JP2002135352A - Format converter, layout decision device and network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a format converter, a layout decision device and a network system that decide the layout of format converters on the basis of statistic information of traffic or the like so as to realize efficiency of data transfer in the network at a low cost. SOLUTION: In the network system including format converters 100-1, 100-2, etc., and a layout decision device 200, each of the format converter stores statistic information of traffic and topology information denoting a connection structure of the network and the layout decision device 200 decides an optimum layout of the format converters in the network on the basis of the statistic information and the topology information acquired from each format converter and a given layout decision condition so as to reduce the traffic in the network and relieve the processing load on each terminal thereby making data transfer efficient and reducing the operation cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a format conversion device for converting the format of information data transmitted via a network, and a layout determination device for determining an optimum layout of the format conversion device according to statistical information such as network traffic. And a network system having the format conversion device and the arrangement determining device.

[0002]

2. Description of the Related Art In recent years, applications for transmitting multimedia information such as audio, moving images, still images, and the like via a network have been increasing, and some new services for providing multimedia information using a network as a business have been developed. It is getting. Transmission of high-quality moving images requires a network with a wide bandwidth, so J is required for information data including still images, moving images, and audio.
Information compression techniques such as PEG, MPEG, and ATRAC have become important technical elements.

[0003] Compression techniques have been developed based on various compression schemes in accordance with characteristics such as the attributes of information to be transmitted. For this reason, the compressed information currently transmitted using the network is a data stream generated by various different applications, each having a different format, and is often incompatible with each other.
When transmitting such information data using a network, the encoder on the transmitting side and the decoder on the receiving side need to support the same format. At present, terminals connected to a network are often PCs (personal computers), for example, and are provided with a plurality of decoder software within an allowable range of a data storage capacity and a processing capacity of a CPU. It is possible to correspond to.

[0004]

By the way, PC and P
In a computer having a performance of C or higher, for example, a network terminal configured by a workstation or the like,
If you have enough processing power, you can download the decoder software corresponding to each format.However, for portable terminal equipment that needs to minimize power consumption and terminals that cannot update functions, server It is desirable to perform format conversion as a service on the side. But in that case, for all servers,
Installing a conversion device that supports all formats used on a network imposes an economic burden on the server. In particular, it is not reasonable to arrange a conversion device that performs conversion that is not frequently used in all servers. For this reason, a conversion device for performing a predetermined format conversion is arranged at a necessary place in the network, and the format conversion of the information data is performed by sending the information data to the necessary conversion device while performing appropriate routing in the network, and the format conversion is performed. A process of delivering information data to a target terminal is effective, but how to determine the arrangement of the format converter is an unsolved problem.

The present invention has been made in view of the above circumstances, and has as its object to provide a format converter having a function of storing statistical information such as traffic in a network as a network terminal, and to provide a format converter in accordance with the stored statistical information. Determine the layout of the format converter,
An object of the present invention is to provide a format conversion device, an arrangement determination device, and a network system that can realize efficient and low-cost data transfer in a network.

[0006]

In order to achieve the above object, a format converter according to the present invention converts information data encoded according to a first format into information data of a second format different from the first format. A format conversion device for converting the information data from the first format to a second format, and a statistical device for accumulating statistical information on traffic of the information data. .

In the present invention, preferably, a plurality of the above-mentioned converting means are provided, and the information data is converted into a predetermined format through at least two converting means.

Further, the present invention preferably has a route determining means for determining a converting means through which the information data passes.

Further, the present invention preferably has storage means for storing topology information indicating a connection structure of the network.

In the present invention, preferably, there is provided an interface means for transmitting the statistical information accumulated by the statistical means via the network.

[0011] Further, an arrangement determining apparatus of the present invention is an arrangement determining apparatus which determines an arrangement of a format conversion apparatus which is arranged on a network and converts a format of information data transferred on the network. Information acquisition means for acquiring statistical information in which traffic information is accumulated by the device; request input means for inputting an externally provided arrangement determination request; and arrangement of the format conversion apparatus according to the statistical information and the arrangement determination request. Determining means for determining.

