JPH10242962A - Multi-cast gateway communication method and system on internet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide multi-cast gateway communication method and system on an internet enabling a receiving host not supporting IP multi-cast combination to receive a message transmitted from a transmitting host as an IP multi-cast datagram. SOLUTION: A message transmitted from the transmitting host is received by a multi-cast gateway and the message is copied by the necessary number of sheets and these copies are individually transmitted to a plurality of receiving hosts as IP unicast datagrams. The multi-cast gateway converts the received message having an IP multi-cast address as a destination into a message having a group identifier and individually transmits the plurality of receiving hosts requesting its reception as IP unicast datagrams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicast gateway communication method and system on the Internet. The present invention relates to a multicast gateway communication method and system on the Internet for transmitting IP.

[0002]

2. Description of the Related Art In the conventional Internet, one-to-one communication (unicast communication) such as e-mail, file transfer, and WWW is mainly performed, and multicast communication for simultaneously broadcasting a message from a sending host to a plurality of receiving hosts. No functionality provided. However, as new applications, demands and expectations for broadcast-type and conference-type multimedia communication services on the Internet are increasing. On the Internet, in order to provide a broadcast-type or conference-type multimedia communication service such as a video / audio conference, it is essential that a multicast communication function be provided.

As a method for providing a multicast communication function on the Internet, there is an IP multicast communication method. FIG. 14 is a diagram for explaining a conventional IP multicast communication method. In the conventional system, a sending host 100 and a plurality of receiving hosts 200 are connected via a plurality of routers 103. Internet 1 consisting of dedicated lines, LANs, routers, etc. between routers
04.

FIG. 15 shows the structure of an IP datagram.
The IP datagram 300 includes a header including a destination IP address section 301 indicating the transmission destination of the IP datagram and a destination IP address section 302 indicating the destination of the datagram, and a data section 303 storing the contents of the message. You. The IP multicast datagram is an IP datagram in which a group address (IP multicast address) is set in the destination IP address section 302. In the IP multicast communication method, a class D IP address is used as a group address.

In such a configuration, the transmission host 10
0 to a plurality of receiving hosts 200 requesting reception of a message addressed to a certain group address.
Source IP address part 3 indicating the destination of the message
01, a destination IP address part 302 in which the group address is set, and an IP multicast datagram composed of a data part 303 storing the contents of the message. Thereby, a plurality of receiving hosts 200
Receive the same message from the sending host 100, respectively.

[0006]

However, most of the current sending hosts, receiving hosts, and routers on the Internet do not support the IP multicast communication method. In addition, the IP multicast communication method has not reached a practical level in the current Internet due to the difficulty in realizing efficient multicast routing. In addition, each sending host, receiving host,
In the router, it is not easy to realize the IP multicast communication method because the software needs to be extended at the operating system level to support the IP multicast communication method.

The present invention has been made in view of the above points, and enables a receiving host that does not support IP multicast communication to receive a message transmitted as an IP multicast datagram from a transmitting host. An object of the present invention is to provide a multicast gateway communication method and system on the Internet.
In this case, in the multicast gateway, a required number of messages received as IP multicast datagrams are copied and individually transmitted to a plurality of receiving hosts as IP unicast datagrams. Destination IP address part 3 in the above-mentioned conventional technique
02, an IP address (class A, B) for one-to-one communication (unicast communication) for identifying the receiving host
Or the IP address of C) is set.

[0008]

SUMMARY OF THE INVENTION The present invention provides at least one
In a multicast gateway communication method on the Internet for simultaneously broadcasting a message to a plurality of receiving hosts from one sending host via the Internet, a message transmitted as an IP multicast datagram from a sending host is transmitted to a multicast gateway. , And simultaneously broadcast to a plurality of receiving hosts that do not support IP multicast communication.

Further, the present invention provides a multicast gateway which associates a destination IP multicast address of an IP multicast datagram with an IP address of a plurality of receiving hosts requesting reception of a message having a group identifier derived from the address. The relationship is managed, and a message addressed to the IP multicast address received from the sending host is broadcast to a plurality of receiving hosts based on the correspondence.

