JP2010186207A - Data receiving terminal and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid distribution of data not desired by a user. <P>SOLUTION: A receiving terminal 50 includes a distribution notification service application and a data receiving service application. The distribution notification service application registers its own global address/port "1.1.1.1:30000" in a connection management server 20. The distribution notification service application receives a command that a transmitting terminal 100 having acquired the global address/port from the connection management server 20 sends to the global address/port. The distribution notification service application sends a request command including the global port number "30001" of the data receiving service application to the transmitting terminal 100. The data receiving service application receives content data that the transmitting terminal 100 having received the request command sends to the global address/port "1.1.1.1:30001". <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a data receiving terminal capable of receiving data transmitted from a data transmitting terminal.

  A connection management server may be used to perform data communication between a pair of terminals. For example, the following Patent Document 1 discloses a data communication system using SIP (Session Initiation Protocol). In a system using SIP, a connection management server called a SIP server is usually used. Each terminal has a service processing unit (application) for executing data communication. Each terminal registers its own ID (for example, SIP URI) and address information (for example, an IP address and a port number assigned to the service) in the connection management server. Each terminal can be connected to another terminal via the connection management server.

JP 2008-99168 A Japanese Patent Laid-Open No. 2007-28185

  By the way, there is a possibility that a third party illegally acquires address information registered in the connection management server and unilaterally distributes data (for example, advertisement data) toward the address information. In this case, data is distributed to the terminal even though the user of the terminal registered in the connection management server does not desire.

  The present specification provides a technique that can suppress distribution of data not desired by the user.

  The technology disclosed in this specification is a data receiving terminal that is communicably connected to a data transmitting terminal. The data receiving terminal includes a first service processing unit and a second service processing unit. The first service processing unit includes a registration processing unit and a notification reception processing unit. The registration processing unit registers a combination of the first address assigned to the data receiving terminal and the first port number assigned to the first service processing unit in the first server. The notification reception processing unit receives a specific notification in which the data transmission terminal that has acquired the combination of the first address and the first port number from the first server transmits the combination of the first address and the first port number as the transmission destination. To do. At least one of the first service processing unit and the second service processing unit sends a positive response including the second port number assigned to the second service processing unit to the data transmission terminal when the specific notification is received. A positive response transmission processing unit for transmitting is provided. Note that “when a specific notification is received” does not exclude the addition of another condition (AND condition and / or OR condition). For example, the positive response transmission processing unit may transmit a positive response to the data transmission terminal when the specific notification is received and other conditions are satisfied. The second service processing unit includes a data reception processing unit that receives data transmitted from the data transmission terminal that has received the positive response using the combination of the first address and the second port number as the transmission destination.

  The data receiving terminal includes at least two service processing units (a first service processing unit and a second service processing unit) for allowing data distribution. Different port numbers (first port number and second port number) are assigned to each service processing unit. The first port number assigned to the first service processing unit is registered in the first server. Even if a third party accesses the first server and obtains the first port number illegally, the first service processing unit to which the first port number is assigned does not execute processing for receiving data. On the other hand, the second port number assigned to the second service processing unit that executes the process of receiving data is not registered in the first server. Therefore, even if the third party accesses the first server, the second port number cannot be acquired. It is possible to suppress a third party from distributing data toward the second port number. By using this data receiving terminal, it is possible to suppress the distribution of data that the user does not want.

  For example, when the second service processing unit includes a positive response processing unit, the positive response includes the second port number assigned to the second service processing unit as the transmission source information. In this case, when the content of the positive response is analyzed, for example, the second port number can be acquired at a lower layer level such as the TCP / IP layer. On the other hand, when the first service processing unit includes a positive response processing unit, the positive response includes the first port number assigned to the first service processing unit as information of the transmission source. . This positive response includes the second port number as data (for example, application data) analyzed at the level of the upper hierarchy. In order to acquire the second port number from this positive response, analysis at a higher hierarchy level is required. Therefore, it can be said that this positive response is more difficult to specify the second port number than the positive response including the second port number as the information of the transmission source. Therefore, in order to suppress an act in which a third party analyzes a positive response and illegally acquires the second port number, it is preferable that the first service processing unit includes a positive response processing unit. Each of the first service processing unit and the second service processing unit may include an affirmative response processing unit. In this case, which processing unit transmits an affirmative response may be switched according to a predetermined condition. In situations where the first service processor can send a positive response, it is preferred that the first service processor send a positive response.

  The data receiving terminal, the data transmitting terminal, and the first server may exist on the downstream side of the same router (the Internet is the upstream side). That is, these devices may exist in the same private network. In this case, a combination of the local address and local port number assigned to the data receiving terminal (address information in the private network) may be registered in the first server. According to this configuration, it is possible to suppress data that is not desired by the user from being distributed within the private network.

