JPH10164132A - Real-time data delivery control method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically decide a proper real-time delivery path of data by properly selecting a delivery path between node groups where the node devices are grouped and also a delivery path in every node group. SOLUTION: A network 101 where a series of nodes are connected is prepared with the node groups 102 consisting of the optional combinations of transmission nodes, reception nodes and relay nodes. The delivery path of a stream data is controlled in every group 102 via an inter-node group control means. For instance, the delivery path of the stream data is set between a transmission node group T and a reception node group R via the relay node groups X and Y or a combination of them. In other words, a node device consists of groups 102 and a real-time delivery path of data is dynamically decided by selecting properly an inter-node group transfer path and a delivery path in every group 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a real-time data delivery control method and storage medium, and more particularly to a real-time data delivery control method and storage medium such as video and audio using a network.

[0002]

2. Description of the Related Art The applicant of the present invention connects a camera server and a camera client on a network first, logs in the camera server from the camera client, freely controls the angle of the camera, and shoots a raw video ( In some cases, audio (including audio) is transferred to the client side for display (and audio output).

[0003] When delivering real-time data such as video and audio over a network, the receiving side evaluates the delay time and its variation, and adjusts the reproduction timing and discards unnecessary data blocks. By the way, many of the causes of such a time delay are often caused by an overload in a transmitting / receiving node, a relay node, or an intervening network. This tendency is particularly remarkable in a wide area network in which the amount of traffic greatly increases and decreases, and in general, it is not always possible to secure a sufficient bandwidth.

[0004] From the above, in order to efficiently deliver real-time data such as video and audio data, it is important to reduce the load of data delivery itself by suppressing the total traffic volume. As means for doing this, known methods include reducing the total traffic by broadcast or multicast, or discarding illegal data or data for which delay is considered extremely unnecessary. However, what is deemed most effective for the delivery of real-time data is to use a means for selecting a delivery route from the sending node to the receiving node that best meets the request.

In general, the selection of a route from a sending node to a receiving node is performed by a relatively low-level route control means in a normal network service. For example, TCP / IP is used as a network protocol in the Internet which has been widely used in recent years, and its route control means is based on a route control protocol such as RIP or BGP and a multicast group control protocol such as IGMP. . According to these means, when the transmitting node performs transmission by designating the receiving node, relaying by a gateway or a router is performed as necessary, but the physical packet transfer destination between the nodes is a given route. The information is individually resolved based on the information, and finally, arbitrary inter-node communication is realized.

[0006]

However, there are the following problems depending on the route selection means such as the low level.

That is, even when there are a plurality of routes from the transmitting node to the receiving node, it is not always easy to select an optimal route according to the purpose of the service. The route selection mechanism itself is supported, for example, as source routing. In this case, it is necessary to enumerate passing points at the transmitting node to the receiving node. In a complicated network, it is generally difficult for a transmitting node to grasp information over all routes, and there is also a problem that flexibility of distribution control by a relay node is impaired. However, when the source routing is not used, the delivery route is uniformly determined by the route control means, and there is no guarantee that the most suitable route for the service is selected. In fact, many route control information interpreting means select the one that minimizes the number of effective relay nodes on the route. It is clear that does not give an optimal path for

[0008] An even more obvious problem is that multicast delivery is not always available. Although the multicast function has entered a period of widespread use and has been implemented in many network devices, many devices are still unsupported and few have complete functions. In addition, with multicast delivery,
Due to the need for resource allocation at relay nodes over a wide range of networks, the establishment of a dynamic multicast distribution path in conjunction with the above problems will generally not be guaranteed. In this case, as an alternative, ordinary unicast data delivery is performed, which causes a very serious problem in terms of reducing the delivery load.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. The present invention has been made in consideration of the above-described problems. It is an object of the present invention to provide a real-time data delivery control method and a storage medium that enable an appropriate real-time delivery route to be dynamically determined by appropriately selecting each delivery route in a group.

