JP2009207205A - Communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform IP multicast communications between an IPv4 terminal and an IPv6 terminal. <P>SOLUTION: A conversion device 1 includes, for example, an IP transmitting and receiving means 2 for transmitting and receiving an IP packet; a conversion IP address holding means 3 for holding an IP address to be used for IP header conversion; an IP address translation information holding means 4 for correspondingly holding IPv4 and IPv6 addresses; an IP header converting means 5 for performing IP header conversion of IPv4 and IPv6; an IP multicast route control information management means 6 for converting IP multicast route control information of IPv4 and IPv6 into each other to perform route control; and an IP multicast membership information management means 7 for managing IP multicast members. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication device, and in particular, a multicast between an IPv4 terminal using IPv4 (IPv4: Internet Protocol version 4) as a communication protocol and an IPv6 terminal using IPv6 (IPv6: Internet Protocol version 6) as a communication protocol. The present invention relates to a communication apparatus that performs communication.

  In recent years, with the rapid increase in the number of hosts connected to the Internet, it is assumed that the address space will be exhausted only with IPv4 (Internet protocol version 4) having a 32-bit address space. In order to avoid this address space depletion, IPv6, which is the next version of IPv4, has been developed and attracts attention as a means for networking new terminals (for example, mobile IP terminals).

  As a method for realizing communication between an IPv4 terminal using IPv4 and an IPv6 terminal using IPv6, for example, a technique described in JP-A-10-136052 can be cited. In this Japanese Patent Laid-Open No. 10-136052, an DNS address expansion table that manages the correspondence between IPv4 addresses and IPv6 addresses is created by a DNS protocol extension technology (DNS: Domain Name System) implemented in a device in the middle of a communication path. Based on this IP address conversion table, IPv4 header-IPv6 header conversion is performed. Thereby, communication between an IPv4 terminal and an IPv6 terminal can be performed.

Japanese Patent Laid-Open No. 10-136052

However, with the above-described technique, IP unicast communication between an IPv4 terminal and an IPv6 terminal can be performed, but IP multicast communication cannot be performed. Here, unicast refers to one-to-one communication, and multicast refers to one-to-specific many communication (communication within a specific group).
In view of the above, the present invention provides a communication apparatus that receives an IP multicast packet broadcast from an IPv4 terminal at the IPv6 terminal and receives an IP multicast packet broadcast from the IPv6 terminal at the IPv4 terminal. With the goal.

According to the first solution of the present invention,
A communication device that relays multicast packets via a network between at least one first device that uses IPv4 as a communication protocol and at least one second device that uses IPv6 as a communication protocol,
Two or more interface units connected to either the at least one first device or the at least one second device via a network;
A transmission / reception unit that relays the multicast packet received from any one of the two or more interface units to any other interface unit;
When a message requesting reception of an IPv6 multicast packet including a first IPv6 multicast address as a destination address is received from one of the interface units from the at least one second device, the interface that has received the message is A storage unit for storing in association with the first IPv4 multicast address corresponding to the first IPv6 multicast address;
When the transmission / reception unit receives an IPv4 multicast packet including the first IPv4 multicast address as a destination address from the at least one first device, the first IPv4 multicast address included in the IPv4 multicast packet as a destination address is set. A converting unit that converts the corresponding first IPv6 multicast address into an IPv6 multicast packet that includes the first IPv6 multicast address as a destination address from the IPv4 multicast packet;
The transmission / reception unit provides a communication device that transmits the created IPv6 multicast packet to an interface stored in the storage unit in association with the first IPv4 multicast address.

  Thereby, the IP multicast packet broadcast by the IPv4 terminal of the IPv4 network can be received by the IPv6 terminal of the IPv6 network. At this time, all processing performed by the conversion apparatus between the IPv4 terminal and the IPv6 terminal is a technique described in RFC, and it is not necessary to add new changes to the IPv4 terminal and the IPv6 terminal.

According to the second solution of the present invention,
A communication device that relays multicast packets via a network between at least one first device that uses IPv6 as a communication protocol and at least one second device that uses IPv4 as a communication protocol,
Two or more interface units connected to either the at least one first device or the at least one second device via a network;
A transmission / reception unit that relays the multicast packet received from any one of the two or more interface units to any other interface unit;
When a message requesting reception of an IPv4 multicast packet including the first IPv4 multicast address as a destination address is received from any of the interface units from the at least one second device, the interface that has received the message is A storage unit for storing in association with the first IPv6 multicast address corresponding to the first IPv4 multicast address;
When the transmission / reception unit receives an IPv6 multicast packet including the first IPv6 multicast address as a destination address from the at least one first device, the first IPv6 multicast address included in the IPv6 multicast packet as a destination address is set. A conversion unit that converts the corresponding first IPv4 multicast address into an IPv4 multicast packet that includes the first IPv4 multicast address as a destination address from the IPv6 multicast packet;
The transmission / reception unit provides a communication device that transmits the created IPv4 multicast packet to an interface stored in the storage unit in association with the first IPv6 multicast address.