In the present invention, preferably, the information acquisition means acquires topology information indicating a connection structure of the network from the format conversion device.

In the present invention, preferably, the determination means determines the arrangement of the format conversion device according to the statistical information, the topology information, and the arrangement determination request.

Further, a network system according to the present invention is provided on a network and includes a format conversion device for converting the format of data transferred to the network, and a layout determination device for determining the layout of the format conversion device. And
The format conversion device includes a conversion unit for converting a format of information data transferred to the network, and a statistical unit for storing statistical information on traffic of the information data. Information obtaining means for obtaining the statistical information accumulated by the above, a request inputting means for inputting an externally provided arrangement determination request, and determining the arrangement of the format conversion apparatus according to the statistical information and the arrangement determination request. Determining means.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a conceptual diagram showing one configuration example of a network system according to the present invention. As shown in the figure, this system includes a plurality of routers (terminals) connected by a network. Some of these routers have a format conversion function (hereinafter referred to as a format conversion device) 10
0 and an arrangement determining device 200. At least one format conversion device 100 is provided. When there are a plurality of format converters, they are denoted by the symbols 100-1, 100-2,.
The arrangement determining apparatus 200 is an apparatus that determines an arrangement place of the format conversion apparatus.

The format converter 100 converts information data from an original format to a new format. For example, the moving image information data compressed according to the MPEG2 format is converted into the DV (Digital Video) format, or the moving image information data compressed according to the MPEG4 format is converted into the MPEG2 format.

The arrangement determining device 200 determines an arrangement place of the format conversion device in the network. If all the routers provided in the network system have a conversion function that can support all formats, there is no need to determine the arrangement. However, in order to reduce costs and improve the efficiency of the system, only a part of the router is provided with a predetermined format conversion function, and when a format conversion on the network becomes necessary, a format conversion device capable of performing the conversion is required. The information data is transferred, and the format-converted data is transferred to a predetermined terminal. For this reason, it is important to optimally determine the location of the format converter on the network. The arrangement determination device 200 shown in FIG. 1 is provided to collect statistical information of traffic in a network and to optimally determine an arrangement location of the format conversion device 100 based on the result. In FIG. 1, the arrangement determining device 2
00 is independently arranged on the network, but the arrangement determining device 200 can be arranged on the network together with any format conversion device.
For example, the arrangement determination device 200 and the format conversion device can be integrated into one terminal.

A description will be given below of how to determine the optimal arrangement of the format conversion devices in the network, including the configuration of the format conversion device and the arrangement determination device. FIG. 2 is a block diagram illustrating a configuration example of the format conversion device. As shown, the format conversion apparatus 100
, 10-m (m is an integer, m ≧ 1), a route control unit 20, a statistics accumulation unit 30, a transfer unit 40, and interface units 50-1, 50-2. ,
.., 50-n (n is an integer, n ≧ 1).

The conversion units 10-1, 10-2, ..., 10-m
Are conversion means each having one or more conversion functions. For example, the conversion unit 10-1 outputs the MPEG2
Information data compressed according to the format of MPE
G4 format, and the conversion unit 10-2
The information data compressed according to the EG4 format is converted to the DV format.

The path control unit 20 selects a conversion unit required for format conversion in accordance with a given format conversion request, and determines a path through which the information data passes through the conversion unit. For example, when a conversion request from the MPEG2 format to the AVI (Audio Video Interleaving) format is received, the path control unit 20 determines the shortest path that can realize the required format conversion according to the conversion function of each conversion unit. look for.

For example, when the conversion unit 10-2 can execute the conversion from the MPEG2 format to the AVI format, the input information data is input via a predetermined interface unit, and further, the conversion unit 1 is input via the transfer unit 40.
Transfer to 0-2. The information data in the AVI format converted by the conversion unit 10-2 is input to a predetermined interface unit via the transfer unit 40, and transmitted to the network by the interface unit.