In order to solve this problem, for example, a real-time data delivery control method of the present invention has the following configuration. That is, a delivery control method in delivery of real-time data using a network, comprising: a data source node; a relay node group including one or more relay nodes; and a transfer destination node; When setting a transfer route of real-time data from the relay node to the transfer destination node, management is performed between the relay node groups and each node in each relay node group, and a delivery route is dynamically set according to the management. I do.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing a configuration of a network environment used in the present embodiment. In the figure, 101
Is a network to which a series of nodes to be described later are connected, and is composed of a large-scale network such as the Internet, a medium-scale network such as a campus network or a company network, and a small-scale network such as a local area network.

The network generally includes a network connection using a router or a gateway.
It is assumed that route control between nodes is performed by known means.

Reference numeral 102 denotes a node group configured as an arbitrary combination of a transmitting node, a receiving node, and a relay node. A node is a device that transmits and receives data such as video and audio, and is a computer system including a CPU, a main storage device, an external storage device, and an input / output device. Node group.

The configuration of the node group is intentionally determined by a network administrator or the like, and is usually located at a location close to the network, for example, a series of nodes connected to the same network segment, or a relatively wide band and high quality. It consists of a series of nodes connected to a local network interconnected by lines. Hereinafter, individual data such as video and audio, and composite data including these as components are collectively referred to as stream data or simply as a stream. The above nodes are classified into one of a transmission node, a reception node, and a relay node with respect to a role in stream data distribution. The transmission node is a node that generates stream data, and is a device that has a video capture function, an audio sampling function, and the like. The receiving node is a node that consumes stream data, and is a device having a video display function, an audio reproduction function, and the like. The relay node is a node that relays the delivery of stream data, and is generally a device having a stream data processing function.

Although the physical node device is a transmitting node for certain stream data, it may be a receiving node or a relay node for other stream data. However, in the present embodiment, to simplify the description,
The stream data is fixed, and the transmitting node is referred to as T / t, the receiving node is referred to as R / r, and the relay node is referred to as X / i. Here, the symbol N / n represents a set of the node group identifier N and the identifier n within the node group.
A node group including a relay node is simply called a relay node group. The same applies to the transmission node group and the reception node group.

[0017] Stream data delivery route control is performed on a node group basis. As means for performing this, inter-node group control means is provided. This means controls the cooperation between the node groups, and is a means for controlling the configuration of the relay node group sequence arranged between the transmission node group and the reception node group. For example, in the configuration shown in FIG. 1, a stream data delivery route is configured by using X and Y or a combination thereof as a relay node group between a transmission node group T and a reception node group R. That is. Here, the relay node group column may be empty. Indeed, if R and T are directly reachable in the network and the route selected at the network level is of sufficiently high quality, it will be understood that there is no need to form a relay node group sequence. .

On the other hand, the delivery of the stream data itself is performed by a node selected in each node group on the delivery route. As a means for selecting this node in the node group, an in-node group control means is provided. The means is, for example, in the configuration of FIG.
When the relay node group X is arranged between / t and the receiving node R / r, X / p is selected as the relay node in charge of the delivery of the stream data in the node group X, and the status within the relay node group is selected. Multiplexing and reconfiguration of relay nodes are performed according to the change.

The inter-node group control means comprises two means relating to a stream delivery route, namely a stream delivery route setting means and a stream delivery route updating means. The inter-node group control means comprises three means relating to stream delivery, namely, a start means, a stop means, and a control means. Hereinafter, each means will be described in order.

FIG. 2 is a flowchart showing the processing procedure of the stream delivery route setting means. The processing procedure is
Prior to making a stream data delivery request such that the transmission node T / t is the transmission source, the relay node or the reception node in the node group N, or the node group located below N, must Used to determine nodes. Therefore, the upper node identifier for the response to the inquiry source is U / u, and this is first initialized as an invalid node identifier (step S21).

