JP2004032334A - Media gateway, stored-data distribution system, method therefor and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stored-data distribution system in which a stored data such as an audio-video storage service having an automatic absence answering function can be distributed with a small delay, reducing deterioration by using the Internet. <P>SOLUTION: When the media gateway 1 receives a data from a transmitter terminal 4, the media gateway stores the data in a transferable file form by a TCP/IP protocol. The media gateway 1 retrieves a network to which a recipent terminal 5 belongs by transmitting and receiving information by mutual gateways, and transfers the stored data to an optimum media gateway 2 by the TCP/IP protocol. When the recipient terminal 5 moves the network, the stored data is transferred to the optimum media gateway 3. The media gateway 3 changes the stored data into an IP/UDP/RTP packet and conducts a transmission when there is a requirement from the recipient terminal 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a media gateway, a stored data distribution system, a stored data distribution method, and a program therefor, and more particularly to data such as A / V (Audio / Video) in a voice / video storage service with an answering machine function using an IP (Internet Protocol) network. Related to a delivery system.
[0002]
[Prior art]
When data such as A / V is to be transferred using the Internet, in order to guarantee real-time performance in the transfer, IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Real-time Transport Protocol) is required. It is common to use protocols. However, quality of service (QoS) control is difficult on the Internet, and deterioration in sound quality / image quality due to occurrence of packet loss cannot be suppressed.
[0003]
In the related art, in order to interpolate a lost packet, measures such as resending the lost packet are taken. However, retransmission of a packet generates extra traffic, which rather causes a congestion state, deteriorating the efficiency of the network and raising the rate of loss of packets to be transmitted.
[0004]
When TCP / IP (Transmission Control Protocol / Internet Protocol) is used to interpolate a lost packet, data integrity is guaranteed by the retransmission packet. However, if a packet is lost at the time of congestion, a delay increases due to retransmission processing, which is not suitable for distribution of data such as A / V with high real-time property.
[0005]
[Problems to be solved by the invention]
In the above-described conventional system for distributing stored data, when data is transferred using the IP network, packets are retransmitted using the TCP / IP protocol in response to packet loss due to congestion on the network. . As described above, in the conventional system, the normality of data transfer is maintained by guaranteeing a lost packet.
[0006]
However, in the TCP / IP protocol, when a packet loss occurs, a retransmission of the packet occurs along with the packet loss, so that a delay occurs. However, in communication of data such as A / V in a videophone or the like using IP, real-time property is strongly required, and it is not desirable to use the TCP / IP protocol.
[0007]
For this reason, in the communication of data such as A / V, a UDP protocol that does not perform retransmission even if a packet loss occurs is generally used, but in IP / UDP / RTP communication that passes through the Internet, Since it is difficult to control QoS over the Internet, it is difficult to guarantee end-to-end quality to users.
[0008]
Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a media gateway and a stored data distribution system capable of distributing stored data, such as a voice / video storage service with an answering machine function, with little deterioration and low delay using the Internet. And a storage data distribution method and a program thereof.
[0009]
[Means for Solving the Problems]
A media gateway according to the present invention is a media gateway connected to each user terminal and connectable to another gateway via the Internet,
Means for filing data from the transmitting user terminal;
Means for storing the filed data on an internal disk;
Means for determining an optimal gateway for the receiving user terminal;
Means for exchanging information stored in the internal disk with the determined optimal gateway by TCP / IP (Transmission Control Protocol / Internet Protocol);
Means for converting a file from another gateway into an IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Protocol) packet and transmitting the packet to the user terminal on the receiving side.
[0010]
A stored data distribution system according to the present invention is a stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet,
Means for filing data from the transmitting user terminal;
Means for storing the filed data on an internal disk;
Means for determining an optimal gateway for the receiving user terminal;
Means for exchanging information stored in the internal disk with the determined optimal gateway by TCP / IP (Transmission Control Protocol / Internet Protocol);
Means for transmitting a file from another gateway to an IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Real-time Transport Protocol) packet and transmitting the packet to the user terminal on the receiving side;
The stored information is transferred to the optimal gateway according to the destination of the user terminal on the receiving side.