  On the other hand, the data receiving terminal may be communicably connected to the data transmitting terminal via a router. That is, the data transmission terminal may exist outside the private network where the data reception terminal exists. In this case, the first address may be a first global address. The first port number may be a first global port number. The second port number may be a second global port number. The notification reception processing unit may receive the specific notification via a router. The data reception processing unit may receive the above data via a router. According to this configuration, it is possible to suppress distribution of data not desired by the user via the Internet.

  The second service processing unit may further include a global port number acquisition processing unit that acquires the second global port number from the second server by transmitting the specific packet to the second server. In this case, the positive response transmission processing unit may transmit a positive response including the second global port number acquired by the global port number acquisition processing unit to the data transmission terminal when the specific notification is received. Good. According to this configuration, the data receiving terminal can acquire the second global port number assigned to the second service processing unit.

  The positive response transmission processing unit may transmit a positive response to the data transmission terminal when the specific notification is received and the data transmission terminal is permitted to transmit the data. As an example of “when the data transmission terminal is permitted to transmit data”, a predetermined operation is executed by the user at the data reception terminal, or predetermined information (for example, the data transmission terminal at the data reception terminal). Information) is stored. The first service processing unit transmits a negative response not including the second port number to the data transmission terminal when the specific notification is received and the data transmission terminal is not permitted to transmit data. You may further have a response transmission process part. Since the second port number is not included in the negative response, it is possible to suppress an action in which a third party analyzes the negative response and illegally acquires the second port number.

  There is a possibility that a third party illegally acquires the second port number by analyzing the positive response and distributes the data toward the second port number. In order to deal with such an injustice, a different port number may be assigned to the second service processing unit every time the second service processing unit is activated. Since the port number assigned to the second service processing unit changes from the second port number to another port number, it is possible to prevent the second service processing unit from receiving data that the user does not want. .

  The first service processing unit may further include an activation processing unit that activates the second service processing unit when the specific notification is received. The second service processing unit may further include a termination processing unit that terminates the second service processing unit when the data reception processing unit completes receiving the data. Note that the end processing unit may end the second service processing unit in accordance with an instruction from the first service processing unit. On the other hand, the termination processing unit may monitor the completion of reception of the data by the data reception processing unit, and may terminate the second service processing unit as a result. According to this configuration, when the data reception processing unit completes the reception of the data, the second service processing unit ends. As described above, when the second service processing unit is activated next time, a different port number is assigned to the second service processing unit. For this reason, it can suppress effectively that the 2nd service processing part receives the data which the user does not desire.

  Note that the above data receiving terminal may function as a terminal for transmitting data to another data receiving terminal. In order to function in this way, the data reception terminal may further include a combination acquisition unit, a notification transmission unit, and a data transmission unit. The combination acquisition unit may acquire a combination of the second address and the third port number assigned to the other data receiving terminal registered in the first server. The notification transmission unit may transmit the specific notification using the combination of the second address and the third port number acquired by the combination acquisition unit as a transmission destination. When the data transmission unit receives a positive response including the fourth port number in response to the specific notification transmitted by the notification transmission unit, the data transmission unit uses the combination of the second address and the fourth port number as the transmission destination. May be sent.

  A data communication system including the data transmission terminal and the data reception terminal is also new and useful. Also, a method and a computer program for realizing the data receiving terminal are novel and useful.

1 shows an example of the configuration of a data communication system. An example of a structure of a receiving terminal is shown. An example of a combination of an address and a port number assigned to each of the delivery notification service application and the data reception service application is shown. An example of a structure of a transmission terminal is shown. The sequence of the process which each device performs is shown. FIG. 6 shows a continuation sequence of FIG. FIG. 7 shows a continuation sequence of FIG. FIG. 8 shows a continuation sequence of FIG. FIG. 9 shows a continuation sequence of FIG.

Here, some of the techniques described in the following examples are listed.
(Mode 1) The technique disclosed in this specification can also be expressed as a single data transmission terminal that is communicably connected to a data reception terminal. The data transmission terminal may include the combination acquisition unit, the notification transmission unit, and the data transmission unit. A method and a computer program for realizing this data transmission terminal are also new and useful.

(Mode 2) The first service processing unit may further include a permission unit that allows the user to perform the selection operation when the specific notification is received. The positive response transmission unit may transmit the positive response when the first selection operation is executed by the user. In addition, the negative response transmission unit may execute the negative response when the second selection operation is performed by the user.

(Mode 3) The data receiving terminal may further include a terminal storage unit that stores information related to a terminal that is allowed to transmit data to itself. The positive response transmission unit may transmit the positive response when information regarding the data transmission terminal is stored in the terminal storage unit. In addition, the negative response transmission unit may transmit the negative response when information regarding the data transmission terminal is not stored in the terminal storage unit.

(Mode 4) Each of the first service processing unit and the second service processing unit may have a positive response transmission unit. In this case, the positive response transmission unit of the first service processing unit may transmit the positive response when the specific notification is received and the router is the first type router. Good. The affirmative response processing unit of the second service processing unit may transmit a positive response when the specific notification is received and the router is a second type router.

(Mode 5) The router may be a NAT (Network Address Translation) router. When the above router also converts the port number, the above router can also be called a NAPT router.

