JP4063786B2 - Multicast packet distribution system - Google Patents

Description

  The present invention relates to a multicast packet distribution system, and more particularly to a multicast packet distribution system in which a plurality of customers can simultaneously receive streaming distributed by a plurality of operators from a plurality of operators.

  As high-speed communications such as ADSL and CATV are spreading, streaming delivery is considered to become an increasingly important content delivery method. In the future, ADSL multicast proxy routers and broadband routers will be able to support multicast (Multicast). It seems to be essential. Here, streaming distribution is a general term for information distribution in which data is read and reproduced on the spot, and multicast refers to distributing the same data to a plurality of destination addresses. (See Patent Document 1 and Patent Document 2)

  A technique required to support this multicast is IGMP / MLD (Internet Group Management Protocol / Multicast Listener Discovery) (described later), which is a protocol for controlling a multicast group. Considering the ease of implementation of this IGMP / MLD, many ADSL modems and broadband routers implement the IGMP / MLD proxy (proxy) function.

Here, a conventional IP multicast packet distribution system (hereinafter referred to as an IP multicast packet distribution system) 100 using the IGMP / MLD proxy function will be described with reference to FIG. An IP multicast packet distribution system using this kind of IGMP / MLD proxy function is described in, for example, Patent Documents 3-5.
Here, the system configuration of FIG. 7 is almost the same as the system configuration of the embodiment of the present invention to be described later (only the configuration and functions of the multicast proxy router are different), so the detailed description of the system configuration will be given in the embodiment. .

  The networks of the first Internet service provider (operator A) 130a and the second Internet service provider (operator B) 130b are connected to the Internet 140. The first and second Internet service providers 130a and 130b include first and second multicast routers 131a and 131b and first and second multicast servers 132a and 132b, respectively. The first and second multicast routers 131 a and 131 b are connected to the first and second upstream interfaces 111 a and 111 b of the multicast proxy router (IGMP / MLD proxy router) 110.

  The first and second downstream interfaces 112a and 112b of the multicast proxy router 110 are connected to a first multicast client terminal (customer C1) 121a and a second multicast client terminal (customer C2) 121b, respectively.

  Here, the upstream interface refers to an interface connected to the upstream side (multicast router), and the downstream interface refers to an interface on the opposite side (downstream side) from the upstream interface.

Here, basic functions of elements (such as a multicast server) constituting the IP multicast packet distribution system 100 will be described with reference to FIGS.
FIG. 8 is a system configuration diagram showing the relationship among a multicast server, a multicast router, and a multicast client terminal in a simplified manner.
FIG. 9 is a system configuration diagram when a multicast proxy router (IGMP / MLD proxy router) is added to the configuration of FIG.

As shown in FIG. 8, the multicast server 132 (132a, 132b) such as a streaming distribution server continues to transmit multicast packets. In this state, the multicast router 131 (131a, 131b) does not transfer the multicast packet to an interface other than the interface that has received the multicast packet.
That is, the multicast packet received by the upstream interface of the multicast router 131 is not transferred to the downstream interface.

  When the multicast client terminal 121 (121a, 121b) wishes to receive a multicast packet from the multicast server 132, a message (reception request message) indicating that the multicast group “X.X.X” is to be received by the multicast router 131. Send. Here, “XX.X.X” is an address of the multicast group.

The multicast router 131 receives the reception request message and transfers the multicast packet from the multicast server 132 to the downstream side for the first time.
The protocol used for this message transmission is the IGMP / MLD.
In an actual network, a plurality of (many) servers, routers, and client terminals are connected.

When a plurality of servers, routers, and client terminals are connected, information (multicast group data, etc.) that the multicast router 131 must manage increases.
Basically, the multicast server 132 continues to transmit multicast packets regardless of the presence or absence of the multicast client terminal 121.

Next, the multicast proxy router (IGMP / MLD proxy router) 110 will be described with reference to FIG.
The multicast proxy router 110 starts operating as the multicast proxy router 110 only after receiving the reception request message “XXXX” from the multicast client terminal 121.

  In the network (system configuration) illustrated in FIG. 9, when the multicast client terminal 121 does not transmit the reception request message “X.X.X.X”, the multicast proxy router 110 does not need to manage information regarding the multicast packet.