[0011]
A stored data distribution method according to the present invention is a stored data distribution method for a stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet,
Filing data from the transmitting user terminal;
Saving the filed data to an internal disk;
Determining an optimal gateway for the receiving user terminal;
Exchanging the stored information of the internal disk by TCP / IP (Transmission Control Protocol / Internet Protocol) with the determined optimal gateway;
A step of forming a file from another gateway into an IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Protocol) packet and transmitting the packet to the user terminal on the receiving side.
[0012]
A program of a stored data distribution method according to the present invention is a program of a stored data distribution method of a stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet, In the process, a process of filing data from the user terminal on the transmitting side, a process of saving the filed data to the internal disk, a process of determining an optimal gateway for the user terminal on the receiving side, A process of exchanging information stored in the internal disk with a TCP / IP (Transmission Control Protocol / Internet Protocol) to an optimal gateway, and a process of transmitting a file from another gateway to an IP / UDP / RTP (Internet Protocol). ocol / User Datagram Protocol / Protocol) and transmitting the packet to the user terminal on the receiving side.
[0013]
That is, the stored data distribution system of the present invention minimizes sound quality / image quality due to packet loss caused by congestion on the network, and provides users with higher quality data such as A / V (Audio / Video). The present invention relates to a method for performing distribution and minimizing a response to a user.
[0014]
In view of the above, the present invention proposes a system capable of distributing stored data, such as a voice / video storage service with an answering machine function, with little deterioration and low delay using the Internet. Therefore, according to the present invention, when distributing the stored data using the Internet, a gateway is installed between the access network [ISP (Internet Service Provider) or the like] to which the user belongs and the Internet, and the stored data such as A / V is transferred to the gateway. In the case of communication across the Internet, the stored data is transferred between the gateways by TCP / IP (Transmission Control Protocol / Internet Protocol) to guarantee the normality of the stored data.
[0015]
In addition, the gateway that transfers the stored data selects the most suitable gateway when distributing the data to the user, so that packet loss between the gateway and the receiving terminal can be minimized.
[0016]
As described above, in the present invention, in the Internet where it is very difficult to control QoS (Quality of Service), a highly reliable TCP / IP protocol is used without using a UDP (User Datagram Protocol) packet, thereby causing a packet loss. It is possible to eliminate deterioration of stored data such as A / V.
[0017]
Further, according to the present invention, it is possible to disperse the gateways for storing the accumulated data such as A / V, so that the load is concentrated on one gateway (or server) and it becomes difficult to provide the service. It is possible to avoid this, and it becomes easy to construct a large-scale network.
[0018]
Further, in the present invention, the gateways communicate with each other, search for a gateway that can provide the service with the highest quality to the network to which the receiver belongs, and store the accumulated data such as A / V in the gateway. In other words, since the stored data is transferred to the optimal gateway according to the destination of the user terminal on the receiving side, it is possible to deliver the stored data with the highest quality and the lowest delay response to the receiver. Become.
[0019]
Still further, according to the present invention, the sender's gateway changes the data from the sender into a general-purpose file format that can be transferred over the IP network, and transfers the data to the receiver's gateway. It is not necessary to communicate with the same terminal using the same protocol, and it becomes easy to communicate between different networks and different models.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a stored data distribution system according to one embodiment of the present invention. In FIG. 1, a stored data distribution system according to an embodiment of the present invention includes media gateways (A to C) 1 to 3, a sender terminal 4, a receiver terminal 5, the Internet 100, and an ISP (Internet Service Provider). (A to C) 101 to 103.
[0021]
In this embodiment, when data such as A / V (Audio / Video) from the sender terminal 4 is received by the media gateway (A) 1, the media gateway (A) 1 converts the data into a file, and converts the data into a file. And store the data.
[0022]
The media gateway (A) 1 acquires information indicating in which network the receiver terminal 5 exists using a protocol defined between the gateways. The media gateway (A) 1 searched for a gateway capable of providing the highest quality service to the receiver from the obtained information, and filed the gateway using the highly reliable TCP / IP protocol. Perform data transfer. Since stored data is exchanged between the gateways using the TCP / IP protocol, no data is lost. Therefore, the stored data does not deteriorate.
[0023]
When the media gateway (A) 1 determines that the media gateway (B) 2 is the optimal gateway for the receiver terminal 5, the media gateway (A) 1 transfers the stored data to the media gateway (B) 2. Thereafter, the stored data on the media gateway (A) 1 is erased in order to use the disk capacity efficiently.
