JP3558977B2 - Stream relay device, stream broadcast distribution network, and recording medium - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention is used for distribution of a stream broadcast including video and audio. In particular, the present invention relates to stream distribution that handles large-scale and high-speed broadcast services.
[0002]
[Prior art]
The conventional stream relay device corresponds to a splitter device manufactured by RealNetworks. One or a plurality of these are installed between a stream server and a client, and receive stream broadcast data by unicast, copy this, and distribute it to downstream clients.
[0003]
As a conventional information distribution system, a "control method of an information distribution system and an information distribution system (JP-A-11-68744)" is known. In this case, when there is a multimedia terminal that has already received the desired content, this terminal performs distribution on behalf of the server.
[0004]
[Problems to be solved by the invention]
According to the technology of the conventional stream relay device, first, in the data distribution from the stream server to the stream relay device, data is dripped based on a preset setting regardless of the presence or absence of a request from a downstream client. Occurs.
[0005]
Therefore, there is no efficient transfer mechanism that starts data relay based on a viewing request from downstream and ends data relay in response to a viewing end request. Also, since the stream relay device directly executes the viewing request processing with the stream server without terminating the stream control protocol, the processing load is concentrated on the server. There is no mechanism for reducing the load concentrated on the server by distributing the load of each stream relay device.
[0006]
In addition, different stream control protocols are used between the client and the relay server and between the relay server and the stream server as the stream control protocol used to instruct the start and end of the stream broadcast. Therefore, the efficiency is poor because two types of software modules and configurations are forced. In terms of easiness of interconnection and operation cost, it is advisable to operate using one type of stream control protocol.
[0007]
On the other hand, in the technology of the conventional information distribution system, it is possible for the multimedia terminal to reduce the processing load on the server by performing the distribution in place of the server. If this occurs, the distribution process of the multimedia terminal itself that performs proxy distribution will increase, and the bandwidth of the line between the multimedia terminal and the distribution network will be consumed by the number of distributions, There is a problem that the communication cost of each client increases. In addition, since distribution is performed between multimedia terminals, waste of distribution network resources increases, and a hierarchical stream relay technique is required.
[0008]
Furthermore, the conventional stream relay device and information distribution system are dedicated to transmitting stream broadcast data, and do not have a function of selecting unicast or multicast according to a profile depending on content to be broadcasted, a destination client, and the like. In broadcast services, multicast is suitable in terms of transfer efficiency, but network devices adapted to protocols such as IP multicast are not sufficiently spread. Therefore, it is necessary to use the unicast and the multicast in the right place at the right place. However, in the conventional stream relay device, it is impossible to use the unicast and the multicast properly, and only the distribution using the unicast or the multicast can be performed. The function of automatically selecting the content and the attribute of the client is necessary to enhance the serviceability.
[0009]
In addition, there is no function of selecting a transfer protocol such as Ethernet, Gigabit Ethernet, or ATM when transferring stream data. Therefore, it is difficult to differentiate the quality of stream broadcasting.
[0010]
The present invention has been made in such a background, the load distribution of stream broadcast data reception processing, streamlining of the amount of relay traffic, stream control protocol unification, transfer protocol selection function, etc., The aim is to increase the scale and efficiency of stream broadcasting service provision and improve compatibility with existing networks.
[0011]
[Means for Solving the Problems]
In the present invention, both the client and the stream server are provided with control protocol processing functions so that the stream relay device can be seen as a client upstream and a server downstream. At this time, in any section between the client and the stream relay device, between the stream relay devices, and between the stream relay device and the stream server, a stream control protocol procedure in which the client and the stream server directly exchange is performed. It is desirable to use. As a result, protocol control can be simplified.
[0012]
Also, in order to realize a function of receiving and copying one stream of broadcast data from an upstream stream server or a stream relay device, a broadcast data memory for temporarily storing the received stream data, It has a table that indicates whether it is medium or not.
[0013]
The stream relay device processes the viewing request from the client from the viewpoint of the server, and when the device receives the stream broadcast data, reads the data from the broadcast data memory and broadcasts the data to the client. However, when the stream broadcast viewing request is the first, the stream relay device requests the upstream stream relay device or stream server on behalf of the client, and finally receives the stream broadcast data. To downstream clients.
[0014]
In addition, the communication protocol must be specified by the profile such as the destination client address and the stream broadcast content, and the broadcast data should be distributed by unicast or multicast according to the profile, or a plurality of transfer protocols should be selected and distributed. Can be. This selection is performed for each stream relay device.