The multicast proxy router 110 that has received the reception request message “XXXX” from the multicast client terminal 121 transmits the reception request message “XXXX” to the multicast router 131.
This is the reason why it is called a proxy, and the upstream interface 111 of the multicast proxy router 110 operates like the multicast client terminal 121.

Receiving this message, the multicast router 131 transfers only the multicast packet of the multicast group “XXXX” to the downstream side.
The multicast proxy router 110 receives this multicast packet and forwards it to the multicast client terminal 121.

Therefore, the multicast proxy router 110 only needs to manage the multicast group “XXXX” that the multicast client terminal 121 wants to receive.
Thus, if the multicast proxy router 110 is used, less information needs to be managed.

JP 2002-064558 A JP 2003-348151 A JP 2002-044130 A JP 2002-152197 A JP 2003-158547 A

  However, the multicast proxy router 110 that implements the conventional IGMP / MLD proxy function operates only a set of logical interfaces (upstream interface and downstream interface) on the upper router side. That is, as shown in FIG. 7, even when the multicast proxy router 110 includes a plurality of logical interfaces, the plurality of logical interfaces cannot be operated simultaneously.

That is, when the first multicast client terminal (customer C1) 121a and the second multicast client terminal (customer C2) are operating on the first route 113a and the second route 113b, respectively (indicated by a solid line), the third The route 114a and the fourth route 114b cannot be operated at the same time (shown with a “x” mark on the dotted line).
Note that which of the plurality of logical interfaces is to be operated can be selected from the multicast client terminal side.

  For this reason, when the business operator A and the business operator B perform a service that delivers streaming content only to their own customers, the common customer C1 and customer C2 of the business operator A and the business operator B are the business operators. Streaming distributed by A and operator B cannot be received simultaneously from both.

  The present invention has been made to solve the above problem, and provides a multicast packet distribution system in which a plurality of customers can simultaneously receive streaming distributed by a plurality of operators from a plurality of operators. With the goal.

In order to achieve this object, the multicast packet distribution system of the present invention is configured so that each provider (first and second Internet service providers 130a) constituting a plurality of lower networks connected to an upper network (Internet 140 in FIG. 1). , 130b (operator A, business operator B)) each of the provider-side multicast routers (first and second multicast routers 131a and 131b) and a plurality of terminals (first and second multicast client terminals 121a and 121b ( In a multicast packet distribution system that distributes contents to a plurality of terminals in a multicast packet via a multicast proxy router (20) to which a customer C1, customer C2)) is connected,
Multicast packets on a plurality of upstream interfaces (on the first and second upstream interfaces 111a and 111b) included in the multicast proxy router are transferred to a plurality of downstream interfaces (first and second downstream interfaces 112a included in the multicast proxy router). 112b) is provided with simultaneous delivery means (database 21, setting table 22, duplication table 23 in FIG. 3) for simultaneous delivery.

  The above configuration is illustrated in FIGS. 1 and 3, for example. In this way, since the multicast packet from the operator A is simultaneously delivered to the two downstream interfaces 112a and 112b via the upstream interface 111a, the customer C1 and the customer C2 are simultaneously sent from the operator A. Can be received (indicated by the solid-line first route 20a and second route 20b).

Further, since the multicast packet from the operator B is simultaneously distributed to the two downstream interfaces 112a and 112b via the upstream interface 111b, the customer C1 and the customer C2 simultaneously receive the multicast packet from the operator B. It can be received (indicated by a solid third route 20c and a fourth route 20d).
That is, a plurality of customers (C1 and C2) can simultaneously receive streaming (multicast packets) distributed by a plurality of operators (A and B).

Further, the multicast packet delivery system of the present invention, the multicast packets on the plurality of downstream-side interface provided for the multicast proxy router, the plurality of upstream interfaces multicast proxy router comprises, is a structure in which the deliverable simultaneously.

  The above configuration is illustrated in FIGS. 1 and 3, for example. In this way, since the multicast packet from the customer C1 is simultaneously delivered to the two upstream interfaces 111a and 111b via the downstream interface 112a, the business operator A and the business operator B can simultaneously transmit from the customer C1. Can be received (indicated by the solid-line first route 20a and third route 20c, however, the directions of the arrows are reversed).