[0024]
The media gateway (B) 2 is waiting for the receiver terminal 5 to retrieve the stored data. However, when the media gateway (B) 2 detects that the receiver terminal 5 has moved further on the network, the gateway exchanges information with each other. Search for a gateway that can provide the best service to the recipient.
[0025]
When the media gateway (B) 2 determines that the media gateway (C) 3 is optimum, the media gateway (B) 2 transfers the stored data to the media gateway (C) 3 using the TCP / IP protocol in the same manner as described above. Delete the data stored in the device.
[0026]
The media gateway (C) 3 waits for the receiver terminal 5 to retrieve the data, and when the receiver terminal 5 starts to retrieve the stored data, the filed stored data is transferred to the IP / UDP / RTP suitable for real-time transmission. (Internet Protocol / User Datagram Protocol / Protocol) It is packetized and the stored data is delivered to the receiver terminal 5.
[0027]
Since the UDP protocol is used between the media gateway (C) 3 and the receiver terminal 5, a recovery function does not exist when a packet loss occurs, but unlike the Internet 100 in which QoS control is difficult, a service provider (such as the ISP 103) ) Is an IP network prepared, it is relatively easy to monitor the state of the network and control the QoS.
[0028]
In addition, since all communication between terminals (End-to-End) is not performed using IP / UDP / RTP packets, only IP-UDP / RTP communication is performed between the terminal and the gateway. Since the section in which packet loss can occur is shortened as compared with the RTP communication, it is possible to suppress the probability of occurrence of loss and to provide a high QoS to the receiver.
[0029]
Further, since the media gateway (C) 3 that minimizes the setting of the call for distributing the stored data to the receiver terminal 5 is selected, the time until the user actually receives the stored data is minimized. It is also possible to suppress to.
[0030]
The sender terminal 4 only needs to be able to communicate with the media gateway (A) 1 using the call setup protocol defined by the ISP (A) 101, and the call setup protocol between the receiver terminal 5 and the end-to-end. There is no need to match.
[0031]
Therefore, it is not necessary to unify various call setting protocols (H.323 / SIP / MeGaCo, etc.) in each network (ISP (A) 101, ISP (B) 102, ISP (C) 103), and stored data It is possible to provide a high-quality, low-delay, audio-visual storage service with an answering machine function by matching only the file format.
[0032]
In this embodiment, the gateways communicate with each other, search for a gateway that can provide the service with the highest quality to the network to which the receiver belongs, and store the accumulated data such as A / V in the gateway. In other words, the stored data is transferred to the optimal gateway according to the destination of the user terminal on the receiving side, so that the stored data can be delivered to the receiver with the highest quality and the lowest delay response. .
[0033]
FIG. 2 is a block diagram showing the configuration of the media gateways (A to C) 1 to 3 in FIG. In FIG. 2, the media gateways (A to C) 1 to 3 are collectively represented as a media gateway 1.
[0034]
The media gateway 1 includes an RTP packet generator (RTP Packetizer) 11, an RTP packet receiver (RTP DePacketizer) 12, a file transmitter (File Sender) 13, a file receiver (File Receiver) 14, and a hard disk (Hard Disk). ) 15, a control unit 16, and a control CPU (central processing unit) 17.
[0035]
The RTP packet generator 11 and the RTP packet receiver 12 perform IP / UDP / RTP communication (transmit / receive data with the terminal) with the terminal, and the file transmitter 13 and the file receiver 14 communicate with each other via the Internet 100. This is the part that communicates with the gateway.
[0036]
The control CPU 17 is a part for controlling a file of transmission / reception data, the control part 16 is a part for exchanging user information between gateways, and the hard disk 15 is a part for storing data.
[0037]
Upon receiving the RTP packet transmitted from the terminal, the RTP packet receiver 12 checks the order of the transmission data and stores the data on the hard disk 15. When the reception of all data is completed, the control CPU 17 performs a filing process based on the received data. As a generally used format format, MP4 [MPEG (Moving Picture Experts Group) -4 File Format] is expected to be widely used in the future, but services that do not depend on the file format format are expected in this system. It is possible.