On the other hand, when none of the conversion units can directly convert from the MPEG2 format to the AVI format, the path control unit 20 uses a plurality of conversion units based on the conversion function of each conversion unit. Find a route to achieve. For example, if the conversion unit 10-2
Convert from PEG2 format to DV format,
When the conversion unit 10-m converts the DV format to the AVI format, the path control unit 20 inputs the input information data to the conversion unit 10-2 via a predetermined interface unit and the transfer unit 40. The information data converted into the DV format by the conversion unit 10-2 is input to the conversion unit 10-m via the transfer unit 40. Conversion unit 1
0-m indicates that the information data in the DV format is AV
Converted to I format. The path control unit 20 transfers the conversion result of the conversion unit 10-m to a predetermined interface unit via the transfer unit 40, and transmits the result to the network. As a result, the required format conversion can be realized with the shortest path inside the converter, that is, with the minimum number of conversions.

The statistic storage unit 30 stores statistic information of information data passing through the format conversion apparatus 100 and registers the stored information in a database. Here, the statistical information includes, for each data transfer, information such as a data sender, a receiver address, a transfer start time and an end time, an input interface unit, an output interface unit, and a passed conversion unit. Further, topology information indicating the structure of the network, for example, information on all routers connected to each router including the format conversion device is stored in the database. It should be noted that the topology information can be stored in a part other than the statistical storage unit 30.
For example, topology information can be stored in the path control circuit 20.

The transfer section 40 transfers information data.
For example, the transfer unit 40 transfers the information data input from the interface unit to the conversion unit specified by the path control unit 20, and transfers the conversion result of any of the conversion units to the specified interface unit. Transfer to another converter. Further, the transfer unit 40 transfers necessary statistical information to the statistics storage unit 30.

The interface units 50-1, 50-2,
, 50-n perform input and output of information data between the network and the format conversion apparatus 100. For example, the interface unit inputs multimedia information data such as image data and audio data from the network, and transfers the multimedia information data via the transfer unit 40 to, for example, the conversion unit designated by the path control circuit 20. Further, the interface unit outputs information data such as a conversion result transferred by the transfer unit 40 to the network.

In the format converter 100 described above, the information data transferred via the network is transmitted to the interface units 50-1, 50-2,.
−n and input to the transfer unit 40. In the path control unit 20, the contents of the requested format conversion and the conversion units 10-1, 10-2, ..., 10-
According to each conversion function of m, a conversion unit to be used to realize the format conversion is determined. The transfer unit 40 transfers the information data to the designated conversion unit according to the determination of the path control unit 20, and transfers the result of the conversion to the specified interface or the next conversion unit. In the statistics storage unit 30, statistical information is stored for each information data, and the contents of the database are updated.

FIG. 3 is a flowchart showing the operation of the statistics accumulation unit 30. Hereinafter, the operation of accumulating statistical information, updating the database, and outputting the statistical information in the statistical accumulation unit 30 will be described with reference to FIG.

In the statistics storage section 30, the collection of the statistical information on the traffic of the information data and the update of the database based on the collection result are repeatedly performed. As shown in FIG. 3, in the event waiting state, the statistics accumulation unit 30 receives a data transfer and a database acquisition request (step S1).

When an event occurs, the following three processes are performed according to the type of the event. 1. Detection of Start of Data Transfer (Step S2) When the start of transfer of information data is detected in the network, the statistics storage unit 30 stores the sender / receiver address, data transfer start time, input interface unit, and output interface in the database. Information on the unit and the conversion unit that passes is recorded (step S3).

2. Detection of end of data transfer (step S
4) When the end of the transfer of the information data is detected, the statistics accumulation unit 3
At 0, the data transfer end time is recorded in the database (step S5).

By the above-described processing, statistical information is accumulated for each information data transferred to the network, and the contents of the database are updated. The statistical information stored in the database is transmitted to the arrangement determining device 200 in response to an acquisition request from the arrangement determining device 200, and is used for the arrangement determination of the format conversion device 100.

3. Receiving a database acquisition request from the placement determining device (step S6) When a request to acquire information from the statistical information database is received from the placement determining device 200, the statistics storage unit 30 stores the requested database information through the network. Transmitted to the determination device 200 (step S
7).