[0015]
By configuring a network in which a plurality of stream relay devices of the present invention are dispersedly arranged, it is possible to achieve load distribution in stream data reception processing and more efficient relay traffic volume.
[0016]
As described above, in the present invention, first, the stream relay apparatus uses the same stream control protocol for both the upstream and the downstream, and has a role of a server on the downstream side and a role of a client on the upstream side. It is easy. In addition, since the relay data is transferred according to a request from the downstream, the transmission efficiency is high. Furthermore, by associating a communication protocol with a destination client or content, it is possible to realize broadcast distribution with high affinity for connected network devices. In particular, since unicast or multicast is selected for each stream relay device, the most suitable broadcast distribution can be realized in the entire network.
[0017]
That is, a first aspect of the present invention is a stream relay device that receives a stream broadcast packet transmitted by a stream server and broadcasts the packet to a client.
[0018]
Here, the features of the present invention include processing means for a protocol exchanged between itself and a client, processing means for a protocol exchanged between itself and a stream server, and broadcast processing for storing stream broadcast data. A data memory, a broadcast management table for displaying broadcasts for each stream broadcast, a means for receiving a viewing request from a client, and the broadcast data memory when the requested stream broadcast is being broadcast based on the display of the broadcast management table. Means for reading data from and starting broadcasting toward the client that transmitted the viewing request, and when the broadcast of the requested stream is not being broadcast based on the display of the broadcast management table, the viewing request is transmitted to the upstream stream relay device or The request stream is sent from the upstream to the stream server. Is in place and means for initiating a broadcast to the client that transmitted the viewing request receives broadcast data later stored in the broadcast data memory.
[0019]
It is desirable to have a means for transmitting a viewing end request to the upstream stream server or stream relay device when the viewing of all the clients or stream relay devices receiving the same stream broadcast content downstream is completed. This allows the upstream stream server or stream relay device to avoid wasting stream broadcasts that are wasted.
[0020]
It is desirable to use the same stream control protocol procedure between the client and the stream relay device, between the stream relay devices, and between the stream relay device and the stream server. As a result, protocol control can be simplified.
[0021]
Means for associating a communication protocol for transmitting stream broadcast data downstream with the stream broadcast content name or the distribution destination client address, and selecting and transmitting a communication protocol according to the association with the received stream broadcast data It is desirable to provide. This makes it possible to flexibly cope with different communication protocols. At this time, the options of the communication protocol may include an IP unicast protocol and an IP multicast protocol. Further, it is desirable to have means for selecting a lower layer protocol for transferring IP unicast or IP multicast. Further, it is desirable to have a means for converting and transmitting the distribution destination address according to the selected communication protocol.
[0022]
A second aspect of the present invention is that the upstream is directly or indirectly connected to one or more stream relay devices and / or one or more stream servers of the present invention, and the downstream is one in the direction in which stream broadcast data is transferred. A stream broadcast distribution network characterized by forming a hierarchical structure directly or indirectly connected to the stream relay device and / or one or more clients of the present invention. By forming such a stream broadcast distribution network, it is possible to distribute the load of the stream broadcast data reception process and increase the efficiency of the relay traffic.
[0023]
According to a third aspect of the present invention, a computer device having predetermined hardware and predetermined basic software installed on the hardware is further installed on the computer device so that the computer device becomes a stream relay device of the present invention. It is a recording medium on which software for a corresponding device is recorded.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
A configuration of a stream relay device and a stream broadcast distribution network according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a stream broadcast distribution network according to the present invention. FIG. 2 is a block diagram of the stream relay device of the present invention. Here, the description will focus on the stream relay device 11.
[0025]
As shown in FIG. 1, the present invention is a stream relay device 11 that receives a stream broadcast packet transmitted by a stream server 21 and broadcasts the packet to the clients 1 and 2.
