JP3693953B2 - Broadcast transmission method, apparatus, and program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication method, apparatus, and program, and more particularly, to a broadcast transmission method, apparatus, and program for transmitting the same data to all terminals on a network.
[0002]
[Prior art]
When transmitting the same data to a plurality of addresses existing in a network, a broadcast type communication in which a dedicated address is determined in advance and data destined for the address is distributed to all addresses belonging to the network It has been known. For example, in IP (Internet Protocol), an address in which the host address part is all 1 in binary is prepared as a broadcast address. Such a broadcast transmission method using a broadcast address has an advantage that the network traffic can be greatly reduced, but has a drawback that it is not suitable for broadcast transmission between networks. The reason for this is that, from the viewpoint of security, such as the occurrence of so-called broadcast storms, a network repeater such as a router at the management boundary of the network is set not to pass packets destined for the broadcast address. It is because that is done.
[0003]
Therefore, in such a case, a method is generally used in which the destination terminal stores the destination list of the terminal on the destination network, and the data is unicast based on the list. In Japanese Patent Laid-Open No. 2000-236328, when the same data is transmitted to a plurality of terminals existing in the network, the above destination table and message are encapsulated and transmitted to any terminal of the target network. Then, the terminal transfers only the message part to other terminals of the network to which the device belongs, and when there is a next destination terminal, the encapsulated message is forwarded to the next destination terminal as a relay terminal. How to do is introduced.
[0004]
[Problems to be solved by the invention]
However, in the former method, it is necessary to update the destination list in accordance with an increase or decrease in the number of terminals on the network serving as a destination or an address change, and the terminals included in the list at the source terminal Since the number of data transmission processes is proportional to the number of network traffic, network traffic may increase. Further, even if the method described in the latter publication is used, it is still necessary to prepare a destination table for which transmission is desired.
[0005]
Therefore, the problem to be solved by the present invention is that it is possible to greatly reduce the network traffic while maintaining the security function of the network repeater in the broadcast transmission between the networks. An object of the present invention is to provide a broadcast transmission method and program capable of broadcasting the same data without being aware of the configuration.
[0006]
[Means for Solving the Problems]
According to a first aspect of the present invention that provides means for solving the above-described problem, a broadcast that transmits the same data from a transmission source terminal outside a certain network to all the terminals on the network. In the transmission method, the source terminal transmits data to all terminals on the network, and a code indicating that the data is data to be transmitted to all terminals on the network Are generated, transmitted to a predetermined terminal on the network, and the terminal that has received the packet detects the code from the packet and determines a data portion included in the packet. Take out, generate a new packet with the broadcast address as the destination address, and broadcast to all terminals on the network To signal, broadcast transmission method is provided, wherein.
[0007]
In addition, if it is important to perform broadcast communication without being aware of the configuration of the destination network, the same data is transmitted from all terminals outside the network to all terminals on the network. In the broadcast transmission method, the source terminal transmits data to all terminals on the network, and the data is data to be transmitted to all terminals on the network. A packet including the code shown in FIG. 5 and transmitting the packet to an arbitrary address on the network, and the transmission source terminal returns an acknowledgment including at least the reception of the packet as a result of the transmission. If not, change the host address part of the arbitrary address at a predetermined interval, retry, and When the terminal corresponding to the dress receives the packet including the code, at least an acknowledgment including the reception of the packet is returned to the transmission source terminal, and further included in the packet. A broadcast transmission method is provided, which extracts a data portion to be transmitted, generates a new packet having a broadcast address as a destination address, and broadcasts it to all terminals on the network. . In the method, the transmission source terminal stops transmission of the generated packet when the acknowledgment is not obtained from all addresses on the network even by the retry. It is preferable.
[0008]
Moreover, it is preferable that the said network in each said method is an internet protocol network (IP network).
[0009]
More preferably, the network in each of the methods is connected to another network via a network repeater that does not pass a packet whose destination address is a broadcast address.