In addition to the above, in the statistics storage unit 30 of the format converter 100, information on all routers connected to each router including the format converter is recorded as network topology information. This topology information, together with the traffic information accumulated by the statistics accumulating unit 30, is assigned to the placement determining device 20.
0 is transmitted to the arrangement determining apparatus 200 in accordance with the request of 0.

The arrangement determining apparatus 200 determines an optimal arrangement place of the format conversion apparatus 100 in the network based on the traffic information and the topology information received from the statistics storage unit 30 of the format conversion apparatus 100. FIG. 4 is a block diagram illustrating a configuration example of the arrangement determination device 200. Hereinafter, the configuration and operation of the arrangement determination device 200 of the present embodiment will be described with reference to FIG.

As shown in FIG. 4, the arrangement determining device 200
Is composed of a determination unit 60, a request input unit 70, a result output unit 80, and an interface unit 90. Hereinafter, the function of each part will be described.

The deciding unit 60 includes the format conversion device 10
According to the statistical information accumulated by the statistics accumulating unit 30 of 0, an optimal arrangement place of the format conversion apparatus 100 is determined. The format conversion device 1 based on the statistical information
The method of determining the optimal arrangement of 00 will be described later.

The request input unit 70 externally inputs a request for a new arrangement determination through a user interface or the like. Further, at the same time as the request for the arrangement determination, if there is an arrangement condition, it is received and sent to the determination unit 60. The arrangement condition includes, for example, a condition such as a cost for changing the arrangement.

The result output unit 80 receives the result of the layout determination from the determination unit 60 and outputs it to the outside through a user interface or the like.

The interface unit 90 connects the arrangement determination device 200 to the network, and connects to another terminal connected to the network, for example, the format conversion device 10.
Information transfer is performed between 0 and 0. For example, the statistical information accumulated in the statistics accumulating unit 30 of the format conversion apparatus 100 is transferred via a network, and the interface unit 90 receives it and transfers it to the determining unit 60.

FIG. 5 is a flowchart showing the determining operation of the arrangement determining section 60 in the arrangement determining apparatus 200. Hereinafter, the operation of the arrangement determination unit 60 when determining the arrangement of the format conversion apparatus 100 will be described with reference to FIG.

The arrangement determining unit 60 is in a standby state until an event such as a transmission request for arrangement determination occurs from the request input unit 70 (step SS1). When a request from the request input unit 70 is detected (step SS2), first, statistical information is obtained from the format conversion device 100 (step SS3). Here, when a plurality of format converters are arranged in the network, the statistical information is obtained from each format converter. Note that the statistical information acquired here is mainly statistical information on traffic accumulated by the statistics accumulating unit 30 of each format converter.

Next, topology information is obtained from the statistics storage unit 30 of each format converter (step SS).
4). Note that information acquisition may be omitted from the format conversion device that has already acquired statistical information and topology information. For example, in the previous placement determination processing, if statistical information and topology information were obtained from a certain format conversion apparatus, and then the statistical information and topology information were not changed, in this placement determination processing, the information was obtained in the previous processing. The information can be used as it is. In addition, not all of the database but only a part of the database may be obtained from the statistics storage unit 30 of the format converter. Further, as for the topology information, if only one network converter in the format conversion apparatus knows the connection of the network in the vicinity, it is also possible to connect them to estimate the structure of the entire network.

Then, based on the obtained statistical information, topology information, and the conditions of the layout determination input from the request input unit 70, the optimum layout location of the format conversion apparatus is calculated (step SS5). Finally, the calculated location of the format conversion device is output to the result output unit 80 (step SS6).

In the arrangement determining apparatus 200, by repeatedly performing the above-described processing from step SS1 to step SS6, an optimal arrangement of the format conversion apparatus can be determined in response to a request from the user.

The following three methods are conceivable for determining the arrangement of the format conversion device in the arrangement determining device 200.