  Thereby, the IP multicast packet broadcast by the IPv6 terminal of the IPv6 network can be received by the IPv4 terminal of the IPv4 network. At this time, all processing performed by the conversion apparatus between the IPv4 terminal and the IPv6 terminal is a technique described in RFC, and it is not necessary to add new changes to the IPv4 terminal and the IPv6 terminal.

According to the third solution of the present invention,
A multicast communication device in a communication network system including a conversion device that is arranged between an IPv4 network including an IPv4 terminal and an IPv6 network including an IPv6 terminal and performs transmission and reception of IP packets,
IP transmission / reception means for transmitting / receiving IP packets;
IP address holding means for conversion that holds an IP address used for IP header conversion;
IP address translation information holding means for holding IPv4 and IPv6 addresses in association with each other;
IP header conversion means for performing IP header conversion between IPv4 and IPv6;
IP multicast route control information management means for performing route control by mutually converting IP multicast route control information related to an IP network that should relay IP multicast packets broadcast from IPv4 and IPv6 IP multicast servers;
IP multicast membership information management means for managing IP multicast members,
IP header conversion means
The IPv4 end point address of the IPv4 multicast packet passed from the IP transmitting / receiving unit is inquired of the IP address conversion information holding unit, and converted into an IPv6 end point address using the corresponding IPv6 address,
By inquiring the IPv4 starting point address of the IPv4 multicast packet from the IP address conversion information holding means and converting it to an IPv6 starting point address using the corresponding IPv6 address,
Creating an IPv6 multicast packet from the IPv4 multicast packet and instructing the IP transmitting / receiving means to send it to the IPv6 network;
The IPv6 end point address of the IPv6 multicast packet passed from the IP transmitting / receiving unit is inquired of the IP address conversion information holding unit, and converted into an IPv4 end point address using the corresponding IPv4 address,
By inquiring the IPv6 starting point address of the IPv6 multicast packet to the IP address conversion information holding means and converting it to an IPv4 starting point address using the corresponding IPv4 address,
Provided is a multicast communication apparatus that creates an IPv4 multicast packet from an IPv6 multicast packet and instructs an IP transmission / reception means to send the packet to an IPv4 network.
In a first aspect, the present invention relates to a method for performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network, an IPv6 network, and a conversion device connected to both of them. Because
(A) The conversion device is described in the IP multicast group membership protocol described in RFC2236 (RFC: Request for Comments), RFC2710, and the like, RFC2362, draft-ietf-pim-v2-dm-03.txt, and the like. Operates as an IPv4 multicast router for an IPv4 network, operates as an IPv6 multicast router for an IPv6 network,
(B) Upon receiving from the IPv6 terminal a request to join the group of IPv6 addresses, which is obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 address of the group of IPv4 multicast packets broadcast by the IPv4 terminal. The IPv6 address is reflected in the management information of the IP multicast group membership protocol, the IPv6 address of the group is associated with the IPv4 address of the group, and the management information of the IP multicast routing protocol as a relay request for the IPv4 address of the group And exchange IP multicast routing information with neighboring IPv4 multicast routers,
(C) Upon receiving an IPv4 multicast packet broadcast by the IPv4 terminal, the conversion device converts an IPv4 end point address included in the IPv4 multicast packet into an IPv6 end point address using an IPv6 address corresponding thereto, and the management An IP for selecting one of IPv6 unicast addresses stored in advance in the conversion device according to the instructions of the user and converting the IPv4 start address included in the IPv4 multicast packet to an IPv6 start address using the selected address An IPv6 multicast packet is created from the IPv4 multicast packet by header conversion, and is sent to the IPv6 network.
(D) The IPv6 terminal receives the IPv6 multicast packet, and provides an IPv4-IPv6 multicast communication method.