  Further, since the multicast packet from the customer C2 is simultaneously delivered to the two upstream interfaces 111a and 111b via the downstream interface 112b, the business operator A and the business operator B simultaneously receive the multicast packet from the customer C2. It can be received (indicated by the solid-line second route 20b and the fourth route 20d, but the directions of the arrows are reversed).

Further, the multicast packet delivery system of the present invention, simultaneous delivery means, a group of at least the multicast address X, a database for managing of information running on which interface (21 in FIG. 3), at least the multicast packet Settings for associating the multicast address with the upstream interface, settings for associating the IP address of the terminal with the upstream interface, settings for associating the MAC address of the terminal with the upstream interface, and the downstream interface and the upstream interface A first setting means (setting table 22) for performing a setting for associating the IP address of the multicast server and a setting for associating the downstream interface, and a single multicast address for a plurality of interfaces The second setting means (duplication table) for performing the setting for associating the upstream interface with the downstream interface and the setting for associating the IP address of the multicast server with the downstream interface. 23).

The above configuration is illustrated in FIGS. 1, 3, and 4, for example. For simultaneous delivery means described above to function properly, a plurality of carriers between (A and B), in order to set a route between a plurality of customer (C1 and C2), a minimum of various data Need.
The database (21) manages information on which interface at least the group of the multicast address X is operating.

  The first setting means (setting table 22) includes a setting for associating at least the multicast address of the multicast packet with the upstream interface, a setting for associating the IP address of the terminal with the upstream interface, the MAC address of the terminal and the upstream A setting for associating the downstream interface, a setting for associating the downstream interface with the upstream interface, and a setting for associating the IP address of the multicast server with the downstream interface are performed.

  When the second setting means (duplication table 23) uses one multicast address for a plurality of interfaces, all the duplicate entries are set to associate the upstream interface with the downstream interface, and the IP address of the multicast server And setting for associating the downstream interface.

Further, in the multicast packet distribution system of the present invention , the first setting means, when the upstream interface is linked down, when there is another upstream interface linked up, is linked up. In this configuration, the upstream interface is set to be used.
In this way, even when a link down occurs, the connectivity between the provider side and the customer side can be maintained.

In the multicast packet distribution system of the present invention, when the IP address of the upstream interface is released , the first setting means uses the upstream interface when there is another upstream interface that can be used. It is configured to make settings.
In this way, even when the IP address of the upstream interface is released, the connectivity between the operator side and the customer side can be maintained.

Further, the multicast packet delivery system of the present invention, the upper level network has a configuration which is the Internet (140).
In this way, multicast packets are transmitted and received between the multicast server (third multicast server 141) existing on the Internet and a plurality of terminals (customer C1, customer C2) via the lower network. Can do.

According to the present invention, since the multicast packet is distributed to the upstream interface, a plurality of customers can simultaneously receive the multicast packet distributed by a plurality of operators.
Conversely, a plurality of operators can simultaneously receive multicast packets distributed by a plurality of customers.

Furthermore, since a minimum amount of various data is provided to set routes between a plurality of businesses and a plurality of customers, the simultaneous distribution means can function normally.
In addition, the setting table is configured to perform settings to use the upstream interface that is linked up when there is another upstream interface that is linked up when the upstream interface is linked down. Therefore, even when link down occurs, the connectivity between the provider side and the customer side can be maintained.

  In addition, when the IP address of the upstream interface is released, and there is another upstream interface that can be used, the setting table is configured to use the upstream interface. Even when the IP address is released, the connectivity between the operator side and the customer side can be maintained.

  Furthermore, since the upper network is configured to be the Internet, multicast packets can be transmitted / received between a multicast server existing on the Internet and a plurality of terminals via the lower network.

Hereinafter, an embodiment of the present invention will be described.
[Embodiment]
FIG. 1 is a system configuration diagram of an IP multicast packet distribution system 10 according to the present embodiment, and FIG. 2 is a list of IP addresses of components such as a multicast proxy router that configure the IP multicast packet distribution system 10. The difference between the conventional example (FIG. 7) whose schematic configuration has already been explained and the present embodiment (FIG. 1) is the configuration and function of the multicast proxy router 20 provided on the customer side.

