WO2014103014A1

WO2014103014A1 - Relay device and relay method

Info

Publication number: WO2014103014A1
Application number: PCT/JP2012/084071
Authority: WO
Inventors: 義則望月; 小泉　稔; 江端　智一
Original assignee: 株式会社日立製作所
Priority date: 2012-12-28
Filing date: 2012-12-28
Publication date: 2014-07-03

Abstract

An objective of the present invention is to provide a relay device whereby communication delay time of data from a transmission source to a transmission destination is reliably ensured. The relay device: retains a transfer destination, a requirement communication delay time which should be maintained until data which is transmitted by a transmission source terminal is received by the transmission destination terminal, and a predicted communication delay time which is predicted to be required until data which is transmitted by the relay device is received by the transmission destination terminal; computes a transmission source communication delay time from transmission of the received data by the transmission source terminal to reception thereof by the relay device; and transfers the data on the basis of the requirement communication delay time, the predicted communication delay time, and the computed transmission source communication delay time, such that the data which is received is received by the transmission destination terminal within the requirement communication delay time.

Description

Relay device and relay method

The present invention relates to a relay device that relays data from a transmission source terminal to a transmission destination terminal, and more particularly to a relay device that guarantees a communication delay time from the transmission source terminal to the transmission destination terminal.

Generally, an IP (Internet Protocol) network is a best-effort communication method that does not guarantee communication quality such as bandwidth and communication delay time (hereinafter referred to as QoS (Quality Service)). However, in recent years, demands for IP network services that guarantee QoS have increased, and development of services that guarantee QoS has been active. Examples of this service include real-time communication such as voice call by telephone and video distribution, real-time communication for robot remote control, and the like. In a service that guarantees QoS, even when there is data loss or when the communication delay time is later than the assumed communication delay time, even one packet has a great influence on the service quality.

In order to solve such a problem, it is generally known that a relay apparatus configuring a network gives priority to data to be transferred and preferentially transfers data with high priority. In other words, an existing relay device such as an IP router sets the priority of data that requires real-time performance (data that guarantees QoS) higher than the priority of data that does not require real-time performance. Transfer with priority. Transfer control based on priority in such a relay device is called priority transfer control.

However, in a relay device that uses priority transfer control, processing concentrates only on data that requires real-time processing, and processing may not be performed on data that does not require real-time processing. In addition, in a network where congestion occurs due to reasons such as narrow bandwidth, even if the relay device uses priority transfer control, there is a possibility that the retransmission time due to congestion will affect the receiving terminal as delay fluctuations. is there.

As techniques for solving the above-mentioned problems, there are JP-A No. 2002-118585 (Patent Document 1) and JP-A No. 2007-13654 (Patent Document 2).

Patent Document 1 states that “input packets are classified into a plurality of classes, a plurality of classes are classified into a priority group and a non-priority group, and packets of each class are stored in queues independent of each other, A first band that satisfies the required delay time is preferentially assigned to the queue that holds the packets of the group, the remaining band is set as the second band, and the non-priority group uses a specific period of frequency for each class. And a part of the second band is dynamically allocated to the queue of the non-priority group with a weight according to the frequency of use in the most recent specific period ”(see summary).

Japanese Patent Laid-Open No. 2004-228688 discloses a configuration in which delay information is inserted into a packet transferred between packet switches in an IP network, and QoS control is performed using the delay information. Specifically, a flow identification unit 601 of a packet switch. The delay information is extracted from the received packet and passed to the transmission control unit 605. The transmission control unit 605 changes the bandwidth setting of the queue based on the delay information and calculates the internal correction time using the delay calculation unit 607. The processing unit 606 updates the delay information using the internal correction time and transmits the packet ”(see summary).

JP 2002-118585 A JP 2007-13654 A

In the techniques described in Patent Document 1 and Patent Document 2, only the delay time from the transmission source terminal that transmitted the data to the relay device that received the data is considered. In the network configuration of the relay system as shown in FIG. 1, data A is transferred in the order of communication channel A, communication channel C, and communication channel E in the required communication delay time (10 ms), and data B is communication channel B, communication channel. Suppose that the relay device C110C shown in FIG. 1 receives data A and data B via the communication path A and the communication path B in the case of transfer with the required communication delay time (10 ms) in the order of D and the communication path F. . In this case, in the techniques described in Patent Document 1 and Patent Document 2, it takes 3 ms from the time when data A is transmitted by the terminal A100A to the time when it is received by the relay device C110C, and the time when the data B is transmitted by the terminal B100B. Since it takes 2 ms until it is received by D110C, data A is preferentially transferred. However, since data A arrives at terminal D100 in 3 ms after relay device C110 and data B arrives at terminal E100E in 7 ms after relay device C110, data B should be transferred with priority.

As described above, in the techniques described in Patent Document 1 and Patent Document 2, since the data to be preferentially transferred is not preferentially transferred, the requirement communication delay time that ensures the data communication delay time is guaranteed. Can not do it.

Therefore, an object of the present invention is to provide a relay device that reliably guarantees a communication delay time of data from a transmission source to a transmission destination.

In order to solve the above-described problem, in the present invention, a relay device that relays data from a transmission source terminal to a transmission destination terminal, the transfer destination of data transmitted by the transmission source terminal, and transmission by the transmission source terminal Required communication delay time to be ensured until received data is received by the destination terminal, and expected communication expected to be required before the data transmitted by the relay device is received by the destination terminal Data transmitted by the transmission source terminal includes time information indicating a transmission time, and included in the received data when the data transmitted by the transmission source terminal is received. Source communication required from the time when the data is transmitted by the source terminal to the time when the data is received by the relay device Calculate the extended time, and based on the requirement communication delay time, the expected communication delay time, and the calculated source communication delay time, the received data is received by the destination terminal within the requirement communication delay time. Then, the data is transferred.

According to the present invention, it is possible to provide a relay device that reliably guarantees the data communication time from the transmission source to the transmission destination.

Issues, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

It is explanatory drawing of a structure of the relay system of Example 1 of this invention. It is explanatory drawing of a structure of the terminal of Example 1 of this invention. It is explanatory drawing of a structure of the relay apparatus of Example 1 of this invention. It is explanatory drawing of a structure of the management server of Example 1 of this invention. It is explanatory drawing of the format of the data communicated in the system of Example 1 of this invention. It is explanatory drawing of the measurement information storage table of Example 1 of this invention. It is explanatory drawing of the data classification table of Example 1 of this invention. It is explanatory drawing of the routing table of Example 1 of this invention. It is explanatory drawing of the routing management table of Example 1 of this invention. It is explanatory drawing of the measurement information management table of Example 1 of this invention. It is explanatory drawing of the data management table of Example 1 of this invention. It is a flowchart of the process at the time of system starting by the management server of Example 1 of this invention. It is a flowchart of the process at the time of system starting by the terminal and relay apparatus of Example 1 of this invention. It is a flowchart of the process at the time of normal mode operation | movement by the management server of Example 1 of this invention. It is a flowchart of the process at the time of normal mode operation | movement by the terminal and relay apparatus of Example 1 of this invention. It is a flowchart of the data transfer process of Example 1 of this invention. It is a flowchart of the data transfer process of Example 1 of this invention. It is a flowchart of the process at the time of system starting by the terminal and relay apparatus of the modification of Example 1 of this invention. It is explanatory drawing of the data communication method of the modification of Example 1. FIG. It is explanatory drawing of a structure of the relay system of Example 2 of this invention. It is a flowchart of the process at the time of system starting by the terminal and relay apparatus of Example 2 of this invention. It is explanatory drawing of a structure of the relay apparatus of Example 3 of this invention. It is explanatory drawing of the data processing time table of Example 3 of this invention. It is explanatory drawing of the data management table of Example 3 of this invention. It is a flowchart of the process at the time of system starting by the management server of Example 3 of this invention. It is a flowchart of the process at the time of system starting by the relay apparatus of Example 3 of this invention. It is a flowchart of the process at the time of system starting by the terminal and relay apparatus of the modification of Example 3 of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. Moreover, in each drawing, the same code | symbol is attached | subjected to the same element and the duplication description is abbreviate | omitted as needed for clarification of description.

Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.

FIG. 1 is an explanatory diagram of a configuration of the relay system according to the first embodiment of this invention.

The relay system includes terminal A100A to terminal E100E (hereinafter collectively referred to as terminal 100), relay device A110A to relay device G110G (hereinafter collectively referred to as relay device 110), and management server 120.

The network connecting terminal A100A to terminal E100E is configured by relay device A110A to relay device G110G, and terminal A100A transmits and receives data via the network. The network is, for example, an Ethernet or a wireless network. The relay system is, for example, an information network system or an FA (Factory Automation) network system. Note that the relay device 110 configuring the network is, for example, a gateway, a switch, or a router.

