JP2008311942A - Data transmitter and data transmitting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently use a communication band when tunneling and transmitting a packet. <P>SOLUTION: A tunneling packet generating part 106 combines payload data of a plurality of RTP packets generated in an RTP packet generating part 105 into one, generates an HTTPS packet that can transmit an FW, transmits the HTTPS packet to a receiver that has made a transmission request for the packet, suppresses the overhead of a packet header small and can efficiently use the communication band. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data transmission device, a data transmission method, a program, and a recording medium, and more particularly to a technique suitable for use in data transmission by tunneling while efficiently using a communication band.

  Conventionally, a tunneling technique is generally used as a technique for connecting a private network via the Internet. The tunneling technique enables communication by encapsulating and encapsulating a packet with a packet of another protocol even when communication cannot be performed with a protocol originally intended for communication.

  For example, HTTP tunneling is used as a means for crossing a firewall (hereinafter simply referred to as FW) using RTP (RealTime Transport Protocol) packets. RTP is a protocol defined by IETF (The Internet Engineering Task Force). RTP is a protocol for transmitting multimedia data such as moving images and voices in real time via a network (for example, see Non-Patent Document 1).

  However, FW is designed to protect private networks and is usually set up to block RTP packets. Therefore, when transmitting using RTP packets, a method called HTTP tunneling is used in which communication is performed over FW by encapsulating and encapsulating RTP packets with HTTP or HTTPS.

Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", RFC3550, July 2003.

  However, when large-capacity data such as multimedia data such as moving images and voices is transmitted using the HTTP tunneling method, the number of packets becomes very large. For this reason, for example, simply encapsulating an RTP packet with HTTP or the like as it is results in a large overhead of the packet header, resulting in a problem that the communication band is wasted.

  An object of the present invention is to make it possible to efficiently use a communication band when a packet is tunneled and transmitted in view of the above-described problems.

The data transmission device of the present invention generates or acquires a plurality of packets according to the protocol of the network segment to which the device belongs, and combines the payload data of the generated or acquired packets into one to transmit the packet When the data format is specified by the tunneling method from the receiving apparatus that has made the request, the packet generating means for generating the tunneled packet and the packet generated by the packet generating means are transmitted to the receiving apparatus. And a packet transmission means.
Another feature of the data transmitting apparatus of the present invention is that a transmission request receiving means for receiving a packet transmission request from a receiving apparatus connected to a network, and a packet transmission request received by the transmission request receiving means. Correspondingly, the first packet generating means for generating a plurality of packets according to the protocol of the network segment to which the device belongs, and the payload data of the plurality of packets generated by the first packet generating means are combined into one. Then, when the data format is specified by the tunneling method from the receiving device, the second packet generating means for generating the tunneled packet and the first packet generating means or the second packet generating Packet transmitting means for transmitting the packet generated by the means to the receiving device It is characterized in.

The data transmission method of the present invention generates or acquires a plurality of packets according to the protocol of the network segment to which the device belongs, and combines the payload data of the generated or acquired packets into one to transmit the packet A packet generating step for generating a tunneled packet and a packet for transmitting the packet generated in the packet generating step to the receiving device when the data format is specified by the tunneling method from the receiving device that has made the request And a transmission step.
According to another aspect of the data transmission method of the present invention, there is provided a transmission request receiving step of receiving a packet transmission request from a receiving device connected to a network, and a response to the packet transmission request received in the transmission request receiving step. A first packet generation step for generating a plurality of packets in accordance with the protocol of the network segment to which the device belongs, and the payload data of the plurality of packets generated in the first packet generation step are combined into one When the data format is specified by the tunneling method from the receiving device, in the second packet generating step for generating the tunneled packet and in the first packet generating step or the second packet generating step A packet transmission step of transmitting the generated packet to the receiving device. And features.