(System configuration)
Embodiments will be described with reference to the drawings. FIG. 1 shows a schematic diagram of a data communication system 2 of the present embodiment. The data communication system 2 includes the Internet 4, the STUN server 10, the connection management server 20, a plurality of private networks 40, 90, and the like. A STUN server 10, a connection management server 20, and a plurality of private networks 40 and 90 are connected to the Internet 4.

(Configuration of STUN server 10)
The STUN server 10 receives a predetermined command transmitted from the private networks 40 and 90. The STUN server 10 acquires the combination of the global IP address and the global port number of the transmission source (for example, the receiving terminal 50) of the predetermined command by analyzing the predetermined command. The STUN server 10 transmits the combination to the transmission source of the predetermined command. Thereby, the transmission source of the predetermined command can know the combination of the global IP address and the global port number assigned to itself.

(Configuration of connection management server 20)
The connection management server 20 includes a terminal information storage unit 22. The terminal information storage unit 22 stores a plurality of combination data 24 and 26. Each combination data 24, 26 is obtained by associating a terminal ID 30, a global IP address 32, and a global port number 34 with each other. As will be described in detail later, a terminal (for example, receiving terminal 50) desiring data distribution from the transmitting terminal 100 registers its own ID, global IP address, and global port number in the connection management server 20. The transmission terminal 100 can know information on a terminal that desires data distribution by accessing the connection management server 20. The connection management server 20 may be a SIP server, for example. In this case, the terminal ID 30 stored in the terminal information storage unit 22 may be a SIP URI assigned to the terminal. On the other hand, the connection management server 20 may execute processing according to a protocol other than SIP. In this case, the terminal ID 30 stored in the terminal information storage unit 22 may be, for example, a terminal MAC address, a node name, or the like.

(Configuration of private network 40)
The private network 40 is connected to the Internet 4 via a router 42. The router 42 is connected to the Internet 4 and to the LAN 44. The private network 40 is composed of devices connected to the LAN 44. In this embodiment, the receiving terminal 50 is connected to the LAN 44.

  The router 42 executes an address conversion process called NAT. The router 42 transmits data transmitted from the private network 40 using the first combination of the local IP address and the local port number as a transmission source to the Internet 4. At this time, the router 42 converts the first combination as the transmission source into a second combination of the global IP address and the global port number. Conversely, when there is data transmitted from the Internet 4 with the second combination as a transmission destination, the router 42 converts the second combination as the transmission destination into the first combination. .

  In the present embodiment, the router 42 transmits data to the transmission destination when the combination of the address and port number of the transmission destination of data transmitted from the Internet 4 exists in the private network 40. That is, the router 42 is called Full Cone NAT. As a different type of router from Full Cone NAT, a router called Restricted Cone NAT is known. The router stores a combination of a source address and a port number of a command transmitted from the private network 40 to the Internet 4 for a predetermined period, receives response data of the command within the predetermined period, and When the combination of the address and port number of the response destination exists in the private network 40, data is transmitted to the destination.

(Configuration of receiving terminal 50)
FIG. 2 shows an exemplary configuration of the receiving terminal 50. The receiving terminal 50 includes a control unit 52, an operation unit 54, a display unit 56, a printing unit 58, an interface 60, a storage unit 70, and the like. The control unit 52 executes processing according to a program (for example, applications 72 and 74) stored in the storage unit 70. The operation unit 54 has a plurality of keys. The display unit 56 displays various information. For example, the printing unit 58 prints data received by the receiving terminal 50 on a print medium. The interface 60 is connected to the LAN 44.

  The storage unit 70 stores various information (programs, data generated during the process of the control unit 52, etc.). The storage unit 70 stores a delivery notification service application 72 and a data reception service application 74. The receiving terminal 50 according to the present embodiment receives data transmitted from the transmitting terminal 100 described later. In order to receive distribution of data from the transmission terminal 100, the user of the reception terminal 50 needs to register predetermined information in the transmission terminal 100. For example, the user of the receiving terminal 50 registers the terminal ID 76 of the receiving terminal 50 in the transmitting terminal 100. Furthermore, in order for the receiving terminal 50 to receive data distribution from the transmitting terminal 100, a dedicated application is required. These applications are a distribution notification service application 72 and a data reception service application 74. For example, the receiving terminal 50 may download these applications 72 and 74 from the transmitting terminal 100. Moreover, the receiving terminal 50 may install these applications 72 and 74 from a program storage medium, for example.

  FIG. 3 shows an example of a combination of an IP address and a port number used when each of the applications 72 and 74 communicates data. In this embodiment, the local IP address assigned to the receiving terminal 50 is “192.168.0.100”. This local IP address is converted into a global IP address by the router 42. In this embodiment, the local IP address “192.168.0.100” is converted to the global IP address “1.1.1.1”. A different local port number is assigned to each of the applications 72 and 74. For example, the local port number “50000” is assigned to the distribution notification service application 72. The local port number “50001” is assigned to the data reception service application 74. These local port numbers are converted into global port numbers by the router 42. In this embodiment, the local port number “50000” is converted into the global port number “30000”, and the local port number “50001” is converted into the global port number “30001”.

