JP4552232B2 - Distribution system, distribution control device, and distribution control method - Google Patents

Description

  The present invention relates to a system that distributes data such as moving images or voices over a network, and more particularly to a technique for controlling a communication band in the system.

  In data distribution technology such as streaming distribution of moving images, it is an important issue to ensure distribution. In Ethernet (registered trademark) widely used in IP communication, the quality of communication in a band up to a certain threshold is maintained, but data loss easily occurs in communication exceeding the threshold. Therefore, communication control of setting a threshold value for a band to be used is effective for stable data distribution.

For example, a technique described in Patent Document 1 (described later) relates to a technique for controlling a use band of an apparatus that distributes data. The technology described in Patent Document 1 is such that a distribution device that receives a viewing request from a client controls distribution to the client based on a correspondence table that defines the upper limit for the number of requests received and the bandwidth used. .
JP 2003-152800 A

  By the way, with recent improvements in performance of distribution devices, there is an increased possibility that the communication performance of a route including a relay device such as a router becomes a bottleneck rather than the performance of the distribution device itself. However, as in the technique described in Patent Document 1, it is difficult to grasp the presence of a communication neck on the route even if distribution is controlled in units of distribution devices. Therefore, there is a possibility that a communication failure may occur due to the selection of a route having a neck.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique for preventing a communication failure by grasping a bottleneck on a route in a distribution system.

A distribution system according to the present invention includes a distribution device that distributes data to a receiving device, a plurality of relay devices that relay communication between the distribution device and the receiving device, and the distribution device and each relay device. The distribution control device, the distribution device has a plurality of interfaces for communication with each of the relay devices, the distribution control device for each of the route comprising the distribution device and the interface and the relay device Means for recording information on usage bandwidth and availability of path element in management table, and recognizing data distribution request, and searching for available path from management table including relay device specified in the distribution request. Whether or not the bandwidth used by each route element exceeds the upper limit by distributing the data of the distribution request through an available route and the available route Means for determining, means for notifying the distribution request originator said determination is possible delivery of data by the path when not, the plurality of paths when retrieved plurality of routes from the management table Selecting a route with a lower bandwidth from among the above, detecting the upper limit of the bandwidth to be used for the selected route, and detecting the presence or absence of a failure in the distribution device, each interface, and each relay device, Means for recording the result of the detection as availability information in a management table, and the distribution control device adds the used bandwidth of the distribution request to the used bandwidth of the route subjected to the determination, The result of the addition is written in the management table, and when the distribution related to the distribution request is completed, the amount used for the distribution is subtracted from the bandwidth used for the distribution. By according to the management table results, and updates the management table.

  According to the present invention, the distribution control device manages the bandwidth used and the availability information of the route including the distribution device, its interface, and the relay device, so that the bottleneck of each route can be grasped. Thereby, an appropriate route for distributing data can be selected.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration of a system 100 according to the embodiment. The distribution device 11 and the distribution device 12 are devices for distributing distribution data held in the content database (content DB) 2 to the reception device 6. The distribution apparatus 11 includes two NICs 111 and 112 which are network interface cards (Network Interface Cards) for communication with two routers described later, and the distribution apparatus 12 includes two NICs 121 and NICs 122.

  The content DB 2 stores content data distributed from the distribution device 11 and the distribution device 12. The content data is, for example, moving image data or audio data.

  The router 41 and the router 42 are relay devices for transmitting information between the distribution device 11 and the distribution device 12 and the reception device 6, and are, for example, a set of hubs, routers, and communication lines. The router 41 and the router 42 are connected to the distribution apparatuses (11, 12) by NICs (111, 112, 121, 122) and cables, and are connected to the reception apparatus 6 through the communication path 5.

  The distribution control device 3 is connected so as to be able to communicate with each of the above devices. The distribution control apparatus 3 includes a management database (management DB) 30 that holds a management table (to be described later) regarding the distribution apparatus, NIC, and router, and each distribution apparatus (11, 12) and each router (41, 42) using the management table. ) Used bandwidth.