  As shown in FIGS. 1 and 2, a multicast proxy router (IGMP / MLD proxy router) 20 that implements an IGMP / MLD proxy function includes a first upstream interface 111a, a second upstream interface 111b, and a first downstream. A stream interface 112a and a second downstream interface 112b are provided.

  The first multicast client terminal 121a is connected to the first downstream interface 112a side of the multicast proxy router 20, and the second multicast client terminal 121b is connected to the second downstream interface 112b side.

  The first upstream interface 111a is connected to the first multicast router 131a in the first Internet service provider 130a, and the second upstream interface 111b is connected to the second multicast router 131b in the second Internet service provider 130b. Yes.

The first multicast server 132a is a multicast server prepared by the first Internet service provider 130a, and is installed in the network of the first Internet service provider 130a.
The second multicast server 132b is a multicast server prepared by the second Internet service provider 130b, and is installed in the network of the second Internet service provider 130b.

  A third multicast server 141 is installed in a network (Internet) 140 other than the first Internet service provider 130a and the second Internet service provider 130b.

As shown in FIG. 3, the multicast proxy router 20 that implements the IGMP / MLD proxy function of this embodiment has three management tables.
The first management table manages the multicast address database 21 created based on the information of the received IGMP packet (in the case of IPv6, MLD packet). The multicast proxy router 20 performs multicast distribution based on the database 21. In the present embodiment, hereinafter, the database 21 is simply referred to as the database 21.

  The second management table is a table 22 for setting a distribution destination. This table 22 is a table that is statically set by the user. When the multicast proxy router 20 receives an IGMP packet that is not registered in the database 21, it creates the database 21 according to this table 22. In the present embodiment, this table is hereinafter referred to as a setting table 22.

The third management table is a setting table 23 used by the multicast proxy router 20 when a single multicast address is used for a plurality of upstream interfaces. In the present embodiment, this table will be referred to as a duplicate table 23 hereinafter.
Hereinafter, these three management tables (database 21, setting table 22, duplication table 23) will be described in order.

  FIG. 4 is an example of the database 21. The database 21 manages information such as which interface the group of the IP multicast address X is operating on. The multicast proxy router 20 transmits a multicast packet to an appropriate interface according to the database 21. The following is information managed by the database 21.

  In IP multicast, IP multicast addresses are managed in units called groups. For example, the nth multicast client terminal 121n belongs to the group of the IP multicast address X.

21a: IP multicast group address 21b: timer remaining time (valid time of this entry)
21c: IGMP or MLD version operating in this entry 21d: Downstream interface used in this entry 21e: Upstream interface used in this entry 21f: Source IP address

In the setting table 22, the following items are set.
1． Settings for associating the multicast address of the multicast packet with the upstream interface.
The multicast address <X> specified in this setting can be used only by the specified upstream interface 111x, and when a multicast packet with the multicast address <X> is received from another upstream interface 111y, it is discarded. To do.

  Further, when a multicast packet of multicast address <X> is received from the downstream interface side of the multicast proxy router 20, it is transmitted to the upstream interface 111 x side of the multicast proxy router 20.

2. Settings for associating the IP address of the multicast client terminal with the upstream interface.
When a multicast packet from the multicast client terminal that is using the IP address <N> specified in this setting is transmitted to the upstream interface side, it is transmitted to the specified upstream interface 111n.

3. Settings for associating the MAC address of the multicast client terminal with the upstream interface.
When a multicast packet from a multicast client terminal that is using the MAC address designated by this setting is transmitted to the upstream interface side, it is transmitted to the designated upstream interface 111n.

4. Settings for associating downstream and upstream interfaces.
Multicast packets from the upstream interface specified by this setting are always transmitted to the specified downstream interface. A multicast packet from the designated downstream interface is always transmitted to the designated upstream interface.

5. Settings to associate the multicast server IP address with the downstream interface.
This setting is effective only when a multicast packet with the specified IP address set as the source IP address is received. At the time of reception, the multicast proxy router 20 associates the destination IP address of the multicast packet in which the source IP address is set with the received upstream interface.
After that, the same operation as 4 above is performed.