The program of the present invention generates or acquires a plurality of packets according to the protocol of the network segment to which the device belongs, combines the payload data of the generated or acquired packets into one, and sends a packet transmission request. A packet generation step for generating a tunneled packet, and a packet transmission step for transmitting the packet generated in the packet generation step to the reception device when the data format is specified by the tunneling method from the received reception device And making the computer execute.
According to another aspect of the program of the present invention, a transmission request receiving step for receiving a packet transmission request from a receiving device connected to a network, and a packet transmission request received in the transmission request receiving step. A first packet generation step for generating a plurality of packets in accordance with the protocol of the network segment to which the device belongs, and the payload data of the plurality of packets generated in the first packet generation step are combined into one When the data format is specified by the tunneling method from the receiving device, in the second packet generating step for generating the tunneled packet and in the first packet generating step or the second packet generating step A packet transmission step of transmitting the generated packet to the receiving device. Characterized in that to execute the data.

  A recording medium according to the present invention records any one of the programs described above.

  According to the present invention, when the payload data of a plurality of packets are combined into one and the data format is specified by the tunneling method from the receiving apparatus, a tunneled packet is generated. Thereby, the overhead of a packet header can be suppressed small when tunneling and transmitting a packet. Therefore, the communication band can be used efficiently.

(First embodiment)
Hereinafter, a preferred embodiment in which a data transmission apparatus of the present invention is applied to an apparatus for transmitting moving image data or audio data will be described in detail with reference to the drawings. In the following, an embodiment in which the present invention is applied to a data transmission apparatus using RTP and HTTPS as data transmission protocols will be described. However, the protocol to be used is not limited to RTP and HTTPS, but can be applied to other protocols in the same layer or other protocols in the OSI reference model.

  The functional configuration of the data transmission apparatus according to the present embodiment will be described with reference to the block diagram shown in FIG. Each of the data transmission devices of the present embodiment may be realized by a single computer device, or may be realized by distributing each function to a plurality of computer devices as necessary. When configured by a plurality of computer devices, it is assumed that the network device is configured by a LAN (Local Area Network) or the like so as to communicate with each other.

  As illustrated in FIG. 1, the data transmission device 100 includes a moving image encoding unit 101, a voice encoding unit 102, a packet configuration determination unit 103, a packet generation unit 104, a transmission request reception unit 107, and packet transmission. Part 108. The packet generation unit 104 includes an RTP packet generation unit 105 and a tunneling packet generation unit 106. In FIG. 1, reference numerals 111 and 112 denote transmission paths represented by various networks. In this embodiment, a transmission request sent from a receiving apparatus is received, or packetized moving image data and audio data are transmitted. Network.

  The moving image encoding unit 101 compresses and encodes moving image data input from a video input device 109 such as a video camera or a Web camera using, for example, the MPEG-4 method. The moving image data compression method is not limited to the MPEG-4 method, but the MPEG-2 method or H.264 format. An encoding method such as the H.264 method can be used.

  On the other hand, the audio encoding unit 102 compresses and encodes audio data input from the audio input device 110 such as a microphone by, for example, the ADPCM method. The audio data encoding method is not limited to the ADPCM method, and an encoding method such as a PCM method or an AMR method can be used. The moving image data compressed and encoded by the moving image encoding unit 101 or the audio data compressed and encoded by the audio encoding unit 102 is input to the packet generation unit 104 and packetized.

FIG. 2 is a flowchart illustrating an example of a processing procedure until the data transmission apparatus 100 according to the present embodiment transmits a packet.
First, the data transmitting apparatus 100 receives the transmission request transmitted from the receiving apparatus at the transmission request receiving unit 107 (step S201). As a protocol for controlling this transmission request, for example, a protocol such as RTSP (Real Time Streaming Protocol) or HTTP can be used.

  When the transmission request receiving unit 107 receives a transmission request from the receiving device, the packet configuration determining unit 103 packetizes the data input from the moving image encoding unit 101 or the audio encoding unit 102 so as to packetize the data. (Step S202). Upon receiving the packetization instruction, the packet generation unit 104 first functions as a first packet generation unit, and the RTP packet generation unit 105 generates an RTP packet (step S203).

  Next, the packet configuration determination unit 103 analyzes the transmission request received from the receiving device (step S204). Then, it is determined whether the configuration of the packet to be transmitted to the receiving device is a tunneling packet (step S205). This determination can be made from information on the data format (for example, MIME type) specified in the transmission request. That is, when the data format is specified by the tunneling method, it is converted into a tunneling packet, and if it is not specified, it can be determined that tunneling is not performed. In addition to the data format, the determination can be made from the destination IP address and the port number specified in the transmission request. Based on these transmission destination IP addresses and port numbers, it is possible to determine that a tunneling packet is formed if the FW cannot be passed, and that no tunneling is made if the FW can be passed.

