JP2012216023A - Communication device, communication program, and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance processing performance by reducing processing loads on a server.SOLUTION: A communication device comprises a transmission/reception unit, a storage unit, an extraction unit, an instruction unit, and a creation unit. The transmission/reception unit transmits a request message to a server via a network, and receives a response message from the server. The storage unit stores identification information including identifiers assigned to a plurality of communication devices, and an identifier of its own communication device. The extraction unit extracts notification information and a command from the received response message. The instruction unit instructs the command according to the extracted notification information. The creation unit creates a request message including the identification information according to the notification information.

Description

  The present invention relates to a communication program and a communication system for a communication device that transmits and receives messages to and from a server via a network.

  In recent years, many terminals (for example, PCs, mobile phones, home appliances, etc.) are connected to the Internet, and services are realized by communicating with servers on the Internet. In the future, new devices such as smart meters in smart grids will also be connected to the Internet, and new services are expected to be realized by communicating with servers on the Internet. Since a server communicates with a large number of terminals, its processing load generally tends to increase, and various proposals have been made for reducing the load on the server.

JP 2000-20385 A

  Previous proposals to improve server processing performance have used data caches. This is based on an empirical rule that the processing load can be reduced by leaving the processed result in the data cache and reusing it. However, the processing performance of the method using the data cache depends on the inquiry pattern from the terminal to the server. For example, if the inquiry from the terminal to the server relates to data that does not exist in the cache, the server processing performance does not improve, and generally the server processing performance decreases by the amount of processing related to the data cache. .

  The communication apparatus according to the embodiment includes a transmission / reception unit, a storage unit, an extraction unit, an instruction unit, and a creation unit. The transmission / reception unit transmits a request message to the server via the network and receives a response message from the server. The storage unit stores identifiers assigned to the plurality of communication devices and identification information including the identifiers of the communication devices. The extraction unit extracts notification information and a command from the received response message. The instructing unit instructs a command according to the extracted notification information. The creation unit creates a request message including identification information according to the notification information.

The figure which shows the system of one Embodiment. The block diagram of a communication apparatus. The block diagram of a server. The flowchart which shows the flow of a process of a communication apparatus. The sequence diagram of a communication apparatus and a server. The block diagram of a communication apparatus. The flowchart which shows the flow of a process of a communication apparatus. The sequence diagram of a communication apparatus and a server. The figure which shows the system of one Embodiment. The flowchart which shows the flow of a process of a communication apparatus. The sequence diagram of a communication apparatus and a server. The flowchart which shows the flow of a process of a communication apparatus. The sequence diagram of a communication apparatus and a server.

Embodiments will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a system according to the first embodiment. A plurality of communication devices 100 are connected to the server 200 via the network 300, and the server 200 is connected to the database 400. When the communication apparatus 100 transmits a request message to the server 200 using, for example, HTTP, the server 200 uses the database 400 as a part of the process and transmits a response message to the communication apparatus. When the server 200 searches the database 400, the data cache previously configured in the server is searched. If there is data to be searched for in the data cache, the data in the data cache is used, and the data cache If there is no data, the data is retrieved from the database 400 and a response message is transmitted to the communication apparatus 100 using the data.

  FIG. 2 is a configuration diagram of the communication apparatus 100 according to the first embodiment. The communication device 100 includes a transmission / reception unit 101, a storage unit 102, an instruction unit 103, an extraction unit 104, and a request creation unit 105.

  The transmission / reception unit 101 transmits a request message to a server connected via a network, and receives a response message in response to the request message from the server. The storage unit 102 stores an identifier assigned to one of the plurality of communication devices 100 and identification information indicated by the identifier assigned to the communication device 100. The request message is a message including identification information, and the response message includes “operation setting”, “no operation setting” indicating the presence / absence of an operation to be set in the communication device, “narrowing request” indicating a request to narrow down the communication device, and the like. A message including notification information including the command and a command indicating an operation desired to be set in the communication device. The extraction unit 104 extracts notification information and commands from the response message received by the transmission / reception unit 101. The instruction unit 103 instructs a corresponding function to perform the operation indicated by the command according to the notification information extracted from the extraction unit 104. For example, when the notification information is “with operation setting”, the operation indicated in the extracted command is instructed. The request creation unit 105 creates a request message including identification information stored in the storage unit 102 in accordance with the notification information extracted from the extraction unit 104. For example, when the notification information is “restriction request”, a request message including the identification information of the communication device whose operation is to be set is created.