  FIG. 2 shows a functional configuration of the distribution control device 3. The configuration shown corresponds to the function of the computer program executed by the distribution control device 3.

  The request receiving unit 31 receives a distribution start request transmitted from the receiving device 6 or the like regarding the distribution of content data, and recognizes the content of the received distribution request such as a router connectable to the receiving device 6 and the data amount of the distribution content. To do. The route search unit 32 searches the management table of the management DB 30 for a currently available route from among the routes including the router specified in the distribution request. The route selection unit 33 selects, based on the management table, a route having a lower current usage rate from the searched available routes. The distribution determination unit 34 determines whether or not the content requested this time can be distributed based on the balance between the route selected by the route selection unit 33 and the upper limit on the used bandwidth.

  The response transmission unit 35 notifies the distribution request source of the result of determination by the distribution determination unit 34. The table update unit 36 updates the management table using information such as a bandwidth used when content distribution is executed. The failure detection unit 37 detects the presence or absence of a failure in each communication device, each NIC, and each router.

  3, 4, and 5 show examples of management tables held in the management DB 30. FIG. The management table 31 </ b> A illustrated in FIG. 3 relates to the distribution device 11 and the distribution device 12. In the management table 31A, the “maximum bandwidth” that is the upper limit of each distribution device (11, 12) relating to distribution performance, the “currently used bandwidth” of each distribution device, and whether each distribution device is operating normally. Is recorded as a “status flag”.

  The management table 31B illustrated in FIG. 4 relates to the NIC (111, 112, 121, 122) of the distribution device (11, 12). In the management table 31B, the relationship between each NIC and each router is shown, and data related to the items similar to the recording items shown in FIG. 3 is recorded.

  As shown in FIGS. 3 and 4, the “currently used bandwidth” of each distribution device corresponds to the total of the “currently used bandwidth” of each NIC that the distribution device has. On the other hand, as described above, the “maximum bandwidth” is set separately based on the performance of the distribution apparatus and NIC related to distribution. Therefore, the “maximum bandwidth” of each distribution device does not necessarily correspond to the sum of the “maximum bandwidth” of each NIC that the distribution device has. For example, while the “maximum bandwidth” of the distribution device 11 (distribution device # 1) is “1000 kbps” (FIG. 3), the NIC 111 (NIC # 1-1) and NIC112 (NIC # 1) of the distribution device 11 -2) "Maximum bandwidth" is "800kbps" (Fig. 4).

  The management table 31C shown in FIG. 5 relates to the router 41 and the router 42, and data related to items similar to the recording items shown in FIG. 3 is recorded for each router.

  In the management tables shown in FIGS. 3 to 5, the unit of the communication band is “kbps”, but this is an example and may be managed in another band unit.

  The operation of the distribution control device 3 will be described with reference to the flowchart shown in FIG. When the distribution control device 3 receives the content distribution start request, the distribution control device 3 recognizes information of a router connectable to the receiving device 6 from the content of the request (step A1). The distribution start request is not limited to the reception device 6 but may be the distribution device (11, 12) or the distribution control device 3 itself.

  The distribution control device 3 searches for a route consisting of a distribution device, NIC, and router whose records in the management table are all in the “distributable” state among the routes that are notified by the distribution request (step A2). This search is performed with reference to “status flags” in the management tables 31A to 31C shown in FIGS.

  As an example of the above search, from FIG. 3 to FIG. 5, the route from the distribution device 11 (distribution device # 1) to the router 41 (router # 1) using the NIC 111 (NIC # 1-1) is Since all the “status flags” of the route elements are “distributable”, they are listed as search results. On the other hand, if the other NIC 112 (NIC # 1-2) is used even if the route is from the same distribution device 11 (distribution device # 1) to the router 41 (router # 1), this NIC is shown in FIG. Is not deliverable because it is “undeliverable”.