[0038]
The RTP packet generator 11 has a function of converting the stored data file stored in the hard disk 15 into an RTP packet toward the receiver terminal 5 and transmitting the file to the terminal.
[0039]
The file transmitter 13 has a function of transmitting a file to another gateway by using the highly reliable TCP / IP protocol in communication of stored data between gateways. The file receiver 14 has a function of receiving a file from another gateway using the TCP / IP protocol and communicating the stored data between the gateways, and storing the data on the hard disk 15.
[0040]
The control unit 16 has a function of exchanging user information between the gateways. The control CPU 17 has a function of managing the data format exchanged between the gateway and the terminal and between the gateways, storing the accumulated data on the hard disk 15, and enabling the exchange of data on the network. The hard disk 15 has a function of storing stored data in a file, and stores programs executed by the above-described units. However, the program may be stored in another recording medium, for example, a memory or the like.
[0041]
FIG. 3 is a flowchart showing the operation of the control unit 16 of FIG. The operation of the control unit 16 will be described with reference to FIGS. Note that the processing shown in FIG. 3 is realized when a computer (not shown) mainly configuring the gateway 1 executes a program stored in the hard disk 15 (or another recording medium such as a memory).
[0042]
When data is transmitted by IP / UDP / RTP from the sender terminal 4 (step S1 in FIG. 3), the controller 16 converts the data into a file and stores it in the hard disk 15 (step S2 in FIG. 3).
[0043]
Thereafter, the control unit 16 searches the position of the receiver terminal 5 (steps S3 and S4 in FIG. 3), and searches for a gateway most suitable for distributing the data stored in the hard disk 15 (step S5 in FIG. 3). When searching for the optimal gateway (step S6 in FIG. 3), the control unit 16 instructs the control CPU 17 to transfer the stored data on the hard disk 15 from the file transmitter 13 using the TCP / IP protocol (FIG. 3). Step S7), and delete the stored data after the transfer (Step S8 in FIG. 3).
[0044]
When the receiver terminal 5 is not found (step S4 in FIG. 3), the control unit 16 saves the stored data (step S9 in FIG. 3), and when the power is turned on or in an area where radio waves can be received. When a new user information is notified from another gateway, for example, when a user terminal is entered (step S10 in FIG. 3), the process returns to step S5 to search for an optimal gateway and store it there. Distribute data.
[0045]
FIG. 4 is a sequence chart showing the operation of the stored data distribution system according to one embodiment of the present invention. The operation of the stored data distribution system according to one embodiment of the present invention will be described with reference to FIGS. 1, 2 and 4.
[0046]
Upon receiving data such as A / V from the sender terminal 4 (a1 in FIG. 4), the media gateway (A) 1 converts the data such as A / V into a file and stores it in the hard disk 15 (a2 in FIG. 4). .
[0047]
The media gateway (A) 1 obtains information on which network the receiver terminal 5 exists in using a protocol defined between the gateways, and obtains the highest quality for the receiver terminal 5 from the obtained information. A gateway that can be provided is searched for (a3 in FIG. 4), and the filed data is transferred to the gateway using the highly reliable TCP / IP protocol (a4 in FIG. 4).
[0048]
Since stored data is exchanged between the gateways using the TCP / IP protocol, no data is lost. Therefore, data such as A / V does not deteriorate.
[0049]
When the media gateway (A) 1 determines that the media gateway (B) 2 is the optimal gateway for the receiver terminal 5, the media gateway (A) 1 transfers the filed stored data to the media gateway (B) 2. When the stored data is transferred, the stored data on the media gateway (A) 1 is deleted to efficiently use the disk capacity (a5 in FIG. 4).
[0050]
The media gateway (B) 2 waits for the receiver terminal 5 to extract the stored data. However, when the media terminal (B) 2 detects that the receiver terminal 5 has moved further over the network (a6 in FIG. 4), the gateways communicate with each other. Information is exchanged to search for a gateway that can provide an optimum service to the receiver terminal 5 (a7 in FIG. 4).
[0051]
When the media gateway (B) 2 determines that the media gateway (C) 3 is optimum, the stored data is transferred to the media gateway (C) 3 using the TCP / IP protocol in the same manner as described above (FIG. 4). A8), and after the transfer, the stored data of the own device is deleted (a9 in FIG. 4).
