JP2010278991A - Overlay multicast system, relay apparatus, conversion apparatus and overlay multicast method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an overlay multicast system and the like for reducing a packet processing load on a router and a relay apparatus by reducing the consumption of a network band or a time lag of data transfer. <P>SOLUTION: A relay apparatus notifies a conversion apparatus about an arrival message of file data transmitted from a server, and the conversion apparatus creates file data process information to transmit the information to the relay apparatus. The relay apparatus transmits file data which are processed by using the information to a client. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a low latency overlay multicast technique.

First, a conventional IP multicast technique will be described with reference to FIGS. The IP multicast system shown in FIG. 11 includes a server 110, a relay device 120, a client 140A, and a client 140B on a network 1100 such as the Internet. Here, it is assumed that the relay device 120 is a router.
The operation will be described with reference to the sequence diagram of FIG. It is assumed that the server 110 holds moving image file data 150. When the request for the file data 150 is issued from the client 140A and the client 140B (S1201), the server 110 receives the request for the file data 150 via the relay device 120 (S1202) (S1203).
Then, the server 110 transmits the file data 150 (S1204). It is assumed that the file data 150 is sequentially transmitted as a UDP packet.
The relay device 120 receives the file data 150 from the server 110 (S1205). Since the relay apparatus 120 recognizes that the request for the file data 150 has been issued from the client 140A and the client 140B (each IP address has already been acquired), in order to transmit the file data 150 to each of the two clients, The file data 150 received from the server 110 is duplicated (S1206). Thereafter, the relay device 120 distributes the file data 150 to each of the client 140A and the client 140B (one of which is duplicated in step S1206) (S1207).
In the IP multicast in which distribution management is performed in such a hierarchy and the relay device 120 directly distributes in the IP layer, it is difficult to meet the demand for changing the file data 150 and transmitting it to the client. Therefore, an overlay multicast using a relay node for changing data in the application layer described below is used.

Hereinafter, a conventional overlay multicast technique will be described with reference to FIGS. 13 and 14. FIG. The overlay multicast system shown in FIG. 13 includes a server 210, a relay device 220, a client 240A, a client 240B, and a relay node (conversion device) 230 on a network 2100 such as the Internet. Here, it is assumed that the relay device 220 is a router.
The operation will be described with reference to the sequence diagram of FIG. It is assumed that the server 210 holds moving image file data 250. When a request for the file data 250 is issued from the client 240A (S1401), the server 210 receives the request for the file data 250 via the relay device 220 (S1402) (S1403).
Then, the server 210 transmits the file data 250 (S1404). It is assumed that the file data 250 is sequentially transmitted as a UDP packet.
The relay device 220 receives the file data 250 from the server 210 (S1405).
The relay device 220 transmits the file data 250 to the relay node 230 (S1406).
The relay node 230 changes the file data 250 (S1407). For example, deletion, addition, correction, etc. of data. Thereafter, the relay node 230 transmits the file data 250 in which the relay device 220 is changed (S1408).
Since the relay device 220 recognizes that the request for the file data 250 has been issued from the client 240A (the IP address of the client 240A has already been acquired), the file data 250 to which the change received from the relay node 230 has been added is stored in the client 220A. It is transmitted to 240A (S1409).
Unlike the case where the request for the file data 250 is issued only from the client 240A described above, when the request for the file data 250 is issued from the client 240A and the client 240B, the relay node 230 determines in step S1407 above. In addition, the relay node 230 duplicates the changed file data 250 to prepare the changed file data 250 to be transmitted to each of the two clients. At this time, it is assumed that the relay node 230 recognizes the client from which the request for the file data 250 is issued by some method. Thereafter, in step S1408, the relay node 230 sequentially transmits the changed file data 250 (for the client 240A) and the changed file data 250 (for the client 240B) to the relay device 220, respectively.

  As a related technique, a data transfer technique for realizing overlay multicast has been proposed (see, for example, Patent Document 1).

JP 2008-236073 A

However, in the overlay multicast system shown in FIG. 13 described above, the file data 250 (strictly, the file data 250 before and after the change) reciprocates between the relay device 220 and the relay node 230 and flows through the network 2100. That is, full data was reciprocated.
As a result, the network bandwidth is squeezed, and data transfer delays may occur. Furthermore, the packet processing load is applied to the relay device 220 and the relay node (conversion device) 230.

  The present invention relates to an overlay multicast system, a relay device, and a conversion device that link an application layer and a network layer in overlay multicast, reduce network bandwidth consumption and data transfer time lag, and reduce the packet processing burden on the relay device and the conversion device. An object of the present invention is to provide an overlay multicast method and program.

A first overlay multicast system of the present invention is an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on a network,
The server includes means for transmitting file data to be transmitted to the client to the relay device,
The relay device notifies the conversion device of an arrival message of a packet of file data transmitted from the server;
Using the information for processing the received file data, processing the file data transmitted from the server already held, and means for transmitting the processed file data to the client,
The conversion device includes means for creating information for processing file data transmitted from the server held by the relay device and transmitting the information to the relay device.