The network shown in FIG. 1 will be described.

The relay device A110A is connected to the terminal A100A and connected to the relay device C110C via the communication path A130. Relay device B110B is connected to terminal B100B and connected to relay device C110C via communication path B132. The relay device C110C is connected to the relay device D110D via the communication path C134, and is connected to the relay device E110E via the communication path D136. The relay device D110D is connected to the relay device F110F via the communication path E138, and the relay device E110E is connected to the relay device G110G via the communication path F140. Relay device F110F is connected to management server 120 and terminal D100D, and relay device G110G is connected to terminal E100E.

In transmission of data from a certain relay device to a certain relay device via a communication path, a communication delay time is generated according to the bandwidth and data amount of the communication path. The communication time of the communication channel A130 is 3 ms, the communication time of the communication channel B132 is 2 ms, the communication time of the communication channel C134 is 2 ms, the communication time of the communication channel D136 is 6 ms, and the communication time of the communication channel E138. Is 1 ms, and the communication time of the communication path F140 is 1 ms.

The management server 120 is a computer that monitors the communication delay time of each communication path and manages the relay device 110. The management server 120 does not necessarily need to be connected to the relay device F110F, and may be connected to any relay device 110.

FIG. 2 is an explanatory diagram of the configuration of the terminal 100 according to the first embodiment of this invention.

The terminal 100 includes a hardware module 200, an OS 202, a terminal application 204, a measurement application 206, and a storage device 208.

The hardware module 200 is hardware necessary for operating the terminal 100, and includes a CPU, a volatile memory, a nonvolatile memory, an external communication interface, an external input / output unit, a display unit, and the like. The CPU loads various programs stored in the nonvolatile memory into the volatile memory and executes the various programs loaded into the volatile memory. The external communication interface is an interface for communicating data with another relay apparatus 110 or the terminal 100. The external input / output unit is an interface for collecting data from an external device such as a sensor.

The OS 202 is basic software that comprehensively controls the operation of the terminal 100, and is executed by a CPU (not shown).

The terminal application 204 is an application that operates on the terminal 100. For example, in the case of an FA network system, the terminal application 204 generates data such as a voltage value or power amount based on power data collected via the external input / output unit. .

The measurement application 206 is an application that measures a communication delay time with the terminal 100 or the relay device 110 existing in the same system. Note that when the communication delay time is measured with high accuracy, the function of the measurement application 206 may be implemented as hardware.

An example of a method for measuring communication delay time will be described.

First, a case where the terminal 100 or the relay device 110 does not synchronize time with another terminal 100 or the relay device 110 will be described. In this case, the terminal 100 or the relay device 110 transmits the measurement request data including the transmission time every predetermined time to the other adjacent terminal 100 or the relay device 110. When the other terminal 100 or the relay device 110 receives the measurement request data, the terminal 100 or the relay device 110 transmits measurement response data including the transmission time to the transmission source of the measurement request data. The measurement response data includes information that can be associated with the measurement request data or the transmission time of the measurement request data. When receiving the measurement response data, the terminal 100 or the relay device 110 divides the time obtained by subtracting the transmission time of the measurement request data corresponding to the measurement response data from the reception time of the measurement response data by 2 to thereby reduce the communication delay. Calculate time.

Next, a case where the terminal 100 or the relay device 110 synchronizes time with another terminal 100 or the relay device 110 will be described. In this case, the terminal 100 or the relay device 110 transmits the measurement request data including the transmission time to the other terminal 100 or the relay device 110 every predetermined time. The other terminal 100 or the relay device 110 calculates the communication delay time by subtracting the transmission time from the reception time of the measurement request data. Even if the terminal 100 or the relay device 110 synchronizes the time with the other terminal 100 or the relay device 110, the terminal 100 or the relay device 110 calculates the communication delay time using the above-described measurement request data and measurement response data. Also good.

The format of data communicated in the system such as measurement request data and measurement response data will be described in detail with reference to FIG.

The storage device 208 stores data necessary for the operation of the terminal 100. Specifically, the storage device 208 stores a measurement information storage table 210 and a data type table 212. In the measurement information storage table 210, a communication delay time measured by the measurement application 206 is registered. Details of the measurement information storage table 210 will be described with reference to FIG. In the data type table 212, the type of data transmitted and received by the terminal 100 and the type of data corresponding to the type are registered. Details of the data type table 212 will be described with reference to FIG.

Note that the storage device 208 is, for example, a nonvolatile memory such as a semiconductor memory or a magnetic storage medium.

FIG. 3 is an explanatory diagram of a configuration of the relay device 110 according to the first embodiment of this invention.

The relay device 110 includes a hardware module 220, an OS 222, a routing application 224, a measurement application 206, and a storage device 226.

The hardware module 220 is hardware necessary for operating the relay device 110, and includes a CPU, a volatile memory, a nonvolatile memory, an external communication interface, a display unit, and the like. The CPU, volatile memory, nonvolatile memory, external communication interface, display unit, and the like are the same as those of the hardware module 200 of the terminal 100 shown in FIG.

The OS 222 is basic software that comprehensively controls the operation of the relay apparatus 110, and is executed by a CPU (not shown).

The routing application 224 is an application that refers to the routing table 228 and transfers data received through the external communication interface included in the hardware module 220 to the terminal 100 or another relay device 110.

The measurement application 206 is the same as the measurement application 206 of the terminal 100 shown in FIG.

The storage device 226 stores data necessary for the operation of the relay device 110. Specifically, the storage device 226 stores a measurement information storage table 210 and a routing table 228. The measurement information storage table 210 is the same as the measurement information storage table 210 of the terminal 100 shown in FIG.

In the routing table 228, a transfer destination address, a communication delay time to be guaranteed, and an expected delay time from the relay apparatus 110 to the transmission destination are registered for each data type. Details of the routing table 228 will be described with reference to FIG.

Note that the storage device 226 is, for example, a nonvolatile memory such as a semiconductor memory or a magnetic storage medium.

FIG. 4 is an explanatory diagram of the configuration of the management server 120 according to the first embodiment of this invention.

The management server 120 includes a hardware module 240, an OS 242, a routing table generation application 244, and a storage device 250.

The hardware module 240 is hardware necessary for operating the management server 120, and includes a CPU, a volatile memory, a nonvolatile memory, an external communication interface, a display unit, and the like. The CPU, volatile memory, nonvolatile memory, external communication interface, display unit, and the like are the same as those of the hardware module 200 of the terminal 100 shown in FIG.

The OS 242 is basic software that comprehensively controls the operation of the management server 120, and is executed by a CPU (not shown).

The routing table generation application 244 is an application that generates the routing table 228 of each relay device 110 and distributes the generated routing table 228 to each relay device 110. The routing table generation application 244 includes a communication state collection unit 246, a routing table generation unit 247, and a routing table distribution unit 248.

The communication state collection unit 246 collects the measurement information storage table 210 from each terminal 100 and the relay device 110, and generates a measurement information management table 254 based on the collected information. The routing table generation unit 247 refers to the measurement information management table 254 and the data management table 256, generates the routing management table 252 and generates the routing table 228 of each relay device 110. The routing table distribution unit 248 distributes the routing table 228 generated by the routing table generation unit 247 to each relay device 110.

The storage device 250 stores a routing management table 252, a measurement information management table 254, and a data management table 256. In the routing management table 252, a communication path from the transmission source terminal 100 to the transmission destination terminal 100 is registered for each data type. Details of the routing management table 252 will be described with reference to FIG. The measurement information management table 254 is a table in which the measurement information storage table 210 collected from the terminal 100 or the relay device 110 is collected. Details of the measurement information management table 254 will be described with reference to FIG. The data management table 256 is a table for managing data communicated in the relay system. Details of the data management table 256 will be described with reference to FIG.

Note that the storage device 250 is, for example, a nonvolatile memory such as a semiconductor memory or a magnetic storage medium.

FIG. 5 is an explanatory diagram of a format of data communicated in the system according to the first embodiment of the present invention.

The data communicated in the system includes a packet header 1000, a transmission time 1002, a data type ID 1004, and data 1006.

In the packet header 1000, the address of the data transmission destination terminal 100, the address of the data transmission source terminal 100, and the like are registered, and the packet header 1000 corresponds to an Ethernet header or an IP header. In the transmission time 1002, a time at which data is transmitted from the terminal 100 as a transmission source is registered.

In the data type ID 1004, an identifier for uniquely identifying the data type is registered. Examples of the data type include the state of the terminal 100, a power value, a measurement request, or a measurement response. The data 1006 stores actual data such as the state of the terminal 100 or the power value.