  The storage unit 70 stores a terminal ID of the receiving terminal 50 (for example, SIP URI of the receiving terminal 50) 76. In the present embodiment, the terminal ID 76 of the receiving terminal 50 is “XXX”. The storage unit 70 also stores router type data 78 relating to the type of the router 42. How the router type data 78 is stored will be described in detail later. The storage unit 70 includes a storage area 80 for storing information other than the information 72 to 78 described above. Information stored in the storage area 80 will be described later if necessary.

(Configuration of private network 90)
The private network 90 (see FIG. 1) is connected to the Internet 4 via a router 92. The router 92 is connected to the Internet 4 and to the LAN 94. The private network 90 is composed of devices connected to the LAN 94. In this embodiment, a receiving terminal 96 and a transmitting terminal 100 are connected to the LAN 94. The router 92 has the same function as the router 42 described above. The receiving terminal 96 has the same configuration as the receiving terminal 50 described above. When the receiving terminal 96 receives data transmitted from the transmitting terminal 100, the receiving terminal 96 receives data without going through the Internet 4. On the other hand, when the receiving terminal 50 receives data transmitted from the transmitting terminal 100, the receiving terminal 50 receives the data via the Internet 4 (that is, the router 42).

(Configuration of transmitting terminal 100)
FIG. 4 shows an exemplary configuration of the transmission terminal 100. The transmission terminal 100 includes a control unit 102, an interface 110, a storage unit 120, and the like. The control unit 102 executes processing according to a program (for example, the application 122) stored in the storage unit 120. The interface 110 is connected to the LAN 94.

  The storage unit 120 stores various information (programs, data generated during the process of the control unit 102, and the like). The storage unit 120 stores a data distribution application 122, content data 124, a terminal list 126, and the like. The data distribution application 122 is an application for distributing the content data 124 to another terminal (for example, the receiving terminal 50). The content data 124 is data to be distributed to other terminals. The terminal list 126 includes each ID of a terminal group that desires data distribution. For example, the terminal list 126 includes the terminal ID “XXX” of the receiving terminal 50. The storage unit 70 has a storage area 128 for storing information other than the information 122 to 126 described above. Information stored in the storage area 128 will be described later if necessary.

(Processing executed by each device)
Next, the contents of processing executed by each device 10, 20, 50, 100 will be described. 5 to 9 show processing sequences executed by the devices 10, 20, 50, and 100. FIG. As shown in FIG. 5, the control unit 52 of the receiving terminal 50 activates the distribution notification service application 72 when the receiving terminal 50 is powered on (S2). Note that the local port number (“50000” in the example of FIG. 3) assigned to the distribution notification service application 72 may be fixed or determined every time the application 72 is activated. A broken line L <b> 1 shown in FIGS. 5 to 9 indicates processing executed by the distribution notification service application 72 (more precisely, processing executed by the control unit 52 according to the application 72). 7 to 9 indicate a process executed by the data reception service application 74 (more precisely, a process executed by the control unit 52 according to the application 74).

  The storage area 80 of the receiving terminal 50 stores the address of the connection management server 20. The distribution notification service application 72 executes command transmission processing for transmitting the Register command 200 using the address of the connection management server 20 as a transmission destination (S4). The Register command 200 includes the terminal ID “XXX” of the receiving terminal 50. The Register command 200 includes the local address-port of the transmission source. This local address-port is a combination of “192.168.0.100”, which is the local IP address of the receiving terminal 50, and the local port number “50000” assigned to the distribution notification service application 72.

  The router 42 receives the Register command 200. The router 42 converts the source local address-port of the Register command 200 into a global address-port. This global address-port is a combination of a global IP address “1.1.1.1” and a global port number “30000”. The router 42 transmits a Register command 202 including the global address-port “1.1.1.1:30000” to the connection management server 20.

  The connection management server 20 receives the Register command 202. The connection management server 20 executes a registration process for registering the terminal ID “XXX” and the global address-port “1.1.1.1:30000” included in the Register command 202 in the terminal information storage unit 22 (S6). . When the connection management server 20 does not receive a Register command from a terminal registered in the terminal ID 30 column of the terminal information storage unit 22 for a predetermined period, the connection management server 20 deletes the combination data 24 and 26 related to the terminal. The distribution notification service application 72 periodically transmits the Register command 200 while it is running.

  The storage area 128 of the transmission terminal 100 stores the address of the connection management server 20. The data distribution application 122 of the transmission terminal 100 executes a first inquiry process for transmitting the first command 210 using the address of the connection management server 20 as a transmission destination (S8). The first command 210 includes the terminal IDs of the terminal list 126 (“XXX” in this embodiment). The timing at which the transmission terminal 100 executes the first inquiry process (S8) is not particularly limited. For example, the transmission terminal 100 may execute the first inquiry process when new content data 124 is acquired, may execute the first inquiry process in accordance with an instruction from the user, or may periodically execute the first inquiry process. Inquiry processing may be executed.