The second overlay multicast system of the present invention is an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on the network,
The server includes means for transmitting file data to be transmitted to the client to the relay device,
The relay device notifies the conversion device of an arrival message of a packet of file data transmitted from the server;
From the server already held by using the information for processing the received file data according to the CPU processing capacity availability of its own device and the CPU processing capacity availability of the conversion device Means for determining whether a device for processing transmitted file data is the own device or the conversion device;
When it is determined that the device to be processed is the relay device, using the received information for processing the file data, means for processing the file data transmitted from the server already held,
Means for transmitting processed file data to the client,
The conversion device creates information for processing the file data transmitted from the server held by the relay device, and transmits the information to the relay device;
When it is determined that the device to be processed is the conversion device, the file data transmitted from the relay device is processed using information for processing the file data, and the processed file data is transferred to the relay device. And means for transmitting.

The first relay device of the present invention is a relay device in an overlay multicast system configured on a network including a server, a relay device, a conversion device, and at least one client,
Means for notifying the conversion device of an arrival message of a packet of file data to be transmitted to the client transmitted from the server;
Means for processing file data transmitted from the server already held using information for processing the file data received from the conversion device, and transmitting the processed file data to the client; It is characterized by that.

The second relay device of the present invention is a relay device in an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on the network,
Means for notifying the conversion device of an arrival message of a packet of file data to be transmitted to the client transmitted from the server;
From the server already held by using the information for processing the received file data according to the CPU processing capacity availability of its own device and the CPU processing capacity availability of the conversion device Means for determining whether a device for processing transmitted file data is the own device or the conversion device;
When it is determined that the device to be processed is the device itself, the file data transmitted from the server that is already held is processed using the information for processing the file data received from the conversion device. Means,
When it is determined that the device to be processed is the conversion device, means for receiving processed file data from the conversion device;
Means for transmitting the processed file data to the client.

The first conversion device of the present invention is a conversion device in an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on the network,
Means for receiving an arrival message of a packet of file data transmitted from the server from the relay device;
In order to cause the relay device to send the processed file data to the client, information for processing the file data transmitted from the server held by the relay device is created and the information is transmitted to the relay device. And means for performing.

The second conversion device of the present invention is a conversion device in an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on the network,
Means for receiving an arrival message of a packet of file data transmitted from the server from the relay device;
Means for creating information for processing the file data transmitted from the server held by the relay device, and transmitting the information to the relay device;
The relay device has already retained the file data processing information received according to the CPU processing capacity availability of the relay device and the CPU capacity of the device itself. If the device that processes the file data transmitted from the server is determined to be its own device, the file data transmitted from the relay device is processed using the information for processing the file data, Means for transmitting file data to the relay device.

The first overlay multicast method of the present invention is an overlay multicast method using a server, a relay device, a conversion device, and at least one client on the network,
The server transmitting file data to be transmitted to the client to the relay device;
The relay device notifying the conversion device of an arrival message of a packet of file data transmitted from the server;
The conversion device creates information for processing the file data transmitted from the server held by the relay device, and transmits the information to the relay device;
The relay device uses the received information for processing the file data to process the file data already transmitted from the server, and transmits the processed file data to the client. It is characterized by having.

The second overlay multicast method of the present invention is an overlay multicast method using a server, a relay device, a conversion device, and at least one client on a network,
The server transmitting file data to be transmitted to the client to the relay device;
The relay device notifying the conversion device of an arrival message of a packet of file data transmitted from the server;
The conversion device creates information for processing the file data transmitted from the server held by the relay device, and transmits the information to the relay device;
The relay device has already retained the processing information of the received file data according to the availability of the processing capability of the CPU of its own device and the availability of the processing capability of the CPU of the conversion device. Determining whether the device that processes the file data transmitted from the server is the own device or the conversion device;
When it is determined that the device to be processed is the conversion device, the conversion device uses the information for processing the file data to process the file data transmitted from the relay device, and the processed file When data is transmitted to the relay device, on the other hand, when it is determined that the device to be processed is the relay device, the relay device has already retained the information for processing the received file data. Processing the file data transmitted from the server,
The relay device includes a step of transmitting processed file data to the client.

  According to the present invention, the application layer and the network layer can be linked in overlay multicast, network bandwidth consumption and data transfer time lag can be reduced, and the packet processing burden on the relay device and the conversion device can be reduced.

It is a figure which shows the system configuration | structure which concerns on 1st embodiment of this invention. It is a figure which shows the layer structure of the MPEG stream which concerns on 1st embodiment of this invention. It is a block diagram which shows the structure of the server which concerns on 1st embodiment of this invention. It is a block diagram which shows the structure of the relay apparatus which concerns on 1st embodiment of this invention. It is a block diagram which shows the structure of the converter which concerns on 1st embodiment of this invention. It is a block diagram which shows the structure of the client which concerns on 1st embodiment of this invention. It is a sequence diagram which shows the processing operation of the overlay multicast which concerns on 1st embodiment of this invention. It is a block diagram which shows the structure of the relay apparatus which concerns on 2nd embodiment of this invention. It is a block diagram which shows the structure of the converter which concerns on 2nd embodiment of this invention. It is a sequence diagram which shows the processing operation of the overlay multicast which concerns on 2nd embodiment of this invention. It is a figure which shows the structure of the conventional IP multicast system. It is a sequence diagram which shows the processing operation of the conventional IP multicast system. It is a figure which shows the structure of the conventional overlay multicast system. It is a sequence diagram which shows the processing operation of the conventional overlay multicast system.

Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. An overlay multicast system according to the present embodiment shown in FIG. 1 includes a server 10, a relay device 20, a relay node (hereinafter referred to as a “conversion device”) 30, a client 40A, and a client on a network 100 such as the Internet. 40B. Although the number of clients is two in FIG. 1 for ease of explanation, it is needless to say that the number may be three or more. Hereinafter, the client 40A and the client 40B are collectively referred to as the client 40 when they are commonly described.
The present invention can be applied to overlay multicast of various data formats. In the present embodiment, for convenience of explanation, stream data of MPEG format moving images will be described below as an example.

  As shown in FIG. 2, the MPEG stream is composed of layers such as a stream, a GOP, a picture, and a packet in order. The stream is divided into GOPs and frames (still images = pictures, which are units constituting moving images), and there are three types of MPEG frames: I pictures, B pictures, and P pictures. An I picture is a frame that is intra-coded. A P picture is a frame that is forward-predictively encoded. A B picture is a frame that is bi-directional predictively encoded.

  Further, GOP (Group Of Picture) is an image group structure including at least one I picture (intra-frame encoded image) in order to form a stream portion and enable random access to stream data. .

  In FIG. 2, the MPEG stream is divided into RTP / UDP / IP packets and transmitted. Each picture (I, B, P) is divided into one or more RTP / UDP / IP packets. The RTP / UDP / IP packet has an RTP header, a UDP header, an IP header, and a streaming header defined by each protocol. The RTP header holds the payload type in 7 bits, and is 32 in the case of an MPEG elementary stream, for example. The streaming header includes a GOP data rate, a stream head packet flag, and a stream end packet flag.

  The server 10 is an information processing apparatus such as a workstation. The relay device 20 is a node that performs data relay, and is a device corresponding to a router (layer 3 switch) on the Internet. The conversion device 30 is an information processing device corresponding to a data relay node. The clients 40A and 40B are information processing apparatuses such as a personal computer, a video deck, a television receiver, and a home server, and may be routers or the like.

  FIG. 3 is a block diagram illustrating a configuration of the server 10. The server 10 includes an MPEG encoder 11, a stream distribution processing unit 12, a CPU 13, a ROM 14, a RAM 15, a network I / F 16, and an HDD (hard disk drive) 17.

  The MPEG encoder 11 is a module that encodes an external video signal (source signal used for distribution) into an MPEG-2 (Moving Picture Experts Group 2) stream having a predetermined data rate. Is remembered. Note that the source signal encoding method may be other than MPEG-2, but in the present embodiment, MPEG-2 is taken as an example.

  The CPU 13 is a processor that performs overall control of the transmission apparatus. The ROM 14 is a read-only memory and stores a program that realizes the processing of the present invention. This program is loaded into the main memory and executed by the CPU 13. The RAM 15 is a memory that temporarily stores various data necessary for processing performed by the CPU 13.

  The network I / F (interface) 16 is a module that performs reception processing of stream transmission request IP packets and transmission processing of stream data IP packets. The HDD 17 is a storage device that reads / writes data from / to the magnetic disk, and stores stream data distributed to the client 40.

  The stream distribution processing unit 12 is a module that performs main processing of stream distribution using RTP / UDP / IP or the like. RTP (Real-time Transport Protocol) is a protocol that assigns a time stamp for synchronous reproduction of a packet. UDP is a connectionless protocol and is used for transmission of stream data. IP is a protocol that handles transfers between networks.

  In addition, the stream distribution processing unit 12 describes information such as a transmission source IP address, a transmission source port number, and a destination port number for each packet constituting the stream.

The relay device 20 is a node that relays data on a transmission path (route) among the server 10, the conversion device 30, and the client 40. The relay device 20 converts a packet storing stream data into the conversion device 30 or the client 40. Process on the other network. The relay device 20 has a role of reducing the traffic of the entire network by not flowing packets to unrelated networks.
FIG. 4 is a block diagram illustrating a configuration of the relay device 20. The relay device 20 includes a stream specifying unit 21, a pair conversion device communication unit 22, a CPU 23, a ROM 24, a RAM 25, a network I / F 26, and a data processing unit 27. The CPU 23, the ROM 24, the RAM 25, and the like play the same role as those in the server 10 described above. The network I / F 26 is provided according to the connected network, and performs transfer processing of packets such as stream transmission requests and stream data.

  The stream specifying unit 21 identifies and specifies a stream with reference to the received packet. At that time, each RTP / UDP / IP header, streaming header, or stream data portion is referred to. A source IP address is identified from the IP header, and a source port number and a destination port number are identified from the UDP header. Also, for example, information such as content No. XX data, how many seconds a CM can be inserted, and at what timing can be inserted, a range in which frames can be thinned out (1/2 or 1/4) etc.) is extracted and analyzed.

  The pair conversion device communication unit 22 notifies the conversion device 30 of the packet source IP address, the source port number, and the destination port number as a packet arrival message. Other information may be added to the packet arrival message. For example, information indicating that the data is content No. XX, how many seconds a CM can be inserted, and at what timing it can be inserted, a range in which frames can be thinned out (1/2 or 1 / 4) and the like. Then, the destination IP address is received from the conversion device 30 as a transfer message. Information for packet data processing (for each client) such as stream data may be added to the transfer message.