  As a result of the search, if there is no route that all elements are in the “distributable” state (step A3: No), the distribution control device 3 notifies the request source that the content cannot be distributed at this time (step A3). A4). In this case, content distribution is not performed.

  If there is a route in which all elements are in the “distributable” state as a result of the search (step A3: Yes), the distribution control device 3 selects a route having a lower “currently used bandwidth”. Select (step A5). The determination of the use band level can be made, for example, from the sum of the “current use bands” of the distribution apparatus, NIC, and router in the management tables of FIGS. In addition, when different delivery devices are included in each of the plurality of combinations that are the search results, a determination may be made with a priority order in which values between the delivery devices are first compared.

  Note that if only one route in the “distributable” state is detected, or if the difference between the “currently used bandwidths” is small even if a plurality of such routes are detected, the process of step A5 The selection process may be omitted.

  The distribution control device 3 determines whether or not the upper limit of the used band is exceeded by performing the current content distribution on the route having the lower “current used band” (step A6). This upper limit is a value set in the “maximum bandwidth” in the management tables of FIGS. The distribution control device 3 determines whether or not the distribution bandwidth in consideration of the added amount of content data notified in the distribution request exceeds the “maximum bandwidth” of the distribution device, NIC, and router. If even one of the distribution device, NIC, and router exceeds the “maximum bandwidth”, it is determined that if the distribution is executed using the route, the upper limit of the used bandwidth is exceeded.

  Here, an example of the determination will be given with reference to FIGS. Now, it is assumed that the route to be determined includes a route from the distribution device 12 (distribution device # 2) to the router 42 (router # 2). At this time, from FIG. 4, the “currently used bandwidth” of the NIC 121 (NIC # 2-1) has already reached “200 kbps” of the “maximum bandwidth”. Therefore, when this NIC 121 (NIC # 2-1) is used for new distribution, it is determined that the upper limit of the used bandwidth is exceeded.

  Further, the “currently used bandwidth” of the other NIC 122 (NIC # 2-2) has not yet reached the “maximum bandwidth”. Therefore, if the bandwidth used for the new distribution does not exceed the difference (500 kbps) between the two, it is determined that this route, that is, the route that passes from the distribution device 12 to the NIC 42 via the router 42 does not exceed the upper limit of the used bandwidth.

  As a result of the determination, if the use band exceeds the upper limit (step A6: Yes), the distribution control device 3 excludes the determination target route, that is, the set of routes selected in step A5 from the options (step A7), and the remaining The same determination is made for the route.

  If the upper limit is not exceeded (step A6: No), the current distribution is added to the “currently used bandwidth” of each management table (FIGS. 3 to 5) relating to the distribution device, NIC, and router that constitute the route to be determined. Are added (step A8). Thereby, the management table is updated. Then, the distribution request source such as the distribution device (11, 12) is notified that the content can be distributed through the route (step A9).

  Thereafter, when the content distribution is completed, the distribution control device 3 uses the “currently used bandwidth” in the distribution table, NIC, and router management tables (FIGS. 3 to 5) of the route used for the distribution. Minutes are subtracted (step A10). Thereby, the management table is updated again.

  Next, referring to the flowchart shown in FIG. 7, processing for reflecting the failure status of the distribution device, NIC, and router in the management table by the failure detection unit 37 and the table update unit 36 (FIG. 2) of the distribution control device 3. explain. Here, the operation related to the failure of any one of the components X is shown, but the other components can be performed with the same logic.

  The distribution control device 3 confirms whether or not the distribution device, NIC, and router are actually operating normally (step B1). As a method for this confirmation, for example, a distribution device, a NIC, and a router are provided with a mechanism for notifying whether the device is operating normally in response to a request from the distribution control device 3, and the result is transmitted to the distribution control device. There is a method that 3 receives.