[0010]
Further, according to the second aspect of the present invention, a packet is received from the transmission source terminal that performs each method, and all the terminals of the network to which the device belongs to receive the packet from the transmission source terminal. A terminal for transmitting information is provided.
[0011]
Further, according to the third aspect of the present invention, there is provided a terminal that receives packets from the transmission source terminal and the transmission source terminal and performs broadcast transmission to all the terminals of the network to which the device belongs. A program to be executed by a computer is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described. In the present invention, a network (20 in FIG. 1) including a group of devices (21, 22, and 23 in FIG. 1) to which an address is assigned and the network (20 in FIG. 1) are connected via a network repeater 100. It is comprised from the terminal (2 of FIG. 1) of the connected transmission source.
[0013]
A terminal (for example, 21 in FIG. 1) included in a device group (21, 22, 23 in FIG. 1) to which an address on the network (20 in FIG. 1) is assigned monitors the received packet, Means is provided for confirming whether or not a code indicating that the data included in the packet is data to be transmitted to all terminals of the network is included at a predetermined position. A list of terminals (7 in FIG. 1) provided with such means is stored and held in the storage means of the transmission source terminal (2 in FIG. 1).
[0014]
If the sender terminal (2 in FIG. 1) desires broadcast transmission to all addresses on another network (20 in FIG. 1), the sender terminal (2 in FIG. 1) A code indicating that the desired data is data to be transmitted to all the terminals of the network (20 in FIG. 1) and the data are included in a predetermined position of the packet, and a terminal list (FIG. 1). 7), the packet (6 in FIG. 1) destined for the address of the terminal (for example, 21 in FIG. 1) of the network (20 in FIG. 1) obtained from 7) is generated and transmitted.
[0015]
Since this packet (6 in FIG. 1) is not a packet addressed to the broadcast address, it passes through the network repeater (100 in FIG. 1) and is transferred to the designated terminal (for example, 21 in FIG. 1). .
[0016]
A terminal (for example, 21 in FIG. 1) that has received this packet (6 in FIG. 1) includes a code indicating that the packet is data to be transmitted to all terminals in the network. Is detected. Then, this terminal (for example, 21 in FIG. 1) takes out the data portion (8 in FIG. 1, 53 in FIG. 3) from the packet (6 in FIG. 1), and creates a new packet with the broadcast address as the destination address. (51 in FIG. 3) is generated and transmitted.
[0017]
Since this new packet (51 in FIG. 3) has a broadcast address designated as a destination address, it is forwarded to all addresses on the network (20 in FIG. 3). If 100) in FIG. 3 is set so as not to pass a packet whose destination address is a broadcast address, it is not transferred to another network (for example, 1 in FIG. 3).
[0018]
This enables broadcast transmission on the target network while suppressing the number of transmission packets and the number of transmissions at the transmission source terminal. Moreover, it is not necessary to grasp the specific configuration of the target network on the transmission side. Of course, the network repeater security settings can be maintained at a high level.
[0019]
In the above embodiment, the address of the receiving terminal in the network to transmit in advance is stored and held. However, the source terminal (2 in FIG. 1) sets the desired host address to the target network address. A method of repeating the transmission by changing the host address unit until transmission is performed and an affirmative response is obtained is also a preferable modification.
[0020]
【Example】
Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating an example of a system configuration according to an embodiment of the present invention. Referring to FIG. 1, a system according to an embodiment of the present invention includes a transmission source terminal 2 belonging to a network 1, terminals 21, 22 and 23 belonging to a network 20, and a network repeater 100 connecting both networks. Is included. Note that the number of terminals in each of the above-described networks is illustrated for explanation and is not particularly limited.
[0021]
The network 1 is a network identified by a network address “192.168.10.0/24”.
[0022]
The network 20 is a network whose network address identified by the network address “192.168.20.0/24” is 24 bits. The broadcast address of the network 20 will be described as being defined as “192.168.20.255”.