  The data processing unit 27 performs data processing on the file data transmitted by the packet such as the stream data from the server 10 using the data processing information of the packet such as the stream data received from the conversion device 30, and the client 40A The file data after the change by the data processing to be individually transmitted to each of the clients 40B is created.

  FIG. 5 is a block diagram illustrating a configuration of the conversion device 30. The conversion device 30 includes a relay device communication unit 31, a data processing information creation unit 32, a CPU 33, a ROM 34, a RAM 35, a network I / F 36, an HDD (hard disk drive) 37, and a destination IP address acquisition unit 38.

  The relay device communication unit 31 receives the packet source IP address, source port number, and destination port number from the relay device 20 as a packet arrival message. Then, the destination IP address is transmitted to the relay device 20 as a transfer message. In addition, information for packet data processing such as stream data is transmitted to the relay apparatus 20 by adding it to the transfer message.

The data processing information creation unit 32 creates data processing information for packets such as stream data to be transmitted to the relay device 20. The data processing information may be different for each of the client 40A and the client 40B. Even though the designation for the relay device 20 is common to the client 40A and the client 40B (the data processing information is transmitted once), each of the client 40A and the client 40B (the data processing information is transmitted twice in total). ).
Types of data processing include deletion (deletion for 10 minutes immediately after the start of moving images, thinning out frames), insertion (adding still images / moving images of advertisements), correction (replace data), and the like.
As an example, when the user of the client 40A likes gambling and the user of the client 40B likes sports, by inserting an advertisement according to each preference into the file data of the original moving image received from the server 10. There may be. Note that client user attributes, history information, and data for insertion / modification may be stored in the HDD 37 or the like. At this time, information such as how many seconds a CM or the like can be inserted and at what timing is added to the packet arrival message from the pair conversion device communication unit 22 of the relay device 20 is thinned out. Information on a possible range (1/2, 1/4, etc.), or a destination IP address acquired by a destination IP address acquisition unit 38 (to be described later) for specifying a client. May be.
The data for insertion / correction stored in the HDD 37 or the like may be used without being retransmitted after being once transmitted to the relay device 20 as a part of information for data processing.

  The CPU 33, the ROM 34, the RAM 35, and the like play the same role as those in the server 10 described above. The network I / F 36 performs transfer processing of packets such as stream data. The HDD 37 is a storage device that reads / writes data from / to the magnetic disk, and stores the changed portion of the changed stream data distributed to the client 40.

  The destination IP address acquisition unit 38 acquires the IP address of the data transfer destination by a predetermined method. In this embodiment, the IP addresses of the clients 40A and 40B are acquired.

  FIG. 6 is a block diagram showing the configuration of the client 40. The client 40 includes an MPEG decoder 41, a stream reception processing unit 42, a CPU 43, a ROM 44, a RAM 45, a network I / F 46, an HDD 47, and a display (output device) 48.

  The MPEG decoder 41 decodes the MPEG stream distributed from the server 10 and temporarily stored in the buffer processed by the relay device 20, and outputs it to the display 48 at the data rate of each stream and its partial section. This is a module that performs processing for playback.

  The stream reception processing unit 42 is a client module in the stream distribution service, and performs processing such as issuing a stream request and other messages and receiving stream data using a predetermined protocol.

  The CPU 43, the ROM 44, the RAM 45, and the like play the same role as those in the server 10 described above. The network I / F 46 is a module that performs processing for transmitting a stream distribution request IP packet to the server 10 and processing for receiving stream data IP packets. The HDD 47 is a storage device that temporarily stores stream data received from the relay device 20 in a buffer.

Hereinafter, the operation of the present embodiment will be described in detail with reference to the drawings.
FIG. 7 is a sequence diagram showing an overlay multicast processing operation in the present embodiment. It is assumed that the server 10 holds moving image file data 50. When a request for the file data 50 is issued from the client 40A and the client 40B (S701), the server 10 receives the request for the file data 50 via the relay device 20 that knows the location of the file data 50 (S702) (S702). S703). Then, the server 10 transmits the file data 50 (S704).
That is, first, the stream reception processing unit 42 of the client 40 issues a stream transmission request to the server 10 when receiving the stream distribution. On the other hand, in the server 10, the reception confirmation of the stream transmission request storing each information about the stream communication issued by the client 40 is performed, and when the stream transmission request is received, each picture of the MPEG stream is converted into an RTP / UDP / IP packet. The processing to be divided and transmitted to the client 40 is started.
Even if there is no request for the file data 50 from the client, the server 10 may automatically transmit the file data 50 to the corresponding client based on the determination based on the user attribute and history information.

Then, the relay device 20 receives the file data 50 from the server 10 (S705).
When an IP packet including an MPEG stream is received, the stream specifying unit 21 of the relay device 20 detects the payload type from the RTP header in the received packet, and interprets it as an MPEG stream if it is 32. When the flag indicating the stream head packet in the stream header is set, the source port number and the destination port number are detected from the UDP packet header, the source IP address is further detected from the IP header, and communication is performed by a combination of these. And consistently control each packet that arrives separately.
In addition, the stream specifying unit 21 of the relay device 20 thins out information and frames such as, for example, content No. XXX data, how many seconds a CM can be inserted, and at what timing. Extract and analyze information of possible range (1/2, 1/4, etc.).