FIG. 6 is an explanatory diagram of the measurement information storage table 210 according to the first embodiment of this invention.

The measurement information storage table 210 is stored in the storage device 208 of the terminal 100 and the storage device 226 of the relay device 110. In the measurement information storage table 210, a communication delay time with the other terminal 100 or another relay device 110 acquired by the measurement application 206 of the terminal 100 or the relay device 110 is registered.

The measurement information storage table 210 includes an address 300, a communication delay time 302, and a communication success rate 304.

In the address 300, the address (for example, IP address) of the terminal 100 or the relay device 110 that is the transmission destination of the measurement request data is registered. In the communication delay time 302, the communication delay time of the communication path between the terminal 100 or the relay device 110 identified by the address registered in the address 300 is registered. In the communication success rate 304, the ratio of the number of received measurement response data to the number of transmitted measurement request data is registered.

Note that the measurement information storage table 210 only needs to include at least the address 300 and the communication delay time 302 and may not include the communication success rate 304. In the measurement information storage table 210, the type of communication path (for example, optical network, wireless communication, etc.) with the device identified by the address registered in the address 300 may be registered.

FIG. 7 is an explanatory diagram of the data type table 212 according to the first embodiment of this invention.

The data type table 212 is stored in the storage device 208 of the terminal 100, and includes a data type ID 310 and a data type 312.

In the data type ID 310, a unique identifier of the type of data communicated via the communication path of the relay system is registered. In the data type 312, the name of the data type corresponding to the data type identified by the data type identifier registered in the data type ID 310 is registered. In the data type 312, for example, a terminal state and a current value are registered.

FIG. 8 is an explanatory diagram of the routing table 228 according to the first embodiment of this invention.

The routing table 228 is stored in the storage device 226 of the relay device 110. The routing table 228 is a table used when data received via the external communication interface included in the hardware module 220 is transferred, and includes a data type ID 320, a priority 322, a transfer destination address 324, a required communication delay time. 326 and a delay time 328 after this relay apparatus.

The data type ID 320 is the same as the data type ID 310 shown in FIG. In the priority 322, a priority corresponding to the type of data identified by the identifier registered in the data type ID 320 is registered. For example, when the relay apparatus 110 receives different types of data, the data with the higher priority is transferred with priority. In the transfer destination address 324, an address (for example, an IP address) of the terminal 100 or the relay device 110 that is the transfer destination is registered.

The requirement communication delay time 326 includes a communication delay to be guaranteed from the time when the data of the type identified by the identifier registered in the data type ID 320 is transmitted by the transmission source terminal 100 to the reception of the transmission destination terminal 100. Time is registered. In the delay time 328 after this relay apparatus, data of the type identified by the identifier registered in the data type ID 320 is received by the terminal 100 that is the transmission destination after being transmitted by the relay apparatus 110 that stores the routing table 228. The communication delay time (expected communication delay time) required until the registration is registered.

FIG. 9 is an explanatory diagram of the routing management table 252 according to the first embodiment of this invention.

The routing management table 252 is stored in the storage device 250 of the management server 120. The routing management table 252 is a table for managing a communication path from the transmission source terminal 100 to the transmission destination terminal 100 for each data type. The data type ID 330, the transmission source address 332, the transmission destination address 334, and the communication Path 336 is included.

The data type ID 330 is the same as the data type ID 310 shown in FIG. Registered in the transmission source address 332 is the address (for example, IP address) of the terminal 100 that is the transmission source of the type of data identified by the identifier registered in the data type ID 330. Registered in the transmission destination address 334 is the address (for example, IP address) of the terminal 100 that is the transmission destination of the type of data identified by the identifier registered in the data type ID 330.

In the communication path 336, a communication path through which data of the type identified by the identifier registered in the data type ID 330 is transmitted from the transmission source terminal 100 to the transmission destination terminal 100 is registered.

Note that the routing management table 252 may include a time zone in which data of the type identified by the identifier registered in the data type ID 330 is communicated.

FIG. 10 is an explanatory diagram of the measurement information management table 254 according to the first embodiment of this invention.

The measurement information management table 254 is stored in the storage device 250 of the management server 120. The measurement information management table 254 is a table in which the measurement information storage tables 210 of the terminal 100 and the relay device 110 are collected, and includes a measurement data transfer source address 340, a measurement data transfer destination address 342, and a communication delay time 344.

In the measurement data transfer source address 340, the address (for example, IP address) of the terminal 100 or the relay device 110 that has transmitted the measurement request data is registered. In the measurement data transfer destination address 342, the address (for example, IP address) of the terminal 100 or the relay device 110 that has received the measurement request data is registered. During the communication delay time 344, data transmitted by the terminal 100 or the relay device 110 registered in the measurement data transfer source address 340 is received by the terminal 100 or the relay device 110 registered in the measurement data transfer destination address 342. Communication delay time until is registered.

FIG. 11 is an explanatory diagram of the data management table 256 according to the first embodiment of this invention.

The data management table 256 is a table for managing data stored in the storage device 250 of the management server 120 and communicated in the relay system. The data management table 256 includes a data type ID 350, a data type 352, a priority 354, a transmission source address 356, a transmission destination address 358, and a requirement communication delay time 360.

The data type ID 350 is the same as the data type ID 310 shown in FIG. The data type 352 is the same as the data type 312 shown in FIG. The priority 354 is the same as the priority 322 of the routing table 228 shown in FIG.

The transmission source address 356 is the same as the transmission source address 332 of the routing management table 252 shown in FIG. The transmission destination address 358 is the same as the transmission destination address 334 shown in FIG. The requirement communication delay time 360 is the same as the requirement communication delay time 326 shown in FIG.

FIG. 12 is a flowchart of processing at the time of system startup by the management server 120 according to the first embodiment of this invention.

Processing at the time of system startup by the management server 120 is executed by a CPU (not shown) included in the hardware module 240 of the management server 120.

First, the management server 120 waits for processing until a predetermined time (X seconds) elapses after the relay system is activated (440). The process of step 440 is executed to secure time for the terminal 100 and the relay apparatus 110 existing in the relay system to generate the measurement information storage table 210 by communicating the measurement request data and the measurement response data.

Next, the management server 120 transmits a measurement information storage table request to the terminal 100 and the relay device 110 in order to acquire the measurement information storage table 210 generated by the terminal 100 and the relay device 110 (442). The measurement information storage table request may be transmitted by broadcast communication with a response. If the address information of the terminal 100 and the relay device 110 existing in the relay system is set in the management server 120 before the relay system is activated, the measurement information storage table request is unicasted using the address information. It may be transmitted by communication.

When the management server 120 acquires the measurement information storage table 210 from all the terminals 100 and the relay devices 110 existing in the relay system, the management server 120 generates the measurement information management table 254 based on the acquired measurement information storage table 210 (444). ).

Specifically, the management server 120 registers the address of the transmission source terminal 100 or relay device 110 of the acquired measurement information storage table 210 in the measurement data transfer source address 340 of the measurement information management table 254, and acquires the acquired measurement information. The address registered in the address 300 of the storage table 210 is registered in the measurement data transfer destination address 342 of the measurement information management table 254, and the communication delay time registered in the communication delay time 302 of the acquired measurement information storage table 210 is Registration is made in the communication delay time 344 of the measurement information management table 254.

Next, the management server 120 can reach the transmission destination terminal 100 from the transmission source terminal 100 with reference to the measurement information management table 254 and the preset data management table 256 generated by the processing of Step 444. Among the communication paths, a communication path satisfying the required communication delay time is specified, and the routing management table 252 is generated (446).

Specifically, the management server 120 adds records to the routing management table 252 by the number of records registered in the data management table 256. Then, the management server 120 registers the identifier registered in the data type ID 350 of the data management table 256 in the data type ID 330 of the added record, and the transmission source address 356 of the data management table 256 in the transmission source address 332 of the added record. The registered address is registered, and the address registered in the transmission destination address 358 of the data management table 256 is registered in the transmission destination address 334 of the added record.

Then, the management server 120 specifies a communication path constituted by communication paths that can reach the transmission destination terminal 100 from the transmission source terminal 100. The management server 120 refers to the data management table 256 and calculates the communication delay time of each identified communication path by summing the communication delay times of the communication paths constituting each identified communication path. Then, the management server 120 determines one communication path out of the communication paths whose communication delay time of the calculated communication path is smaller than the communication delay time registered in the requirement communication delay time 360 of the data management table 256 as the routing management table 252. Are registered in the communication path 336 of the added record. Thereby, the management server 120 can specify a communication path that satisfies the required communication delay time for each data type.