  The connection management server 20 receives the first command 210. The connection management server 20 specifies the global address-port “1.1.1.1:30000” stored in the terminal information storage unit 22 in association with the terminal ID “XXX” included in the first command 210. . The connection management server 20 executes response processing for transmitting the response 212 including the specified global address-port to the transmission terminal 100 (S10).

  The data distribution application 122 of the transmission terminal 100 receives the response 212. The data distribution application 122 acquires the global address-port “1.1.1.1:30000” by analyzing the response 212. Next, as shown in FIG. 6, the data distribution application 122 executes the second inquiry process for transmitting the second command 220 with the global address-port “1.1.1.1:30000” as the transmission destination. (S20). The second command 220 includes an inquiry message 222, a destination global address-port “1.1.1.1:30000”, and a source address-port 224. The inquiry message 222 is a text message to be displayed on the receiving terminal 50. The transmission source address-port 224 is a combination of a local address assigned to the transmission terminal 100 and a local port number assigned to the data distribution application 122. That is, when the second command 220 is transmitted from the transmission terminal 100, the transmission source address-port 224 of the second command 220 is a local address-port. This local address-port is converted to a global address-port by the router 92. Therefore, on the Internet 4 side from the router 92, the source address-port 224 of the second command 220 is a global address-port.

  The router 42 receives the second command 220. The router 42 converts the global address-port “1.1.1.1:30000” of the transmission destination of the second command 220 into a local address-port “192.168.0.100:50000”. The router 42 transmits the second command 226 including the destination local address-port “192.168.0.100:50000” to the receiving terminal 50.

  The distribution notification service application 72 of the receiving terminal 50 receives the second command 226. The delivery notification service application 72 executes display processing for displaying the inquiry message 222 included in the second command 226 on the display unit 56 (S22). The inquiry message 222 is a message that prompts the user to select whether or not data distribution is desired. The delivery notification service application 72 determines whether or not the user's operation is a positive operation (S24). If the user operation is a negative operation, the process proceeds to S76 in FIG. On the other hand, when the user's operation is an affirmative operation, the distribution notification service application 72 determines whether or not the router type data 78 is stored in the storage unit 70 (S26). In the case of YES here, the process proceeds to S40 in FIG.

  The storage area 80 of the receiving terminal 50 stores the address of the STUN server 10. In the case of NO in S26, the delivery notification service application 72 executes a type inquiry process for transmitting the type inquiry command 228 using the address of the STUN server 10 as a transmission destination (S28). The STUN server 10 receives the type inquiry command 228. The STUN server 10 transmits a response 230 including router type data 232 indicating the type of the router 42 (Full Cone NAT or Restricted Cone NAT). The delivery notification service application 72 receives the response 230. The delivery notification service application 72 executes a storage process of storing the router type data 232 included in the response 230 in the storage unit 70 (S30). As a result, router type data 78 (Full Cone NAT in this embodiment) is stored in the storage unit 70. When S30 ends, the process proceeds to S40 in FIG.

  In S40 of FIG. 7, the delivery notification service application 72 executes a process of starting the data reception service application 74 (S40). The data reception service application 74 is assigned a local port number at the timing when the data reception service application 74 is activated. In this embodiment, every time the data reception service application 74 is activated, the distribution notification service application 72 determines the local port number of the data reception service application 74. The delivery notification service application 72 stores the previous local port number assigned when the data reception service application 74 was last activated. The distribution notification service application 72 determines a local port number different from the previous local port number when the data reception service application 74 is activated. In the present embodiment, the following description will be continued by taking as an example the case where the local port number “50001” illustrated in FIG. 3 is assigned to the data reception service application 74.

  For example, the data reception service application 74 may determine the local port number at random when the data reception service application 74 is activated. Even in this case, it is highly likely that the local port number is different from the previous local port number. This example is also equivalent to determining a local port number different from the previous local port number.

  The delivery notification service application 72 determines whether or not the router 42 is a Full Cone NAT based on the router type data 78 stored in the storage unit 70 (S42). In the case of YES here, the process proceeds to S60 of FIG. On the other hand, in the case of NO in S42, the distribution notification service application 72 executes a first instruction process for supplying the first instruction 240 to the data reception service application 74 (S44). As a result, the data reception service application 74 sends the request command 242 to the transmission destination global address-port 224 (that is, the data distribution application 122 of the transmission terminal 100) included in the second command 226 of FIG. The request process to be transmitted is executed (S46). The request command 242 includes the source local address-port. This local address-port is a combination of “192.168.0.100”, which is the local IP address of the receiving terminal 50, and a local port number “50001” assigned to the data reception service application 74.

  The router 42 receives the request command 242. The router 42 converts the local address-port “192.168.0.100:50001” of the transmission source of the request command 242 to the global address-port “1.1.1.1:30001”. The router 42 transmits a request command 244 including the global address-port of the transmission source to the transmission terminal 100.