  FIG. 3 is a configuration diagram of the server 200 according to the first embodiment. The server 200 includes a transmission / reception unit 201, a data cache 202, a request analysis unit 203, a data access unit 204, and a response creation unit 205.

  The transmission / reception unit 201 receives a request message from the communication apparatus 100 connected via the network, and transmits a response message in response to the request message to the communication apparatus 100. The data cache 202 stores notification information and commands in association with identification information (an identifier assigned to a communication device or an identifier assigned to a plurality of communication devices as one). The request analysis unit 203 analyzes whether the identification information included in the request message received by the transmission / reception unit 201 is stored in the data cache 202. If the identification information included in the request message is not stored in the data cache 202 as a result of the analysis by the request analysis unit 203, the data access unit 204 accesses the database 400 and associates the notification information and command with the identification information. Is stored in the data cache 202. The response creation unit 205 creates a response message including notification information and command information associated with the identification information stored in the data cache 202 according to the analysis result of the request analysis unit 203. For example, when the identification information included in the request message is stored in the data cache 202, a response message including “notification of operation setting” notification information and “start operation” command associated with the identification information is created. To do.

The processing flow of the communication apparatus 100 will be described using the flowchart of the communication apparatus 100 shown in FIG.
The transmission / reception unit 101 transmits a request message including identification information (identifiers assigned in advance to a plurality of communication devices) to the server 200 (S401), and the server 200 uses the identification information included in the received request message to communicate with the communication device 100. And a response message to the communication apparatus 100 is transmitted to the communication apparatus 100. When the server 200 transmits a response message to the communication apparatus 100, the data cache is searched using the identification information as a key. If there is data associated with the identification information, a response is made based on the data in the data cache. Create a message (you can access the database if you need data other than data cache). Examples of the identification information include the MAC address, FQDN name, product serial number, and product model number of the communication device 100 itself.

  The transmission / reception unit 101 receives the response message transmitted by the server (S402), and the extraction unit 104 extracts notification information and a command from the received response message. When the extracted notification information includes “with operation setting” (S403 (Yes)), the instruction unit 103 instructs the operation indicated by the extracted command (S404), and waits for the next request message transmission (S406). . Similarly, when the extracted notification information does not include “with operation setting” (S403 (No)) and includes “without operation setting” (S405 (Yes)), it waits until the next request message transmission (S406). When the extracted notification information does not include “with / without operation setting” (S405 (No)) and includes “restriction request”, the identification information stored in the storage unit in response to this “restriction request” ( A request message including an identifier assigned in advance to the communication device is created (S407). Further, the transmission / reception unit 101 transmits the request message created by the request creation unit 105 to the server 200 (S401).

  Here, the operation will be described with reference to the sequence diagram shown in FIG. FIG. 5A shows a sequence when the response message includes notification information “no operation setting”, and FIG. 5B shows a sequence when the notification information further includes “restriction request” and “operation setting” notification information. Is shown.

The air conditioner receives commands from the server (operation start, operation stop, operation mode setting (energy saving operation ON, energy saving operation OFF)).
1. Each air conditioner (communication devices 0, 1) transmits a request message to the server periodically (for example, every hour). At this time, the identification information included in the request message is “region”, and as a specific example is “region A” (this region A is better matched with the management region classification of the power supply organization).

2. In response to this request message, the server transmits one of the following response messages (1) to (3) to the air conditioner in “Area A”.
(1) When there is an operation to be set uniformly, a response message including the operation is transmitted to the air conditioner. For example, a response message including notification information of “operation setting exists” and a command of “operation mode setting (energy saving operation ON)” is transmitted.

(2) When there is no operation to be set for all the “region A” air conditioners, a response message including notification information of “no operation setting” is transmitted to the air conditioners.
(3) If there is an operation to be set for some air conditioners in “Area A”, a response message including notification information of “narrowing request” is transmitted to the air conditioner.
3. When the air conditioner receives the response message including the notification information of “restriction request”, the air conditioner transmits a request message including more detailed identification information (for example, “region A” “product model number: ABC”) to the server.