[0026]
Here, the features of the present invention are, as shown in FIG. 2, a server protocol processing unit 104 as processing means for a protocol exchanged between the client and the clients 1 and 2; A client protocol processing unit 106 as a processing means of a protocol exchanged between the two; a broadcast data memory 114 for storing stream broadcast data; a broadcast management table 113 for displaying a broadcast for each stream broadcast; And a client 1 and 2 that have read the data from the broadcast data memory 114 and transmitted the viewing request when the request stream broadcast is being broadcast based on the display of the broadcast management table 113. Broadcast to the broadcast management table 11 When the broadcast of the request stream is not being broadcast based on the display of the above, the viewing request is transmitted to the upstream stream relay device 13 or the stream server 21, the request stream broadcast data is received from the upstream, and stored in the broadcast data memory 114, and A transfer control unit 107 is provided as a means for starting broadcasting to the clients 1 and 2 that transmitted the viewing request.
[0027]
In addition, the transfer control unit 107 transmits a viewing end request to the upstream stream relay device 13 when the viewing of all the clients 1 and 2 receiving the same stream broadcast content at the downstream ends. At this time, the transfer control unit 107 of the stream relay device 13 transmits a viewing end request from the stream relay device 12 and the clients 5 and 6 to the stream broadcast content distributed to the stream relay device 12 and the clients 5 and 6. If so, a viewing end request is transmitted to the stream server 21.
[0028]
The same stream control protocol procedure is used between the clients 1 to 6 and the stream relay devices 11 to 13, between the stream relay devices 11 to 13, and between the stream relay devices 11 to 13 and the stream server 21.
[0029]
Further, the transfer control unit 107 associates a communication protocol for transmitting the stream broadcast data downstream with the stream broadcast content name or the distribution destination client address, and communicates the received stream broadcast data according to the association. Select a protocol and send. At this time, the options of the communication protocol include the IP unicast protocol and the IP multicast protocol. Further, a lower layer protocol for transferring IP unicast or IP multicast is selected. Further, the transmission destination address is converted according to the selected communication protocol and transmitted.
[0030]
In the stream broadcast distribution network of the present invention, for example, focusing on the stream relay device 13 in FIG. 1, the upstream is directly connected to the stream server 21 and the downstream is the stream relay device 11 in the direction in which the stream broadcast data is transferred. And 12 and the clients 1 to 6 are directly or indirectly connected to form a hierarchical structure.
[0031]
The stream relay device 11 of the present invention is further installed on a computer device having predetermined hardware and predetermined basic software installed on the hardware, thereby connecting the computer device to the stream relay device 11 of the present invention. It can be realized by installing the software in a computer device using a recording medium on which software is recorded as a device corresponding to.
[0032]
Hereinafter, embodiments of the present invention will be described in more detail.
[0033]
FIG. 1 shows a connection configuration of clients 1 to 6, stream relay devices 11 to 13, and a stream server 21 in the embodiment of the present invention. These are connected by lines 31 to 39, and the lines may be directly connected or may include a network device such as a switch or a router.
[0034]
Further, as a stream control protocol, a Real Time Streaming Protocol (RTSP) protocol specified by RFC (Request for Comments) 2326 of the Internet Engineering Task Force (IETF) is assumed, and a viewing / listening request and a viewing / listening end are assumed. Perform the request or their response procedure. The RTSP packet is assumed to be transferred as a lower layer by a TCP (Transmission Control Protocol) protocol or an IP (Internet Protocol) unicast protocol. Further, the RTSP relays the stream broadcast data in the order of the stream server 21, the stream relay apparatuses 11, 12, 13, and the clients 1, 2, 3, 4, 5, and 6, and this data is defined by IETF RFC1889. It is transferred by RTP (Real-time Transport Protocol) protocol, and UDP (User Datagram Protocol) and IP unicast protocol are used as lower-layer protocols.
[0035]
Regarding the connection configuration, the stream relay device 11 is directly connected to the clients 1 and 2 downstream and the stream relay device 13 upstream, and the stream relay device 13 is connected to the clients 5 and 6 and the stream relay devices 11 and 12 downstream. The stream server 21 is directly connected upstream. Among these, the stream relay device 13 is connected to the downstream clients 1, 2, 3, 4, 5, and 6 and the stream relay devices 11 and 12, and responds to a viewing request from those downstream devices. A viewing request is executed on behalf of the stream server 21 and relayed while receiving stream broadcast data.
[0036]
In FIG. 1, an embodiment will be described in which a viewing reception request is transmitted in the order of clients 1, 2, and 3. First, the client 1 transmits a viewing request to the stream relay device 11 to view the stream broadcast of the server 21. Since the stream relay device 11 has not yet received the broadcast data of the requested content, the stream relay device 11 transmits a viewing request to the upstream stream relay device 13. Since the stream relay device 13 has not yet received the broadcast data of the requested content, it also transmits a viewing request to the stream server 21. The stream server 21 receives the request and distributes the stream broadcast data to the client 1 via 39 → 13 → 35 → 11 → 31.