Further, according to the present invention, when a multicast gateway receives a request to start receiving a message having a certain group identifier from a receiving host, the multicast gateway registers the IP address of the receiving host. In addition, the present invention, in the multicast gateway, from the receiving host,
Upon receiving a request to end receiving a message having a certain group identifier, the registered IP address of the receiving host is deleted.

FIG. 1 is a diagram for explaining the principle of the present invention. According to the present invention, a receiving host issues a request to start receiving a message having a certain group identifier to a multicast gateway that broadcasts a message (step 1). The IP address is registered (step 2), the multicast gateway receives an IP multicast datagram having the same value as the group identifier as the value of the destination IP multicast address from the transmitting host (step 3), and the message having the group identifier is received. (Step 4) and broadcast to the registered receiving host as an IP unicast datagram (step 5).

FIG. 2 is a diagram showing the principle of the present invention. The multicast gateway communication system of the present invention has an IP
At least one sending host that sends a message using multicast communication, a plurality of receiving hosts 200 that do not support IP multicast communication that requests to receive the message, and a sending host 10
0, and a multicast gateway 400 that is present between the receiving host 200 and temporarily receives the message transmitted by the transmitting host and broadcasts the message to a plurality of receiving hosts.

The multicast gateway 400 includes a message receiving means 404 for receiving a message from the transmitting host 100 as an IP multicast datagram, and a destination of the IP multicast datagram received from the transmitting host 100 by the message receiving means 404. It comprises a group identifier detecting means 420 for deriving a group identifier from the IP multicast address, and a broadcasting means 410 for broadcasting the message to a plurality of receiving hosts 200 requesting reception of a message having the group identifier.

The broadcasting means 410 of the multicast gateway 400 comprises: a group identifier management means 402 for managing the IP addresses of a plurality of receiving hosts requesting reception of a message having a group identifier in a group identifier management table; On the basis of the group identifier detected by the group identifier detecting means 420, a plurality of receiving hosts 20 to be broadcasted are referred to by referring to a group identifier management table.
Address conversion means 403 for obtaining an IP address of 0
And the plurality of receiving hosts 20 using the IP addresses of the receiving hosts acquired by the address converting means 403.
0, the sending host 10
The message transmission means 405 simultaneously broadcasts the messages received from 0.

When the group identifier management means 402 of the multicast gateway 400 receives the message reception start request from the reception host 200, the group address management means 402 registers the IP address of the reception host 200 in the group identifier management table. , Receiving host 200
When receiving the message reception end request from the group identifier management table, the IP address deletion unit deletes the reception host IP address from the group identifier management table.

According to the present invention, a message transmitted as an IP multicast datagram from a sending host is once received by a multicast gateway, the message is copied by a necessary number, and a plurality of receiving hosts requesting to receive the message are copied. , Are individually transmitted as IP unicast datagrams. In a multicast gateway, an IP addressed to an IP multicast address
A message received as a multicast datagram is converted into a message having a group identifier, and individually transmitted as an IP unicast datagram to a plurality of receiving hosts requesting reception. In the present invention, the destination IP
The value of the multicast address is used as it is as the value of the group identifier.

As described above, the present invention provides a correspondence relationship between a group identifier derived from an IP multicast address and the IP addresses of a plurality of receiving hosts requesting to receive a message having the group identifier. Is managed by a multicast gateway using a group identifier management table, and a message received as an IP multicast datagram from a transmitting node is individually sent to a plurality of receiving hosts whose IP addresses are registered in the group identifier management table. Broadcast as IP unicast datagrams.

Thus, a message transmitted as an IP multicast datagram can be broadcast to a plurality of receiving hosts that do not support IP multicast communication.