4). Similarly, the server notifies the air conditioner “product model number: ABC” of “region A” of “not set operation” notification information or the air conditioner of “product model number: XYZ” of “region A” “ A response message including notification information of “operation set” and a command of operation “start operation” to be set or notification information of “restriction request” (if there is an operation set for some air conditioners) is sent to the air conditioner. Send.

5). By continuing the above sequence between the server and the communication device, the communication device can receive a response message of “with operation setting” or “without operation setting”. (When the communication device transmits a uniquely assigned identifier to the server, the server always transmits a response message including either “operation setting exists” or “no operation setting”.)

  Thus, the communication device can increase the hit rate of the data cache by transmitting a request message including identifiers assigned to a plurality of communication devices to the server. This is particularly effective when the same operation is set for a group of communication devices such as power control of a smart grid.

(Second Embodiment)
In the first embodiment, the communication device is selected using the identification information. However, the communication device may be selected from the server.
FIG. 6 is a configuration diagram of the communication apparatus 100 according to the second embodiment. The communication device 100 includes a transmission / reception unit 101, a storage unit 102, an instruction unit 103, an extraction unit 104, a request creation unit 105, and a determination unit 106.

  The transmission / reception unit 101 transmits a request message to a server connected via a network, and receives a response message in response to the request message from the server. The storage unit 102 stores an identifier assigned to one of the plurality of communication devices 100 and identification information indicated by the identifier assigned to the communication device 100. The request message is a message including identification information, and the response message is a notification including “operation setting present” and “no operation setting” indicating the presence / absence of an operation to be set in the communication device, and selection information for selecting the communication device from the server. The message includes a command indicating information and an operation desired to be set in the communication apparatus. The extraction unit 104 extracts notification information and commands from the response message received by the transmission / reception unit 101. The instruction unit 103 instructs a corresponding function to perform the operation indicated by the command according to the notification information extracted from the extraction unit 104. For example, when the notification information is “with operation setting”, the operation indicated in the extracted command is instructed. The determination unit 106 determines whether the identification information stored in the storage unit 102 is assigned from the selection information included in the notification information. The request creation unit 105 creates a request message including identification information stored in the storage unit 102 in accordance with the notification information extracted from the extraction unit 104. For example, in the case of “with operation setting” included in the notification information, a request message including the identification information of the communication device whose operation is to be set is created. The transmission / reception unit 101 transmits the request message created by the request creation unit 105 to the server 200 according to the determination result of the determination unit 106. For example, when the identification information stored in the storage unit 102 is assigned from the selection information, a request message is transmitted. When the identification information is not assigned, the request message is not transmitted.

The processing flow of the communication apparatus 100 will be described using the flowchart of the communication apparatus 100 shown in FIG.
The transmission / reception unit 101 transmits a request message including identification information (identifiers or the like assigned in advance to a plurality of communication devices) to the server 200 (S701), and the server 200 determines the communication device 100 from the identification information included in the received request message. And a response message to the communication apparatus 100 is transmitted to the communication apparatus 100. The transmission / reception unit 101 receives the response message transmitted by the server (S702), and the extraction unit 104 extracts notification information and a command from the received response message. When the extracted notification information does not include “operation setting present” (S703 (No)), the notification information includes “no operation setting” and waits until the next request message transmission (S707). When the notification information includes “operation setting exists” (S703 (Yes)) and the selection information is not included (S704 (No)), the instruction unit 103 instructs the operation indicated in the extracted command (S705). (S707). When the determination unit 106 determines that the identification information stored in the storage unit 102 is assigned to the selection information (S706 (Yes)), the response creation unit 105 includes the identification information assigned to the selection information. A request message is created (S708), and the transmission / reception unit 101 transmits the request message created by the request creation unit 105 to the server 200 (S701). On the other hand, if the determination unit 106 determines that the identification information stored in the storage unit 102 is not assigned to the selection information (S706 (No)), the request message is not transmitted and the process waits for the next request message transmission. (S707).