[0023]
The terminal 2 is a data transmission source terminal to which an IP (Internet Protocol) address “192.168.10.1” is assigned. Although not shown, the terminal 2 stores desired data and a code (hereinafter referred to as a flag) indicating that the data is data to be transmitted to all terminals of the network at a predetermined position. A program 5 used on the transmission side that constitutes means for generating the packet 6 and means for transmitting the packet 6 to a predetermined terminal on the network 20 is installed to be executable. Further, the terminal 2 stores and holds the terminal list 7 in its storage means.
[0024]
The terminals 21, 22, and 23 are terminals to which IP addresses “192.168.20.21”, “192.168.20.22”, and “192.168.20.23” are respectively assigned. Among these, although not shown, the terminal 21 includes a flag indicating that the data is data to be transmitted to all terminals of the network at the predetermined position of the received packet. If the flag is included in the received packet as a result of the monitoring, a broadcast packet having the broadcast address as the destination address is extracted from the data portion included in the packet. A broadcast program 41 is installed in advance, which constitutes means for generating and means for broadcasting the broadcast transmission packet to all terminals on its own network. The terminal 21 monitors whether or not at least a flag indicating that the data included in the received packet is data to be transmitted to all the terminals of the network is included in the packet. The broadcast program 41 or a part thereof is loaded into the memory.
[0025]
The network repeater 100 is, for example, a device that connects the network 1 and the network 20 such as a router, and does not pass a packet having a broadcast address.
[0026]
An example of the terminal list 7 is shown in FIG. Referring to FIG. 2, the terminal list 7 stores a network and an address of a terminal to be a destination when performing broadcast transmission in association with each other. For example, when broadcast transmission is desired to the network 20, the address “192.168.20.21” of the corresponding terminal 21 is selected.
[0027]
Next, the operation of the present embodiment will be described with reference to FIGS. First, when the terminal 2 transmits desired data to the network 20 to be broadcasted, the desired data 8 and a flag indicating that the data should be transferred to all terminals in the same network. 9 is selected, the address “192.168.20.21” of the terminal 21 belonging to the network 20 is selected from the terminal list 7, and the packet 6 destined for the address is generated and transmitted. Since the packet 6 is not a packet addressed to the broadcast address, it passes through the network repeater 100 and is transferred to the terminal 21.
[0028]
The storage location of the flag 9 indicating that the data included in the packet 6 should be transferred to all terminals in the same network is identified on the terminal 21 side as a packet that does not include other flags 9. Although it is not particularly limited as long as it can be detected, for example, it is stored in a specific position (option: OPTIONS) in a header area not shown so as to be identifiable.
[0029]
FIG. 3 is a diagram for explaining processing performed by the terminal 21 that continuously monitors received packets. Referring to FIG. 3, the terminal 21 that continuously monitors the received packet reads the flag 9 from, for example, a specific position (option: OPTIONS) of the header area in the packet 6. The address of the data 53 having the same contents as the data 8 and the broadcast address “192.168.20.255” for transmission to all addresses on the network 20 A broadcast transmission packet 51 storing the address is generated and transmitted.
[0030]
The broadcast transmission packet 51 is sent to all host addresses on the network 20 because the broadcast packet address “192.168.20.255” is the destination.
[0031]
In this way, it is possible to transmit the same data to all terminals of a desired network by performing a single transmission process in the transmission source terminal 2. Of course, as described above, since the packet 6 does not have a broadcast address, the network repeater 100 does not discard it. That is, broadcasting to a desired network is realized while maintaining the security level of the network 20.
[0032]
Next, another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 is a diagram illustrating an example of a system configuration according to the embodiment of this invention. Referring to FIG. 4, a system according to an embodiment of the present invention includes a transmission source terminal 202 belonging to a network 201, terminals 221, 222, and 223 belonging to a network 220, and a network repeater 300 that connects both networks. Is included. Also here, the number of terminals in each network described above is illustrated for explanation and is not particularly limited.
[0033]
The network 201 is a network identified by a network address “192.168.10.0/24”.