Next, the relay device 20 transmits a packet arrival message to the conversion device 30 (S706).
The pair conversion device communication unit 22 of the relay device 20 notifies the conversion device 30 of the packet source IP address, the source port number, and the destination port number as a packet arrival message. Other information may be added to the packet arrival message. For example, information indicating that the data is content No. XXX, how many seconds a CM can be inserted, and at what timing can be inserted, a range in which frames can be thinned out (1/2 or 1 / 4) and the like.

The relay device communication unit 31 of the conversion device 30 receives the packet source IP address, the source port number, and the destination port number from the relay device 20 as a packet arrival message, and the data processing information creation unit 32 of the conversion device 30 relays the packet. Information for data processing of packets such as stream data to be transmitted to the apparatus 20 is created (S707).
Here, the information for data processing is different for each of the clients 40A and 40B, and the designation for the relay device 20 is for each of the clients 40A and 40B (the transmission of information for data processing is a total of two). Times).
Types of data processing include deletion (deletion for 10 minutes immediately after the start of moving images, thinning out frames), insertion (adding still images / moving images of advertisements), correction (replace data), and the like.
Here, when the user of the client 40A likes gambling and the user of the client 40B likes sports, the CM corresponding to each preference is inserted into the file data of the original moving image received from the server 10. To do. Note that the information added to the packet arrival message from the relay device 20 about how many seconds the CM can be inserted and at what timing can be referred to. Further, in order to specify the client, the destination IP address acquired by the destination IP address acquisition unit 38, which will be described later, the client user attribute and history information stored in the HDD 37, and data for insertion / modification are referred to.

  Further, the destination IP address acquisition unit 38 of the conversion device 30 acquires the IP address of the data transfer destination by a predetermined method (S708). In this embodiment, the IP addresses of the clients 40A and 40B are acquired. This step may precede step S707 described above.

Thereafter, the conversion device 30 transmits a transfer message to the relay device 20 (S709).
The relay device communication unit 31 of the conversion device 30 transmits the IP addresses of the clients 40A and 40B to the relay device 20 as a transfer message. In addition, information for packet data processing such as stream data is transmitted to the relay apparatus 20 by adding it to the transfer message. Here, as data processing information, for the client 40A, gambling-related CM data for 30 seconds is inserted at the time of 5 minutes from the start of the moving image, while for the client 40B, 5 minutes from the start of the moving image. The information created in step S707 above for inserting 30-second sports-related CM data at the time is used. In addition, the corresponding gambling-related CM data and sports-related CM data are also transmitted to the relay device 20.
In a system in which a plurality of relay apparatuses 20 are provided, the optimum relay apparatus 20 may be selected.

The pair conversion device communication unit 22 of the relay device 20 receives the transfer message including the destination IP address from the conversion device 30 (including information for data processing of packets such as stream data), and the data processing unit 27 of the relay device 20. Creates the changed file data by data processing (S710). Note that the IP addresses of the clients 40A and 40B as the destination IP addresses may be acquired by the relay device 20 itself.
The data processing unit 27 of the relay device 20 processes the data of the file data transmitted by the packet such as the stream data from the server 10 using the data processing information of the packet such as the stream data received from the conversion device 30. The file data after modification by data processing to be individually transmitted to each of the client 40A and the client 40B is created. That is, for the client 40A, file data in which 30 seconds of gambling-related CM data is inserted is created at the time of 5 minutes from the start of the moving image, while for the client 40B, the file data is 30 at the time of 5 minutes from the start of the moving image. Create file data with sports-related CM data for a second inserted. Instead of creating the changed file data itself, the transmission order of packets such as stream data may be controlled so that the changed file data is reproduced on the client side.

The relay device 20 transmits the changed file data 50 for the client 40A to the client 40A, and transmits the changed file data 50 for the client 40B to the client 40B (S711). At this time, the IP address of the client 40A and the IP address of the client 40B are used.
The client 40A and the client 40B start receiving a plurality of RTP / UDP / IP packets constituting the stream, extract MPEG data from the RTP / UDP / IP packets received in the buffer, and a data rate required by the MPEG decoder 41 To administer.
When the packet final flag of the transmitted packet is set, the relay device 20 determines that the packet is the final packet of the stream, and ends the transmission of the stream. On the other hand, when the final flag indicating the final packet of the stream is set in the RTP / UDP / IP packet including the MPEG data given to the MPEG decoder 41, the client 40A and the client 40B end the stream reproduction.

  According to the present embodiment described above, the application layer and the network layer can be linked in overlay multicast, the network bandwidth consumption and data transfer time lag can be reduced, and the packet processing burden on the relay device and the conversion device can be reduced. .