[0019]

FIG. 3 shows a configuration of a multicast gateway communication system according to the present invention. The configuration shown in the figure is a configuration in which one transmission host 100, one multicast gateway 400, and three reception hosts 200 are connected via the Internet 104.
The multicast gateway 400
0 to receive the message as an IP multicast datagram. The multicast gateway 400
The received message is converted into an IP unicast datagram and broadcast to a plurality of receiving hosts 200.

The sending host 100 sends the message in FIG.
Is transmitted as an IP multicast datagram having the following configuration. FIG. 4 shows a structure of a message transmitted from the multicast gateway of the present invention to a plurality of receiving hosts. As shown in the figure, the message 600 includes a message type section 601 indicating the type of the message, a group identifier section 602 for identifying a host group requesting reception of the message, and a data section 603 for storing the content of the message. . What is set in the message type unit 601 is one type of a route message for transmitting a message from the multicast gateway to a plurality of receiving hosts 200.

The multicast gateway 400 sends a message 600 received from the sending host 100 to a plurality of receiving hosts 200. In addition, between the multicast gateway 400 and the receiving host 200,
Exchange the control command 700. FIG. 5 is a configuration diagram of a control command exchanged between the multicast gateway and the receiving host according to the present invention. The control command 700 is
Command type section 70 indicating the type of control command 700
1. The receiving host 200 includes a group identifier unit 702 for setting a group identifier of a message requesting start or end of reception. There are two types of control commands: a message reception start command and a message reception end command.

Transmission message 600 and control command 7
00 is positioned as an application protocol on UDP / IP. That is, the message 600 and the control command 700 are stored in the destination IP address section 302 by the ID indicating the destination of the message 600 and the control command 700.
P address (Class A, B, for normal one-to-one communication)
C IP address) to the source IP address 301
The message 600 and the control command 700
IP address indicating the transmission source of the
It is transmitted and received on the Internet 104 as a unicast datagram 300.

FIG. 6 shows the configuration of the multicast gateway of the present invention. The multicast gateway 400 shown in the figure includes a message distribution unit 401, a group identifier management table 402, and an address management unit 403. When the message distribution unit 401 receives a message from the transmission host 100 as an IP multicast datagram, the message distribution unit 401 sets the IP address set in the destination IP address unit 302 of the IP multicast datagram 300.
Using the value of the P multicast address as the value of the group identifier, searching the group identifier management table 402 using the group identifier as a key, and receiving a plurality of receiving hosts 2 receiving messages having the found group identifier.
00, the message is transmitted as a root message. Group identifier part 60 of route message
2, a group identifier is set, and a message is set in the data section 603.

The address management unit 403 is connected to the receiving host 20
Command type part 7 of the control command 700 received from 0
01 is a message reception start command, the group identifier management table 402 is searched using the group identifier set in the group identifier part 702 of the control command 700 as a key, and the control command 700 source IP addresses are added.

When the address management unit 403 receives the message reception end command from the reception host 200, the address management unit 403 stores the group identifier 70 in the control command 700.
The group identifier management table 402 is searched using the group identifier set to 2 as a key, and the source IP address of the control command 700 is deleted from the line starting with the group identifier.

FIG. 7 shows the structure of the group identifier management table of the present invention. The group identifier management table 402 includes a plurality of rows. Each row includes a list of a group identifier and an IP address of one or more receiving hosts 200 receiving a message having the group identifier. The operation of the multicast gateway communication system on the Internet according to the present invention will be described below.

First, the operation of the sending host 100 will be described. FIG. 8 is a flowchart showing the operation of the transmission host of the present invention. Step 1001) The transmission host 100 checks the data unit 3
In step 03, a message of the sending host 100 is transmitted, and in the destination IP address section 302, an IP multicast datagram 300 in which an IP multicast address for identifying a group is set is transmitted.

Step 1002) Transmission host 100
Sends one or more messages until transmission is complete. Next, an operation when the multicast gateway 400 receives a control command from the receiving host 200 will be described. FIG. 9 is a flowchart of the operation when the multicast gateway of the present invention receives a control command from a receiving host.