[0034]
The network 220 is a network whose network address identified by the network address “192.168.20.0/24” is 24 bits. Note that the broadcast address of the network 220 is described as being defined as “192.168.20.255”.
[0035]
The terminal 202 is a data transmission source terminal to which the IP address “192.168.10.1” is assigned. Although not illustrated, the terminal 202 includes data to be transmitted to all terminals on the target network 220 and a flag indicating that the data is to be transmitted to all terminals on the network. Means for generating the packet 206 in a predetermined position, means for transmitting the packet 206 to a predetermined terminal on the network 220, and if no acknowledgment is returned for the transmission, A program 205 used on the transmission side, which constitutes means for changing the host address part of the arbitrary address at a predetermined interval and retrying, is installed so as to be executable. The terminal 202 stores and holds the network list 207 in its storage means, and further includes a timer 215.
[0036]
Terminals 221, 222, and 223 are terminals to which IP addresses “192.168.20.21”, “192.168.20.22”, and “192.168.20.23” are respectively assigned. The terminals 221, 222, and 223 include a flag indicating that the data should be transmitted to all terminals of the network at the predetermined position of the received packet (not shown). And means for monitoring whether or not the received packet includes the flag, and if the flag is included in the received packet, the data portion included in the packet is extracted and the broadcast address is used as the destination address. Means for generating a packet, means for sending back an acknowledgment that the packet containing at least the code is received to the source terminal in this case, and all broadcast transmission packets on the local network. A broadcast program 241 comprising a means for sending a broadcast to other terminals is installed in advance. To have. The terminal 221 monitors whether or not at least a flag indicating that the data included in the received packet is data to be transmitted to all terminals of the network is included in the packet. The broadcast program 241 or a part thereof is loaded into the memory.
[0037]
The network repeater 300 is a device that connects the network 201 and the network 220, such as a router, and does not pass a packet having a broadcast address.
[0038]
An example of the network list 7 is shown in FIG. Referring to FIG. 5, the network list 207 stores a list of network addresses that need to be broadcast from the terminal 202. For example, when performing broadcast transmission to the network 220, the network address “192.168.20.0” of the network 220 is used.
[0039]
Next, the operation of the present embodiment will be described with reference to FIG. 7 or FIG. 8 as appropriate, centering on the flowcharts of FIG. 4 and FIG. FIG. 6 is a flowchart illustrating an example of a processing flow in the present embodiment. Referring to FIG. 6, first, the terminal 202 selects an address “192.168.20.0” of the network 220 from the network list 207 when transmitting desired data to the network 220 to be broadcasted. 192.168.20.1 "is set as an initial value address, indicating that the desired data 208 and the data destined for the address are to be transferred to all terminals in the same network A packet 206 storing the flag 209 is generated (step S1), the timer 215 is operated, and the packet 206 is transmitted (step S2). Since the packet 206 is not a packet destined for the broadcast address, it passes through the network repeater 300 and is transferred to “192.168.20.1”.
[0040]
However, since there is no device having the address “192.168.20.1” on the network 220, the terminal 202 gives an acknowledgment returned to the packet 206 for a predetermined time counted by the timer 215. Can not be received within. Similarly, even when there is a node having the address “192., 168.0.1” on the network 220, if the node is inactive, the acknowledgment is sent to the timer 215. It will not be possible to receive within a predetermined time counted by.
[0041]
Therefore, if the terminal 202 cannot receive the acknowledgment within a predetermined time after the transmission of the packet 206, the terminal 202 changes the host address portion “1” of “192.168.0.1” (step S1). S3), the timer 215 is restarted, and transmission of the packet 206 is retried. The change of the host address part is performed, for example, by incrementing the number of the host address part by one. In this way, the host address portion of the transmission address is changed and the packet after the change is transmitted every time a certain time counted by the timer 215 elapses until the acknowledgment 261 is returned. Note that if the packet 206 is transmitted to all host addresses on the network 220 but the reception confirmation packet 261 is not received, the server terminal 202 stops transmitting the packet 206. (Step S4).