  The data distribution application 122 of the transmission terminal 100 receives the request command 244. The data distribution application 122 analyzes the request command 244 to obtain the transmission source global address-port “1.1.1.1: 30001”. The data distribution application 122 can acquire the global address-port “1.1.1.1: 30001” of the transmission source by executing the analysis at the TCP / IP layer level. The data distribution application 122 executes a data transmission process for transmitting the transmission command 246 with the global address-port “1.1.1.1: 30001” as the transmission destination (S48). The transmission command 246 includes content data 124 and a global address-port “1.1.1.1: 30001” of the transmission destination.

  The router 42 receives the transmission command 246. The router 42 converts the destination global address-port “1.1.1.1: 30001” of the transmission command 246 into a local address-port “192.168.0.100:50001”. The router 42 transmits a transmission command 248 including the transmission destination local address-port to the receiving terminal 50.

  The data reception service application 74 of the reception terminal 50 receives the transmission command 248. That is, the data reception service application 74 executes processing for receiving the content data 124. When the reception of the content data 124 is completed, the data reception service application 74 executes a process for terminating the data reception service application 74 (S50).

  As described above, if the router 42 is a Full Cone NAT, YES is determined in S42 described above, and the process proceeds to S60 in FIG. In S <b> 60, the delivery notification service application 72 executes a second instruction process for supplying the second instruction 250 to the data reception service application 74. As a result, the data reception service application 74 executes an inquiry process for transmitting the inquiry command 252 using the address of the STUN server 10 as a transmission destination (S62). The inquiry command 252 includes a source local address-port “192.168.0.100:50001”.

  The router 42 receives the inquiry command 252. The router 42 converts the local address-port “192.168.0.100:50001” of the transmission source of the inquiry command 252 to the global address-port “1.1.1.1:30001”. The router 42 transmits an inquiry command 254 including the global address-port of the transmission source to the STUN server 10.

  The STUN server 10 receives the inquiry command 254. The STUN server 10 identifies the source global address-port “1.1.1.1: 30001” by analyzing the inquiry command 254. The STUN server 10 transmits a response 256 including the specified global address-port.

  The data reception service application 74 of the receiving terminal 50 receives the response 256. The data reception service application 74 analyzes the response 256 to acquire the global address-port “1.1.1.1: 30001”. The data reception service application 74 executes notification processing for supplying the notification 258 including the global address-port “1.1.1.1: 30001” to the distribution notification service application 72 (S64). When S64 ends, the process proceeds to S70 of FIG.

  In S70, the distribution notification service application 72 sends a request command 260 to the transmission destination global address-port 224 (that is, the data distribution application 122 of the transmission terminal 100) included in the second command 226 of FIG. Execute request processing to send. The request command 260 includes the source local address-port “192.168.0.100:50000” and the global address-port “1.1.1.1:30001” included in the notification 258. .

  The router 42 receives the request command 260. The router 42 converts the local address-port “192.168.0.100:50000” of the transmission source of the request command 260 into the global address-port “1.1.1.1:30000”. The router 42 transmits to the transmitting terminal 100 a request command 262 including the source global address-port.

  The data distribution application 122 of the transmission terminal 100 receives the request command 262. The data distribution application 122 acquires the global address-port “1.1.1.1: 30001” by analyzing the request command 262. The data distribution application 122 can acquire the global address-port “1.1.1.1: 30001” included in the request command 262 by executing analysis at the application layer level. The data distribution application 122 executes a data transmission process for transmitting the transmission command 264 using the global address-port “1.1.1.1: 30001” as a transmission destination (S72). The transmission command 264 includes content data 124 and a destination global address-port “1.1.1.1: 30001”.

  The router 42 receives the transmission command 264. The router 42 converts the destination global address-port “1.1.1.1: 30001” of the transmission command 264 into a local address-port “192.168.0.100:50001”. The router 42 transmits a transmission command 266 including the transmission destination local address-port to the reception terminal 50.

  The data reception service application 74 of the reception terminal 50 receives the transmission command 266. When the reception of the content data 124 is completed, the data reception service application 74 executes a process for terminating the data reception service application 74 (S74).

  If NO is determined in S24 of FIG. 6, the distribution notification service application 72 sends the global address-port 224 of the transmission source included in the second command 226 of FIG. 6 (that is, the data distribution application of the transmission terminal 100). The non-request process for transmitting the non-request command 268 is executed with the address 122) as the transmission destination (S78). Unlike the request command 260, the non-request command 268 does not include the global address-port “1.1.1.1: 30001”. When receiving the non-request command 268, the transmission terminal 100 ends the process for distributing the content data 124 to the reception terminal 50.