  If the result of determination in step S205 is that the packet configuration is not a tunneling packet, the RTP packet generated by the RTP packet generation unit 105 is transmitted to the receiving device as it is, and the process proceeds to step S207. On the other hand, if the result of determination in step S205 is that the packet configuration is a tunneling packet, the packet generator 104 functions as a second packet generator, and the tunneling packet generator 106 generates a tunneling packet (step S204). ). Details of the method for generating the tunneling packet will be described later with reference to FIG.

  Finally, the packet transmission unit 108 transmits the RTP packet generated by the RTP packet generation unit 105 or the tunneling packet generated by the tunneling packet generation unit 106 to a predetermined destination (step S207). At this time, the packet transmission unit 108 transmits the packet as a TCP / IP packet or a UDP / IP packet.

FIG. 3 is a flowchart illustrating an example of a processing procedure in which the tunneling packet generation unit 106 generates a packet in the present embodiment.
First, the tunneling packet generation unit 106 initializes the number of payload data n of the RTP packet to be combined to “0” (step S301). Next, the RTP packet generated by the RTP packet generation unit 105 is acquired (step S302). Then, 1 is added to the payload data number n (step S303).

  Then, a size s is calculated by adding the header size of the tunneling packet to the total payload size of n RTP packets (step S304). Here, the header of the tunneling packet includes, for example, an Ethernet (registered trademark) header, an IP header, a TCP header, an HTTPS header, and an RTP header in order from the lower layer, and the size s is the size of the entire tunneling packet. Note that the protocol used for tunneling is not limited to HTTPS, and a protocol such as HTTP can be used.

  Next, the size s is compared with an MTU (Maximum Transmission Unit) size to determine whether the size s is larger than the MTU size (step S305). The MTU size is the maximum value of data that can be transmitted in a single transfer in the communication network, and about 1500 bytes is optimal for Ethernet frames, and about 576 bytes is optimal for dial-up connections.

  If the size s is equal to or smaller than the MTU size (within the range of the MTU size) as a result of the determination in step S305, the process returns to step S302 to obtain the next RTP packet. On the other hand, if the size s is larger than the MTU size as a result of the determination in step S305, all of the acquired payload data of n RTP packets cannot be configured as the current tunneling packet. Therefore, one HTTPS packet is generated by combining payload data of (n−1) RTP packets acquired from the RTP packet generation unit 105 so far and adding an HTTPS header (step S306). Then, the tunneling packet generation process ends. Note that the same procedure is used when generating an HTTP packet instead of an HTTPS packet.

FIG. 4 is a diagram illustrating an example of a detailed structure of a packet transmitted by the data transmission apparatus 100 of the present embodiment and a detailed structure of a conventional tunneling packet.
FIG. 4A is a diagram illustrating a packet structure when the data transmitting apparatus 100 transmits to a receiving apparatus in the same network segment that does not pass through the FW, and each packet includes an RTP header and an RTP payload. RTP packet. In FIG. 4A, protocol headers (for example, an Ethernet header, an IP header, a UDP header, etc.) lower than the RTP header are not shown. In addition, the RTP header size of each RTP packet is 12 bytes, and the payload size is 400 bytes. The standard size of the RTP header is 12 bytes, but if an option is added, it may exceed 12 bytes.

  FIG. 4B is a diagram illustrating a structure of a tunneling packet generated from the RTP packet illustrated in FIG. 4A by the data transmission device 100 according to the present embodiment. As shown in FIG. 4B, the tunneling packet of this embodiment adds an HTTPS header to the RTP packet obtained by combining the payload (1) to the payload (3) of the RTP packet shown in FIG. And encapsulated. In FIG. 4B, protocol headers (for example, an Ethernet header, an IP header, a TCP header, etc.) lower than the HTTPS header are not shown.

  When the payload size of each RTP packet shown in FIG. 4A is 400 bytes, when payload (1) to payload (4) are combined, the total packet size exceeds 1500 bytes of the MTU size of the Ethernet frame. End up. Therefore, in this embodiment, the tunneling packet is configured to combine payload (1) to payload (3), and payload (4) is configured by the next tunneling packet.