  The following items are prepared as settings (images like the default gateway in the routing table) used when multicast packets that do not fall under the settings 1 to 5 above are received.

6. Specify the upstream interface to use by default
6-1. Upstream interface fixed specification
6-2. Using the first linked upstream interface

6-3. When the IP address of the upstream interface is set to be acquired by PPP (Point-to-point Protocol) or DHCP (Dynamic Host Configuration Protocol), the upstream interface from which the IP address was first acquired is used.
6-4. Use the upstream interface with the smaller IP address
6-5. Discard packets that are not fixedly set

In order to improve connectivity, the following settings are prepared.
7. Handling when the upstream interface goes down (LINK DOWN)
7-1. If there is another upstream interface that is linked up (LINK UP), use that upstream interface. At this time, it is necessary to set priorities for the upstream interface to be used in advance. In accordance with the priority order set by the user, multicast packets are transmitted using the upstream interface having the highest priority among the upstream interfaces linked up.

7-2. If the link goes down, all IP multicast packets that are supposed to use the upstream interface are discarded.

8. Handling when the IP address of the upstream interface is released (when the IP address of the upstream interface is set to be acquired by PPP or DHCP)

8-1. If there is another available upstream interface, use that upstream interface. At this time, it is necessary to set priorities for the upstream interface to be used in advance. According to the priority set by the user, multicast packets are transmitted using the upstream interface having the highest priority among the available upstream interfaces.
8-2. When an IP address is released, all IP multicast packets that are supposed to use the upstream interface are discarded.

In the duplication table 23, the following items are set.
When a single multicast address is used on multiple interfaces, all duplicate entries must be configured as shown below.
-Settings for associating the upstream interface with the downstream interface-Settings for associating the IP address of the multicast server with the downstream interface

  In cases other than the above, unless the first operating entry (the entry currently registered in the database 21) is deleted from the database 21, multicast packets from interfaces other than that entry are discarded.

The operation of this embodiment will be described below.
Here, the multicast proxy router 20 needs to have a conventional IGMP / MLD proxy function, and this embodiment is an extended position of the conventional IGMP / MLD proxy function.

  First, the handling of special multicast addresses will be described. The addresses described below operate regardless of the information in the database 21 and the setting table 22.

`` 224.0.0.1 (IPv4) / FF02 :: 1 (IPv6) ''
When the apparatus is activated, the multicast proxy router 20 sends an IGMP Query packet with the destination IP address set to 224.0.0.1 (FF02 :: 1 in the case of IPv6) to the first downstream interface 112a and the second downstream. Transmit to interface 112b (transmit to all downstream interfaces operating multicast).

  This Query packet is periodically transmitted to the first and second downstream interfaces 112a and 112b. When a response (IGMP report) from the multicast client terminal to the Query packet is received, the contents are reflected in the database 21. Let

  When the multicast packet having the destination IP address set to 224.0.0.1 (FF02 :: 1 in the case of IPv6) is received from the first upstream interface 111a, the multicast proxy router 20 refers to the database 21 and registers in the database 21. An IGMP report packet in which the set multicast address is set is transmitted to the first upstream interface 111a side. (If the database 21 of FIG. 4 is possessed, an IGMP report packet in which multicast addresses 224.1.1.1 and 239.255.255.255 are set is transmitted.)

「224.0.0.2 (IPv4) / FF02 :: 2 (IPv6)」
Leave group packet (group leaving packet) with destination IP address 224.0.0.2 (FF02 :: 2 in IPv6) for which multicast proxy router 20 sets 224.3.3.3 as the group address from the second upstream interface 111b side Is received, after confirming that there is no other host belonging to the multicast group of 224.3.3.3, according to the database 21, the Leave Group packet is transmitted to the second upstream interface 111b.

The operation when a multicast packet other than the above is received is as follows.
When receiving the IP multicast packet, the multicast proxy router 20 operates as follows.
1. Search the database 21, the setting table 22, and the duplication table 23, and search for an entry that matches the received IP multicast.