[0042]
FIG. 7 is a diagram for explaining the processing performed by the terminal 221 that has received the packet 206 when the destination address reaches “192.168.0.21” as a result of the above processing. As shown in FIG. 7, the terminal 221 that continuously monitors the received packet reads the flag 209 in the packet 206 and determines that it should be sent to all terminals on the same network. In this case, an acknowledgment 261 including at least that the packet has been received is transmitted to the terminal 202 of the transmission source. The terminal 202 that has received the positive response 261 stops the operation of the timer 215 and stops the transmission process of the packet 206 (step S5).
[0043]
FIG. 8 is a diagram for explaining processing performed by the terminal 221 after transmitting the positive response 261. Referring to FIG. 8, the terminal 221 extracts data 252 having the same content as the data 208 (step S6), and transmits the data 252 and a broadcast address “192.168.” To all addresses on the network 220. The broadcast transmission packet 251 storing the destination address ".20.255" is generated (step S7) and transmitted (step S8).
[0044]
As in the previous embodiment, since the broadcast packet 251 is addressed to the broadcast packet address “192.168.20.255”, it is delivered to all host addresses on the network 220.
[0045]
In this way, it is possible to transmit the same data to all terminals of a desired network by performing a single transmission process in the transmission source terminal 202. Of course, as described above, since the packet 206 does not have a broadcast address, the network repeater 300 does not discard it. In other words, broadcasting to a desired network is realized while maintaining the security level of the network 220. Further, in this embodiment, the terminal 202 only needs to manage the network list 207, and it is not necessary to know the terminal to which a packet for performing broadcast transmission should be transmitted in each network.
[0046]
In the above-described embodiment, the terminal 202 includes the timer 215, and if an acknowledgment is not returned within a certain time after the transmission of the packet 206, it is considered that there is no valid terminal at the transmitted address. Although it has been described that the address to be transmitted is changed, if no acknowledgment is obtained even if the packet is transmitted a predetermined number of times without using the timer 215, there is no valid terminal at the address. It is possible to adopt various modifications such as a configuration in which the address to be transmitted is changed.
[0047]
【The invention's effect】
According to the present invention, in broadcast transmission between networks, the network traffic can be greatly reduced while maintaining the security function of the network repeater, and the specific configuration of the target network is conscious. It is possible to broadcast the same data without transmission. The reason is that the number of transmission packets and transmission destinations from the transmission source terminal is suppressed, and a broadcast transmission by broadcast address is performed in the reception side network.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a system configuration according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of a terminal list.
FIG. 3 is a diagram for explaining processing performed by a receiving terminal.
FIG. 4 is a diagram illustrating an example of a system configuration according to another embodiment of the present invention.
FIG. 5 is a diagram illustrating an example of a network list.
FIG. 6 is a flowchart showing an example of a processing flow in another embodiment of the present invention.
FIG. 7 is a diagram for explaining processing performed by a receiving terminal according to another embodiment of the present invention.
FIG. 8 is a diagram for explaining processing performed by a receiving terminal according to another embodiment of the present invention.