  The data communication system 2 of the present embodiment has been described in detail. The receiving terminal 50 has two applications 72 and 74 for allowing distribution of the content data 124. Different global port numbers (30000 and 30001) are assigned to the applications 72 and 74, respectively. The global port number “30000” assigned to the distribution notification service application 72 is registered in the connection management server 20. Even if a third party accesses the connection management server 20 and obtains the global IP address “1.1.1.1” and the port number “30000” illegally, the port number “30000” is assigned. The distribution notification service application 72 that is present does not execute the process of receiving the content data 124. On the other hand, the port number “30001” assigned to the data reception service application 74 that executes the process of receiving the content data 124 is not registered in the connection management server 20. Therefore, a third party cannot obtain the port number “30001” even when accessing the connection management server 20. It can be suppressed that a third party distributes data toward the port number “30001”. When the receiving terminal 50 of the present embodiment is used, it is possible to suppress distribution of content data 124 that the user does not want.

  In the present embodiment, when the router 42 is a Full Cone NAT, the delivery notification service application 72 transmits a request command 260 (see S70 in FIG. 9). That is, the transmission source of the request command 260 is the distribution notification service application 72. Therefore, even if a third party analyzes the request command 260 at a lower layer (for example, TCP / IP layer) level, the global address-port number “1.1. Only 1.1: 30000 "can be acquired. In order to obtain the global address-port number “1.1.1.1: 30001” of the data reception service application 74 included in the request command 260, analysis at a higher layer level (for example, the application layer) is necessary. is there. It can be said that the global address-port number of the data reception service application 74 is difficult to leak. In this embodiment, the non-request command 268 does not include the global address-port number of the data reception service application 74. Also in this respect, the global address-port number of the data reception service application 74 is difficult to leak.

  A third party illegally acquires the global address-port number of the data reception service application 74 from the request command 262 (see FIG. 9), and sends data (hereinafter referred to as illegal transmission data) toward the global address-port number. May be sent. In this embodiment, each time the data reception service application 74 is activated, a different local port number is assigned to the data reception service application 74. As a result, every time the data reception service application 74 is activated, the global port number assigned to the data reception service application 74 by the router 42 also changes. Since the global port number of the data reception service application 74 changes, the data reception service application 74 can be prevented from receiving unauthorized transmission data.

(First modification of the embodiment)
The receiving terminal 50 may have the same function as the transmitting terminal 100. That is, the receiving terminal 50 may have the data distribution application 122. In this case, information regarding the receiving terminal 96 may be registered in the connection management server 20, and the receiving terminal 50 may transmit content data to the receiving terminal 96. The receiving terminal 50 may execute the first inquiry process in S8 in FIG. 5, the second inquiry process in S20 in FIG. 6, the data transmission process in S48 in FIG. 7 or S72 in FIG. 9 in accordance with the data distribution application 122. Good.

(Second modification of the embodiment)
In the above embodiment, the delivery notification service application 72 of the receiving terminal 50 displays the inquiry message 222 included in the second commands 220 and 226 in FIG. 6, and executes the determination process of S24 according to the user's selection operation. However, the storage area 80 of the receiving terminal 50 may store a terminal ID of a terminal (for example, the transmitting terminal 100) that the user desires to distribute data. The second commands 220 and 226 may include the terminal ID of the transmission terminal 100. The delivery notification service application 72 may determine YES in S24 when the terminal ID included in the second commands 220 and 226 is stored in the storage area 80, and may determine NO in S24 otherwise.

(Third modification of the embodiment)
In the above embodiment, in the request process of S70 of FIG. 9, a request command 260 including a combination of the global IP address “1.1.1.1” and the port number “30001” is transmitted. However, the request command 260 may include only the port number “30001” instead of the above combination (that is, the global IP address “1.1.1.1” may not be included). Even in this case, the transmission terminal 100 can specify the global IP address “1.1.1.1” based on the transmission source information included in the request command 262.

(Fourth modification of the embodiment)
The STUN server 10 and the connection management server 20 may be integrally configured. Further, two or more other devices (for example, the STUN server 10 and the router 42) described in the embodiments may be configured integrally.

  As can be seen from the above description, the receiving terminal 50, the transmitting terminal 100, the connection management server 20, the STUN server 10, and the router 42 of the present embodiment are respectively a data receiving terminal, a data transmitting terminal, a first server, It corresponds to the second server and router. In addition, the control unit 52 that executes the delivery notification service application 72 and the data reception service application 74 of the receiving terminal 50 corresponds to the first service processing unit and the second service processing unit of the data receiving terminal, respectively. Further, the global IP address “1.1.1.1” of the receiving terminal 50 corresponds to the first address, the global port number “30000” of the delivery notification service application 72 and the global port number “30000” of the data reception service application 74. 30001 "corresponds to the first port number and the second port number, respectively.

  The command transmission process (S4 in FIG. 5) corresponds to the process executed by the registration processing unit of the present invention, and the process of receiving the second command 226 shown in FIG. 6 is executed by the notification reception processing unit of the present invention. Corresponding to the process. Further, the request processing (S46) for transmitting the request command 242 shown in FIG. 7 and the request processing (S70) for transmitting the request command 260 shown in FIG. Corresponds to the transmission process. The processing for receiving the transmission command 248 including the content data 124 illustrated in FIG. 7 and the processing for receiving the transmission command 266 including the content data 124 illustrated in FIG. 9 correspond to the processing executed by the data reception processing unit. To do.