[0052]
The media gateway (C) 3 waits for the receiver terminal 5 to retrieve the stored data, and when the receiver starts collecting the stored data (a10 in FIG. 4), the filed stored data is suitable for real-time transmission. IP / UDP / RTP packets are formed (a11 in FIG. 4), and the stored data is delivered to the receiver terminal 5 (a12 in FIG. 4).
[0053]
Since the UDP protocol is used between the media gateway (C) 3 and the receiver terminal 5, there is no recovery function when a packet loss occurs, but unlike the Internet 100 in which QoS control is difficult, the service provider [ISP (C) 103 etc.] is an IP network prepared, so that it is relatively easy to monitor the state of the network and control QoS.
[0054]
In addition, since all communication between terminals (End-to-End) is not performed using IP / UDP / RTP packets, only IP-UDP / RTP communication is performed between the terminal and the gateway. Since the section in which packet loss can occur is shortened as compared with the RTP communication, it is possible to provide a high QoS to the receiver terminal 5 while suppressing the probability of occurrence of loss.
[0055]
Further, since the media gateway (C) 3 that minimizes the setting of the call for distributing the stored data to the receiver terminal 5 is selected, the time until the user actually receives the stored data is minimized. Can also be suppressed.
[0056]
The data of the sender terminal 4 only needs to be able to communicate with the media gateway (A) 1 using the call setting protocol defined by the ISP (A) 101, and the receiver terminal 5 and the end-to-end There is no need to match the call setup protocol in the. Therefore, it is not necessary to unify various call setting protocols (H.323 / SIP / MeGaCo, etc.) in each of the networks ISP (A) 101, ISP (B) 102, and ISP (C) 103, and the stored data is gatewayed. By performing matching on the data plane transferred between the devices and matching only the file format of the stored data, it is possible to provide a storage service such as an answering machine with high quality and low delay.
[0057]
As described above, in the present embodiment, in the Internet where QoS control is extremely difficult, the stored data is transferred between the gateways using the highly reliable TCP / IP protocol without using the UDP packet, and thus the packet loss is reduced. The deterioration of the stored data such as A / V due to the above can be eliminated.
[0058]
Further, in this embodiment, since it is possible to disperse the gateways for storing data, it is possible to avoid a situation in which the load is concentrated on a certain gateway (or server) and it becomes difficult to provide the service. Makes it easy to construct a large-scale network.
Further, in this embodiment, the gateways communicate with each other, search for a gateway that can provide the service with the highest quality to the network to which the receiver terminal belongs, and store the accumulated data, that is, the receiver Since the stored data is transferred to the optimal gateway according to the destination of the terminal 5, the data can be delivered to the receiver terminal with the highest quality and the lowest delay response.
[0060]
Furthermore, in the present embodiment, the data from the sender terminal is changed to a general-purpose file format that can be transferred through the IP network at the sender gateway, and the data is transferred to the receiver gateway. There is no need to communicate with the receiving terminal using the same protocol, and it becomes easy to communicate between different networks and different models.
[0061]
【The invention's effect】
As described above, according to the present invention, in a stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet, the data from the user terminal on the transmission side is filed. It is stored in the internal disk, an optimal gateway is determined for the user terminal on the receiving side, information stored in the internal disk is exchanged with the gateway by TCP / IP, and a file from another gateway is transmitted to the IP / UDP / By forming the RTP packet and transmitting it to the user terminal on the receiving side, it is possible to obtain the effect that the stored data such as the voice / video storage service with the answering machine function can be distributed using the Internet with little deterioration and with low delay.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a stored data distribution system according to one embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration of a media gateway of FIG.
FIG. 3 is a flowchart illustrating an operation of a control unit in FIG. 2;
FIG. 4 is a sequence chart showing the operation of the stored data distribution system according to one embodiment of the present invention.