Step 1101) If the control command 700 received by the multicast gateway 400 is a message reception start command, step 1102
Otherwise, to step 1105. Step 1102) Search the group identifier management table 402 using the group identifier set in the group identifier section 702 of the message reception start command as a key, and register the source IP address of the control command 700 in the line starting with the group identifier. .

Step 1103) If the source IP address is the first IP address registered in the line beginning with the group identifier in the group identifier management table 402, the process proceeds to step 1104; To end. Step 1104) The reception of the IP multicast datagram 300 destined for the IP multicast address having the same value as the group identifier transmitted from the transmission host 100 is started, and the process ends.

Step 1105) If it is determined that the received command is a message reception end command, step 1106
Otherwise, the process ends. Step 1106) Using the group identifier set in the group identifier part 702 in the message reception end command as a key, search the group identifier management table 402 and delete the source IP address of the command from the line starting with the group identifier. I do.

Step 1107) If the source IP address is the last deleted IP address from the line beginning with the group identifier in the group identifier management table 402, the process proceeds to step 1108; otherwise, the process is terminated. finish. Step 1108) The reception of the IP multicast datagram 300 destined for the IP multicast address having the same value as the group identifier transmitted from the transmission host 100 ends, and the process ends.

Next, the multicast gateway 400
Is received from the sending host 100 as a message as an IP multicast datagram.
FIG. 10 is a flowchart of the operation when the multicast gateway of the present invention receives a message from a sending host as an IP multicast datagram.

Step 1201) The multicast gateway 400 receives a message from the sending host 100 as an IP multicast datagram. Step 1202) The value of the IP multicast address set in the destination IP address section 302 of the received IP multicast datagram 300 is set as the value of the group identifier.

Step 1203) The group identifier management table 402 is searched using the group identifier as a key, and the message received as an IP multicast datagram is sent to one or more receiving hosts 200 receiving the message having the group identifier. Is converted to a root message and sent individually. Next, the operation of the receiving host 200 will be described.

FIG. 11 is a flowchart of the operation of the receiving host of the present invention. Step 1301) The receiving host 200 transmits to the multicast gateway 400 a message reception start command in which the group identifier of the group requesting to start reception is set in the group identifier section 702. Step 1302) Thereafter, the receiving host 200 receives from the multicast gateway 400 as a root message having the group identifier of the group that has requested to receive the message.

Step 1303) If the reception of the message has been completed, the process proceeds to step 1304; otherwise, the process proceeds to step 1302. Step 1304) When ending the message reception, the multicast gateway 400 sends a message reception end command in which the group identifier of the group requesting to end the reception is set in the group identifier section 702.
Send to

[0038]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 12 shows a detailed configuration of the multicast gateway according to one embodiment of the present invention. The multicast gateway 400 shown in the figure includes a message receiving unit 404, an address managing unit 403, a group identifier management table 402, a message transmitting unit 405, and a control command receiving unit 406.

The message receiving unit 404 is connected to the sending host 1
00 is received as an IP multicast datagram, and the message is
Transfer to 3. The address management unit 403 is a destination IP address unit 3 of the IP multicast datagram 300.
The value of the IP multicast address set to 02 is used as the value of the group identifier, and the group identifier management table 402 is searched using the group identifier as a key. The IP address of one or more receiving hosts 200 receiving the message having the group identifier registered in the group identifier management table 402 and the message are transferred to the message transmitting unit 405.

The message transmitting unit 405 converts the message into a root message and transmits it individually to one or more receiving hosts 200 receiving the message having the group identifier. Control command receiving unit 406
Receives the control command 700 from the receiving host 200 and sends the control command 700 to the address management unit 403
Transfer to

When receiving the message reception start command from the control command receiving unit 406, the address management unit 403 registers the source IP address of the control command in the group identifier management table 402. Address management unit 4
In step 03, when a message reception end command is received from the control command receiving unit 406, the source IP address of the control command is deleted from the group identifier management table 402.