In a second aspect, the present invention relates to a method for performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network, an IPv6 network, and a conversion device connected to both of them. Because
(A) The conversion device includes an IP multicast group membership protocol described in RFC2236, RFC2710, etc., and an IP multicast routing protocol described in RFC2362, draft-ietf-pim-v2-dm-03.txt, etc. The IPv4 network operates as an IPv4 multicast router, the IPv6 network operates as an IPv6 multicast router, and (b) a fixed data (IPv6 multicast prefix from an IPv6 address of a group of IPv6 multicast packets broadcast by the IPv6 terminal). ) Is received from the IPv4 terminal, the IPv4 address of the group is assigned to the IP multicast group membership protocol. The IPv4 address of the group is associated with the IPv6 address of the group, and further reflected in the management information of the IP multicast routing protocol as a relay request for the IPv6 address of the group, and adjacent to the IPv6 multicast router Exchange IP multicast routing information with
(C) Upon receiving an IPv6 multicast packet broadcast by the IPv6 terminal, the conversion device converts an IPv6 end point address included in the IPv6 multicast packet into an IPv4 end point address using an IPv4 address corresponding thereto, and the management IP which converts one of the IPv4 unicast addresses stored in the conversion device in advance according to the instructions of the user and converts the IPv6 start address included in the IPv6 multicast packet into an IPv4 start address using the selected address. An IPv4 multicast packet is created from the IPv6 multicast packet by header conversion, and sent to the IPv4 network;
(D) The IPv4 terminal provides the IPv4-IPv6 multicast communication method, wherein the IPv4 multicast packet is received.

In a third aspect, the present invention relates to a method for performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network, an IPv6 network, and a conversion device connected to both of them. Because
(A) The conversion device includes an IP multicast group membership protocol described in RFC2236, RFC2710, etc., and an IP multicast routing protocol described in RFC2362, draft-ietf-pim-v2-dm-03.txt, etc. The IPv4 network operates as an IPv4 multicast router, the IPv6 network operates as an IPv6 multicast router, and (b) a fixed data (IPv6 multicast prefix is assigned to an IPv4 address of a group of IPv4 multicast packets broadcast by the IPv4 terminal. ) Is received from the neighboring IPv6 multicast router to receive the IP multicast routing control information requesting the relay of the packet of the IPv6 address group. Pv6 associated address and an IPv4 address of the group, further reflected in the management information of the IP multicast routing protocol as a relay request for IPv4 address of the group, to replace the adjacent IPv4 multicast router and IP multicast routing control information,
(C) Upon receiving an IPv4 multicast packet broadcast by the IPv4 terminal, the conversion device converts an IPv4 end point address included in the IPv4 multicast packet into an IPv6 end point address using an IPv6 address corresponding thereto, and the management IP that converts one of the IPv6 unicast addresses previously stored in the conversion device in accordance with an instruction from the user and converts the IPv4 start address included in the IPv4 multicast packet into an IPv6 start address using the selected address. An IPv6 multicast packet is created from the IPv4 multicast packet by header conversion, and is sent to the IPv6 network.
(D) The IPv6 terminal receives the IPv6 multicast packet, and provides an IPv4-IPv6 multicast communication method.

  Thereby, the IP multicast packet broadcast by the IPv4 terminal of the IPv4 network can be received by the IPv6 terminal of the IPv6 network. At this time, all the processing performed by the conversion device between the IPv4 terminal and the IPv6 terminal is a technique described in RFC, and it is not necessary to add new modifications to the IPv4 terminal and the IPv6 terminal.

In a fourth aspect, the present invention relates to a method for performing IP multicast communication between an IPv4 terminal of an IPv4 network and an IPv6 terminal of an IPv6 network in a communication network system including an IPv4 network, an IPv6 network, and a conversion device connected to both of them. Because
(A) The conversion device includes an IP multicast group membership protocol described in RFC2236, RFC2710, etc., and an IP multicast routing protocol described in RFC2362, draft-ietf-pim-v2-dm-03.txt, etc. The IPv4 network operates as an IPv4 multicast router, the IPv6 network operates as an IPv6 multicast router, and (b) a fixed data (IPv6 multicast prefix from an IPv6 address of a group of IPv6 multicast packets broadcast by the IPv6 terminal). When the IP multicast routing information for requesting the relay of the packet of the IPv4 address group that can be deleted is received from the adjacent IPv4 multicast router, the group Associating the IPv6 address of the IPv4 address and the group, further reflected in the management information of the IP multicast routing protocol as a relay request to the IPv6 address of the group, to replace the adjacent IPv6 multicast router and IP multicast routing control information,
(C) Upon receiving an IPv6 multicast packet broadcast by the IPv6 terminal, the conversion device converts an IPv6 end point address included in the IPv6 multicast packet into an IPv4 end point address using an IPv4 address corresponding thereto, and the management IP that converts one of the IPv4 unicast addresses stored in the conversion device in advance according to the instructions of the user and converts the IPv6 start address included in the IPv6 multicast packet into an IPv4 start address using the selected address. An IPv4 multicast packet is created from the IPv6 multicast packet by header conversion, and sent to the IPv4 network;
(D) The IPv4 terminal provides the IPv4-IPv6 multicast communication method, wherein the IPv4 multicast packet is received.