1. Relocation Relocation moves format converters already running in the network system to more appropriate locations. However, if the conversion unit of the format conversion apparatus is physically detachable in the form of an extension module, the whole or a part of the conversion unit module is relocated.

2. Add Determine the type, number and position of format converters to be newly added. Here, the type of the format conversion device is, for example, from format A to format B.
The conversion ability is expressed as conversion. Further, as in the case of the rearrangement, it is possible to add only the conversion module to the existing format conversion apparatus.

3. Deletion In order to reduce the operating cost of the network, for example, if the removal of a format converter that is low in importance and that is not used frequently does not significantly affect the traffic on the network, the format conversion is performed. Delete the device from the network system. Further, only the conversion unit in the format conversion apparatus may be deleted.

The above three change processes may be used alone or in a combination of two or three in a certain arrangement determination. For example, a part of the format conversion device may be rearranged, and an arrangement determination may be made to add some new format conversion devices or conversion units.

Next, the respective processes of rearrangement, addition and deletion in the arrangement determination will be described with reference to the drawings. FIG. 6 is a diagram showing the rearrangement of the format conversion device. FIG. 6A shows a configuration example of a network system. As illustrated, this configuration example is a simplified network system configured by four nodes and one arrangement determination device 200. Node 1 is a terminal that transmits information data, node 4 is a terminal that receives information data, and nodes 2 and 3 are
This is a node including a format conversion device that performs format conversion on information data.

The node 1 transmits the information data formed by the format A. On the other hand, the node 4 can handle only the format C information data.
For this reason, it is necessary to convert the format A information data transmitted from the node 1 into the format C information data by the format conversion device arranged in the network and to provide the format C information data to the node 4.

Here, for example, it is assumed that the format converter of the node 2 performs the conversion from the format B to the format C, and the format converter of the node 3 performs the conversion from the format A to the format B. As shown in FIG. 6A, the information data transmitted from the node 1 is first transmitted to the node 3, and is converted from the format A to the format B in the node 3.
Next, the format-converted information data is transmitted from the node 3 to the node 2, and the format conversion device of the node 2 further converts the format B into the format C.
Is converted to Finally, the information data converted into the format C is transferred from the node 2 to the node 4.

The information data of format A transmitted from the node 1 is converted into the format C by the above-described conversion processing and transferred to the node 4. by this,
Information data can be transmitted and received between the node 1 and the node 4 that handle only the different formats A and C.

However, in the arrangement of the format conversion apparatus shown in FIG. 6A, the data transmitted from the node 1 is first transmitted to the node 3 via the node 2 and the data whose format has been converted by the node 3 is transmitted to the node 2 And the next format conversion is performed, and the result is transmitted to the node 4 via the node 3. Therefore, node 2 and node 3
In between, the information data is transferred back and forth, the traffic at the nodes 2 and 3 increases, and the load of data transfer at these nodes increases.

When the rearrangement is requested, the deciding unit 60 of the arrangement deciding unit 200 stores the statistical information stored by the statistic storing units of the respective nodes from node 1 to node 4,
The topology information is acquired, and the format conversion device is rearranged in accordance with the information and conditions inputted from outside. First, when the obtained information is integrated, it can be seen that in the arrangement shown in FIG. 6A, there is room for improvement in a portion where data reciprocates between the nodes 2 and 3. in this case,
FIG. 6 shows a possible relocation plan of the format conversion apparatus.
(B), (c) and (d).

In the relocation plan shown in FIG.
The function of converting the format, ie, the function of converting the format A to the format B, is moved to the node 2. This movement can be realized by, for example, replacing the module of the conversion unit in the node 3 with the node 2 and moving all the partial circuits related to the format conversion of the node 3 to the node 2.

By such rearrangement, the information data of format A transmitted from node 1 is converted twice at node 2, that is, from format A to format B and from format B to format C. , Is transmitted to the node 4 via the node 3. As a result of the rearrangement, information data transfer in the network can be smoothly realized, traffic is reduced, and network efficiency is improved.