  Note that the processing (FIG. 8) for transmitting the inquiry command 252 and receiving the response 256 shown in FIG. 8 corresponds to the processing executed by the global port number acquisition processing unit of the present invention. Further, the non-request process (S76) for transmitting the non-request command 268 shown in FIG. 9 corresponds to the negative response transmission process executed by the negative response transmission processing unit. Further, the start process (S40 in FIG. 7) corresponds to the process executed by the start processing unit, and the end process (S50 in FIG. 7, S74 in FIG. 9) corresponds to the process executed by the end processing unit. .

  Another data receiving terminal of the present invention corresponds to the receiving terminal 96 described in the first modified example. The combination acquisition unit, notification transmission unit, and data transmission unit of the present invention are realized by the reception terminal 50 having the data distribution application 122. The process of the combination acquisition unit corresponds to the first inquiry process (S8 in FIG. 5). The second address corresponds to a global IP address (for example, “1.1.1.2”) assigned to the receiving terminal 96. The third port number corresponds to a global port number (for example, “40000”) assigned to the distribution notification service application of the receiving terminal 96. The notification transmission unit corresponds to the second inquiry process (S20 in FIG. 6). The data transmission means corresponds to the data transmission process (S48 in FIG. 7 and S72 in FIG. 9). The fourth port number corresponds to a global port number (for example, “40001”) assigned to the data reception service application of the receiving terminal 96.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2: data communication system, 4: internet, 10: STUN server, 20: connection management server, 22: terminal information storage unit, 40: private network, 42: router, 50 receiving terminal, 72: delivery notification service application, 74: Data reception service application, 90: private network, 92: router, 96: reception terminal, 100: transmission terminal, 122: data distribution application, 124: content data

Claims (8)

A data receiving terminal communicably connected to the data transmitting terminal,
A first service processing unit;
A second service processing unit;
With
The first service processing unit
A registration processing unit for registering a combination of a first address assigned to the data receiving terminal and a first port number assigned to the first service processing unit in a first server;
The data transmission terminal that acquired the combination of the first address and the first port number from the first server receives a specific notification transmitted by using the combination of the first address and the first port number as a transmission destination. A notification reception processing unit,
With
At least one of the first service processing unit and the second service processing unit is:
A positive response transmission processing unit for transmitting a positive response including a second port number assigned to the second service processing unit to the data transmission terminal when the specific notification is received;
The second service processing unit
The data transmission terminal that receives the positive response includes a data reception processing unit that receives data transmitted with a combination of the first address and the second port number as a transmission destination. . The data reception terminal according to claim 1, wherein the first service processing unit includes the positive response transmission processing unit. Connected to the data transmission terminal via a router,
The first address is a first global address;
The first port number is a first global port number;
The second port number is a second global port number;
The notification reception processing unit receives the specific notification via the router,
The data reception terminal according to claim 1, wherein the data reception processing unit receives the data via the router. The second service processing unit further includes a global port number acquisition processing unit that acquires the second global port number from the second server by transmitting a specific packet to the second server,
The positive response transmission processing unit transmits the positive response including the second global port number acquired by the global port number acquisition processing unit to the data transmission terminal when the specific notification is received. The data receiving terminal according to claim 3, wherein: The positive response transmission processing unit transmits the positive response to the data transmission terminal when the specific notification is received and the data transmission terminal is permitted to transmit the data,
The first service processing unit sends a negative response not including the second port number to the data transmission when the specific notification is received and the data transmission terminal is not permitted to transmit the data. The data receiving terminal according to any one of claims 1 to 4, further comprising a negative response transmission processing unit that transmits to the terminal. 6. The data receiving terminal according to claim 1, wherein each time the second service processing unit is activated, a different port number is assigned to the second service processing unit. The first service processing unit further includes an activation processing unit that activates the second service processing unit when the specific notification is received,
The second service processing unit further includes a termination processing unit that terminates the second service processing unit when the data reception processing unit completes receiving the data. The data receiving terminal according to any one of 6. A computer program for a data receiving terminal communicably connected to a data transmitting terminal,
A first service process;
A second service process;
To the computer,
The first service process includes:
A registration process for registering a combination of a first address assigned to the data receiving terminal and a first port number assigned to the first service process in a first server;
The data transmission terminal that acquired the combination of the first address and the first port number from the first server receives a specific notification transmitted by using the combination of the first address and the first port number as a transmission destination. Notification receiving processing to include,
At least one of the first service process and the second service process is:
A positive response transmission process for transmitting a positive response including a second port number assigned to the second service process to the data transmission terminal when the specific notification is received;
The second service process includes
A computer program comprising: a data reception process in which the data transmission terminal that has received the positive response receives data to be transmitted with a combination of the first address and the second port number as a transmission destination.

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