[0037]
Next, the client 2 transmits a viewing request to the stream relay device 11 for the same content. In this case, the stream relay device 11 has already received the stream broadcast data and has delivered it to the client 1. Therefore, the stream relay device 11 receives the viewing request from the client 2, reads the content data from the broadcast data memory 114, and distributes the same content to the client 2.
[0038]
Further, when the client 3 transmits a viewing request for the same content to the stream relay device 12, the stream relay device 12 is not receiving the content in response to the viewing request of the client 3. Send a viewing request to. Here, since the stream relay apparatus 13 has already received the content, the request is accepted, and the same content is delivered from the stream relay apparatus 13 to the client 3 through the route of 36 → 12 → 33 → 3.
[0039]
Also, a flow in the case where the broadcast to these three clients 1 to 3 ends in the order of 3, 2, 1 will be described. When the client 3 sends a viewing end request to the stream relay device 12, the stream relay device 12 stops relaying the same content to the client 3 and determines that all the downstream clients have ended the viewing. The viewing end request is transmitted on behalf of the relay device 13. The stream relay device 13 does not transmit a viewing end request to the upstream stream server 21 because the downstream stream relay device 11 is still delivering to the clients 1 and 2.
[0040]
Next, when both the clients 1 and 2 transmit a viewing end request to the stream relay device 11, the stream relay device 11 understands that the downstream has been completely viewed, and sends a representative request to the upstream stream relay device 13 for the viewing end request. To send. At this point, the stream relay device 13 knows that the downstream viewing has been completed, and transmits a viewing end request to the stream server 21 as a representative. Thereby, the entire distribution service of the content is ended.
[0041]
As described above, the stream broadcast content distributed by the stream server 21 starts data relay in response to a request from the client, and stops relaying from the part where the client has finished viewing, so that use of the network is wasted. There is no. The stream control protocol such as a viewing request or a viewing end request exchanged on the lines 31 to 39 is the same RTSP protocol procedure in any section, and the left end of the line performs client processing and the right end performs server processing. . Therefore, the interconnectivity and network expandability are excellent, and the scale can be increased by hierarchically increasing the number of stream relay devices.
[0042]
FIG. 2 is a configuration diagram of the stream distribution devices 11 to 13 in the embodiment of the present invention. In FIG. 2, stream data transfer in each section between the stream server and the stream relay device, between the stream relay devices, and between the stream relay device and the client must be performed using the RTP, UDP, and IP unicast protocols. And
[0043]
Here, the downstream line terminating unit 101 connects to a downstream stream distribution device or a line addressed to the client, and the receiving driver unit 102 extracts the received packet from the downstream line terminating unit 101 and transfers it to the server protocol processing unit 104. It is a processing unit. The transmission driver unit 103 is a processing unit that transfers a processed stream control protocol packet or stream data to the downstream line termination unit 101, and the server protocol processing unit 104 analyzes a request signal received from a downstream stream distribution device or a client. The processing unit transmits the analysis result to the request reception processing unit. Upon receiving the viewing request, the request reception processing unit 105 refers to the reception state of each content described in the broadcast management table 113, and if the requested content has already been received, the request reception processing unit 105 directly receives the request content in the server protocol processing unit 104. Is updated, and information of the distribution destination that has received the request is updated in the distribution table 112.
[0044]
On the other hand, if the content described in the viewing request has not been received, the client protocol processing unit 106 is instructed to transmit the viewing request to the upstream. As a result, upon receiving the reception request signal of the viewing request from the upstream, the request reception processing unit 105 sets the broadcast management table 113 to “on the air”, adds the destination information to the distribution table, and sets the server protocol processing unit. It instructs the downstream to send an acceptance signal to the downstream. The distribution table 112 is a table in which address information for direct distribution to downstream is described, and the broadcast management table 113 is a table for displaying contents being received from upstream. The transfer control unit 107 receives the stream data packet selected by the distribution unit 108 from the data received from the upstream line termination unit 111, rewrites packet header information such as destination information based on the distribution table 112, and transmits the packet data. It is a processing unit.