In the relocation plan shown in FIG.
The format conversion function, ie, the conversion function from the format B to the format C, is moved to the node 3. This movement can be realized by, for example, replacing the module of the conversion unit in the node 2 with the node 3 and moving all of the format conversion-related partial circuits of the node 2 to the node 3.

By such a rearrangement, the format A information data transmitted from the node 1 is transmitted to the node 3 via the node 2, and the node 3 obtains the format C information data by two conversions. Can be
The converted information data is transmitted to the node 4. That is, the rearrangement plan has substantially the same effect as the rearrangement plan shown in FIG.

In the relocation plan shown in FIG.
And the conversion function of the node 3 is exchanged. That is, the function of converting the format B to the format C in the node 2 is moved to the node 3, and the function of converting the format A to the format B in the node 3 is moved to the node 2.
This movement can be realized by, for example, exchanging the modules of the conversion units of the node 2 and the node 3 or exchanging all the partial conversion-related partial circuits of the node 2 and the node 3.

As a result of this conversion, information data of format A transmitted from node 1 is converted to format B at node 2 and transmitted to node 3. Node 3
, The information data of format B is converted to format C, and the conversion result is transmitted to node 4. That is, as a result of the rearrangement, there is no round-trip transfer of information data,
Data transfer can be performed smoothly, and network traffic can be reduced.

Then, in the arrangement determining device 200, FIG.
The three relocation plans shown in (b), (c) and (d) are compared, and an optimum relocation plan is determined according to the relocation conditions input from the outside. At this time, for example, if the relocation condition input from the outside is to maximize the amount of traffic reduction due to the relocation, the relocation decision device 2
00 evaluates the amount of traffic reduction due to the three relocation plans, respectively. In the case of FIG. 6, since the amount of reduction in traffic by the three relocation plans is almost the same, the optimum relocation plan cannot be determined only by these conditions.
Next, when determining the rearrangement in accordance with the condition that the cost associated with the rearrangement is minimized, the allocation determination device 200 compares the costs of the three rearrangement plans and selects the one with the lowest cost. The cost can be evaluated, for example, based on various conditions such as man-hours required for replacing the conversion module. That is, when the man-hour for replacing the conversion module from the format A to the format B is smaller than that of the conversion module from the format B to the format C, the plan (b) having the lowest cost is selected.

The arrangement determination device 200 outputs a result to the user interface via the result output unit 80 if the required conditions cannot be satisfied as a result of comparison and examination of all the rearrangement plans. It may not be done.

Next, an additional case will be described with reference to FIG. The arrangement of the network shown in FIG. 7A is almost the same as that shown in FIG. That is, of the four nodes from node 1 to node 4, node 2 includes a format conversion device for converting from format B to format C, and node 3 includes a format conversion device for converting from format A to format B. Equipment. The node 1 transmits the format A information data to the node 4, and the node 4 can handle only the format C information data.

In the arrangement example of FIG. 7A, since information data reciprocates between the node 2 and the node 3, the traffic increases, and the transfer load on the node 2 and the node 3 increases. When this problem is solved by adding a format conversion device, an arrangement determining device 200 shown in FIG. 6A determines a location where the format conversion device is added.

FIGS. 7B, 7C and 7D show three examples of adding a format converter. FIG.
(B) shows an example in which a conversion function from format A to format B is added to node 2. This addition can be realized, for example, by adding a module for converting the format A to the format B to the format conversion device of the node 2.

As a result of this addition, the format A information data transmitted from the node 1 is converted twice from the format A to the format B and from the format B to the format C at the node 2, and the conversion result is transmitted via the node 3. Transmitted to the node 4. As a result, information data is prevented from being transferred back and forth between the node 2 and the node 3, and traffic is reduced.

FIG. 7C shows an example in which a conversion function from format B to format C is added to node 3. This addition can be realized, for example, by adding a module for converting the format B to the format C to the format conversion device of the node 3.

As a result of this addition, the information data of format A transmitted from the node 1 is transmitted to the node 3 via the node 2, and the node 3 converts the format A into the format B and converts the format B into the format C. Is performed, and the conversion result is transmitted to the node 4. As a result, information data is prevented from being transferred back and forth between the node 2 and the node 3, and traffic is reduced.