  In addition, when signals are periodically communicated between the distribution devices (11, 12) and routers (41, 42) and the distribution control device 3, and the distribution control device 3 cannot receive the signal at a certain reception timing. A method of recognizing that a failure has occurred in a device corresponding to the signal may be used.

  As a result of the confirmation, if it is detected that a failure has occurred in the component X (step B2: No), the distribution control device 3 sets the “status flag” in the management table related to the component X to be undistributable (step B3). If it is confirmed that the device is operating normally (step B2: Yes), the “status flag” of the management table related to the component X is set to be distributable (step B4). By periodically performing the above processing, it is possible to maintain a “status flag” in accordance with the current situation.

  According to the present embodiment, the distribution table (11, 12), their NIC (111, 112, 121, 122), and information on the bandwidth used and availability of each router (41, 42) are stored in the management table. Since it is recorded, each time the distribution control device 3 receives a call request, the bottleneck of each route can be grasped. This makes it possible to select an appropriate route for distributing the content data.

  In addition, by managing the distribution bandwidth of the distribution device, NIC, and router in this way, distribution that makes the best use of the distribution performance of the distribution device, NIC, and router becomes possible. In particular, as in the above embodiment, when the distribution device has a plurality of NICs and the maximum bandwidth of the distribution device is larger than the maximum bandwidth of one NIC attached to the distribution device, the distribution device has control in the distribution device unit control. I can't take full advantage of the performance. This is because in the control of only the bandwidth of the distribution device, the used bandwidth is controlled so as not to exceed the maximum bandwidth of one NIC. Therefore, by managing the status of the bandwidth used by the distribution device and the NIC as in the present embodiment, it becomes possible to perform bandwidth management according to a different neck for each scene.

  Furthermore, since the distribution control device 3 detects the presence / absence of a failure in the distribution device, NIC, and router and reflects it in the management table, an appropriate route can be selected from the path that is configured by the components that are actually operating normally. You can choose one. Thereby, communication failure can be prevented.

  In the above-described embodiment, the distribution control device 3 is configured to automatically detect the failure location of the system by the failure detection unit 37, but instead of this, the “status” of the management table is input by external input to the distribution control device 3. The “flag” may be updated.

  In the above embodiment, the number of distribution apparatuses (11, 12) and routers (41, 42) is two, but instead of this, one or three or more may be used. Further, the number of NICs may be 1 or 3 or more for each distribution device. The present invention is more effective when the number of NICs is plural.

  The content data may be distributed and stored in a plurality of locations instead of being stored in one location (content DB 2) as in the above embodiment, and the same content is stored in a plurality of locations. May be. Furthermore, the storage location may be inside the distribution apparatus.

  The NIC and the cable are examples of transmission means using the Internet protocol (IP), and the information transmission means may be other means. The router may be a device having another hub function such as a switch. In addition, the router may provide the distribution control device with information about whether or not distribution can be performed via its own router including the communication path. In this case, the distribution control device confirms the communication status of the communication channel itself from the communication channel, and creates information to the distribution control device based on the confirmation. Even with this method, the entire distribution control including the communication path can be performed.

  The present invention can be applied to a service that distributes video and audio in response to a request from a viewer. Further, the present invention can be applied not only to moving images and voices but also to services that require data to be sent from a distribution device in real time.

It is a block diagram which shows the system configuration | structure of embodiment of this invention. It is a block diagram which shows the function structure of the delivery control apparatus of embodiment. It is explanatory drawing regarding the management table of embodiment. It is explanatory drawing regarding the management table of embodiment. It is explanatory drawing regarding the management table of embodiment. It is a flowchart which shows operation | movement of embodiment. It is a flowchart which shows operation | movement of embodiment.