[0045]
The distribution unit 108 is a processing unit that identifies a stream control protocol packet and a stream data packet by a port number and transfers the packets to the client protocol processing unit 106 and the transfer control unit 107, respectively. The transmission driver unit 109 has a function of transmitting a packet processed by the client protocol processing unit 106 upstream. The reception driver unit 110 receives the data from the upstream line termination unit 111 and transfers the data to the distribution unit 108. Arrows connecting the functional blocks indicate the flow of data and control.
[0046]
In the flow of the basic stream control protocol process of the stream relay device of FIG. 2, the process of a portion that receives a viewing request from downstream will be described with reference to FIG.
[0047]
Arrows 201 to 206 show the processing flow when the content requested by the downstream client or the stream relay device is already being received. When a viewing request arrives from the downstream, the request is transmitted to the receiving driver unit 102 by 201 and transferred to the server protocol processing unit 104 by 202. The server protocol processing unit 104 analyzes the signal content, extracts the requested content name, and inquires of the request reception processing unit 105 via 203 whether the content is being received. As a result of referring to the broadcast management table 113, the server protocol processing unit 104 is notified that the reception is being performed by 204, and the address information of the distribution destination client or the downstream stream relay device is set in the distribution table 112.
[0048]
The server protocol processing unit 104 creates a permission response to the viewing request, transfers it at 205 to the transmission driver unit 103, and transmits it to the downstream by 206. Thereby, the stream broadcast for the content being received can be connected downstream.
[0049]
Next, arrows 211 to 223 indicated by arrows indicate a processing flow when the content requested by the downstream client or the stream relay device has not been received. Steps 211 to 213 are the same as steps 201 to 203, and a description thereof will be omitted. The request reception processing unit 105 refers to the broadcast management table 113 for the content information received by 213, and when it is found that the content information has not been received, instructs the client protocol processing unit 106 to issue a viewing request upstream. (214). This viewing request is transmitted to an upstream stream server or a stream relay device via 215 and 216, and finally, an authorization response is returned by 217, 218 and 219. In response, the client protocol processing unit 106 transmits a permission response to the request reception processing unit 105 (220).
[0050]
As a result, the request reception processing unit 105 updates the broadcast management table 113 during reception, and sets the address information of the distribution destination client or the downstream stream relay apparatus in the distribution table 112. Subsequent processing is the same as the flow from 204 to 206, and thus the description is omitted. As a result, stream broadcasting for unreceived content can be connected downstream.
[0051]
Next, in FIG. 2, the processing of the part for receiving the viewing / listening end request from the downstream in the flow of the basic stream control protocol processing of the stream relay device will be described with reference to FIG. In this case, the stream broadcast is provided to two clients, and the viewing end request is transmitted one by one. Further, the two downstream units may be stream relay devices.
[0052]
Arrows 301 to 306 indicate the flow in which the stream distribution device processes the first viewing / listening end request. The viewing end request arrives at the server protocol processing unit 104 via 301 and 302. The server protocol processing unit 104 inquires the request reception processing unit 105 of the number of streams currently being distributed to the downstream through 303. As a result, a reply 304 indicates that the destination address registration number after the request processing is one. As a result, it is understood that the viewing and listening has not been completed for all of the downstreams, and an acceptance response is returned to the client that has requested viewing and finishing through 305 and 306. As a result, only one client is disconnected.
[0053]
Arrows 311 to 323 indicate a flow in which the stream distribution device processes the second viewing end request. The viewing end request arrives at the server protocol processing unit 104 via 311 and 312. After that, the same inquiry as in 303 is made in 313, and as a result of this viewing / listening end request, 314 is informed that all downstream will leave. As a result, the server protocol processing unit 104 returns an acceptance response as in the first process, deletes the address information of the distribution table 112, and initializes the state of the broadcast management table 113.
[0054]
Separately from this, the request reception processing unit 105 sends a viewing end request to the client protocol processing unit 106 upstream in order to end reception of stream data obtained from the upstream, since all downstreams have been departed by 316 to the client protocol processing unit 106. (317). In response, the viewing end request is transmitted to the upstream line, and a response to the request is returned to the request reception processing unit 105 (318 to 323). As a result, the distribution of all downstream clients ends, and the stream reception obtained from the upstream ends. As described above, the distribution using the minimum necessary transmission resources can be realized with reference to FIGS.