2. An IP multicast packet is transmitted according to the database 21, the setting table 22, and the duplication table 23.
3. Registration or transmission of the database 21 is performed simultaneously with the distribution of the IP multicast packet.

  When the multicast proxy router 20 receives an IP multicast packet from the downstream interface side, the multicast proxy router 20 transmits the received IP multicast packet to an appropriate interface according to the flowchart of FIG.

FIG. 5 is a flowchart on the downstream interface side in IPv4. FIG. 6 is a flowchart on the upstream interface side in IPv4 of this embodiment.
Hereinafter, the case of IPv4 will be described using the flowcharts of FIGS.

  When the multicast proxy router 20 receives a multicast packet from the downstream interface, it first determines whether the multicast packet is an IGMP packet (MLD packet in the case of IPv6) (step S1).

  If the received multicast packet is an IGMP report in step S1, it is confirmed whether the multicast address of the received multicast packet is in the database 21 managed by the multicast proxy router 20 (step S2).

  In step S2, if the multicast address entry of the received multicast packet is registered in the database 21 (= yes), it is confirmed whether the downstream interface of the entry matches the downstream interface that received the IGMP report. (Step S3).

If they match at step S3 (= yes), the database 21 is updated (step S4).
If they do not match at step S3 (= no), it is searched whether there is an entry in the setting table 22 that matches the received multicast packet (IGMP report) (step S5).

  If there is a matching entry in the database 21 (= yes) in step S5, the duplication table 23 is referred to and it is searched whether the matching entry matches the entry registered in the duplication table 23 (step S6). .

In step S6, if the contents of the entry matching the duplication table 23 are registered (= yes), the contents are registered in the database 21 (step S7), and the IGMP in which the group address registered in the entry is set. The report packet is transmitted to the corresponding upstream interface side (step S8).
If there is no matching entry in steps S5 and S6, the received multicast packet (IGMP report) is discarded (step S9).

  In step S2, if the multicast address entry of the received multicast packet is not registered in the database 21 (= no), the setting table 22 is referred to and there is an entry that matches the received multicast packet (IGMP report). Whether or not is searched (step S10).

If there is a matching entry in step S10 (= yes), the contents are registered in the database 21 (step S11), and an IGMP report in which the group address of the registered entry is set is transmitted to the corresponding upstream interface. (Step S12).
If no matching entry exists in step S10, the received multicast packet (IGMP report) is discarded (step S9).

If the received multicast packet is an IGMP Leave Group in step S1, an IGMP Group-Specific Query (specific group IGMP inquiry) is transmitted for the set number of retransmissions (step S13), and there is a response (IGMP report) to that. Whether or not (step S14).
If a response is returned in step S14 (= yes), the multicast proxy router 20 takes no action (step S15).

  If no response is returned in step S14 (= no), an IGMP Leave Group packet in which the group address set in the received IGMP Leave Group is set is transmitted to the corresponding upstream interface side (Step S16), and the database is sent. The corresponding entry is deleted from 21 (step S17).

  If the received multicast packet is not an IGMP packet (MLD packet in the case of IPv6) in step S1, the received multicast packet is transmitted to the appropriate interface side according to the database 21. If there is no corresponding entry in the database 21, the received packet is discarded.

  When the multicast proxy router 20 receives a multicast packet from the upstream interface side, the multicast proxy router 20 transmits the received multicast packet to an appropriate interface according to the flowchart shown in FIG.

As shown in FIG. 6, first, it is determined whether or not the received multicast packet is an IGMP packet (step S21).
If it is an IGMP packet, it confirms that the packet is an IGMP Query, and responds with an IGMP report to the upstream interface side that received the packet (step S22). If it is not an IGMP Query packet, the packet is discarded.

  If the packet is not an IGMP packet, the received multicast packet is transmitted to an appropriate interface according to the database 21 managed by the multicast proxy router 20 (step S23), and the database 21 is updated (step S24). If there is no corresponding entry in the database 21, the packet is discarded.

  Here, the outline of the effect of the present embodiment will be described as follows. That is, by using the distribution function (distribution function) of the IGMP / MLD proxy implemented by the multicast proxy router 20, multicast packets from the first multicast server 132a, the second multicast server 132b, or the third multicast server 141 are used. Can be received simultaneously by the first multicast client terminal 121a and the second multicast client terminal 121b.