  Thereby, the IP multicast packet broadcast by the IPv6 terminal of the IPv6 network can be received by the IPv4 terminal of the IPv4 network. At this time, all the processing performed by the conversion device between the IPv4 terminal and the IPv6 terminal is a technique described in RFC, and it is not necessary to add new modifications to the IPv4 terminal and the IPv6 terminal.

In a fifth aspect, the present invention provides (a) IP transmission / reception means for performing transmission / reception and relay of IPv4 packets with an IPv4 network, transmission / reception and relay of IPv6 packets with an IPv6 network,
(B) a conversion IP address holding means for holding an IPv4 unicast address and an IPv6 unicast address used for IP header conversion;
(C) IPv4 end point address of an IPv4 multicast packet broadcast by an IPv4 terminal of the IPv4 network, an IPv6 multicast address obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 end point address, and an IPv4 start point address of the IPv4 multicast packet And the IPv6 unicast address (obtained if not already acquired) acquired from the conversion IP address holding means, the IPv6 end point address of the IPv6 multicast packet broadcast by the IPv6 terminal of the IPv6 network, and the IPv6 end point address, the fixed data (IPv6 IPv4 multicast address obtained by deleting (multicast prefix), and IPv6 start address of the IPv6 multicast packet IP address conversion information holding means less said conversion IP address obtained from the holding means IPv4 unicast address (if not yet obtains) holding in association with,
(D) IP multicast route control information is managed according to the IP multicast route control protocol described in RFC2362, draft-ietf-pim-v2-dm-03.txt, etc., and IPv6 multicast packets broadcast by the IPv6 terminal When IP multicast routing control information for requesting relay of a packet of an IPv4 address group, which is obtained by deleting fixed data (IPv6 multicast prefix) from the IPv6 address of the group, is received from an adjacent IPv4 multicast router, the IPv4 multicast group An IPv6 address obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 address and the IPv4 address is instructed to be registered in the IP address translation information holding means, and the group It is reflected in the management information of the IP multicast route control protocol as a relay request for the Pv6 address, exchanges IP multicast route control information with the adjacent IPv6 multicast router, and similarly to the IPv4 address of the group of IPv4 multicast packets broadcast by the IPv4 terminal. When IP multicast routing control information requesting relay of a packet of an IPv6 address group formed by adding fixed data (IPv6 multicast prefix) is received from an adjacent IPv6 multicast router, the IPv6 address of the IPv6 multicast group and the IPv6 An IPv4 address that can be obtained by deleting fixed data (IPv6 multicast prefix) from the address is instructed to the IP address translation information holding means. Is registered, further reflected in the management information of the IP multicast routing protocol as a relay request for IPv4 address of the group, and IP multicast routing control information management means for exchanging adjacent IPv4 multicast router and IP multicast routing control information,
(E) When managing a member of an IPv4 multicast group according to the IP multicast group membership protocol described in RFC2236 or the like, and receiving a join request to an IPv4 multicast group transmitted from an IPv4 terminal in the connected IPv4 network, The IPv6 address which is reflected in the management information of the IP multicast group membership protocol and which is obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 address and the IPv4 address of the IPv4 multicast group is stored in the IP address conversion information holding means. IP multicast route control information for instructing and registering and requesting relay of the packet of the IPv6 address is sent to the IP multicast route control information tube IPv6 multicast group transmitted from an IPv6 terminal in the connected IPv6 network, instructing means to register, managing IPv6 multicast group members in accordance with the IP multicast group membership protocol described in RFC2710, etc. Is received in the management information of the IP multicast group membership protocol, and the IPv6 address of the IPv6 multicast group and the IPv4 address obtained by deleting the fixed data (IPv6 multicast prefix) from the IPv6 address are received. Instructing the IP address translation information holding means to register, and further, IP multicast routing control information requesting relay of the packet of the IPv4 address And IP multicast membership information management means for registering instructs the P multicast routing information management means,
(F) The IPv4 end point address of the IPv4 multicast packet passed from the IP transmission / reception unit is inquired of the IP address conversion information holding unit, converted into an IPv6 end point address using the corresponding IPv6 address, and the IPv4 multicast packet The IPv4 start point address is inquired of the IP address translation information holding means, and the IPv6 multicast packet is created from the IPv4 multicast packet by the IP header translation that converts the IPv4 start point address to the IPv6 start point address using the corresponding IPv6 address. The IP transmission / reception means is instructed to send to the network, and the IPv6 end point address of the IPv6 multicast packet passed from the IP transmission / reception means is also set as the IP address. An inquiry is made to the address translation information holding means to convert it to an IPv4 end address using the corresponding IPv4 address, and the IPv6 start address of the IPv6 multicast packet is inquired to the IP address translation information holding means to correspond to the corresponding IPv4. IP header conversion means for creating an IPv4 multicast packet from the IPv6 multicast packet by IP header conversion for converting to an IPv4 start point address using an address, and further instructing the IP transmission / reception means to send to the IPv4 network. A conversion device characterized by the above is provided.