Next, in N, the upper node N related to T / t
It is determined whether / u already exists, and if it exists, U / u is changed to N / u (step S22). Here, it is determined whether U / u is a valid node identifier (step S23). If there is no upper node in N in step S23, U / u is still an invalid node identifier, so the process proceeds to the next step. That is, an attempt is made to select an upper node group of N related to T (step S24). If U can be selected as the upper node group, an inquiry is made to U regarding N upper nodes U / u regarding T / t (step S25). N obtains the upper node identifier U / u as a response from U, and it is checked again whether this is valid in step S23.

If the upper node identifier U / u obtained in step S25 is invalid, the procedure from step S24 is repeated as long as the upper node group can be selected. If the upper node identifier is obtained, the repetition processing is terminated and the flow proceeds to the execution of the stream delivery control procedure (step S26). At this time, as described later, the upper node identifier U / u may be modified so as to be different from the node identifier used for the final response. Finally, U / u is notified to the inquiry source as the upper node identifier, and the process ends (step S27).

In the above description, the entity of the node group is typically a dedicated node group management server, and is realized using a known means such as a remote procedure call. In this case, the node group identifier may be the transport address of the management server, and in TCP / IP, is represented by a set of an IP address and a port number. However, this is not generally the case, and when distributed management is performed by known group communication means, the group identifier in the means may be used as the node group identifier.

Some supplementary explanations will be given for the steps of the processing procedure shown in FIG.

First, in step S22, an upper node N / u relating to T / t exists when N / u is T / t itself or a relay node of T / t, or when N / u is T / t.
/ T receiving node, and N / u itself has a relay function, or a new T / t relay node can be provided in N.

The selection of the upper node group in step S24 is performed using the upper node group reference table managed in N. The look-up table defines a direct upper node group for a designated node group. For example, in the configuration of FIG.
The lookup table entry for T in R will include X and Y. The reference table is intentionally constructed by the administrator of N, and has predetermined initial settings.
It can be dynamically updated by the delivery management information exchange means between node groups. The implementation of the delivery management information exchange means is performed by a configuration similar to a known network level path information exchange means.

Finally, in the inquiry processing to the upper node group in step S25, if the inquiry relating to the same T / t has already been made, the processing is performed without performing the inquiry processing for the subsequent request. Shall be If a valid node identifier is not obtained in the preceding inquiry process, the inquiry process is determined to be highly unlikely to succeed for a while, and the subsequent T / t inquiry process is stopped for a predetermined period. You may do so.

FIG. 3 is a flowchart showing a processing procedure of the stream delivery route updating means. The processing procedure is
This is means for the node group to grasp the stream data transmission / reception status of each node.
Is used to perform upper node determination processing within a node group and collect delivery management information referred to by stream delivery control means described later.

First, if a series of nodes N / n belonging to the node group N are transmission or relay nodes, they report the transmission status of the relevant transmission target stream per unit time (step S31), and whether they are reception or relay nodes. For example, the reception status per unit time of the relevant reception target stream is notified (step S32). Steps S31 and S
At 32, the transmission / reception status per unit time to be notified is:
Data amount, number of packets, number of errors, CPU load value, I
It is node operation information including a / O load value and the like, and an empty status notification is performed even when there is no related target stream. The node group updates the stream delivery management table using the notified transmission / reception status (step S33). In particular, when the stream delivery is stopped and it is determined that the stream delivery route is no longer needed, the entry is deleted from the stream delivery management table.

Subsequently, the stream delivery control means is applied to reconfigure the delivery mode in the node group as needed (step S34). Finally, transmission / reception status of the entire node group with respect to the adjacent node group, that is, the upper node group registered in the node group reference table and the lower node group of the stream registered in the delivery management table And terminates the process (step S35).

Note that steps S34 and S34 in this procedure are performed.
The process of 35 need not always be executed immediately after the process of step S33. Actually, even if these processes are performed, there is a possibility that the effect will be adversely effected unless the change of the delivery situation is remarkable, and the process of step S35 may be ignored in the adjacent node group. That is, it is more effective to delay step S34 by a predetermined time interval, and it is more effective not to execute step S35 unless there is a predetermined situation change.

FIG. 4 is a flowchart showing the processing procedure of the stream delivery start means.