Hereinafter, a second embodiment of the present invention will be described.
The system configuration is basically the same as that of the first embodiment described above, and redundant description is omitted. The difference is that in the first embodiment, the file data modified for the client 40A and the client 40B is created by the data processing unit 27 of the relay device 20, but is converted under a predetermined condition. It is in the point created with the apparatus 30. In the first embodiment described above, in step S710 of FIG. 7, the pair conversion device communication unit 22 of the relay device 20 transmits the destination IP address from the conversion device 30 to the transfer message (information for processing data of packets such as stream data). And the data processing unit 27 of the relay device 20 creates the file data after the change by the data processing.

  FIG. 8 is a block diagram illustrating a configuration of the relay device 20. The relay device 20 in the present embodiment is different from the relay device 20 in the first embodiment in that it further includes a processing capacity confirmation unit 281, a band confirmation unit 282, and a processing determination unit 283.

  The processing capability confirmation unit 281 confirms the availability of the processing capability of the CPU 23 of the relay device 20 itself and the availability of the processing capability of the CPU 33 of the conversion device 30. For example, when the conversion device 30 is inquired about the availability of the processing capacity of the CPU 33, an answer such as “70% free” is obtained.

  The bandwidth confirmation unit 282 confirms the availability of the bandwidth of the network 100. For example, it may be possible to measure the return time of the echo message and confirm the degree of delay.

  The processing determination unit 283 compares the availability of the processing capability of the CPU 23 of the relay device 20 itself confirmed by the processing capability confirmation unit 27 with the availability of the processing capability of the CPU 33 of the conversion device 30 confirmed by inquiry to the conversion device 30. Further, according to the availability of the bandwidth of the network 100 confirmed by the bandwidth confirmation unit 28, the device that creates the file data modified for each client is determined as the relay device 20 or the conversion device 30. For example, since the CPU 33 of the conversion device 30 is “70% free” and the return time of the echo message is short and the delay is small, the device that creates the file data modified for each client is a relay device. The conversion device 30 is determined instead of 20. It should be noted that a threshold value or the like serving as a determination criterion at this time may be stored in a predetermined storage unit.

FIG. 9 is a block diagram illustrating a configuration of the conversion device 30. The conversion device 30 in the present embodiment is different from the relay device 20 in the first embodiment in that it further includes a data processing unit 39.
The data processing unit 39 performs data processing on the file data transmitted by the packet such as stream data from the relay device 20 using the data processing information of the packet such as the stream data created by the data processing information creation unit 32. The file data after modification by data processing to be individually transmitted to each of the client 40A and the client 40B is created. Note that the relay device communication unit 31 may receive a part of a packet such as stream data from the relay device 20. This is because only the part necessary for data processing may be sufficient.

  The processing operation of the present embodiment will be described below with reference to the sequence diagram of FIG. This is basically the same as the first embodiment described above, and redundant description is omitted. The difference is step S710 in FIG. 7 of the first embodiment described above. The processing of this embodiment corresponding to this processing is as follows.

  The pair conversion device communication unit 22 of the relay device 20 receives a destination IP address transfer message (including information for packet data processing such as stream data) from the conversion device 30 and receives the processing capability confirmation unit 281 of the relay device 20. Confirms the availability of the processing capability of the CPU 23 of the relay device 20 itself and the availability of the processing capability of the CPU 33 of the conversion device 30. In addition, the bandwidth confirmation unit 282 of the relay device 20 confirms the availability of the bandwidth of the network 100 (S1010).

  Then, the processing determining unit 283 of the relay device 20 determines the availability of the processing capability of the CPU 23 of the relay device 20 itself confirmed by the processing capability confirmation unit 27 and the processing capability of the CPU 33 of the conversion device 30 confirmed by inquiring of the conversion device 30. In addition, the relay device 20 or the conversion device 30 is used as a device for creating file data modified for each client in accordance with the bandwidth availability of the network 100 confirmed by the bandwidth confirmation unit 28. Is determined (S1011). Here, since the CPU 33 of the conversion device 30 is “70% free” and the return time of the echo message is short and the delay is small, the device that creates the file data modified for each client is relayed. Assume that the conversion device 30 is determined instead of the device 20.

  The pair conversion device communication unit 22 of the relay device 20 notifies the conversion device 30 that the conversion device 30 has been determined as the device that creates the file data modified for each client (S1012). In addition, the relay device 20 transmits file data transmitted by a packet such as stream data to the conversion device 30. A part of the packet such as stream data may be transmitted to the conversion device 30.

  The data processing unit 39 of the conversion device 30 uses packet data processing information such as stream data created by the data processing information creation unit 32 for file data transmitted by packets such as stream data from the relay device 20. The data processing is performed, and the file data after the change by the data processing to be individually transmitted to the client 40A and the client 40B is created (S1013). Note that the information for packet data processing such as stream data created by the data processing information creation unit 32 may be received from the relay device 20 again after being transmitted to the relay device 20.

  The inter-relay device communication unit 31 of the conversion device 30 transmits the file data changed for the client 40A and the client 40B to the relay device 20 (S1014).

  Then, the relay device 20 transmits the file data 50 modified for the client 40A to the client 40A, and transmits the file data 50 modified for the client 40B to the client 40B (S1015). When a part of the packet such as stream data is transmitted to the conversion device 30, the data processing unit 27 of the relay device 20 uses the conversion device for the file data transmitted by the packet such as the stream data from the server 10. 30. Data processing is performed using a part of the file data changed for the client 40A and the client 40B received from the client 30, and the changed file data by the data processing transmitted individually to each of the client 40A and the client 40B. It may be created.