  Here, using the sequence diagram shown in FIG. 8, the operation will be described using an example in which the communication device is an air conditioner and the selection information is used as a hash value. The unique identifier of the identification information is an integer from 0 to N-1, and the hash value is mbits long. The server sets 1 to the bit position corresponding to the remainder obtained by dividing the unique identifier of the communication device to be assigned by m. For example, there will be described a case where there are eight communication devices, each of which is assigned a unique identifier of 0 to 7, and the hash value is 4 bits long. When the server wants to assign communication devices having unique identifiers 0, 4, and 5, the bit position corresponding to the remainder (0, 0, 1) obtained by dividing these by 4 is set to 1, (1, 1, 0, 0). Get the hash value.

1. Each air conditioner (communication devices 0, 1, 2) transmits a request message to the server periodically (for example, every hour). At this time, the identification information included in the request message is “region”, and as a specific example is “region A” (this region A is better matched with the management region classification of the power supply organization).

2. 2. The server sends a response message including the hash value (1, 1, 0, 0) and “with operation setting” to the air conditioner. The air conditioner that has received the response message determines whether or not its own unique identifier is assigned using the hash value. That is, it is confirmed whether or not the bit at the remainder position obtained by dividing its own unique identifier by 4 is 1 (if it is 1, it is determined that it is assigned).

(1) If it is determined that the unique identifier is assigned, the air conditioner transmits the next request message to the server. (This request message may include new identification information such as “Product Model Number: ABC” of “Region A”, or a new type of request message such as “Setting Operation Request” may be transmitted. May be)

(2) If it is determined that the unique identifier is not assigned, the air conditioner does not transmit the next request message. Similarly, the server obtains the selection information for the air conditioner whose operation is to be set for the air conditioner of “Product Model Number: ABC” in “Area A”, and transmits a response message including this to the air conditioner.

5). By continuing the above-described sequence between the server and the communication device, the communication device can receive a response message including either “with operation setting” or “without operation setting”.

  In the above description, the embodiment using the hash value as the selection information has been described. However, various methods other than the method of calculating the hash value can be used. As another example, a Bloom filter can be used. The Bloom filter is a bit string having a length of mbits, and all bits are 0 as an initial value. K hash functions having values ranging from 0 to m−1 are prepared, and 1 is set to the bit position corresponding to the value obtained by the k hash functions for the value to be assigned. For example, a hash value of a unique identifier is calculated using two hash functions H0 and H1, assuming that k = 2 and m = 4. For example,

H0 (2) = 0 H1 (2) = 1
H0 (3) = 1 H1 (3) = 2
As a result, the Bloom filter is (1, 1, 1, 0).
On the other hand, the identification determination of identification information by the Bloom filter by the communication device is performed by obtaining a hash value with k hash functions for the unique identifier of the communication device itself, and identifying if the bit at the position corresponding to each value is 1. It is determined that information is assigned.

  For example, when the Bloom filter is (1, 1, 1, 0) and the unique identifier is 2, since H0 (2) = 0 and H1 (2) = 1, all of the 0th bit and the 1st bit are This Bloom filter, which is 1, is assigned identification information.

The selection information may be false positive (it is wrong if an unassigned communication device is assigned), but it must not be false negative (it is wrong if an assigned communication device is not assigned). The above hash value example and Bloom filter example satisfy this condition. If this condition is satisfied, the sorting information may be obtained using another method.

  So far, the case where the notification information includes the “restriction request” and the case where the notification information includes the selection information has been described with reference to FIG. 4. Response messages including one or both may be mixed in a sequence between a series of servers and communication devices.

  Thus, when the server sends the selection information, the server receives less request messages from the communication device, and the load on the server can be reduced. Further, by making the selection information the same value as the identification information, the selection information can also be held in the data cache, and the load on the server can be reduced.

(Third embodiment)
A third embodiment will be described with reference to FIG. FIG. 9 is a diagram illustrating a system configuration according to the third embodiment. In the first and second embodiments, all inquiries from the communication device 100 arrive at the server 200 and are efficiently processed using the data cache behind. Here, an embodiment in which the load on the server is further reduced using the domain name service system 600 will be described. Although the data cache used in the first and second embodiments can be used in this embodiment, the description is omitted here because they are redundant.