  On the other hand, FIG.4 (c) is a figure which shows the structure of the conventional tunneling packet produced | generated from the packet shown to Fig.4 (a). In FIG. 4C, as in FIG. 4B, protocol headers (for example, an Ethernet header, an IP header, and a TCP header) at a lower layer than the HTTPS header are not shown. As shown in FIG. 4 (c), each conventional tunneling packet has a simple configuration in which an HTTPS header is added to each RTP packet shown in FIG. 4 (a) and encapsulated.

  Next, the structure of the tunneling packet shown in FIG. 4B is compared with the structure of the tunneling packet shown in FIG. Compared to the tunneling packet shown in FIG. 4C, the tunneling packet shown in FIG. 4B can reduce header information for 2 × (tunneling packet header size + RTP header size) bytes. Therefore, n is the number of payload data of RTP packets that are combined during tunneling. In this case, the tunneling packet according to the present embodiment can reduce the header information of (n−1) × (tunneling packet header size + RTP header size) bytes compared to the tunneling packet according to the prior art.

FIG. 5 is a diagram illustrating a configuration example of the entire system including the data transmission device of the present embodiment.
The first network segment 500 and the second network segment 502 that are isolated from each other are connected to each other via the Internet 501. The data transmission device 504 and the reception device 503 in the first network segment 500 are connected to the Internet 501 via the FW 505. In addition, the receiving device 507 and the receiving device 508 in the second network segment 502 are connected to the Internet 501 via the FW 506.

  It is assumed that the FW 505 and the FW 506 are set so that a normal Web port is open, and other communication is set to be blocked. As a normal Web port number, the 80th port is generally used for HTTP, and the 443th port is used for HTTPS.

  The reception device 503 can receive the RTP packets 509 to 511 transmitted from the data transmission device 504 in the first network segment 500. However, RTP packets 509 to 511 are blocked at FW 505. For this reason, the receiving device 507 and the receiving device 508 in the second network segment 502 cannot receive the RTP packets 509 to 511 transmitted from the data transmitting device 504 in the different first network segment 500.

  However, the tunneling packet 512 transmitted by the data transmission apparatus 504 according to the present embodiment can pass if the FW is set so that the normal Web port is open. Therefore, the tunneling packet 512 transmitted from the data transmission device 504 passes through the FW 505 and the FW 506 without changing any setting. Then, the data is transmitted to the receiving device 507 and the receiving device 508 in different second network segments 502.

  As described above, according to the data transmitting apparatus of the present embodiment, the payload data of a plurality of RTP packets are combined into one payload data to generate an HTTPS packet that can pass through the FW. As a result, RTP packets that are normally blocked by FW can pass through FW while pretending to be Web communication during tunneling. Further, the overhead of the packet header can be kept small, and the communication band can be used efficiently.

(Second Embodiment)
In the data transmission apparatus 100 according to the first embodiment, the packet generation unit 104 receives the moving image data compressed and encoded by the moving image encoding unit 101 or the audio data compressed and encoded by the audio encoding unit 102. Packet was generated. In the present embodiment, as shown in FIG. 6, a configuration in which the packet generation unit 104 acquires moving image data or audio data from other than the moving image encoding unit and the audio encoding unit will be described.

FIG. 6 is a block diagram illustrating a basic configuration example of the data transmission device 600 according to the present embodiment. In FIG. 6, the same components as those in FIG.
In FIG. 6, multimedia content (multimedia data) is recorded in the multimedia data storage device 602. The multimedia data extraction unit 601 reads the multimedia data stored in the multimedia data storage device 602 and outputs it to the packet generation unit 104. As in the first embodiment, the multimedia data input to the packet generation unit 104 is transmitted in an optimal packet configuration according to the receiving device of the transmission destination.

  The data transmission device 600 of this embodiment reads the multimedia data recorded in the multimedia data storage device 602, generates a packet, and transmits the packet to the reception device. As a result, even for recorded multimedia data, an RTP packet that is normally blocked by the FW can be made to pass through the FW while making it appear as Web communication during tunneling. Further, the overhead of the packet header can be kept small, and the communication band can be used efficiently.