  According to the above-described embodiment, packet processing is performed by efficiently using two resources according to the availability of the processing capability of the CPU 23 of the relay device 20 and the availability of the processing capability of the CPU 33 of the conversion device 30. Can be speeded up. Further, considering the availability of the bandwidth of the network 100, it is more realistic by considering not only the availability of the two resources but also the efficiency in transferring data to the conversion device 30 via the network 100. In addition, packet processing can be speeded up.

  The program for executing the processing described in each embodiment is recorded in various recording media such as a CD-ROM, a DVD (Digital Versatile Disc), a floppy (registered trademark) disk, and a memory card. Can be provided. The program controls the operation of the computer of each device, and each device controlled by the program executes the processing of the present invention.

  The embodiment of the present invention has been described above. The above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. .

10 server 20 relay device 30 relay node (conversion device)
40A, 40B client 100 network

Claims (29)

An overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
The server includes means for transmitting file data to be transmitted to the client to the relay device,
The relay device notifies the conversion device of an arrival message of a packet of file data transmitted from the server;
Using the information for processing the received file data, processing the file data transmitted from the server already held, and means for transmitting the processed file data to the client,
The conversion apparatus comprises an overlay multicast system comprising means for creating information for processing file data transmitted from the server held by the relay apparatus and transmitting the information to the relay apparatus . An overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
The server includes means for transmitting file data to be transmitted to the client to the relay device,
The relay device notifies the conversion device of an arrival message of a packet of file data transmitted from the server;
From the server already held using the information for processing the received file data in accordance with the availability of the processing capability of the CPU of the own device and the availability of the processing capability of the CPU of the conversion device Means for determining whether a device for processing the transmitted file data is the own device or the conversion device;
When it is determined that the device to be processed is the relay device, using the received information for processing the file data, means for processing the file data transmitted from the server already held,
Means for transmitting processed file data to the client,
The conversion device creates information for processing file data transmitted from the server held by the relay device, and transmits the information to the relay device;
When it is determined that the device to be processed is the conversion device, the file data transmitted from the relay device is processed using information for processing the file data, and the processed file data is converted to the relay device. And an overlay multicast system.   The overlay multicast system according to claim 2, wherein the relay device takes into consideration the availability of the bandwidth of the network when determining the device to be processed.   The overlay multicast system according to any one of claims 1 to 3, wherein the processing of the file data is any one of deletion, insertion and correction of data. The client comprises means for requesting file data held by the server;
The server transmits the requested file data to the relay device;
The overlay multicast system according to any one of claims 1 to 4, wherein the relay device transmits the processed file data to a client that has requested the file data.   When the relay device notifies the conversion device of an arrival message of a packet of file data transmitted from the server, and the conversion device creates information for processing the file data transmitted from the server The overlay multicast system according to any one of claims 1 to 5, further comprising means for transmitting usable information to the network. The conversion device transmits to the relay device information for processing the file data transmitted from the server held by the relay device, and transmits the IP address information of the client that requested the acquired file data. Means to
The said relay apparatus transmits the file data after processing to the said client based on the IP address information of the client which requested | required the received said file data, The any one of Claim 1 to 6 characterized by the above-mentioned. Overlay multicast system. A relay device in an overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
Means for notifying the conversion device of an arrival message of a packet of file data to be transmitted to the client transmitted from the server;
Means for processing file data transmitted from the server already held using information for processing the file data received from the conversion device, and transmitting the processed file data to the client; A relay device characterized by that. A relay device in an overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
Means for notifying the conversion device of an arrival message of a packet of file data to be transmitted to the client transmitted from the server;
From the server already held by using the information for processing the received file data according to the CPU processing capacity availability of its own device and the CPU processing capacity availability of the conversion device Means for determining whether a device for processing transmitted file data is the own device or the conversion device;
When it is determined that the device to be processed is the device itself, the file data transmitted from the server that is already held is processed using the information for processing the file data received from the conversion device. Means,
When it is determined that the device to be processed is the conversion device, means for receiving processed file data from the conversion device;
A relay apparatus comprising: means for transmitting processed file data to the client.   10. The relay device according to claim 9, wherein when determining the device to be processed, the availability of the bandwidth of the network is taken into consideration.   The relay apparatus according to any one of claims 8 to 10, wherein the processing of the file data is any one of deletion, insertion and correction of data.   Information that can be used when notifying the conversion device of the arrival message of the packet of the file data transmitted from the server and creating information for processing the file data transmitted from the server by the conversion device The relay apparatus according to any one of claims 8 to 11, further comprising: a means for transmitting.   13. The relay according to claim 8, wherein the processed file data is transmitted to the client based on IP address information of the client that requested the file data received from the conversion device. apparatus. A conversion device in an overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
Means for receiving an arrival message of a packet of file data transmitted from the server from the relay device;
In order to cause the relay device to send the processed file data to the client, information for processing the file data transmitted from the server held by the relay device is created and the information is transmitted to the relay device. And a conversion device. A conversion device in an overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
Means for receiving an arrival message of a packet of file data transmitted from the server from the relay device;
Means for creating information for processing the file data transmitted from the server held by the relay device, and transmitting the information to the relay device;