  The system of the third embodiment includes a plurality of communication devices 100, a server 200, a database 400, a front DNS server 500, and a domain name server system 600. The domain name server system 600 is a DNS server group described in IETF RFC 1035, and the front DNS server 500 receives a DNS request message from the communication apparatus 100 by the DNS server 500 prepared by the ISP, for example. In cooperation with the server system 600, a DNS response message is transmitted to the communication device.

The processing flow of the communication apparatus 100 will be described using the flowchart of the communication apparatus 100 shown in FIG.
The transmission / reception unit 101 of the communication device 100 transmits a DNS request message including the identification information of the communication device 100 to the front DNS server 500 (S1001). For example, the communication device 100 transmits a name resolution request for the TXT record of c0.toshiba.co.jp to the front DNS server 500. Here, c0 is identification information of the communication device (unique identifier of the communication device). If the value of the TXT record of c0.toshiba.co.jp is stored in the cache of the front DNS server 500, the front DNS server 500 transmits a DNS response message describing the value to the communication apparatus 100. If not stored in the cache, the DNS server managing the domain of toshiba.co.jp is checked. Specifically, the root DNS server 601 preset in the front DNS server 500 is inquired of the DNS server that manages the jp domain, and the jp domain DNS server 602 that manages the jp domain is co.jp domain. The co.jp domain DNS server 603 that manages the co.jp domain and the toshiba.co.jp domain that manages the toshiba.co.jp domain in the co.jp domain DNS server 603 that manages the co.jp domain This is done by inquiring the DNS server 604. When the front DNS server 500 knows the toshiba.co.jp domain DNS server 604 managing toshiba.co.jp, the value of the TX record of c0.toshiba.co.jp is stored in the toshiba.co.jp domain DNS server. A DNS response message describing the obtained value is sent to the communication apparatus 100. (The communication device 100 operates according to the value of the TXT record).

  The transmission / reception unit 101 receives a DNS response message transmitted by the DNS server (S1002), and the extraction unit 104 extracts notification information and a command from the received DNS response message. When the extracted notification information includes “operation setting exists” (S403 (Yes)), the instruction unit 103 instructs the operation indicated by the extracted command (S1004), and waits for the next DNS request message transmission (S406). ). Similarly, when the extracted notification information does not include “with operation setting” (S403 (No)) and includes “without operation setting” (S1005 (Yes)), it waits until the next request message transmission (S1006). When the extracted notification information does not include “with / without operation setting” (S1005 (No)) and includes “restriction request”, the identification information stored in the storage unit in response to this “restriction request” ( A DNS request message including an identifier assigned in advance to the communication device is created (S1007). Further, the transmission / reception unit 101 transmits the DNS request message created by the request creation unit 105 to the server 200 (S1001).

At this time, the front DNS server 500 obtains the TTL (survival time) together with the value of the TXT record from the toshiba.co.jp domain DNS server 604. This TTL represents the time for caching the value of the TXT record. The front DNS server 500 stores the value of the TXT record in the cache for the obtained TTL time, and thereafter discards the cache value. By using DNS in this way, it is possible to send a DNS response message to the communication apparatus 100 without inquiring the server 200 with the value stored in the cache of the front DNS server 500 for the inquiry from the communication apparatus 100. The load on the server can be reduced.

  Operations in the system configuration will be described with reference to the sequence diagram shown in FIG. In the third embodiment, as in the first and second embodiments, the communication device can use an identifier (identification information) to which a plurality of communication devices are assigned. For example,

1. The communication device 0 transmits a DNS request message for toshiba.co.jp.
2. When the communication device 0 receives the DNS response message including the “narrowing request”, the communication device 0 transmits a DNS request message to c0.toshiba.co.jp.
3. When the communication device 0 receives a DNS response message including “operation set” and “operation start”, the communication device 0 executes the command “operation start”.
4). The communication apparatus 1 transmits a DNS request message for toshiba.co.jp.
5. When the communication apparatus 1 receives the DNS response message including the “narrowing request”, the communication apparatus 1 transmits a DNS request message to c0.toshiba.co.jp.
6). When receiving the DNS response message including “no operation setting”, the communication device 1 waits until the next DNS request message transmission.
As described above, the difference between the first and second embodiments and the third embodiment is that the DNS protocol is used for the sequence of the request message and the response message. However, by using an identifier shared by a plurality of clients as described above, the size of data held in the cache of the front DNS server 500 can be reduced.