When there is no communication path whose communication delay time is smaller than the communication delay time registered in the requirement communication delay time 360 of the data management table 256, the management server 120 displays the communication path on the display unit included in the hardware module 240. You may display.

Next, the management server 120 generates a routing table 228 for each relay device 110 existing on the communication path registered in the communication path 336 of the routing management table 252 generated in the process of step 446, and generates the generated routing table 228. Is transmitted to the relay apparatus 110 existing on the communication path (448).

The generation process of the routing table 228 in the process of step 448 will be specifically described.

First, the management server 120 selects a record to be processed among the records registered in the routing management table 252. Then, the management server 120 identifies the relay device 110 existing on the communication path registered in the communication path 336 of the record to be processed in the routing management table 252, and from the identified relay device 110 to the processing target relay device 110. Select.

Next, the management server 120 adds a new record to the routing table 228 corresponding to the relay device 110 to be processed. Then, the management server 120 registers the identifier registered in the data type ID 330 of the record to be processed in the routing management table 252 in the data type ID 320 of the added record.

The management server 120 also records that the identifier registered in the data type ID 350 matches the identifier registered in the data type ID 320 of the record to be processed in the routing management table 252 among the records registered in the data management table 256. The priority registered in the priority 354 and the requirement communication delay time registered in the requirement communication delay time 360 are acquired. Then, the management server 120 registers the acquired priority in the priority 322 of the added record in the routing table 228 corresponding to the processing target relay device 110 and acquires the required communication delay in the required communication delay time 326 of the record. Register time.

Next, the management server 120 refers to the communication path registered in the communication path 336 of the record to be processed in the routing management table 252 and identifies the address of the transfer destination relay apparatus 110 of the relay apparatus 110 to be processed. Then, the management server 120 registers the address of the identified forwarding destination relay device 110 in the forwarding destination address 324 of the added record in the processing target routing management table 252.

Next, the management server 120 refers to the communication path registered in the communication path 336 of the record to be processed in the routing management table 252 and the measurement information management table 254, and then transmits the processing target relay device 110 to the destination terminal. Communication delay time up to 100 is calculated. Then, the management server 120 registers the calculated communication delay time in the delay time 328 after this relay device of the record added to the routing table 228 corresponding to the processing target relay device 110.

When the above-described processing is executed for all the relay devices 110 existing on the communication path registered in the communication path 336 of the record to be processed in the routing management table 252, all the relay devices existing on the communication path are executed. Information about a certain data type is registered in the routing table 228 of 110.

The management server 120 selects an unprocessed record in the routing management table 252 as a record to be processed, and executes the above-described process.

As described above, the routing tables 228 of all the relay devices 110 existing on the communication path are generated.

When the routing table 228 is generated in the process of step 448 and the generated routing table 228 is transmitted to each relay device 110, the management server 120 sends a mode transition request to the terminal 100 and the relay device 110 that exist in the relay system. (450), the terminal 100 and the relay apparatus 110 existing in the relay system are shifted to the normal mode, and the terminal 100 is shifted to the normal mode.

Note that the processing when the management server 120 operates in the normal mode will be described in detail with reference to FIG.

FIG. 13 is a flowchart of processing at the time of system startup by the terminal 100 and the relay device 110 according to the first embodiment of this invention.

The system activation process by the terminal 100 and the relay device 110 is executed by a CPU (not shown) included in the hardware module 200 of the terminal 100 and a CPU (not shown) included in the hardware module 220 of the relay device 110.

In the following description, processing at the time of system startup by the relay device 110 will be described as an example, but the same processing can also be applied to the terminal 100.

First, when the relay system is activated, the relay device 110 determines whether received data exists (400).

When it is determined in step 400 that received data exists, the relay apparatus 110 determines whether the received data is measurement request data (402).

If it is determined in the process of step 402 that the received data is measurement request data, the relay apparatus 110 transmits measurement response data to the terminal 100 or the relay apparatus 110 that is the transmission source of the measurement request data (404). Return to the process.

When it is determined in the process of step 402 that the received data is not measurement request data, the relay apparatus 110 determines whether the received data is measurement response data (406).

If it is determined in step 406 that the received data is measurement response data, the relay device 110 subtracts the time obtained by subtracting the transmission time of the measurement request data corresponding to the measurement response data from the reception time of the measurement response data. The communication delay time is calculated by dividing by (4), the measurement information storage table 210 is updated (408), and the process returns to step 400. Note that the transmission time of the measurement request data is included in the measurement response data data 1006 (see FIG. 4).

Specifically, the relay device 110 adds a new record to the measurement information storage table 210, registers the address of the terminal 100 or the relay device 110 that has transmitted the measurement response data to the address 300 of the added record, and adds it. The calculated communication delay time is registered in the communication delay time 302 of the record. If a record already exists, the communication delay time registered in the communication delay time 302 of the record is compared with the calculated communication delay time, and the larger one is registered. Further, the relay device 110 calculates the ratio of the number of received measurement response data to the number of transmitted measurement request data, and sets the calculated ratio as the communication success rate 304 of the added record in the measurement information storage table 210. sign up.

When it is determined in step 406 that the received data is not measurement response data, the relay apparatus 110 determines whether the received data is a measurement information storage table request (410).

When it is determined in the process of step 410 that the received data is a measurement information storage table request, the relay apparatus 110 transmits the measurement information storage table 210 to the management server 120 (412), and returns to the process of step 400.

If it is determined in step 410 that the received data is not a measurement information storage table request, the relay apparatus 110 determines whether the received data is the routing table 228 (414).

When it is determined in the process of step 414 that the received data is the routing table 22, the relay apparatus 110 stores the received routing table 228 in the storage device 226 (416), and returns to the process of step 400.

If it is determined in step 414 that the received data is not the routing table 228, the relay apparatus 110 determines whether the received data is a mode transition request (418).

If it is determined in the process of step 418 that the received data is a mode transition request, the relay apparatus 110 transitions to the normal mode (420). Details of processing when the terminal 100 and the relay apparatus 110 operate in the normal mode will be described in detail with reference to FIG.

When it is determined in the process of step 418 that the received data is not a mode transition request, the relay apparatus 110 executes a packet process corresponding to the received data, and returns to the process of step 400 (422).

If it is determined in step 400 that no received data exists, the relay apparatus 110 determines whether or not a predetermined time (Y seconds) has elapsed since the measurement request data was transmitted (430).

If it is determined in step 430 that the predetermined time (Y seconds) has elapsed since the transmission of the measurement request data, the relay apparatus 110 transmits the measurement request data to the terminal 100 and the relay apparatus 110 existing in the relay system. (432), and the process returns to step 400.

When it is determined that the predetermined time (Y seconds) has not elapsed since the transmission of the measurement request data in the process of step 430, the process returns to the process of step 400.

12 and 13, the terminal 100 and the relay device 110 measure the communication delay time between the other terminal 100 and the relay device 110 before shifting to the normal mode for actually transferring data. The routing table 228 is set in the relay device 110.

FIG. 14 is a flowchart of processing during normal mode operation by the management server 120 according to the first embodiment of this invention.

Processing in the normal mode operation by the management server 120 is executed by a CPU (not shown) included in the hardware module 240 of the management server 120.

The management server 120 sends a measurement information storage table request to the terminal 100 and the relay device 110 in order to update the routing table 228 of each relay device 110 generated by the process at system startup based on the latest communication delay time. Transmit (600). Since the transmission process of the measurement information storage table is the same as the process of step 442 shown in FIG. 12, detailed description thereof is omitted.

Next, when the management server 120 acquires the measurement information storage table 210 from the terminal 100 and the relay device 110, the management server 120 updates the measurement information management table 254 based on the acquired measurement information storage table 210 (602).

Specifically, the management server 120 registers the address of the terminal 100 or the relay device 110 of the transmission source of the measurement information storage table 210 acquired in the measurement data transfer source address 340 of the measurement information management table 254, and the measurement data When there is a record in which the address registered in the measurement information storage table address 300 acquired in the transfer destination address 342 is registered, the record is registered in the communication delay time 302 of the measurement information storage table 210 acquired in the communication delay time 344 of the record. Registered communication delay time. Further, when the measurement information management table 254 does not have the above-described record, the management server 120 adds a record to the measurement information management table 254, and acquires the acquired measurement information storage table 210 in the measurement data transfer source address 340 of the added record. The address of the terminal 100 or the relay device 110 that is the source of the transmission is registered, the address registered in the address 300 of the acquired measurement information storage table 210 is registered in the measurement data transfer destination address 342 of the added record, and the added record The communication delay time registered in the communication delay time 302 of the acquired measurement information storage table 210 is registered in the communication delay time 344.