First, the node N / n is connected to the transmitting node T
/ T stream delivery route setting (step S
41). The request is processed in the node group N in accordance with the procedure of FIG. 2, and as a result, N / n obtains U / u as an upper node, but if the obtained U / u is an invalid node identifier, the delivery route setting is performed. The process is determined to be impossible, and the process ends (step S42). Conversely, if U / u is a valid node identifier, the following processing is performed.

N / n makes a delivery start request to U / u and waits for a response to the request (step S43).
On the other hand, U / u judges the validity of the N / n delivery start request,
If it is determined to be legitimate, a response is accepted as acceptable, and if it is determined to be invalid, a response is rejected (step S44). N / n is U
The wait is canceled by the response from / u, and it is determined whether the request has been accepted (step S45). If it is determined that the reception has been received, a reception start notification is sent to the node group N (step S46).

On the other hand, since the upper node U / u starts transmission when receiving the request, it notifies U of transmission start (step S47). When all the above processes are completed, the process is completed. Note that the start notifications in steps S46 and S47 are processed by each node group according to the procedure shown in FIG.

The U / u validity determination process performed in step S44 is performed after a delivery route has been established, and may be basically accepted. However, this is not always the case when, for example, the transmitting node T / t restricts the access of the receiving node, and when access from the receiving node R / r that has first requested delivery is prohibited, the U The validity determination processing result in / u is invalid. Therefore, in such a case, the transmission request processing is not performed at the intermediate relay node, but is performed after being transmitted to the highest transmission node. It is assumed that necessary additional information, for example, a user identifier is appropriately transmitted.

FIG. 5 is a flowchart showing the processing procedure of the stream delivery stopping means.

The processing procedure is such that the node N / n executing the stream delivery start means shown in FIG.
It is started by sending a transmission stop request to / u (step S51). Subsequently, N / n notifies the node group N of the reception stop and ends the process (step S52). On the other hand, the U / u having received the delivery stop request notifies the U of the stop of transmission related to N / n (step S53). Further, when U / u is a relay node, it is determined whether or not the stream reception processing by U / u itself is necessary (step S54). Here, a necessary condition for determining that the stream reception processing by U / u is unnecessary is that U / u does not perform stream relay processing for nodes other than N / n. If it is determined in step S54 that the node is unnecessary, the procedure from step S51 is performed on the upper node of U / u, and the process is terminated (step S55).

FIG. 6 is a flowchart showing the processing procedure of the stream delivery control means.

The processing procedure is started in the inter-node group control means, more specifically, in step S26 of FIG. 2 and step S34 of FIG. 3, and is performed for the purpose of reconstructing the delivery form in the node group.

First, the node group N performs the following processing on all streams included in the node group (step S61). That is, all the receiving nodes related to the stream are obtained, and the optimum delivery mode is determined (step S62). Here, the optimal delivery mode is determined based on the network configuration within a given node group, and is performed as a change from unicast delivery to multicast delivery, a change from multicast delivery to unicast delivery, and installation of a new relay node. Will be

Note that the determined delivery mode is calculated for the purpose of reducing the load on the network.
It is not always necessary to minimize the load on the network, and a suboptimal delivery form using a heuristic technique may be used.

If reconfiguration of the delivery mode is recognized in the process of step S62, the following process is performed (step S62).
63). That is, if it is necessary to set or reset the delivery route for each of all the relay node groups N / [p] including the newly established relay node, the stream delivery route setting means is applied (step S64). Finally, if it is necessary to reset the delivery route for each of the series of receiving node groups N / [r], the stream delivery route setting means is applied as in S64 (step S65). If the above processing is applied to all the streams, the processing ends. The stream delivery route setting means used in steps S64 and S65 basically follows the procedure shown in FIG. However, in this case, since the upper node is always determined in step S22, the processes in steps S23 to S25 are not performed, and step S26 is ignored since it is separately activated.

Although the present invention basically requires hardware for network connection to a general-purpose information processing device (such as a personal computer or a workstation), the present invention is based on a program that operates on each device. realizable.