FIG. 13 is a sequence chart showing a series of operations in one embodiment of the present invention. In the sequence chart shown below, an example will be described in which a message transmitted by one transmission host 100a is transmitted to two reception hosts 200c and 200d via a multicast gateway 400b. Step 1501) The receiving host 200c sets a command reception start command in the command type section 701, and transmits a message reception start command in which “group identifier 1” is set in the group identifier section 702 to the multicast gateway 400b. Similarly, the receiving host 200d also transmits a message reception start command in which “group identifier 1” is set to the group identifier 702 to the multicast 400b.

Step 1502) Upon receiving the message reception start command from the receiving hosts 200c and 200d, the control command receiving unit 406 of the multicast gateway 400b transfers the control command to the address management unit 403. The address management unit 403 sets the IP address for “group identifier 1” in the control command 700.
The IP address of the receiving host 200c, 200d as the address
Register an address.

Step 1503) Transmission host 100a
Is the content of the message to be transmitted to the data portion 303 in the IP multicast datagram 300 (for example,
In the case of a video distribution type application, a video packet) is set in the destination IP address section 302 by setting an IP multicast address for identifying a group.
Send the P multicast datagram 300.

Step 1504) The message receiving unit 404 of the multicast gateway 400b transfers the message received from the sending host 100 as an IP multicast datagram to the address management unit 403. The address management unit 403 uses the value of the IP multicast address set in the destination IP address unit 302 of the IP multicast datagram as the value of the group identifier (in this case, “group identifier 1”),
The group identifier management table 402 is searched using the group identifier as a key. In the group identifier management table 402,
Since the receiving hosts 200c and 200d requesting to receive the message having the “group identifier 1” are registered, the message transmitting unit 405 transmits the message to the message transmitting unit 405.

Step 1505) Message transmitting section 4
05 converts the message into a root message,
It is individually transmitted to the receiving hosts 200c and 200d. Step 1506) Receiving host 200c, 200d
Is the command type part 70 of the control command 700
1 is set to “end of message reception”, the group identifier 702 is set to “group identifier 1”, and transmitted to the multicast gateway 400b.

Step 1507) The control command receiving section 406 of the multicast gateway 400b transfers the received control command 700 to the address management section 403. The address management unit 403 includes the receiving host 200c,
200d IP address is assigned to the group identifier management table 402
Remove from. In the present embodiment, for example, a message that is transmitted by the transmission host a on the Internet as an IP multicast datagram is received by the multicast gateway 400b of the head office connected to the Internet, and the in-house network that does not support the IP multicast communication ( Via the intranet), the receiving host 200 of the branch office
c, 200d.

The present invention is not limited to the above embodiment, but can be variously modified and applied within the scope of the claims.

[0049]

As described above, according to the multicast gateway communication method and system on the Internet of the present invention, a message transmitted as an IP multicast datagram from a transmission host is transmitted to a multicast gateway via a multicast gateway. It is possible to simultaneously broadcast to a plurality of unsupported receiving hosts.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a principle configuration diagram of the present invention.

FIG. 3 is a configuration diagram of a multicast gateway communication system of the present invention.

FIG. 4 is a configuration diagram of a message transmitted from the multicast gateway system of the present invention to a plurality of receiving hosts.

FIG. 5 is a configuration diagram of a control command exchanged between a multicast gateway and a receiving host according to the present invention.

FIG. 6 is a configuration diagram of a multicast gateway of the present invention.

FIG. 7 is a configuration diagram of a group identifier management table of the present invention.

FIG. 8 is a flowchart showing the operation of the transmission host of the present invention.

FIG. 9 is a flowchart of an operation when the multicast gateway of the present invention receives a control command from a receiving host.

FIG. 10 is a flowchart of an operation when the multicast gateway of the present invention receives a message from a transmission host as an IP multicast datagram.

FIG. 11 is a flowchart of the operation of the receiving host of the present invention.

FIG. 12 is a detailed configuration diagram of a multicast gateway according to an embodiment of the present invention.

FIG. 13 is a sequence chart showing a series of operations of one embodiment of the present invention.