  According to the present invention, an IP multicast packet broadcast from an IPv4 terminal can be received by the IPv6 terminal. Further, according to the present invention, an IP multicast packet broadcast from an IPv6 terminal can be received by the IPv4 terminal.

  As another feature of the present invention, the IP address translation information holding means deletes the IPv4 unicast address and the IPv6 unicast address that are not referenced for a certain period of time, and uses it for the conversion. You may make it return to an IP address holding means. As a result, unused IPv4 unicast addresses and IPv6 unicast addresses are returned to the conversion IP address holding means, so that consumption of IPv4 unicast addresses and IPv6 unicast addresses can be suppressed.

  According to the present invention, as described above, the IP multicast packet broadcast from the IPv4 terminal can be received by the IPv6 terminal, and the IP multicast packet broadcast from the IPv6 terminal can be received by the IPv4 terminal.

The block diagram of 1st Embodiment of the converter 1 regarding this invention. The block diagram of the IPv4 unicast address table 31. FIG. The block diagram of the IPv6 unicast address table 32. FIG. The block diagram of the IP address conversion table 41. FIG. FIG. 3 is a configuration diagram of an IP multicast route information table 51. The block diagram of the IPv4 adjacent router information table 71. FIG. The block diagram of the IPv6 adjacent router information table 72. FIG. The block diagram of the IPv4 multicast member information table 61. FIG. The block diagram of the IPv6 multicast member information table 62. FIG. The block diagram of the communication network system 100 using the converter 1 regarding this invention. The block diagram of the communication network system 200 using the converter 1 regarding this invention. The communication sequence diagram about the processes 201 and 202. The communication sequence diagram about the processing 203,204. The communication sequence diagram about the processes 205-207. The communication sequence diagram about the process 208,209. The communication sequence diagram about the processes 210-214. The communication sequence diagram about the process 215. The communication sequence diagram about the process 217. The communication sequence figure about the processes 231-233. FIG. 11 is a communication sequence diagram for processing 234. The communication sequence diagram about the processes 235-237. FIG. 24 is a communication sequence diagram for processing 238.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a configuration diagram of a first embodiment of a conversion apparatus 1 according to the present invention.
The conversion device 1 is mainly located between the IPv4 networks 111 and 112 and the IPv6 networks 121 and 122, and IP multicast communication between the IPv4 terminal and the IPv6 terminal by IP header conversion of the IPv4 multicast packet and the IPv6 multicast packet described later. For example, an IP transmission / reception means 2 including electronic devices such as a CPU, an ASIC, and a RAM, a conversion IP address holding means 3, an IP address conversion information holding means 4, an IP header conversion means 5, An IP multicast route control information management means 6, an IP multicast membership information management means 7, and interfaces 8 to 11 are provided. The interfaces 8 to 11 refer to locations where the IP transmitting / receiving means 2 is connected to the IPv4 networks 111 and 112 and the IPv6 networks 121 and 122.
The IP transmission / reception means 2 performs transmission / reception and relay of IPv4 packets with the IPv4 networks 111 and 112 and transmission / reception and relay of IPv6 packets with the IPv6 networks 121 and 122.
The conversion IP address holding unit 3 holds an IPv4 unicast address and an IPv6 unicast address used in IP header conversion described later. The IPv4 unicast address and the IPv6 unicast address used for this IP header translation are input in advance by an administrator (or a maintenance person or the like) of the translation apparatus 1, and are respectively described in an IPv4 unicast address table 31 and an IPv6 unicast address table. 32.

FIG. 2 is a configuration diagram of the IPv4 unicast address table 31.
In the IPv4 unicast address table 31, an IPv4 unicast address used for IP header conversion is registered in advance according to an instruction from an administrator, for example. Here, an IPv4 address (here, as an example, 133.144. 94.100 to 133.144.94.200 (in the following, examples are similarly shown in parentheses).