The relay device has already retained the file data processing information received according to the CPU processing capacity availability of the relay device and the CPU capacity of the device itself. If the device that processes the file data transmitted from the server is determined to be its own device, the file data transmitted from the relay device is processed using the information for processing the file data, A conversion device comprising: means for transmitting file data to the relay device.   16. The conversion apparatus according to claim 14, wherein the processing of the file data is any one of deletion, insertion and correction of data.   Means for receiving an arrival message of a packet of file data transmitted from the server and receiving information usable when creating information for processing the file data transmitted from the server from the relay device; The conversion device according to any one of claims 14 to 16, wherein:   Means for transmitting to the relay device information for processing the file data transmitted from the server held by the relay device and transmitting IP address information of the client that requested the acquired file data; The conversion device according to any one of claims 14 to 17, wherein: An overlay multicast method using a server, a relay device, a conversion device, and at least one client on a network,
The server transmitting file data to be transmitted to the client to the relay device;
The relay device notifying the conversion device of an arrival message of a packet of file data transmitted from the server;
The conversion device creates information for processing the file data transmitted from the server held by the relay device, and transmits the information to the relay device;
The relay device uses the received information for processing the file data to process the file data already transmitted from the server, and transmits the processed file data to the client. An overlay multicast method comprising: An overlay multicast method using a server, a relay device, a conversion device, and at least one client on a network,
The server transmitting file data to be transmitted to the client to the relay device;
The relay device notifying the conversion device of an arrival message of a packet of file data transmitted from the server;
The conversion device creates information for processing the file data transmitted from the server held by the relay device, and transmits the information to the relay device;
The relay device has already retained the processing information of the received file data according to the availability of the processing capability of the CPU of its own device and the availability of the processing capability of the CPU of the conversion device. Determining whether the device that processes the file data transmitted from the server is the own device or the conversion device;
When it is determined that the device to be processed is the conversion device, the conversion device uses the information for processing the file data to process the file data transmitted from the relay device, and the processed file When data is transmitted to the relay device, on the other hand, when it is determined that the device to be processed is the relay device, the relay device has already retained the information for processing the received file data. Processing the file data transmitted from the server,
The relay apparatus includes a step of transmitting the processed file data to the client.   21. The overlay multicast method according to claim 20, wherein when the relay device determines the device to be processed, the network bandwidth is also taken into consideration.   The overlay multicast method according to any one of claims 19 to 21, wherein the processing of the file data is any one of deletion, insertion and correction of data. The client requesting file data held by the server;
The server sends the requested file data to the relay device;
The overlay multicast method according to any one of claims 19 to 22, wherein the relay device transmits the processed file data to a client that has requested the file data.   When the relay device notifies the conversion device of the arrival message of the packet of the file data transmitted from the server and the conversion device creates information for processing the file data transmitted from the server The overlay multicast method according to any one of claims 19 to 23, wherein usable information is transmitted. The conversion device transmits to the relay device information for processing the file data transmitted from the server held by the relay device and transmits the IP address information of the client that requested the acquired file data. And
The said relay apparatus transmits the file data after processing to the said client based on the IP address information of the client which requested | required the received said file data, The any one of Claim 19 to 24 characterized by the above-mentioned. Overlay multicast method. A relay device program in an overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
Processing for notifying the relay device of an arrival message of a packet of file data to be transmitted to the client transmitted from the server to the conversion device;
Using the information for processing the file data received from the conversion device, processing the file data transmitted from the server already held, and executing the processing of transmitting the processed file data to the client A program characterized by letting A relay device program in an overlay multicast system including a server, a relay device, a conversion device, and at least one client on a network,
Processing for notifying the relay device of an arrival message of a packet of file data to be transmitted to the client transmitted from the server to the conversion device;
From the server already held by using the information for processing the received file data according to the CPU processing capacity availability of its own device and the CPU processing capacity availability of the conversion device A process for determining whether a device for processing the transmitted file data is the own device or the conversion device;
When it is determined that the device to be processed is the device itself, the file data transmitted from the server that is already held is processed using the information for processing the file data received from the conversion device. Processing,
When it is determined that the device to be processed is the conversion device, processing for receiving processed file data from the conversion device;
A program for executing processing for transmitting processed file data to the client. A program for a conversion device in an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on a network,
A process of receiving an arrival message of a packet of file data transmitted from the server from the relay device;
In order to cause the relay device to send the processed file data to the client, information for processing the file data transmitted from the server held by the relay device is created and the information is transmitted to the relay device. And a program for executing the processing. A program for a conversion device in an overlay multicast system configured to include a server, a relay device, a conversion device, and at least one client on a network,
A process of receiving an arrival message of a packet of file data transmitted from the server from the relay device;
Creating information for processing file data transmitted from the server held by the relay device, and transmitting the information to the relay device;
The relay device has already retained the file data processing information received according to the CPU processing capacity availability of the relay device and the CPU capacity of the device itself. If the device that processes the file data transmitted from the server is determined to be its own device, the file data transmitted from the relay device is processed using the information for processing the file data, A program for executing processing for transmitting file data to the relay device.

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