(Third embodiment)
In the configuration of the entire system including the data transmission apparatus in the first embodiment shown in FIG. 5, the data transmission apparatus 504 has a function of generating both RTP packets and tunneling packets. In this embodiment, as shown in FIG. 7, an example in which a tunneling packet is generated in a device different from the packet generation device will be described.

FIG. 8 is a block diagram showing a functional configuration example of the tunneling server in the present embodiment.
In FIG. 8, a packet receiving unit 801 receives an RTP packet transmitted from the packet generation device 701. Then, the tunneling packet generation unit 802 generates a tunneling packet from the acquired RTP packet. A method for generating a tunneling packet is the same as that in the first embodiment, and thus description thereof is omitted. Then, the packet transmission unit 803 transmits the generated tunneling packet via the transmission path 804.

FIG. 7 is a diagram showing a configuration of the entire system including a tunneling server (data transmission device) in the present embodiment. In FIG. 7, the same components as those in FIG.
In FIG. 7, a first network segment 700 and a second network segment 502 that are isolated from each other are connected to each other via the Internet 501. Further, a tunneling server 702 is installed between the packet generation device 701 and the FW 505 in the first network segment 700.

  The packet generation device 701 of this embodiment does not have a tunneling packet generation function. RTP packets 509 to 511 transmitted from the packet generation device 701 to the reception device 507 and the reception device 508 in different second network segments 502 are first input to the tunneling server 702. Then, the tunneling server 702 encapsulates the packet with the optimum packet configuration as in the first embodiment, and generates a tunneling packet 512. The tunneling packet 512 generated in the tunneling server 702 is transmitted to the reception device 507 and the reception device 508 in different second network segments 502 without being blocked by the FW 505 and the FW 506.

  According to the tunneling server 702 shown in this embodiment, a tunneling packet is generated from an RTP packet received from a packet generation device 701 that does not have a tunneling packet generation function, and is transmitted to the reception device. In this way, even when the entire system is configured by a packet generation device that does not have a tunneling packet generation function, it is the same as that of the first embodiment only by installing a tunneling server between the packet generation device and the FW. An effect is obtained.

  As described above, according to the present embodiment, the tunneling server 702 combines the payload data of a plurality of RTP packets into one to generate an HTTPS packet that can pass through the FW. As a result, RTP packets that are normally blocked by FW can pass through FW while pretending to be Web communication during tunneling. Further, the overhead of the packet header can be kept small, and the communication band can be used efficiently.

(Other embodiments according to the present invention)
An object of the present invention is to supply a recording medium on which a program code of software realizing the functions of the above-described embodiments is recorded to a system or apparatus. Needless to say, this can also be achieved by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the recording medium. In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiments, and the computer-readable recording medium storing the program code constitutes the present invention.

  As a recording medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, a DVD, or the like is used. it can.

  Further, the functions of the above-described embodiments are realized by executing the program code read by the computer. In addition to this, the operating system (OS) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. This is also included.

  Further, the program code read from the recording medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. After that, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instruction of the program code, and the function of the above-described embodiment is realized by the processing. Needless to say.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

It is a block diagram which shows the function structural example of the data transmitter in the 1st Embodiment of this invention. 5 is a flowchart illustrating an example of a processing procedure for transmitting a packet by a data transmission device in the first embodiment of the present invention. 5 is a flowchart illustrating an example of a processing procedure in which a tunneling packet generation unit generates a packet in the first embodiment of the present invention. It is a figure which shows the detailed structure of the packet transmitted by the data transmitter in the 1st Embodiment of this invention. It is a figure which shows the structural example of the whole system by the data transmitter in the 1st Embodiment of this invention. It is a block diagram which shows the function structural example of the data transmitter in the 2nd Embodiment of this invention. It is a figure which shows the structural example of the whole system by the tunneling server in the 3rd Embodiment of this invention. It is a block diagram which shows the function structural example of the tunneling server in the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Data transmission apparatus 101 Moving image encoding part 102 Audio | voice encoding part 103 Packet structure determination part 104 Packet generation part 105 RTP packet generation part 106 Tunneling packet generation part 107 Transmission request reception part 108 Packet transmission part 109 Video input apparatus 110 Audio | voice input Device 111 Transmission path 112 Transmission path

Claims (14)