Accordingly, a storage medium storing program codes of software for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and the computer (or CPU or MPU) of the system or the apparatus is stored in the storage medium. Needless to say, this can also be achieved by reading and executing the program code.

In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also an OS or the like running on the computer is actually executed based on the instructions of the program code. It goes without saying that a part or all of the above-described processing is performed, and the functions of the embodiments are realized by the processing.

Further, after the program code read from the storage medium is written in a memory provided in an extension function board inserted into the computer or a function extension unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU provided in the function expansion board or the function expansion unit performs a part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

As described above, according to the present embodiment,
Means for providing a node group in which various nodes that transmit and receive data are grouped in a real-time data distribution process such as video and audio using a network, a distribution path selection means between node groups, and a distribution path selection means within a node group , It is possible to avoid concentration of delivery routes by selecting a network level route, reduce global traffic by sharing the same stream between nodes, and reduce traffic by selectively using the multicast function. Can be efficiently and with high quality.

The network to which the present invention is applied may be a wide area or a small scale. For example, I
A network called EEE1394 may be used.

[0052]

As described above, according to the present invention, node devices related to individual data distribution are grouped and configured as a node group, and a distribution route between the node groups and a distribution route in the node group are respectively determined. By making an appropriate selection, it is possible to dynamically determine an appropriate real-time delivery route.

[0053]

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a network environment in the present embodiment.

FIG. 2 is a flowchart showing a processing procedure of a stream delivery route setting means.

FIG. 3 is a flowchart showing a processing procedure of a stream delivery route updating means.

FIG. 4 is a flowchart showing a processing procedure of a stream delivery start means.

FIG. 5 is a flowchart showing a processing procedure of a stream delivery stopping means.

FIG. 6 is a flowchart showing a processing procedure of a stream delivery control means.

[Explanation of symbols]

101 Network to which transmitting node, receiving node, and relay node are connected 102 Node group configured as any combination of transmitting node, receiving node, and relay node

Claims (7)

[Claims] 1. A delivery control method for delivering real-time data using a network, comprising: a data generation source node, a relay node group including one or more relay nodes, and a transfer destination node; When setting a transfer route for real-time data from a source node to the transfer destination node, management is performed between the relay node groups and each node in each relay node group, and a delivery route is operated according to the management. A real-time data delivery control method characterized in that: 2. The method according to claim 1, wherein the management comprises forming a node group in which nodes related to individual data delivery are grouped, selecting a data delivery route within the node group, and selecting a neighbor when a data delivery route is not established within the node group. Specifying a node group by selecting a node group and requesting the selected adjacent node group to set a data delivery route, and by repeatedly using the intra-node group delivery route selection process and the inter-node group delivery route selection process 2. The real-time data delivery control method according to claim 1, wherein a node having said data transmission means is specified. 3. The real-time data according to claim 2, wherein, as the step of selecting an adjacent node group, an adjacent node group reference table is provided, and an adjacent node group specified in advance is set at the time of initialization. Delivery control method. 4. The method according to claim 3, further comprising a step of exchanging delivery load information between adjacent node groups, and a step of updating the adjacent node group lookup table by using the step. Real-time data delivery control method. 5. A step of providing a data delivery management table as a delivery route selection step in the node group, and updating the data delivery management table based on a transmission / reception load status per unit time notified from each node in the node group. 5. The real-time data delivery control method according to claim 3, wherein the addition of the intra-node group delivery route is controlled so that the load on the network is minimized or equivalent thereto. 6. A process for adding and deleting a delivery route in a node group, the process including a process of newly establishing a relay node and a process of switching between unicast delivery and multicast delivery, and reconfiguring a delivery mode by applying the process. 6. The real-time data distribution control method according to claim 5, comprising: 7. A storage medium storing a program for performing delivery control in real-time data delivery using a network, comprising: a data source node; a relay node group including one or more relay nodes; On a network having nodes, when setting a transfer path for real-time data from the data source node to the transfer destination node, management of each node between the relay node groups and within each relay node group is performed. A storage medium for storing a program code for executing and dynamically setting a delivery route according to the management.