In FIG. 7D, a conversion function from format A to format B is added to node 2, and
An example in which a conversion function from format B to format C is added to node 3 is shown. This addition, for example,
A module for converting from format A to format B is added to the format conversion device of node 2;
This can be realized by adding a module for converting the format B to the format C to the format conversion device of the node 3.

As a result of this addition, the format A information data transmitted from the node 1 is converted into the format C information data by either the node 2 or the node 3 by performing the format conversion twice. The conversion result is sent to the node 4. As a result, information data is prevented from being transferred back and forth between the node 2 and the node 3, and traffic is reduced.

The arrangement determining device 200 selects one of the above-mentioned three alternatives in accordance with an externally provided additional condition. Note that the three additional proposals shown in FIGS. 7B, 7C and 7D have substantially the same effect of reducing traffic in the network. Therefore, for example, when the condition that the additional cost is minimized is required, the costs of the three additional plans are compared, and the additional plan with the lowest cost is selected. In this case, in the plan shown in FIG. 7D, two modules need to be added, and the cost is higher than the other two plans. For this reason, FIG.
By calculating the cost for the two alternatives (c) and (c),
The optimal addition is obtained. A module for converting from format A to format B;
By comparing the additional cost of the module for converting the format into the format C, it is possible to determine a low-cost additional plan.

Next, the case of deletion will be described with reference to FIG. FIG. 8A illustrates an example of a network system including six nodes and the arrangement determination device 200. In this network system, the node 1 transmits format A information data to the node 3, and the node 4 transmits format A information data to the node 6. Node 3 and Node 6
Can handle only format B information data. For this reason, the nodes 2 and 5 are provided with format converters for converting from format A to format B, respectively.

However, in this system, it is inefficient to provide two format converters having the same conversion function, and one format converter is reduced in order to reduce operating costs. In this case, the format conversion device to be reduced by the arrangement determination device 200 is determined.

FIGS. 8B and 8C show a deletion plan of the format conversion apparatus. In the deletion plan of FIG.
The format conversion device at node 5 is deleted. In this case, the information data transmitted from the node 4 is transmitted to the node 2 via the node 5. The format is converted from the format A to the format B by the node 2, and the conversion result is transferred to the node 6 via the node 5. Although this deletion plan increases the traffic of the node 5 and increases the transfer load, one format conversion device can be deleted, and the cost of the network system can be reduced.

In the deletion plan shown in FIG. 8C, the format conversion device of the node 2 is deleted. In this case, the information data transmitted from the node 1 is transmitted to the node 5 via the node 2.
Sent to. The format is converted from the format A to the format B by the node 5, and the conversion result is transferred to the node 3 via the node 2. Although this deletion plan increases the traffic of the node 2 and increases the transfer load, one format conversion device can be deleted and the cost of the network system can be reduced.

Which of the two plans shown in FIGS. 8B and 8C is optimal can be determined, for example, according to the traffic of each node before deletion. When receiving the instruction to delete, the arrangement determination device 200 acquires the statistical information accumulated by the statistical accumulation unit of each node up to that time, and views the network traffic.

For example, when the traffic on the route from the node 1 to the node 3 is smaller than the traffic on the route from the node 4 to the node 6, by removing the format conversion function of the node 2, the increase in the traffic on the entire network is small. Therefore, it is determined that the format conversion device of the node 2 is deleted. Conversely, when the traffic on the route from the node 4 to the node 6 is smaller than the traffic on the route from the node 1 to the node 3, the increase in the traffic in the entire network can be reduced by removing the format conversion device of the node 5. Therefore, it is determined that the format conversion device of the node 5 is deleted.

As described above, according to the present embodiment, according to the statistical information summarizing the traffic and the like in the network and the topology information indicating the structure of the network, and further according to the condition of the arrangement decision given from the outside, Relocation, addition, or deletion can be performed on the format conversion device, and the efficiency of the network system can be improved, the operating cost can be reduced, and the data transfer load can be reduced. In addition, a slight increase in the transfer load can reduce the number of format converters and reduce the operating cost of the network system.