Tunneling is performed from a receiving apparatus that has generated or acquired a plurality of packets in accordance with the protocol of the network segment to which the own apparatus belongs, combined the payload data of the plurality of generated or acquired packets into one, and requested transmission of the packet When the data format is specified by the method, packet generation means for generating a tunneled packet,
A data transmission apparatus comprising: packet transmission means for transmitting the packet generated by the packet generation means to the reception apparatus. A transmission request receiving means for receiving a packet transmission request from a receiving device connected to the network;
First packet generation means for generating a plurality of packets according to the protocol of the network segment to which the device belongs, in response to a packet transmission request received by the transmission request receiving means;
Combines the payload data of a plurality of packets generated by the first packet generation unit into one, and generates a tunneled packet when the data format is specified by the tunneling method from the receiving device Second packet generating means for
A data transmission device comprising: a packet transmission unit configured to transmit a packet generated by the first packet generation unit or the second packet generation unit to the reception device.   The second packet generation unit generates a packet by combining the payload data of the plurality of packets generated by the first packet generation unit into one so as to become the maximum within the range of the MTU size. The data transmission device according to claim 2, wherein the data transmission device is a data transmission device. Determining means for determining whether the data format specified in the transmission request of the packet received by the transmission request receiving means is a tunneling method;
The second packet generation unit generates a tunneled packet as a packet to be transmitted to the receiving device when a tunneling method is designated as a result of the determination by the determination unit. 2. The data transmission device according to 2. Whether the packet generated by the first packet generator can pass through the firewall based on the destination IP address and port number specified in the transmission request of the packet received by the transmission request receiver A determination means for determining whether or not
The second packet generating means is a tunneled packet as a packet to be transmitted to the receiving apparatus when the packet generated by the first packet generating means cannot pass through the firewall as a result of the determination by the determining means. The data transmission apparatus according to claim 2, wherein the data transmission apparatus generates the data.   The data transmission device according to claim 2, wherein the first packet generation unit generates a packet from encoded moving image data or encoded audio data.   The data transmission apparatus according to claim 2, wherein the first packet generation unit generates an RTP packet.   The data transmission apparatus according to claim 2, wherein the second packet generation unit generates an HTTP packet or an HTTPS packet.   The data transmission apparatus according to claim 1 or 2, wherein the packet transmission unit transmits a packet as a TCP / IP packet or a UDP / IP packet. Tunneling is performed from a receiving apparatus that has generated or acquired a plurality of packets in accordance with the protocol of the network segment to which the own apparatus belongs, combined the payload data of the plurality of generated or acquired packets into one, and requested transmission of the packet When the data format is specified by the method, a packet generation process for generating a tunneled packet,
And a packet transmission step of transmitting the packet generated in the packet generation step to the receiving device. A transmission request receiving step of receiving a packet transmission request from a receiving device connected to the network;
A first packet generation step of generating a plurality of packets according to the protocol of the network segment to which the device belongs, in response to the packet transmission request received in the transmission request reception step;
The payload data of the plurality of packets generated in the first packet generation step are combined into one, and when the data format is specified by the tunneling method from the receiving apparatus, a tunneled packet is generated. A second packet generation step;
A data transmission method comprising: a packet transmission step of transmitting a packet generated in the first packet generation step or the second packet generation step to the reception device. Tunneling is performed from a receiving apparatus that has generated or acquired a plurality of packets in accordance with the protocol of the network segment to which the own apparatus belongs, combined the payload data of the plurality of generated or acquired packets into one, and requested transmission of the packet When the data format is specified by the method, a packet generation process for generating a tunneled packet,
A program causing a computer to execute a packet transmission step of transmitting a packet generated in the packet generation step to the receiving device. A transmission request receiving step of receiving a packet transmission request from a receiving device connected to the network;
A first packet generation step of generating a plurality of packets according to the protocol of the network segment to which the device belongs, in response to the packet transmission request received in the transmission request reception step;
The payload data of the plurality of packets generated in the first packet generation step are combined into one, and when the data format is specified by the tunneling method from the receiving apparatus, a tunneled packet is generated. A second packet generation step;
A program causing a computer to execute a packet transmission step of transmitting a packet generated in the first packet generation step or the second packet generation step to the receiving device.   14. A computer-readable recording medium on which the program according to claim 12 or 13 is recorded.

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