FIG. 14 is a diagram for explaining a conventional IP multicast communication method on the Internet.

FIG. 15 is a configuration diagram of a message in an IP multicast datagram.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 100 Sending host 104 Internet 200 Receiving host 301 Source IP address part 302 Destination IP address part 303 Data part 400 Multicast gateway 401 Message distribution part 402 Group identifier management means, Group identifier management table 403 Address conversion means, Address management part 404 Message reception Means, message receiving unit 405 message transmitting unit, message transmitting unit 406 control command receiving unit 410 broadcasting unit 420 group identifier detecting unit 600 message 601 message type unit 602 group identifier unit 603 data unit 700 control command 701 command type unit 702 group identifier Department

Claims (9)

[Claims] 1. A multicast gateway communication method on the Internet for simultaneously broadcasting a message to a plurality of receiving hosts from at least one sending host via the Internet, wherein the sending host transmits the message as an IP multicast datagram. A multicast gateway communication method on the Internet, characterized by simultaneously broadcasting, through a multicast gateway, a plurality of receiving hosts that do not support IP multicast communication. 2. The correspondence between the destination IP multicast address of the IP multicast datagram and the IP addresses of a plurality of receiving hosts requesting reception of a message having a group identifier derived from the address in the multicast gateway. 2. The multicast gateway communication method on the Internet according to claim 1, wherein a message addressed to the IP multicast address received from the sending host is broadcast to the plurality of receiving hosts based on the correspondence. 3. The multicast gateway communication method on the Internet according to claim 2, wherein when the multicast gateway receives a request to start receiving a message having a certain group identifier from the receiving host, the IP address of the receiving host is registered. . 4. The Internet according to claim 3, wherein the multicast gateway deletes the registered IP address of the receiving host when receiving a request to end receiving a message having a certain group identifier from the receiving host. Multicast gateway communication method. 5. The receiving host issues a request to start receiving a message having a certain group identifier to a multicast gateway that broadcasts the message, and the multicast gateway issues an IP address of a receiving node that has received the request to start receiving the message. The multicast gateway receives an IP multicast datagram having the same value as the group identifier as a value of the destination IP multicast address from the sending host, converts the message into a message having a group identifier, and registers the multicast gateway. 2. The multicast gateway communication method on the Internet according to claim 1, wherein the multicast is broadcast to the receiving host as an IP unicast datagram. 6. At least one sending host that sends a message using IP multicast communication, a plurality of receiving hosts that do not support IP multicast communication requesting to receive the message, and a sending host A multicast communication system comprising a multicast gateway, which is located between the receiving host and the receiving host, temporarily receives the message transmitted by the transmitting host, and broadcasts the message to a plurality of receiving hosts. 7. The multicast gateway, a message receiving means for receiving a message from the transmitting host as an IP multicast datagram, and a destination IP of the IP multicast datagram received from the transmitting host by the message receiving means.
The group identifier detecting means for deriving a group identifier from a multicast address, and a broadcasting means for broadcasting the message to a plurality of receiving hosts requesting reception of the message having the group identifier. Multicast communication system. 8. The multicast gateway of the multicast gateway includes: a group identifier management unit that manages, in a group identifier management table, IP addresses of a plurality of receiving hosts that request reception of a message having the group identifier; Address conversion means for referring to the group identifier management table based on the group identifier detected by the identifier detection means and obtaining the IP addresses of a plurality of receiving hosts to be broadcast; Host I
8. The multicast communication system according to claim 7, further comprising a message transmitting unit that simultaneously broadcasts the message received from the transmitting host by the message receiving unit to the plurality of receiving hosts using a P address. 9. The group identifier management unit of the multicast gateway, upon receiving a message reception start request from the reception host, an IP address registration unit for registering an IP address of the reception host in the group identifier management table; When a message reception end request is received from the receiving host, the receiving host IP is received from the group identifier management table.
9. The multicast communication system according to claim 8, further comprising an IP address deletion unit for deleting an address.