[Explanation of symbols]
1-3 Media gateway 4 Sender terminal 5 Receiver terminal 11 RTP packet generator 12 RTP packet receiver 13 File transmitter 14 File receiver 15 Hard disk 16 Controller 17 Control CPU
100 Internet 101-103 ISP

Claims (17)

Media gateways each connected to a user terminal and connectable to another gateway via the Internet,
Means for filing data from the transmitting user terminal;
Means for storing the filed data on an internal disk;
Means for determining an optimal gateway for the receiving user terminal;
Means for exchanging information stored in the internal disk with the determined optimal gateway by TCP / IP (Transmission Control Protocol / Internet Protocol);
Means for transmitting a file from another gateway into an IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Real-time Transport Protocol) packet and transmitting the packet to the receiving-side user terminal. The media gateway according to claim 1, wherein the means for determining the optimal gateway exchanges user terminal information with another gateway to determine the optimal gateway. Means for capturing an IP / UDP / RTP packet from the user terminal on the transmitting side,
3. The media gateway according to claim 1, wherein the captured IP / UDP / RTP packet is filed. 4. The service according to claim 1, wherein voice / image data from the user terminal on the transmission side is stored and used for a service for distributing in response to a transfer request from the user terminal on the reception side. The described media gateway. 5. The media gateway according to claim 1, wherein the user terminal is connected via an access network to which the user terminal belongs. A stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet,
Means for filing data from the transmitting user terminal;
Means for storing the filed data on an internal disk;
Means for determining an optimal gateway for the receiving user terminal;
Means for exchanging information stored in the internal disk with the determined optimal gateway by TCP / IP (Transmission Control Protocol / Internet Protocol);
Means for transmitting a file from another gateway into an IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Real-time Transport Protocol) packet and transmitting the packet to the user terminal on the receiving side;
A stored data distribution system, wherein the stored information is transferred to the optimal gateway according to a destination of the user terminal on the receiving side. 7. The stored data distribution system according to claim 6, wherein the means for determining the optimum gateway exchanges user terminal information with another gateway to determine the optimum gateway. A means for taking in an IP / UDP / RTP packet from the user terminal on the transmitting side is included in each of the plurality of gateways;
8. The stored data distribution system according to claim 6, wherein the captured IP / UDP / RTP packet is filed. 9. The service according to claim 6, wherein audio / image data from the user terminal on the transmission side is stored and used for a service for distributing in response to a transfer request from the user terminal on the reception side. The stored data distribution system described. 10. The stored data distribution system according to claim 6, wherein the user terminal connects to the gateway via an access network to which the user terminal belongs. A stored data distribution method for a stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet,
Filing data from the transmitting user terminal;
Saving the filed data to an internal disk;
Determining an optimal gateway for the receiving user terminal;
Exchanging the stored information of the internal disk by TCP / IP (Transmission Control Protocol / Internet Protocol) with the determined optimal gateway;
Said plurality of gateways comprising a step of forming a file from another gateway into an IP / UDP / RTP (Internet Protocol / User Datagram Protocol / Real-time Transport Protocol) packet and transmitting the packet to a user terminal on the receiving side. Data distribution method to be used. 12. The stored data distribution method according to claim 11, wherein, in the step of determining the optimal gateway, the optimal gateway is determined by exchanging user terminal information with another gateway. 13. The stored data distribution method according to claim 11, wherein an IP / UDP / RTP packet from the user terminal on the transmission side is fetched, and the fetched IP / UDP / RTP packet is filed. 14. The service according to claim 11, wherein voice / image data from the user terminal on the transmission side is stored and used for a service for distributing in response to a transfer request from the user terminal on the reception side. The stored data distribution method described. 15. The stored data distribution method according to claim 11, wherein the user terminal is connected to the gateway via an access network to which the user terminal belongs. 16. The stored data distribution method according to claim 11, wherein the stored information is transferred to the optimum gateway according to a destination of the user terminal on the receiving side. A program for a stored data distribution method of a stored data distribution system including a plurality of gateways each connected to a user terminal and connectable to another gateway via the Internet, comprising: transmitting data from a user terminal on a transmission side to a computer; A process for making a file, a process for saving the filed data to an internal disk, a process for determining an optimum gateway for the user terminal on the receiving side, and a TCP / IP (Transmission) for the determined optimum gateway. A process of exchanging information stored in the internal disk by Control Protocol / Internet Protocol, and a process of transmitting a file from another gateway to an IP / UDP / RTP (Internet Protocol / User Datagram P). otocol / Real-timeTransport Protocol) program for packetized by executing the process of transmitting to the user terminal of the receiving side.

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