[Explanation of symbols]
1, 20, 201, 220 network
2, 21, 22, 23, 202, 221, 222, 223 terminal
5, 205 Sender program
6,206 packets
7 Terminal list
8, 53, 208, 253 Transmission data
9, 209 flag
41, 241 Broadcast program
51,251 Broadcast transmission packet
100, 300 network repeater
207 Network list
215 timer
261 Acknowledgment

Claims (15)

In a broadcast transmission method for transmitting the same data from a terminal of a transmission source outside a certain network to all terminals on the network,
A packet including data to be transmitted to all terminals on the network by the transmission source terminal and a code indicating that the data is to be transmitted to all terminals on the network And send it to any address on the network,
The transmission source terminal changes the host address portion of the arbitrary address at a predetermined interval when at least an acknowledgment including the reception of the packet is not returned as a result of the transmission, Try again,
When the terminal corresponding to the arbitrary address receives the packet including the code, at least an acknowledgment including the fact that the packet has been received is returned to the transmission source terminal, and Take out the data part contained in the packet, generate a new packet with the broadcast address as the destination address, and broadcast to all terminals on the network,
Broadcast transmission method characterized by the above. The source terminal stops transmission of the generated packet if the acknowledgment is not obtained from all addresses on the network even by the retry;
The broadcast transmission method according to claim 1 . The network is an internet protocol network;
The broadcast transmission method according to any one of claims 1 and 2 . The network is connected to another network via a network repeater that does not pass packets whose destination address is a broadcast address;
The broadcast transmission method according to any one of claims 1 to 3 . A terminal for transmitting the same data from outside a network to all terminals on the network,
Means for generating a packet including data to be transmitted to all terminals on the network and a code indicating that the data should be transmitted to all terminals on the network;
Means for transmitting the packet to an arbitrary address on the network;
As a result of the transmission, if an acknowledgment including at least the reception of the packet is not returned, means for retrying transmission of a packet in which the host address portion of the arbitrary address is changed at a predetermined interval;
A terminal characterized in that any one of the destination terminals performs broadcast transmission. The terminal according to claim 5 , wherein
As a result of transmitting the packet to all addresses on the network by the retry, if the acknowledgment is not obtained from all addresses on the network, transmission of the generated packet is stopped. Providing further means,
A terminal characterized by. A terminal that receives a packet from the terminal according to claim 5 or 6 and performs broadcast transmission to all terminals of a network to which the device belongs.
Means for monitoring whether the received packet includes a code indicating that the data should be transmitted to all terminals of the network;
As a result of the monitoring, if the received packet includes the code, means for extracting a data portion included in the packet and generating a new packet having a broadcast address as a destination address,
A terminal that broadcasts the new packet to all terminals on the network. The terminal according to claim 7 , wherein
Means for returning an acknowledgment including at least that the packet including the code is received to the transmission source terminal when the packet including the code is received;
A terminal characterized by. The network is an internet protocol network;
A terminal according to any one of claims 5 to 8 , characterized in that: The network is connected to another network via a network repeater that does not pass packets whose destination address is a broadcast address;
10. The terminal according to any one of claims 5 to 9, wherein: A program to be executed by a transmission source terminal for transmitting the same data to all terminals on the network from outside a certain network,
Generating a packet including data to be transmitted to all terminals on the network and a code indicating that the data is data to be transmitted to all terminals of the network; Processing to send to any address of
If an acknowledgment including that at least the packet including the code is received is not returned for the transmission, the host address part of the arbitrary address is changed at a predetermined interval and the retry is performed. Processing,
The program which makes the said transmission origin terminal perform each said process. The program according to claim 11 ,
If the acknowledgment is not obtained from all addresses on the network even after the retry, a process of stopping transmission of the generated packet is further performed.
A program to be executed by the transmission source terminal.   A program that receives a packet from a transmission source terminal and causes a terminal that performs broadcast transmission to all the terminals of the network to which the device belongs,
  A process of monitoring whether or not the received packet includes a code indicating that the data is data to be transmitted to all terminals of the network;
  As a result of the monitoring, when the received packet includes the code, a process of returning an acknowledgment including at least the reception of the packet including the code to the transmission source terminal;
  As a result of the monitoring, when the received packet includes the code, the data part included in the packet is extracted, a new packet having a broadcast address as a destination address is generated, Processing to broadcast to all terminals,
  A program that receives a packet from the transmission source terminal and causes a terminal that performs broadcast transmission to all the terminals of the network to which the device belongs. The network is an internet protocol network;
The program according to any one of claims 11 to 13 , characterized in that: The network is connected to another network via a network repeater that does not pass packets whose destination address is a broadcast address;
Claims 11, characterized in to 14 program according to any one.

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