Next, the management server 120 can reach the transmission destination terminal 100 from the transmission source terminal 100 with reference to the measurement information management table 254 and the preset data management table 256 updated in the process of Step 602. Among the communication paths, a communication path satisfying the required communication delay time is specified for each data type, and the routing management table 252 is updated (604).

Specifically, when the communication path specified this time has a data type different from the communication path registered in the routing management table 252, the management server 120 sets the communication path 336 of the routing management table 252 corresponding to the data type. The routing management table 252 is updated by updating the communication path specified this time.

Next, the management server 120 determines whether or not there is a relay device 110 that needs to be changed in the routing table 228 (606).

Specifically, when the communication path 336 of the routing management table 252 has been updated in the process of step 604, the management server 120 determines that the relay device 110 existing on the communication path registered in the communication path 336 It is determined that the routing table 228 needs to be changed.

If it is determined in step 606 that there is a relay device 110 that needs to be changed in the routing table 228, the management server 120 generates the routing table 228 of the relay device 110, and the generated routing table 228 is The data is transmitted to the relay apparatus 110 (608), and the process returns to step 600.

The generation process of the routing table 228 of the process of step 608 is performed by the routing of the relay apparatus 110 existing on the communication path registered in the communication path 336 of the record whose communication path 336 has been updated by the process of step 604 of the routing management table 252. Except for generating the table 228, the process is the same as the process of generating the routing table 228 in the process of step 448, and a specific description thereof will be omitted.

Also, in the process of step 608, the management server 120 records the routing table 228 of the relay apparatus 110 that no longer exists on the communication path due to the update of the communication path 336 of the routing management table 252 in the process of step 604. Is deleted. Specifically, the management server 120 acquires the identifier registered in the data type ID 330 of the record updated in the process of step 604 of the routing management table 252, and the communication path 336 in the process of step 604 of the routing management table 252. An instruction to delete a record that matches the identifier acquired by the data type ID 320 among the records in the routing table 228 is transmitted to the relay apparatus 110 existing on the communication path registered in the communication path 336 before the update.

On the other hand, if it is determined in step 606 that there is no relay device 110 that needs to be changed in the routing table 228, the management server 120 returns to the process in step 600.

In the flowchart of the processing in the normal mode operation shown in FIG. 14, when it is determined in step 606 that there is no relay device 110 that needs to be changed in the routing table 228, and after the execution of step 608. Returning to the process of step 600, the management server 120 transmits a measurement information storage table request to the terminal 100 and the relay device 110. However, if the measurement information storage table request is frequently transmitted, the measurement information storage table 210 is frequently transmitted to the management server 120, which may cause a load on the network. Therefore, if it is determined in step 606 that there is no relay device 110 that needs to be changed in the routing table 228, and after the processing in step 608 is executed, the management server 120 waits for processing for a predetermined time. Accordingly, it is desirable to transmit the measurement information storage table request at a predetermined cycle.

FIG. 15 is a flowchart of processing during normal mode operation by the terminal 100 and the relay device 110 according to the first embodiment of this invention.

Processing in the normal mode operation by the terminal 100 and the relay device 110 is executed by a CPU (not shown) included in the hardware module 200 of the terminal 100 and a CPU (not shown) included in the hardware module 220 of the relay device 110.

In the following description, processing in the normal mode operation by the relay device 110 will be described as an example, but the same processing can be applied to the terminal 100.

Since the processes other than

steps

612 and 614 in the normal mode operation shown in FIG. 15 are the same as the processes at the time of starting the system shown in FIG.

When it is determined in step 610 that received data exists, the relay apparatus 110 determines whether the received data is transfer data (612). The transfer data is data transmitted from the terminal 100 that is the transmission source, and is data that should be transferred to any one of the terminals 100 or the relay device 110 when the relay device 110 receives the data.

If it is determined in step 612 that the received data is transfer data, the relay apparatus 110 executes data transfer processing for transferring the transfer data (614), and returns to step 610. Details of the data transfer process will be described with reference to FIGS. 16 and 17.

On the other hand, if it is determined in step 612 that the received data is not transfer data, the relay device 110 executes the process in step 616.

16 and 17 are flowcharts of the data transfer process according to the first embodiment of the present invention.

First, when the relay device 110 determines that the received data is transfer data (hereinafter referred to as transfer data to be processed) in the process of step 612 shown in FIG. 15, among the records registered in the routing table 228, A record corresponding to the data type of the transfer data to be processed is referenced (700).

Next, the relay device 110 subtracts the transmission time included in the transfer data from the time when the transfer data to be processed is received, so that the transmission source communication taken until the transfer data to be processed reaches the relay device. Calculate the delay time. Then, the relay device 110 communicates the communication delay time registered in the requirement communication delay time 326 of the record in the routing table 228 referred to in the processing of Step 700, and the communication delay registered in the delay time 328 of the record after the relay device. Based on the time (expected delay time) and the calculated source communication delay time, a processable time until the transfer data is transferred by the relay device 110 is calculated (702).

For example, when the data type of the transfer data to be processed is “0x0001”, referring to the routing table 228 shown in FIG. 8, the required communication delay time is 50 ms and the expected delay time is 30 ms. Further, if the transmission source communication delay time of the transfer data is 10 ms, the processable time of the transfer data is 10 ms.

Here, in general, the relay apparatus 110 has a transfer queue including at least one stage (element) which is a storage area for storing data. For the data stored in the stage of the transfer queue, processing corresponding to the data is executed in a predetermined order. If the data stored in the stage of the transfer queue is transfer data, the transfer data is transferred. In this embodiment, the processing is executed in the order in which data is stored in the stages of the transfer queue. However, the processing order of the stages is not limited to this, and the transfer queue may be described as a transfer buffer. In the following description, transfer control using a transfer queue will be described as an example.

The relay device 110 sets the first stage of the transfer queue as the search stage when the processable time is calculated in the process of step 702 (704). That is, in the process of step 704, the stage processed first among the stages included in the transfer queue is set as the search stage. Next, the relay apparatus 110 determines whether or not the processable time is 0 or more in order to determine whether or not the transfer data to be processed can be transferred within the processable time (706).

If it is determined in step 706 that the processable time is less than 0, the transfer data to be processed cannot be transferred to the destination terminal 100 within the required communication delay time. Is discarded (708), and the process is terminated. Note that when the transfer data to be processed is discarded, the relay device 110 notifies at least one of the transmission source terminal 100 and the management server 120, and the transmission source terminal notified that the transfer data has been discarded. 100 or the like may display the fact on a display unit or the like included in the hardware module 200 and notify the user to that effect.

On the other hand, if it is determined in the process of step 706 that the processable time is 0 or more, the relay apparatus 110 determines whether other transfer data is stored in the current search stage (710).

If it is determined in step 710 that no other transfer data is stored in the current search stage, the relay apparatus 110 sets the transfer data to be processed in the current search stage (712), and ends the process. To do.

On the other hand, if it is determined in the process of step 710 that other transfer data is stored in the current search stage, the relay device 110 is stored in the current search stage and the processable time of the transfer data to be processed. The transferable data processing time is compared (714). Then, the relay apparatus 110 determines whether the processable time of the transfer data to be processed is longer than the processable time of the transfer data stored in the current search stage (716).

When it is determined in step 716 that the processable time of the transfer data to be processed is longer than the processable time of the transfer data stored in the current search stage, the relay apparatus 110 adds 1 to the current search stage. The transfer queue of the added stage is set as a new search stage (718). In other words, the relay device 110 sets the next search stage in the processing order of the current search stage among the stages included in the transfer queue as a new search stage. Then, the relay apparatus 110 calculates a new processable time by calculating Expression 1 (720), and returns to the process of Step 706. That is, in the process of step 720, the management server 120 calculates a new processable time by subtracting the time required until the data stored in the new search stage is processed from the current processable time. To do.

New processing time = processing time-(number of search stages-1) x processing time for 1-stage transfer queue (Equation 1)

On the other hand, if it is determined in step 716 that the processable time of the transfer data to be processed is not longer than the processable time of the transfer data stored in the current search stage, the relay apparatus 110 returns to FIG. Then, it is determined whether or not the processable time of the transfer data to be processed is shorter than the processable time of the transfer data stored in the current search stage (722).

If it is determined in step 722 that the processable time of the transfer data to be processed is shorter than the processable time of the transfer data stored in the current search stage, the relay device 110 determines that each stage after the search stage It is determined whether the data stored in can be moved to a stage obtained by adding 1 to the number of stages (724).