  Furthermore, it is also possible to use selection information as in the second embodiment. The processing flow of the communication apparatus 100 will be described using the flowchart of the communication apparatus 100 shown in FIG.

  The transmission / reception unit 101 transmits a DNS request message including identification information (identifiers assigned in advance to a plurality of communication devices) to the server 200 (S1201), and the server 200 communicates from the identification information included in the received DNS request message. The device 100 is identified, and a DNS response message for the communication device 100 is transmitted to the communication device 100. The transmission / reception unit 101 receives the DNS response message transmitted by the server (S1202), and the extraction unit 104 extracts the notification information and the command from the received DNS response message. When the extracted notification information does not include “operation setting exists” (S1203 (No)), the notification information includes “no operation setting” and waits until the next DNS request message transmission (S1207). When the notification information includes “operation setting exists” (S1203 (Yes)) and the selection information is not included (S1204 (No)), the instruction unit 103 instructs the operation indicated in the extracted command (S1205). Until the DNS request message is sent (S1207). When the determination unit 106 determines that the identification information stored in the storage unit 102 is assigned to the selection information (S1206 (Yes)), the response creation unit 105 includes the identification information assigned to the selection information. A DNS request message is created (S1208), and the transmission / reception unit 101 transmits the DNS request message created by the request creation unit 105 to the server 200 (S1201). On the other hand, when the determination unit 106 determines that the identification information stored in the storage unit 102 is not assigned to the selection information (S1206 (No)), the DNS request message is not transmitted, and the next DNS request message is transmitted. Wait (S1207).

  Here, using the sequence diagram shown in FIG. 13, the operation will be described using an example in which the communication device is an air conditioner and the selection information is used as a hash value. The unique identifier of the identification information is an integer from 0 to N-1, and the hash value is mbits long. The server sets 1 to the bit position corresponding to the remainder obtained by dividing the unique identifier of the communication device to be assigned by m. For example, there will be described a case where there are eight communication devices, each of which is assigned a unique identifier of 0 to 7, and the hash value is 4 bits long. When the server wants to assign communication devices having unique identifiers 0, 4, and 5, the bit position corresponding to the remainder (0, 0, 1) obtained by dividing these by 4 is set to 1, (1, 1, 0, 0). Get the hash value.

1. Each air conditioner (communication devices 0, 1) transmits a DNS request message to the server periodically (for example, every hour). At this time, the identification information included in the DNS request message is “region”, which is toshiba.co.jp as a specific example (this region is preferably coincident with the management region classification of the power supply organization).

2. The server transmits a DNS response message including the hash value (1, 1, 0, 0) and “with operation setting” to the air conditioner (communication device 0).
3. The communication device 0 that has received the DNS response message tests the hash value with its own identification information (unique identifier). That is, it is confirmed whether or not the bit at the remainder position obtained by dividing its own unique identifier by 4 is 1 (if it is 1, it is determined that it is assigned).

(1) If it is determined that the unique identifier is assigned, the air conditioner transmits the next DNS request message to the server. (This DNS request message may include new identification information such as c0.toshiba.co.jp, or may include new identification information, or a new “setting operation request”. Type of request message may be sent)

(2) If it is determined that the unique identifier is not assigned, the air conditioner does not transmit the next request message. Similarly, the server obtains the selection information for the air conditioner whose operation is desired to be set for the air conditioner of c0.toshiba.co.jp, and transmits a DNS response message including this to the air conditioner.

5). By continuing the above-described sequence between the server and the communication device, the communication device can receive a response message including either “with operation setting” or “without operation setting”.

By using the selection information in this way, it is possible to reduce DNS request messages transmitted by the communication device.
Although the embodiment using the hash value as the selection information has been described above, various methods can be used other than the method of calculating the hash value. As another example, the present invention can also be applied to use a Bloom filter.

