means is equal to or more than a predetermined threshold value. 8. The information according to claim 7, further comprising: a determining unit, wherein when the second determining unit determines that the delay time is equal to or longer than a predetermined threshold value, the determining unit performs the determination again. Processing equipment. 10. A transmission control step of controlling transmission of a request for providing content to another device, and information of the other device and information of the device receiving the content provided from the other device. A reception control step of controlling the reception of the list, and a determination step of determining a device having the shortest response time among the devices described in the list received in the process of the reception control step; An instruction step for instructing the device, which has been determined to have the shortest response time in the process of the determination step, to start providing the content; and a device provided by the device according to the instruction by the process of the instruction step. An information processing method comprising: receiving a content and processing the content. 11. A transmission control step for controlling transmission of a request for content provision to another device, and information of the other device and information of the device receiving the content provision from the other device. A reception control step of controlling the reception of the list, and a determination step of determining a device having the shortest response time among the devices described in the list received in the process of the reception control step; An instruction step for instructing the device, which has been determined to have the shortest response time in the process of the determination step, to start providing the content; and a device provided by the device according to the instruction by the process of the instruction step. A computer readable program, comprising: processing steps for receiving content and processing the content. That it is recorded in a recording medium. 12. A transmission control step for controlling transmission of a request for providing content to another device, and information of the other device and information of a device receiving the content provided from the other device. A reception control step of controlling the reception of the list, and a determination step of determining a device having the shortest response time among the devices described in the list received in the process of the reception control step; An instruction step for instructing the device, which has been determined to have the shortest response time in the process of the determination step, to start providing the content; and a device provided by the device according to the instruction by the process of the instruction step. A program that causes a computer to execute processing steps for receiving content and processing the content.