For example, when the transfer data stored in the nth stage moves to the (n + 1) th stage, and the processable time of the transfer data moved to the (n + 1) th stage becomes longer than the required communication delay time, the process in step 724 It is determined that the data cannot be moved.

If it is determined in step 724 that the data stored in each stage after the search stage can be moved to the stage obtained by adding 1 to the number of stages, the relay apparatus 110 adds 1 to the number of stages. The transfer data to be processed is set in the current search stage (728), and the process ends. As a result, the transfer data to be processed is transferred with priority over the data stored in the stages after the search stage.

On the other hand, if it is determined in step 724 that the data stored in each stage after the search stage cannot be moved to the stage obtained by adding 1 to the number of stages, the relay apparatus 110 performs processing when the relay apparatus 110 moves to the stage added by 1. Data whose possible time is longer than the required communication delay time, that is, data that cannot be moved to the stage added by 1, is discarded (730).

Then, the relay apparatus 110 moves to the stage obtained by adding 1 to the number of stages stored in each stage after the retrieval stage (732), sets the transfer data to be processed in the current retrieval stage (734), and performs processing. Exit.

If it is determined in step 722 that the processable time of the transfer data to be processed is not shorter than the processable time of the transfer data stored in the current search stage, that is, the processable transfer data can be processed. When the time and the processable time of the transfer data stored in the current search stage are the same, the relay apparatus 110 determines the priority of the transfer data to be processed and the transfer data stored in the current search stage. The priority is compared (736). The relay device 110 obtains the priority registered in the priority 322 of the record registered in the routing table 228 whose identifier registered in the data type ID 320 matches the identifier of the data type of the transfer data. By doing so, the priority of the transfer data can be known.

Next, the relay device 110 refers to the priority comparison result of the two transfer data in the process of Step 736, and the priority of the transfer data stored in the current search stage is the priority of the transfer data to be processed. It is determined whether it is higher than the degree (738).

If it is determined in step 738 that the priority of the transfer data to be processed is higher than the priority of the transfer data stored in the current search stage, the relay apparatus 110 sets the transfer data to be processed as the current transfer data. The transfer data stored in the current search stage is discarded in order to transfer the data prior to the transfer data stored in the search stage (740). Then, the relay apparatus 110 sets transfer data to be processed in the current search stage (742), and ends the process.

On the other hand, if it is determined in step 738 that the priority of the transfer data to be processed is equal to or lower than the priority of the transfer data stored in the current search stage, the relay device 110 is stored in the current search stage. The transfer data to be processed is discarded (744) and the processing is terminated in order to transfer the transfer data having priority over the transfer data to be processed.

In the process of step 730, the relay apparatus 110 discards the data that cannot be moved. However, as in the processes of steps 736 to 744, the priority of the transfer data to be processed is higher than the priority of the data that cannot be moved. In this case, the data that cannot be moved may be discarded, and the transfer data to be processed may be discarded if the priority of the transfer data to be processed is equal to or lower than the priority of the data that cannot be moved.

Further, in the processing of steps 736 to 744, the relay apparatus 110 discards the data with the lower priority without moving the transfer data stored in the stages after the search stage to the stage obtained by adding 1 to the number of stages. However, the processing of steps 724 to 734 may be executed instead of the processing of steps 740 to 744. As a result, when the priority of the transfer data to be processed is higher than the priority of the data stored in the search stage, the relay apparatus 110 moves to the stage obtained by adding 1 to the number of stages stored in the search stage. The transfer data to be processed can be stored in the search stage.

As described above, in the data transfer process, the relay apparatus 110 subtracts the expected communication delay time and the source communication delay time from the requirement communication delay time corresponding to the data type of the received transfer data in the process of Step 702. The processing time is calculated. When it is determined in step 706 that the processable time is less than 0, the relay device 110 determines that the data received within the processable time cannot be transferred to the transfer destination, and the relay apparatus 110 receives the process in step 708. Discard the data. If it is determined in step 706 that the processable time is 0 or more, the relay apparatus 110 proceeds to the process in step 714 to transfer the data received within the processable time to the transfer destination. Note that the relay device 110 may determine whether or not the received data can be transferred within the processable time by determining whether or not the processable time is equal to or greater than a predetermined value in the process of step 706. Good.

As a result, when it is determined that the received data cannot be transferred within the processable time, the relay device 110 transfers the data whose required communication delay time cannot be guaranteed, and receives the data so as not to put a load on the network. It is possible to discard the data and guarantee the required communication delay time of the data already stored in the transfer queue.

If the relay device 110 determines that the received data can be transferred within the processable time, the processable time of the received data is stored in the current search stage set in the process of step 704. If it is longer than the processable time, the process in step 718 sets the next search stage in the transfer order of the current search stage as a new search stage, and the process in step 720 newly starts from the current processable time. A time obtained by subtracting the processing time until reaching the set search stage is calculated as a new processable time, and the process returns to step 706 to determine whether or not the received data can be transferred within the new processable time. To do.

On the other hand, when the processable time of the received data is shorter than the processable time stored in the current search stage set in the process of step 704, the relay apparatus 110 performs the process of step 724 in the current search stage. If it is determined that the data stored in the stage where the data to be transferred thereafter is stored can be moved to the next stage, the data is moved to the next stage in step 726. At the same time, the received data is stored in the current search stage in the process of step 728. As a result, the relay apparatus 110 can guarantee the requirement communication delay time of the received data while guaranteeing the requirement communication delay time for the data already stored in the transfer queue.

Next, a modification of the first embodiment will be described with reference to FIGS.

In the first embodiment, since the terminal 100 and the relay device 110 measure the communication delay time using the measurement request data and the measurement response data without synchronizing the time with the other terminals 100 or the relay device 110, the communication is performed. It is difficult to accurately measure the delay time. Therefore, in the present modification, the terminal 100 and the relay device 110 are equipped with time synchronization modules (for example, GPS modules) as the

hardware modules

200 and 220, and the terminal 100 and the relay device 110 included in the relay system are installed. After the time synchronization, the measurement request data is transmitted to the other terminal 100 and the relay device 110.

FIG. 18 is a flowchart of processing at the time of system startup by the terminal 100 and the relay device 110 according to a modification of the first embodiment of the present invention. In addition, the process same as the process shown in FIG. 13 among the processes shown in FIG. 18 is provided with the same code | symbol, and description is abbreviate | omitted.

When the relay system is activated, the terminal 100 and the relay device 110 synchronize the time with the other terminal 100 and the relay device 110 using the time synchronization module (500), and proceed to the process of step 400. The processing after step 400 is the same as the processing shown in FIG.

Thereby, since the time of the terminal 100 and the relay device 110 existing in the relay system is synchronized, an accurate communication delay time can be measured.

Here, in the relay system described above, data communication between the terminals 100 and communication for updating the routing table 228 are mixed, so that the communication for updating the routing table 228 affects the data communication between the terminals 100. May give.

A data communication method of the terminal 100 and the relay apparatus 110 for preventing the data communication between the terminals 100 and the communication for updating the routing table 228 from being mixed will be described with reference to FIG.

FIG. 19 is an explanatory diagram of a data communication method according to a modification of the first embodiment.

The terminal 100 and the relay apparatus 110 whose times are synchronized divide the communication cycle of data communication into a periodic frame 1100 that is a constant cycle. The periodic frame 1100 is further divided into a data transfer period 1110 for data communication between the terminals 100 and a measurement period 1112 for communication for updating the routing table 228.

Thereby, it is possible to prevent data communication between the terminals 100 and communication for updating the routing table 228 from being mixed.

Hereinafter, the relay system according to the second embodiment will be described with reference to FIGS. 20 and 21. FIG.

The relay system according to the second embodiment does not include the management server 120, and each relay apparatus 110 collects communication delay times and generates a routing table 228.

FIG. 20 is an explanatory diagram of the configuration of the relay system according to the second embodiment of the present invention. Of the configuration of the relay system shown in FIG. 20, the same configuration as the configuration of the relay system shown in FIG.

As described above, the relay system according to the present embodiment is different from the relay system according to the first embodiment in that the management server 120 is not provided, and the remaining configuration is the same as that of the relay system according to the first embodiment.

FIG. 21 is a flowchart of processing at the time of system startup by the terminal 100 and the relay device 110 according to the second embodiment of the present invention.

In the first embodiment, the management server 120 manages the timing of collecting the measurement information storage table 210 of each terminal 100 and the relay device 110 and the timing of switching each terminal 100 and the relay device 110 to the normal mode. However, in this embodiment, since the relay system does not include the management server 120, these timings are managed based on the timing when each terminal 100 and the relay device 110 are activated. In addition, the time of each terminal 100 and the relay apparatus 110 may be synchronized and does not need to be synchronized.