Explanation of symbols

100 System 11, 12 Distribution device 111, 112, 121, 122 NIC (network interface card)
2 content database 3 distribution control device 30 management database 41, 42 router 5 communication path 6 receiving device

Claims (4)

A distribution device that distributes data to the receiving device, a plurality of relay devices that relay communication between the distribution device and the receiving device, and a distribution control device that is connected to the distribution device and each relay device. ,
The distribution device has a plurality of interfaces for communication with the relay devices,
The distribution control device recognizes a data distribution request and a means for recording information on usage bandwidth and availability of each route element in a management table for a route including the distribution device, an interface, and a relay device. Means for searching available routes from the management table among routes including the specified relay device, and distributing the data of the distribution request by available routes, the bandwidth used by each route element exceeds the upper limit. Means for determining whether or not, a means for notifying the distribution request source that data can be distributed via the route when the determination is negative, and when a plurality of routes are retrieved from the management table Means for selecting a route having a lower bandwidth from the plurality of routes and making the determination on the upper limit of the bandwidth to be used for the selected route; Detecting the presence or absence of a failure in communication apparatus and each interface and each of the relay devices, and means for recording the results of the detection known as information availability in the management table, and
The delivery control device adds the use bandwidth of the delivery request to the use bandwidth of the route subjected to the determination, describes the addition result in the management table, and the delivery related to the delivery request is completed. The distribution system is characterized in that the management table is updated by describing, in the management table, a result of subtracting the amount used for the distribution from the bandwidth used for the path used for the distribution. A distribution control device connected to a distribution device that distributes data to a reception device and a plurality of relay devices that relay communication between the distribution device and the reception device,
Recognizing the data distribution request, means for recording information on usage bandwidth and availability of each path element in the management table for the distribution device, an interface for the distribution device to communicate with the relay device, and a route comprising the relay device And means for retrieving an available route from the management table among routes including the relay device specified in the delivery request, and use of each route element by delivering the data of the delivery request by the available route. Means for determining whether or not the bandwidth exceeds the upper limit; means for notifying the transmission source of the distribution request that data can be distributed by the route when the determination is negative ; When a route is searched, a route having a lower use band is selected from the plurality of routes, and the above-mentioned judgment regarding the upper limit of the use bandwidth is selected for the selected route. And means for performing, detecting the presence or absence of a fault in the distribution system and the interfaces as well as the relay devices, and means for recording the results of the detection known as information availability in the management table, and
The used bandwidth of the distribution request is added to the used bandwidth of the route subjected to the determination, the added result is written in the management table, and used for the distribution when the distribution related to the distribution request is completed. A distribution control apparatus, wherein the management table is updated by describing, in the management table, a result obtained by subtracting the amount used for the distribution from the used bandwidth of the route. A program causing a computer to function as the distribution control device according to claim 2 . A distribution control device connected to a distribution device that distributes data to a reception device and a plurality of relay devices that relay communication between the distribution device and the reception device,
Recording the distribution device, the interface through which the distribution device communicates with the relay device, and the use band and availability information of each path element for the route comprising the relay device, and recognizing the data distribution request And searching for a usable route out of the routes including the relay device specified in the distribution request from the management table, and using each of the route elements by distributing the data of the distribution request through the available route. and notifying the originator of the distribution request that bandwidth determining whether more than the upper limit, the determination is possible delivery of data by the path when not a plurality of said management table When a route is searched, a route having a lower bandwidth is selected from the plurality of routes, and the bandwidth used for the selected route is selected. Comprising a step of performing the determination of the upper limit, to detect the presence or absence of a fault in the distribution system and the interfaces as well as the relay devices, and recording the result of the detection known as information availability in the management table, and
The delivery control device adds the use bandwidth of the delivery request to the use bandwidth of the route subjected to the determination, describes the addition result in the management table, and the delivery related to the delivery request is completed. The distribution control method is characterized in that the management table is updated by describing, in the management table, a result obtained by subtracting the amount used for the distribution from the use band of the route used for the distribution.

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