[0080]

As described above, according to the format conversion apparatus, the arrangement determination apparatus and the network system of the present invention, statistical information of traffic in a network can be collected and accumulated by each format conversion apparatus.
It is possible to determine the optimum arrangement of the format conversion device in the network based on the statistical information, the topology information, and the arrangement determination conditions given from the outside. By optimizing the arrangement of format converters, it is possible to reduce traffic in the network system, reduce the data transfer load on each terminal including the format converter, and improve the efficiency of the network system and reduce operating costs. There is an advantage that can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one configuration example of a network system including a format conversion device and an arrangement determination device according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a format conversion apparatus.

FIG. 3 is a flowchart illustrating an operation of a statistics accumulation unit.

FIG. 4 is a block diagram illustrating a configuration example of an arrangement determining device.

FIG. 5 is a flowchart illustrating an operation of a determination unit.

FIG. 6 is a diagram showing rearrangement of a format conversion device.

FIG. 7 is a diagram showing addition of a format conversion device.

FIG. 8 is a diagram showing deletion of a format conversion device.

[Explanation of symbols]

10-1, 10-2,..., 10-m conversion unit, 20 route control unit, 30 statistics storage unit, 40 transfer unit, 50-
1, 50-2,..., 50-n.
0: determination unit, 70: request input unit, 80: result output unit, 9
0: interface unit, 100: format conversion device, 200: arrangement determination device.

Claims (13)

[Claims] 1. A format conversion apparatus for converting information data encoded according to a first format into information data of a second format different from the first format, wherein A format conversion apparatus comprising: conversion means for converting from one format to a second format; and statistics means for accumulating statistical information on the traffic of the information data. 2. The format conversion apparatus according to claim 1, further comprising a conversion means for converting the information data of the second format into a third format different from the first and second formats. 3. The format conversion apparatus according to claim 1, further comprising a plurality of said conversion means, wherein said information data is converted into a predetermined format through at least two conversion means. 4. A format conversion apparatus according to claim 3, further comprising a path determination means for determining a conversion means through which said information data passes. 5. The format conversion apparatus according to claim 1, further comprising storage means for storing topology information indicating a connection structure of the network. 6. The format conversion apparatus according to claim 1, further comprising an interface unit for transmitting the statistical information accumulated by the statistical unit via the network. 7. An arrangement determining device arranged on a network for determining an arrangement of a format converter for converting a format of information data transferred to the network, wherein the statistical information is stored traffic information by the format converter. And a request input unit for inputting an externally provided placement determination request; and a determination unit for determining the placement of the format conversion apparatus according to the statistical information and the placement determination request. apparatus. 8. The arrangement determining device according to claim 7, wherein said information acquiring means acquires topology information indicating a connection structure of said network from said format conversion device. 9. The arrangement determining apparatus according to claim 8, wherein said determining means determines the arrangement of said format conversion apparatus according to said statistical information, said topology information and said arrangement determination request. 10. The arrangement determining apparatus according to claim 7, further comprising a result output means for outputting a result of the determination by said determining means to the outside. 11. A network system, comprising: a format conversion device arranged on a network for performing format conversion of data transferred to the network; and a layout determination device for determining the layout of the format conversion device. The apparatus has conversion means for converting the format of information data transferred to the network, and statistical means for accumulating statistical information on the traffic of the information data. The arrangement determination device is stored by the statistical means. Information obtaining means for obtaining the statistical information, request input means for inputting an externally provided arrangement determination request, and determination means for determining the arrangement of the format conversion device according to the statistical information and the arrangement determination request. A network system having: 12. The network system according to claim 11, wherein said format conversion device has storage means for storing topology information indicating a connection structure of said network. 13. The network system according to claim 12, wherein said deciding means of said arrangement deciding device decides the arrangement of said format conversion device according to said statistical information, said topology information and said arrangement deciding request.