In order to generate the routing table 228, it is necessary to specify a communication path from the transmission source terminal 100 to the transmission destination terminal 100. In the configuration of the terminal 100 and the relay device 110 according to the first embodiment, the terminal 100 It is difficult for the relay apparatus 110 to specify the communication path. For this reason, the terminal 100 and the relay apparatus 110 hold the data management table 256, the measurement information management table 254, and the routing management table 252. It is assumed that the data management table 256 is set in each terminal 100 and the relay device 110.

First, the terminal 100 and the relay device 110 determine whether or not a predetermined time (A seconds) has elapsed since starting up (900).

If it is determined in step 900 that the predetermined time (A seconds) has not elapsed since the terminal 100 and the relay device 110 are activated, the terminal 100 and the relay device 110 transmit and receive measurement request data and measurement response data. Thus, the communication delay time is measured (902). Then, the terminal 100 and the relay device 110 update the measurement information management table 254 based on the communication delay time in the process of step 902 (904), and return to the process of step 900. Note that the specific process of step 904 is the same as the process of step 444 shown in FIG.

On the other hand, if it is determined in step 900 that a predetermined time (A seconds) has elapsed since the terminal 100 and the relay device 110 are activated, the terminal 100 and the relay device 110 are activated for a predetermined time ( It is determined whether or not (B seconds) has elapsed (906). Note that the predetermined time (B seconds) in the process of step 906 is set to be longer than the predetermined time (A seconds) in the process of step 900.

If it is determined in step 906 that the predetermined time (B seconds) has not elapsed since the terminal 100 and the relay device 110 are activated, the own measurement information storage table 210 is transferred to the other terminals 100 and the relay device 110. The measurement information storage table 210 transmitted by the other terminal 100 and the relay device 110 is received (908).

Then, the terminal 100 and the relay device 110 update the measurement information management table 254 based on the measurement information storage table 210 updated in the process of step 904 and the measurement information storage table 210 received in the process of step 908, The routing management table 252 is updated based on the updated measurement information management table 254, the routing table 228 is updated based on the routing management table 252 (910), and the process returns to step 906. Note that the specific processing of step 910 is the same as the processing of steps 444 to 448 shown in FIG. 12 of the first embodiment.

On the other hand, if it is determined in the processing of step 906 that a predetermined time (B seconds) has elapsed since the terminal 100 and the relay apparatus 110 are activated, the terminal 100 shifts itself to the normal mode.

Since the processing in the normal mode by the terminal 100 and the relay device 110 is the same as the processing shown in FIGS. 15 to 17, description thereof will be omitted.

In the present embodiment, the relay device 110 updates its own routing table 228, and in the first embodiment, the management server 120 updates the routing table 228 of each relay device 110, so that the processing load of the relay device 110 of this embodiment is increased. Is higher than Example 1. However, in the present embodiment, each relay apparatus 110 updates the routing table 228, so that it is not necessary for the management server 120 to distribute the routing table 228 to each relay apparatus 110 as in the first embodiment. For this reason, the network load of a present Example is reduced from Example 1. FIG.

Hereinafter, the relay system according to the third embodiment will be described with reference to FIGS.

In this embodiment, the processable time is calculated in consideration of the processing time required for each relay apparatus 110 to execute a predetermined process on the transfer data. In addition, although the description of the present embodiment describes differences from the first embodiment, it can also be applied to the second embodiment.

FIG. 22 is an explanatory diagram of a configuration of the relay device 110 according to the third embodiment of this invention. Among the configurations of the relay device 110 illustrated in FIG. 22, the same configurations as those of the relay device 110 illustrated in FIG. 3 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The relay device 110 according to the present embodiment includes a data processing application 1202 in addition to the configuration of the relay device 110 according to the first embodiment. In addition to the measurement information storage table 210 and the routing table 228, the storage device 226 includes data A processing time table 1204 is stored.

The data processing application 1202 is an application that executes predetermined processing (encryption processing, encapsulation processing, etc.) corresponding to the data type of the received transfer data on the received transfer data.

The data processing time table 1204 is a table for managing the processing time required for the relay device 110 to execute processing on the transfer data for each data type. Details of the data processing time table 1204 will be described with reference to FIG.

In this embodiment, since the management server 120 manages the processing time of each relay apparatus 110, the configuration of the data management table 256 is also different from the configuration of the data management table 256 of the first embodiment. Details of the data management table 256 of this embodiment will be described with reference to FIG.

FIG. 23 is an explanatory diagram of the data processing time table 1204 according to the third embodiment of this invention.

The data processing time table 1204 includes a data type ID 1205 and a data processing time 1206.

In the data type ID 1205, an identifier for uniquely identifying the data type is registered. In the data processing time 1206, the processing time for the transfer data is registered.

FIG. 24 is an explanatory diagram of the data management table 256 according to the third embodiment of this invention.

The data management table 256 includes a processing time 1208 of each relay device in addition to a data type ID 350, a data type 352, a priority 354, a transmission source address 356, a transmission destination address 358, and a requirement communication delay time 360.

In the processing time 1208 of each relay device, the processing time of the processing executed by each relay device 110 on the transfer data is registered based on the data processing time table 1204 collected from each relay device 110.

FIG. 25 is a flowchart of processing at the time of system startup by the management server 120 according to the third embodiment of the present invention. 25, the same processes as those shown in FIG. 12 of the first embodiment are assigned the same reference numerals, and descriptions thereof are omitted.

The management server 120 transmits a data processing time table request to each relay device 110 after generating the measurement information management table in the process of step 444 (1306).

In addition, the transmission method of the data processing time table request may be transmitted by broadcast communication with a response. Further, when the address information of the relay device 110 existing in the relay system is set in the management server 120 before the relay system is activated, the data processing time table request is transmitted by unicast communication using the address information. May be.

When the management server 120 acquires the data processing time table 1204 from all the relay apparatuses 110 existing in the relay system, the management server 120 updates the data management table 256 based on the acquired data processing time table 1204 (1308). Proceed to processing.

Specifically, the management server 120 matches the identifier registered in the data type ID 1205 of the acquired data processing time table 1204 among the records registered in the data management table 256. Select a record. Then, the management server 120 acquires the data management table acquired at the processing time 1208 of the relay device corresponding to the transmission source relay device 110 of the acquired data processing time table 1204 out of the processing time 1208 of the relay device of the selected record. The processing time registered in 256 data processing time 1206 is registered. As a result, the data management table 256 is updated.

Next, in the process of step 448, the management server 120 will be described with respect to the process of generating the routing table 228.

In the first embodiment, the management server 120 refers to the measurement information management table 254 to calculate a communication delay time from the relay apparatus 110 that holds the generated routing table 228 to the destination terminal 100, and calculates the calculated communication delay. The time is registered in the delay time 328 after the present relay device in the routing table 228. In this embodiment, the management server 120 refers to not only the communication delay time but also the data management table 256 and exists in the communication path from the relay apparatus 110 that holds the generated routing table 228 to the destination terminal 100. The total value of the data processing time of the relay device 110 is calculated. Then, a value obtained by adding the communication delay time from the relay apparatus 110 holding the generated routing table 228 to the destination terminal 100 and the total value of the data processing time is used as the delay time 328 after the present relay apparatus in the routing table 228. sign up.

When the processing time of each relay device 110 is registered in advance in the data management table 256, the management server 120 does not need to transmit a data processing time table request.

FIG. 26 is a flowchart of processing at the time of system startup by the relay apparatus 110 according to the third embodiment of the present invention. In addition, the process same as the process shown in FIG. 13 of Example 1 among the processes shown in FIG. 26 is provided with the same code | symbol, and description is abbreviate | omitted.

When it is determined in the process of step 410 that the received data is not a measurement information storage table request, the relay apparatus 110 determines whether the received data is a data processing time table request (1302).

If it is determined in step 1302 that the received data is not a data processing time table request, the process proceeds to step 414.

On the other hand, if it is determined in step 1302 that the received data is a data processing time table request, the relay apparatus 110 transmits the data processing time table 1204 to the management server 120 (1304), and the processing in step 400 is performed. Return.

Next, a case where the third embodiment is applied to the second embodiment will be described as a modification of the third embodiment with reference to FIG.

FIG. 27 is a flowchart of processing at the time of system startup by the terminal 100 and the relay device 110 according to a modification of the third embodiment of the present invention.

The terminal 100 and the relay device 110 according to the present modification include a routing management table 252, a measurement information management table 254, and a data management table 256 in addition to the configuration illustrated in FIG. The routing management table 252 and the measurement information management table 254 are the same as those in FIGS. 9 and 10 of the first embodiment, and the data management table 256 is the same as that in FIG. 24 of the third embodiment.