  Conversely, multicast packets from the first multicast client terminal 121a or the second multicast client terminal 121b can be distributed to the first upstream interface 111a or the second upstream interface 111b of the multicast proxy router 20.

  In the present embodiment, description will be made assuming that the multicast proxy router 20 has two upstream interfaces and two downstream interfaces, but there may be three or more upstream interfaces and downstream interfaces. .

1 is a system configuration diagram of an IP multicast packet distribution system according to an embodiment of the present invention. 3 is a list of IP addresses of components such as a multicast proxy router configuring the IP multicast packet distribution system of the embodiment. It is a figure which shows the three management tables which the multicast proxy router which comprises the embodiment has. It is a figure which shows an example of the database which is one of the management tables. It is a flowchart figure which shows the operation | movement of the embodiment. It is a flowchart figure which shows another operation | movement of the same embodiment. It is a system configuration | structure figure of the conventional IP multicast packet delivery system. It is a system block diagram which simplifies and shows the relationship between the conventional multicast server, a multicast router, and a multicast client terminal. It is a system block diagram at the time of adding a multicast proxy router (IGMP / MLD proxy router) to the structure of FIG.

Explanation of symbols

10 IP multicast packet distribution system 20 Multicast proxy router (IGMP / MLD proxy router)
21 Database 21a IP multicast group address 21b Timer remaining time (valid entry time)
IGMP or MLD version operating in 21c entry Downstream interface used in 21d entry Upstream interface used in 21e entry Source IP address 22 Setting table 23 Duplicate table 100 Conventional IP multicast packet distribution System 110 Multicast proxy router (IGMP / MLD proxy router)
111a first upstream interface 111b second upstream interface 112a first downstream interface 112b second downstream interface 121 multicast client terminal 121a first multicast client terminal (customer C1)
121b Second multicast client terminal (customer C2)
121n nth multicast client terminal 130a first Internet service provider (operator A)
130b Second Internet service provider (operator B)
131 Multicast router 131a First multicast router 131b Second multicast router 132 Multicast server 132a First multicast server 132b Second multicast server 140 Internet 141 Third multicast server

Claims (5)

Each provider configuring a plurality of lower networks connected to the upper network transmits the contents to the plurality of terminals in a multicast packet via the multicast router on the provider side and the multicast proxy router connected to the plurality of terminals. In a multicast packet distribution system for distribution,
Multicast packets on a plurality of upstream interfaces the multicast proxy router comprises, a plurality of downstream interface the multicast proxy router comprises, e Bei simultaneous distribution means for distributing the same time,
The simultaneous distribution means includes a database for managing information on which interface at least the group of the multicast address X is operating;
Settings for associating at least the multicast address of the multicast packet with the upstream interface, settings for associating the IP address of the terminal with the upstream interface, settings for associating the MAC address of the terminal with the upstream interface, and the downstream interface A first setting means for performing a setting for associating the upstream interface with the upstream interface, and a setting for associating the IP address of the multicast server with the downstream interface;
When one multicast address is used for multiple interfaces, all duplicate entries are set to associate the upstream interface with the downstream interface, and to associate the multicast server IP address with the downstream interface. With second setting means
A multicast packet distribution system comprising: The multicast packet distribution system according to claim 1,
A multicast packet distribution system, wherein multicast packets on a plurality of downstream interfaces included in the multicast proxy router can be simultaneously distributed to a plurality of upstream interfaces included in the multicast proxy router. The multicast packet distribution system according to claim 1 or 2 ,
When the upstream interface is linked down, and the other upstream interface is linked up, the first setting means performs setting to use the upstream interface that is linked up. A multicast packet distribution system characterized by the above. The multicast packet distribution system according to claim 1 or 2 ,
When the first setting means releases the IP address of the upstream interface, and there is another upstream interface that can be used, the multicast packet is configured to use the upstream interface. Distribution system. In the multicast packet distribution system according to claims 1 to 4 ,
The multicast packet distribution system, wherein the upper network is the Internet.

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