[0055]
Next, the operation of the transfer control unit in FIG. 2 will be described with reference to FIG. FIG. 5 is a diagram illustrating an embodiment of a process related to communication protocol selection. The protocol selection unit 401 subtracts the transmission IP protocol (510) described in the distribution table 112 and shifts the control to 402 for IP unicast transfer and 404 for IP multicast transfer, and the copy processing unit 402 A processing unit for copying a received packet with reference to the distribution table 112; a unicast IP address conversion unit 403; a processing unit for obtaining and rewriting a destination IP address of a downstream stream relay device or a client from the distribution table 112; The conversion unit 404 is a processing unit that replaces the port number obtained from the distribution table 112, and the checksum calculation unit 405 is a processing unit for recalculating the checksum by rewriting the IP header and the UDP port number. The lower layer mapping unit 406 is a processing unit that encapsulates the IP packet using the lower layer transfer protocol obtained from the distribution table. Here, arrows indicate the flow of control and data, and it is assumed that the broadcast data memory is stored in each of the processing blocks 401 to 406. Note that a memory common to each processing block can be used as the broadcast data memory.
[0056]
The flow of the process of the transfer control unit 107 will be described with reference to FIG. In addition, FIG. 6 mentioned later is quoted in this. The received stream data first analyzes the packet header in the protocol selection unit 401 and obtains the corresponding content identifier 501 from the IP address (SA) (503), the IP address (DA) (504), and the Dest port number 505. I do. According to the transmission IP protocol 510 corresponding to the content identifier, the data is transferred to the copy processing unit 402 for unicast and to the port number conversion unit 404 for multicast. In the case of multicast, received packets are copied by the number of registrations of the transmission packet rewrite data 506 described in the content identifier. Next, the unicast IP address conversion unit 403 and the port number conversion unit 404 rewrite the header with reference to the transmission packet rewrite data 506 of the distribution table 112. In the case of multicast, the port number conversion unit 404 obtains the Dest port number from the distribution table by referring to the transmission packet rewrite data 506, and replaces it with a value corresponding to the Dest port number 505 of the received packet.
[0057]
Since the checksum value of the IP header and the UDP packet of the packet whose header has been converted in each route is changed, the checksum recalculation unit 405 performs the recalculation. Further, lower layer mapping section 406 maps the corresponding lower layer protocol in distribution table 112.
[0058]
According to the above description, the stream relay apparatus can perform distribution by selecting a specified IP multicast or unicast or a lower layer protocol for each relay. This makes it possible to realize a stream broadcasting service that matches the protocol of the connection network.
[0059]
FIG. 6 shows the configuration of the distribution table 112. This table shows the stream relay apparatus, for each content, the rewrite pattern from the header pattern of the received packet to the transmitted packet, and the selection of the transmission IP protocol and the lower layer protocol. Here, the content identifier 501 is a number that uniquely identifies a stream broadcast content. The received packet reference data 502 has an IP address (SA) (503), an IP address (DA) (504), and a UDP Dest port number (505) of the received packet header. The transmission packet rewrite data (506) describes header information to be converted at the time of reception and at the time of transmission, and has an IP address (SA) (507), an IP address (DA) (508), and a Dest port number (509). . The above data is written when a stream session is first established by the RTSP control protocol, and is deleted when the session is released.
[0060]
Next, the transmission IP protocol (510) displays a selection of whether to transfer by unicast or multicast when transmitting. The transmission lower layer protocol (511) indicates a lower layer protocol of the IP packet. From these data, a transmission IP protocol (510) and a transmission lower layer protocol (511) corresponding to the content identifier are obtained from the transfer mode table shown in FIG.
[0061]
Here, in the case of the content identifier 1, when the stream broadcast data packet received at the upstream multicast address 224.1.10.5 is encapsulated in the Ethernet packet and transferred by multicast, in the case of the content identifier 2, the upstream Of the stream broadcast data packet received at the multicast address 224.0.0.20.2 from the three downstream destinations, the IP addresses 129.60.111.22, 129.60.111.23, 129.60.1111. 24 shows a case where the data is converted to unicast and distributed by ATM cells. It should be noted that the function of receiving the multicast described above and performing unicast conversion is not provided in the existing stream relay device. Further, in this embodiment, the transfer mode and the protocol on the transmission side are designated for each content.
[0062]
FIG. 7 shows a broadcast management table. This indicates whether or not the content is being broadcast (the stream broadcast data is received from the upstream) for each content identifier.