In step 908, the terminal 100 and the relay device 110 transmit / receive the measurement information storage table 210, update the measurement information management table 254, and update the routing management table 252 based on the updated measurement information management table 254. Thereafter, the own data processing time table 1204 is transmitted to the other terminal 100 and the relay device 110, the data processing time table 1204 is received from the other terminal 100 and the relay device 110, and the data management table 256 is updated (1400). . The update process of the data management table 256 is the same as the process of step 13308 in the third embodiment, and thus the description thereof is omitted.

Next, the terminal 100 and the relay device 110 proceed to the process of step 910, update the routing table 228 based on the updated routing management table 252 and the updated data management table 256 (910), Return to processing. Note that the update process of the routing table 228 is the same as the process of step 448 shown in FIG.

As described above, the value registered in the delay time 328 after the present relay device in the routing table 228 includes the communication delay time from the relay device 110 that holds the routing table 228 to the destination terminal 100, and the routing table 228. The total value of the data processing time of the relay apparatus 110 existing in the communication path from the relay apparatus 110 to be held to the destination terminal 100 is registered. For this reason, data transfer satisfying the required communication delay time can be performed in consideration of the data processing time in the relay apparatus 110.

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

In addition, each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a recording device such as a memory, a hard disk, and an SSD (Solid State Drive), or a recording medium such as a CI card, an SD card, and a DVD.

Claims

A relay device that relays data from a source terminal to a destination terminal,
Transfer destination of data transmitted by the source terminal, requirement communication delay time to be ensured until the data transmitted by the source terminal is received by the destination terminal, and data transmitted by the relay device Holds an expected communication delay time that is expected to be required before it is received by the destination terminal,
The data transmitted by the transmission source terminal includes time information indicating the time of transmission,
When the data transmitted by the transmission source terminal is received, it is necessary from the time when the data is transmitted by the transmission source terminal until it is received by the relay device based on the time information included in the received data. Calculate the source communication delay time,
Based on the requirement communication delay time, the expected communication delay time, and the calculated source communication delay time, the data is received by the destination terminal within the requirement communication delay time. A relay apparatus characterized by transferring
The relay device according to claim 1,
By subtracting the expected communication delay time and the calculated source communication delay time from the requirement communication delay time, a processable time that is a time from when the relay device receives the data to when it is transferred is calculated. And
Determining whether the received data can be transferred within the calculated processable time;
If it is determined that the received data cannot be transferred within the calculated processable time, the received data is discarded,
The relay apparatus, wherein when it is determined that the received data can be transferred within the calculated processable time, the received data is transferred within the calculated processing time.
The relay device according to claim 2,
A transfer buffer including an element which is a storage area for storing the received data;
The data stored in the transfer buffer elements is transferred in a predetermined transfer order;
The element storing the data to be transferred first among the elements of the transfer buffer is set as a search element,
If it is determined that the received data can be transferred within the calculated processing time, the processing time of the data stored in the search element is compared with the processing time of the received data,
When the processable time of the received data is shorter than the processable time of the data stored in the search element, the data transferred after the data stored in the search element is stored in the stored element Determining whether the data can be moved to the next element in the transfer order;
When it is determined that the data stored in the element storing the data transferred after the data stored in the search element can be moved to the next element in the transfer order, the data is transferred in the transfer order. Transfer the received data within the processable time by moving to the next element and storing the received data in the search element,
When the processable time of the received data is longer than the processable time of the data stored in the search element, the transfer element of the search element is set to the next search element as a new search element, Calculate the new processing time by subtracting the processing time from the current processing time to the newly set search element,
A relay apparatus that executes again the process of determining whether or not the received data can be transferred within the calculated new processable time.
The relay device according to claim 1,
Measure the communication delay time between itself and other relay devices,
Hold the measured communication delay time,
Obtaining a communication delay time measured by the other relay device;
Based on the measured communication delay time and the acquired communication delay time, to calculate the expected communication delay time,
A relay apparatus that holds the calculated expected communication delay time.
The relay device according to claim 4,
Execute processing corresponding to the received data;
Holds the data processing time required to execute the process,
Obtaining a communication delay time measured by the other relay device and a data processing time held by the other relay device;
The relay apparatus, wherein the expected communication delay time is calculated based on the measured communication delay time, the acquired communication delay time, the measured data processing time, and the acquired data processing time.
The relay device according to claim 1,
The relay device is connected to a management computer that manages the relay device,
Measure the communication delay time between itself and other relay devices,
Send the measured communication delay time to the management computer,
The management computer calculates the expected communication delay time based on the communication delay time, and transmits the calculated expected communication delay time to the relay device.
A relay apparatus that holds an expected communication delay time transmitted by the management computer.
The relay device according to claim 6,
Execute processing corresponding to the received data;
Sending the data processing time required for the execution of the processing to the management computer;
The relay apparatus according to claim 1, wherein the management computer calculates the expected communication delay time based on the communication delay time and the data processing time.
The relay device according to claim 1,
A relay device that synchronizes time information with another relay device.
A relay method for relaying data received by a relay device,
The relay device includes a transfer destination of data transmitted by the transmission source terminal, a requirement communication delay time to be ensured until the data transmitted by the transmission source terminal is received by the transmission destination terminal, and transmission by the relay device. An expected communication delay time that is expected to be necessary before the received data is received by the destination terminal,
The data transmitted by the transmission source terminal includes time information indicating the time of transmission,
The method
When the relay device receives data transmitted by the transmission source terminal, the data is received by the relay device after being transmitted by the transmission source terminal based on time information included in the received data. Calculate the source communication delay time required until
Based on the requirement communication delay time, the expected communication delay time, and the calculated source communication delay time, the relay apparatus receives the received data within the requirement communication delay time by the destination terminal. Thus, the relay method characterized by transferring the data.
The relay method according to claim 9,
It is a time from when the relay device receives the data to transfer it by subtracting the expected communication delay time and the calculated source communication delay time from the requirement communication delay time. Calculate the processing time,
Determining whether the relay device can transfer the received data within the calculated processable time;
If it is determined that the relay device cannot transfer the received data within the calculated processable time, the received data is discarded,
When it is determined that the relay device can transfer the received data within the calculated processable time, the relay method transfers the received data within the calculated processing time.
The relay method according to claim 10, wherein
The relay device is
A transfer buffer including an element which is a storage area for storing the received data;
The data stored in the transfer buffer elements is transferred in a predetermined transfer order;
The method
The relay device sets, as a search element, an element in which data to be transferred first among elements of the transfer buffer is stored,
When it is determined that the relay device can transfer the received data within the calculated processing time, the processing time of the data stored in the search element and the processing time of the received data are determined. Compare and
In the case where the processing time of the received data is shorter than the processing time of the data stored in the search element, the relay device stores data to be transferred after the data stored in the search element. Determining whether the data stored in the element can be moved to the next element in the transfer order;
When it is determined that the relay apparatus can move the data stored in the element storing the data transferred after the data stored in the search element to the element whose transfer order is one after, Transfer the received data within the processable time by storing the received data in the search element and moving the transfer order to the next element
When the relay device has a processable time of the received data longer than a processable time of the data stored in the search element, the element whose transfer order of the search element is the next is changed to a new search element. And the time obtained by subtracting the processing time from the current processing time to the newly set search element is calculated as the new processing time,
The relay method, wherein the relay apparatus executes again the process of determining whether or not the received data can be transferred within the calculated new processable time.
The relay method according to claim 9,
The relay device measures a communication delay time between itself and another relay device,
The relay device holds the measured communication delay time,
The relay device acquires a communication delay time measured by the other relay device,
The relay device calculates the expected communication delay time based on the measured communication delay time and the acquired communication delay time,
The relay method, wherein the relay device holds the calculated expected communication delay time.
The relay method according to claim 12, comprising:
The relay device executes processing corresponding to the received data;
The previous relay device holds the data processing time required to execute the processing,
The relay device acquires a communication delay time measured by the other relay device, and a data processing time held by the other relay device,
The relay device calculates the expected communication delay time based on the measured communication delay time, the acquired communication delay time, the measured data processing time, and the acquired data processing time. Relay method.
The relay method according to claim 9,
The relay device is connected to a management computer that manages the relay device,
The relay device measures a communication delay time between itself and another relay device,
The relay device transmits the measured communication delay time to the management computer,
The management computer calculates the expected communication delay time based on the communication delay time, and transmits the calculated expected communication delay time to the relay device;
The relay method, wherein the relay device holds an expected communication delay time transmitted by the management computer.
The relay method according to claim 9,
A relay method, wherein the relay device synchronizes time information with other relay devices.