FIG. 3 is a configuration diagram of the IPv6 unicast address table 32.
In the IPv6 unicast address table 32, for example, an IPv6 unicast address used for IP header conversion is registered in advance according to an instruction from the administrator. Here, an IPv6 address (4 :: 100 to 4: 200) is registered. Is registered.
The IP address conversion information holding unit 4 has an IP address conversion table. The IP address translation information holding unit 4 includes an IPv4 multicast address broadcast by an IPv4 terminal, an IPv6 multicast address that can be obtained by adding fixed data (IPv6 multicast prefix) to the IPv4 endpoint address, and an IPv4 multicast. Fixed from the IPv4 start point address of the packet, the IPv6 unicast address obtained from the translation IP address holding means 3 (obtained if not yet), the IPv6 end point address of the IPv6 multicast packet broadcast by the IPv6 terminal, and the IPv6 end point address IPv4 multicast address that can be deleted by deleting data (IPv6 multicast prefix), and IPv6 start address of IPv6 multicast packet and translation IP address holding unit 3 and the IPv4 unicast address acquired from the (if not yet obtains) holds in association respectively with. The IP address conversion information holding unit 4 is configured by an electronic device such as a CPU, ASIC, or RAM, for example.

FIG. 4 is a configuration diagram of the IP address conversion table 41.
The IP address conversion table 41 includes, for example, the IPv4 end point address of the received IPv4 multicast packet and the corresponding IPv6 address (item number 1), the IPv4 start point address of the received IPv4 multicast packet, and the corresponding IPv6 address (item number 2). ), The IPv6 end point address of the received IPv6 multicast packet and the corresponding IPv4 address (item number 3), and the IPv6 start point address of the received IPv6 multicast packet and the corresponding IPv4 address (item number 4), respectively. ing.

  The IP header conversion means 5 receives the IPv4 multicast packet transmitted from the IP transmission / reception means 2, creates an IPv6 multicast packet by performing IP header conversion, and transmits it again to the IP transmission / reception means 2. Specifically, in the IP header conversion, the IPv4 end point address of the IPv4 multicast packet is converted to an IPv6 end point address by using the IPv6 address corresponding to the IPv4 end point address by inquiring the IP address conversion information holding unit 4. Further, similarly, the IPv4 start point address of the IPv4 multicast packet is inquired to the IP address conversion information holding means 4 to be converted into an IPv6 start point address using the IPv6 address corresponding to the IPv4 start point address.

  The IP header conversion unit 5 receives the IPv6 multicast packet transmitted from the IP transmission / reception unit 2, performs IP header conversion to create an IPv4 multicast packet, and transmits it again to the IP transmission / reception unit 2. Specifically, in the IP header conversion, the IPv6 end point address of the IPv6 multicast packet is converted into an IPv4 end point address by using the IPv4 address corresponding to the IPv6 end point address by inquiring the IP address conversion information holding unit 4. Further, similarly, by inquiring the IPv6 start point address of the IPv6 multicast packet to the IP address conversion information holding means 4, the IPv4 start point address corresponding to the IPv6 start point address is converted into the IPv4 start point address. The IP header conversion means 5 is composed of an electronic device such as a CPU, ASIC, or RAM.

  The IP multicast route control information management means 6 determines the relay destination of the IPv4 multicast packet and the IPv6 multicast packet based on IPv4 multicast route control information and IPv6 multicast route control information described later. The IPv4 multicast routing control information is exchanged and collected with an adjacent IPv4 multicast router, for example, according to the IP multicast routing control protocol, and takes into account IPv4 multicast group member information notified from the IP multicast membership information management means 7 Can be obtained. Similarly, the IPv6 multicast route control information is exchanged, collected and managed with, for example, an adjacent IPv6 multicast router, and takes into account IPv6 multicast group member information notified from the IP multicast membership information management means 7. It is obtained with. The IP multicast route control information management means 6 is composed of an electronic device such as a CPU, ASIC, or RAM, for example. The IPv4 multicast route control information and the IPv6 multicast route control information are held in the IP multicast route information table 51, respectively. The IP multicast route information table 51 is stored in the IP multicast route control information management means 6 or other appropriate memory.

FIG. 5 is a configuration diagram of the IP multicast route information table 51.
The IP multicast route information table 51 holds information on an IP network to which an IP multicast packet broadcast from an IP multicast server is to be relayed. The IPv4 multicast route control information is a part of the information held in the IP multicast route information table 51 where IP multicast address = IPv4 multicast address. The IPv6 multicast route control information is a part of the information held in the IP multicast route information table 51 where IP multicast address = IPv6 multicast address.