  In the third embodiment, the server sends information to the communication device using the TXT record of the DNS response message. However, for example, information from the server to the communication device can be transmitted using another record such as a HINFO record. You may send it.

  A communication device according to the first to third embodiments is connected to a control device such as a CPU (Central Processing Unit), a storage device such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and a network. Connects the communication I / F, external storage devices such as HDD (Hard Disk Drive) and CD (Compact Disc) drive devices, display devices such as display devices, input devices such as keyboards and mice, etc. And a hardware configuration using a normal computer.

The server program executed by the communication device according to the first to third embodiments is a file in an installable format or an executable format, and is a CD-ROM (Compact Disk Read Only Memory), a flexible disk (FD), a CD. It may be recorded on a computer-readable recording medium such as -R (Compact Disk Recordable) or DVD (Digital Versatile Disk) and provided as a computer program product.

  Further, the server program executed by the communication device according to the first to third embodiments is stored on a computer connected to a network such as the Internet and is provided by being downloaded via the network. Also good. The server program executed by the communication device according to the first to third embodiments may be provided or distributed via a network such as the Internet.

In addition, the communication program of the first to third embodiments may be provided by being incorporated in advance in a ROM or the like.
The server program executed by the communication device according to the present embodiment has a module configuration including the above-described units (transmission / reception unit, storage unit, instruction unit, extraction unit, request creation unit, and determination unit). As hardware, a CPU (processor) reads out and executes a communication program from the storage medium, so that the respective units are loaded onto the main storage device, and the above-described units are generated on the main storage device. Also good.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 100 Communication apparatus 101 Transmission / reception part 102 Storage part 103 Instruction part 104 Extraction part 105 Request creation part 106 Determination part 200 Server 201 Transmission / reception part 202 Data cache 203 Request analysis part 204 Data access part 205 Response creation part 300 Network 400 Database

Claims (7)

A transmission / reception unit for transmitting a request message to the server via the network and receiving a response message from the server;
A storage unit storing identification information including identifiers assigned to a plurality of communication devices, and identifiers of the communication devices;
An extraction unit for extracting notification information and a command from the received response message;
An instruction unit for instructing the command according to the extracted notification information;
A communication apparatus, comprising: a request creation unit that creates a request message including the identification information according to the notification information. The notification information includes selection information for selecting a communication device from a server,
And a determination unit that determines whether the identification information stored in the storage unit is assigned from the selection information.
The communication apparatus according to claim 1, wherein the transmission / reception unit transmits the request message to a server according to a determination result of the determination unit.   The communication apparatus according to claim 1, wherein the request message and the response message use a DNS protocol.   The communication apparatus according to claim 1, wherein a hash value is used as the selection information.   The communication apparatus according to claim 1, wherein a bloom filter is used for the selection information. A computer connected to the server via the network
A transmission / reception unit for transmitting a request message to the server via the network and receiving a response message from the server;
A storage unit storing identification information including identifiers assigned to a plurality of communication devices, and identifiers of the communication devices;
An extraction unit for extracting notification information and a command from the received response message;
An instruction unit for instructing the command according to the extracted notification information;
A communication program for causing a request creation unit to create a request message including the identification information in accordance with the notification information. In a communication system in which a communication device and a server are connected via a network,
The communication device
A transmission / reception unit for transmitting a request message to the server via a network and receiving a response message from the server;
A storage unit storing identification information including identifiers assigned to a plurality of communication devices, and identifiers of the communication devices;
An extraction unit for extracting notification information and a command from the received response message;
An instruction unit for instructing the command according to the extracted notification information;
A request creating unit that creates a request message including the identification information according to the notification information;
The server
A transmission / reception unit for receiving a request message from the communication device via a network and transmitting a response message to the communication device;
A data cache for storing the notification information and a command for operating the communication device in association with the identification information of the communication device;
An analysis unit that analyzes whether the identification information included in the received request message is stored in the data cache;
A data access unit that acquires identification information from a database according to the analysis result of the analysis unit, and stores the identification information in the data cache;
A response creation unit that creates a response message including the identification information stored in the data cache and the command associated with the identification information according to an analysis result of the analysis unit; Communication system.

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