[0063]
As described above, the stream relay device of the present invention is advantageous in that multi-stage connection is easy with the same protocol, that the stream relay device distributes the load of the viewing request processing executed by the stream server, and that the transmission resources of the relay section are reduced. There is an effect that the stream broadcasting network can be flexibly and economically increased in scale because it can be used efficiently. In addition, since a transfer protocol can be selected in a relay section or between a stream relay apparatus and a client section, it is possible to provide a service compatible with a network to be used. In particular, there is a great merit that the existing network can be used as it is by selecting, for each section, a case where multicast can be used and a case where distribution is performed by unicast.
[0064]
【The invention's effect】
As described above, according to the present invention, it is possible to increase the scale and efficiency of providing a stream broadcasting service and improve the affinity with an existing network.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a stream broadcast distribution network according to an embodiment of the present invention.
FIG. 2 is a block diagram of a stream relay device according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining a process of receiving a viewing request from downstream.
FIG. 4 is a view for explaining a process of receiving a viewing / listening end request from downstream.
FIG. 5 is a diagram illustrating a communication protocol selection process.
FIG. 6 is a configuration diagram of a distribution table.
FIG. 7 is a configuration diagram of a broadcast management table.
[Explanation of symbols]
1-6 clients
11-13 stream relay device
21 Stream Server
31-39 lines
101 Downstream line termination
102, 110 reception driver unit
103, 109 Transmission driver section
104 server protocol processing unit
105 Request reception processing unit
106 client protocol processing unit
107 Transfer control unit
108 Sorting unit
111 Upstream line termination
112 distribution table
113 Broadcast Management Table
114 Broadcast data memory
401 Protocol Selector
402 Copy processing unit
403 Unicast IP address converter
404 Port number converter
405 Checksum recalculation unit
406 Lower layer mapping unit
501 Content identifier
502 Received packet reference data
504, 508 IP address (DA)
503, 507 IP address (SA)
505, 509 Dest port number
506 Transmission packet rewrite data
510 Transmission IP protocol
511 Transmission lower layer protocol
701 Content identifier
702 Broadcast display

Claims (7)

In a stream relay device that receives a stream broadcast packet transmitted by a stream server and broadcasts the packet to a client,
Processing means for the protocol exchanged between itself and the client;
Processing means of a protocol exchanged between itself and the stream server;
A broadcast data memory for storing stream broadcast data,
A broadcast management table for displaying a broadcast for each stream broadcast,
Means for receiving a viewing request from a client;
Means for reading data from the broadcast data memory and starting broadcasting toward the client that transmitted the viewing request when the request stream broadcast is being broadcast based on the display of the broadcast management table;
When the request stream broadcast is not being broadcast based on the display of the broadcast management table, the viewing request is transmitted to an upstream stream relay device or a stream server, and the request stream broadcast data is received from the upstream and stored in the broadcast data memory. Means for starting broadcasting to the client that has transmitted the viewing request later;
An IP unicast protocol or an IP multicast protocol is associated with the stream broadcast content name or the distribution destination client address as a communication protocol for transmitting the stream broadcast data downstream, and the received stream broadcast data follows the association. Means for selecting a communication protocol and transmitting the data according to the selected communication protocol . 2. The stream relay device according to claim 1, further comprising means for transmitting a viewing end request to an upstream stream server or a stream relay device when the viewing of all clients or stream relay devices receiving the same stream broadcast content at the downstream end. . 3. The stream relay device according to claim 1, wherein the same stream control protocol procedure is used between the client and the stream relay device, between the stream relay devices, and between the stream relay device and the stream server. 2. The stream relay device according to claim 1, further comprising means for selecting a lower layer protocol for transferring IP unicast or IP multicast . 2. The stream relay device according to claim 1, further comprising means for converting a delivery destination address according to the selected communication protocol and transmitting the converted address . An upstream is connected directly or indirectly to one or more stream relay apparatuses and / or one or more stream servers according to any one of claims 1 to 5 with respect to a direction in which the stream broadcast data is transferred, and one or more is connected downstream. A stream broadcast distribution network, which forms a hierarchical structure connected directly or indirectly to the stream relay device according to any one of claims 1 to 5 and / or one or more clients . The computer device having predetermined hardware and predetermined basic software installed in the hardware is further installed on the computer device so that the computer device corresponds to the stream relay device according to any one of claims 1 to 5. A recording medium on which software to be used as a device for recording is recorded .

Images