FIG. 6 is a configuration diagram of the IPv4 neighboring router information table 71.
The IPv4 neighboring router information table 71 holds information on neighboring IPv4 multicast routers. Here, as an entry for each item number, for example, in the item number “1”, the neighboring router information corresponding to the interface 8 is “OFF”, and in the item number “2”, the neighboring router information corresponding to the interface 9 is used. Is “OFF”, in the item number “3”, the neighboring router information corresponding to the interface 10 is “OFF”, and in the item number “4”, the neighboring router information corresponding to the interface 11 is “OFF”. .

FIG. 7 is a configuration diagram of the IPv6 neighboring router information table 72.
The IPv6 neighboring router information table 72 holds information on neighboring IPv6 multicast routers. Here, as an entry for each item number, for example, in the item number “1”, the neighboring router information corresponding to the interface 8 is “OFF”, and in the item number “2”, the neighboring router information corresponding to the interface 9 is used. Is “OFF”, in the item number “3”, the neighboring router information corresponding to the interface 10 is “OFF”, and in the item number “4”, the neighboring router information corresponding to the interface 11 is “OFF”. .

  The IP multicast membership information management means 7 receives a request to join or leave an IPv4 multicast group transmitted from an IPv4 terminal according to the IPv4 multicast group membership protocol described in RFC2236 or the like, and connects directly. Collects and manages IPv4 multicast group member information in the IPv4 network, and notifies the IPv4 multicast group member information to the IP multicast route control information management means 6.

  Further, the IP multicast membership information management means 7 receives a request to join or leave an IPv6 multicast group transmitted from an IPv6 terminal according to the IPv6 multicast group membership protocol described in RFC2710 or the like, and directly Collects and manages IPv6 multicast group member information in the connected IPv6 network, and notifies IPv6 multicast group member information to the IP multicast route control information management means 6. Here, PIM (Protocol Independent Multicast) protocol Dense Mode (PIM-DM protocol) described in RFC 2362, draft-ietf-pim-v2-dm-03.txt, etc. is used as the IP multicast routing protocol. However, an appropriate protocol may be used.

  The IPv4 multicast group member information is held in the IPv4 multicast member information table 61, and the IPv6 multicast group member information is held in the IPv6 multicast member information table 62, respectively.

FIG. 8 is a configuration diagram of the IPv4 multicast member information table 61.
The IPv4 multicast member information table 61 holds information on the IPv4 network to which the IPv4 terminal that has joined the IPv4 multicast address belongs. Here, as an entry for each item number with respect to the IPv4 address (238.0.0.2), for example, in the item number “1”, the member presence information corresponding to the interface 8 is “OFF”, and the item number “ In “2”, the member enrollment information corresponding to the interface 9 is “ON”, in the item number “3”, the member enrollment information corresponding to the interface 10 is “OFF”, and in the item number “4”, the interface 11 The member enrollment information corresponding to is “OFF”. Therefore, in this example, the IPv4 address (238.0.0.2) belongs to the interface 9.

FIG. 9 is a configuration diagram of the IPv6 multicast member information table 62.
The IPv6 multicast member information table 62 holds information on the IPv6 network to which the IPv6 terminal that has joined the IPv6 multicast address belongs. Here, as an entry for each item number for the IPv6 address (ff1e :: 238.0.0.1), for example, in the item number “1”, the member enrollment information corresponding to the interface 8 is “OFF”. In the item number “2”, the member enrollment information corresponding to the interface 9 is “OFF”, in the item number “3”, the member enrollment information corresponding to the interface 10 is “OFF”, and in the item number “4” The member enrollment information corresponding to the interface 11 is “ON”. Therefore, in this example, IPv6 (ff1e :: 238.0.0.1) belongs to the interface 11.

FIG. 10 is a configuration diagram of a communication network system 100 using the conversion apparatus 1 according to the present invention.
In this communication network system 100, for example, the conversion device 1 (here, as an example, an IPv4 address; 133.144.93.1 and 133.144.95.1, an IPv6 address; 1 :: 1 and 2 :: 1 IPv4 networks 111 and 112 and IPv6 networks 121 and 122 are connected to each other via IPv4 network 111 and IPv4 multicast server 101 (IPv4 address; 133) that broadcasts multicast packets using IPv4. 144.93.2), and the IPv4 network 112 includes an IPv4 multicast client 102 (IPv4 address; 133.144.95.2) that receives multicast packets in IPv4, and an IPv6 network 121 includes an IPv6 multicast server 103 (IPv6 address; 1 :: 2) that broadcasts multicast packets in IPv6. An IPv6 multicast client 104 (IPv6 address; 2) that receives multicast packets in IPv6 is included in the IPv6 network 122. :: 2) is included.

  The IPv4 multicast server 101 broadcasts an IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 111, and the IPv6 multicast server 103 sends an IPv6 multicast packet (IPv6 address; ff1e :: 238. 0.0.2) is broadcast to the IPv6 network 121, respectively. Here, the IPv4 networks 111 and 112 and the IPv6 networks 121 and 122 are completely separated, but the IPv4 networks 111 and 112 and the IPv6 networks 121 and 122 are mixed in the physically same network. It is the same even when doing.

  Next, in this communication network system 100, the IPv4 multicast server 101 broadcasts the IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 111, and transmits the IPv4 multicast packet to the IPv6 multicast client. A case of receiving at 104 will be described.

First, processing (processing 201 to 204) that the conversion apparatus 1 periodically performs according to the IGMP protocol (IGMP: Internet Group Management Protocol), the MLD protocol (MLD: Multicast Listener Discovery), and the PIM-DM protocol will be described.
FIG. 12 is a communication sequence diagram for the processes 201 and 202.

(Processing 201)
The IP multicast membership information management means 7 creates an IGMP Query message according to the IGMP protocol, and instructs the IP transmission / reception means 2 to send it to the IPv4 networks 111 and 112. The IP transmission / reception means 2 sends an IGMP Query message to the IPv4 networks 111 and 112. Further, when the IP transmission / reception means 2 receives the IGMP Report message from the IPv4 network 111 or 112, the IP transmission / reception means 2 passes this IGMP Report message to the IP multicast membership information management means 7.

  The IP multicast membership information management means 7 analyzes the IGMP Report message in accordance with the IGMP protocol and creates an IPv4 multicast member information table 61 (IPv4 address = IPv4 multicast group address of which the subscription is requested by the IGMP Report message). Set member enrollment information interface = ON.) However, here, since there is no subscriber of the IPv4 multicast group, the IP transmission / reception means 2 does not receive this IGMP Report message.

(About processing 202)
The IP multicast membership information management means 7 creates an MLD Query message according to the MLD protocol and instructs the IP transmission / reception means 2 to send it to the IPv6 networks 121 and 122. The IP transmission / reception means 2 sends an MLD Query message to the IPv6 networks 121 and 122. Further, when receiving the MLD Report message from the IPv6 network 121 or 122, the IP transmitting / receiving unit 2 passes this MLD Report message to the IP multicast membership information management unit 7.

The IP multicast membership information management means 7 analyzes the MLD Report message according to the MLD protocol, and creates an IPv6 multicast member information table 62 (IPv6 address = IPv6 multicast group address of which the subscription is requested by the MLD Report message). Set member enrollment information interface = ON.) However, since there is no subscriber of the IPv6 multicast group here, the IP transmitting / receiving means 2 does not receive this MLD Report message.
FIG. 13 is a communication sequence diagram for the processes 203 and 204.

(Processing 203)
The IP multicast route control information management means 6 creates a Hello message according to the PIM-DM protocol and instructs the IP transmission / reception means 2 to send it to the IPv4 networks 111 and 112. The IP transmission / reception means 2 sends a Hello message to the IPv4 networks 111 and 112. Further, when receiving the Hello message from the IPv4 network 111 or 112, the IP transmission / reception means 2 passes this Hello message to the IP multicast route control information management means 6.

  The IP multicast route control information management means 6 analyzes the Hello message according to the PIM-DM protocol and creates an IPv4 neighboring router information table 71 (the neighboring router information of the interface that has received the Hello message is set to ON). . However, since there is no IPv4 multicast router here, the IP transmission / reception means 2 does not receive this Hello message.

(About processing 204)
The IP multicast route control information management means 6 creates a Hello message according to the PIM-DM protocol and instructs the IP transmission / reception means 2 to send it to the IPv6 networks 121 and 122. The IP transmission / reception means 2 sends a Hello message to the IPv6 networks 121 and 122. Further, when the IP transmission / reception means 2 receives the Hello message from the IPv6 network 121 or 122, it passes it to the IP multicast route control information management means 6.

  The IP multicast route control information management means 6 analyzes the Hello message according to the PIM-DM protocol and creates an IPv6 neighboring router information table 72 (the neighboring router information of the interface that has received the Hello message is set to ON). . However, since there is no IPv6 multicast router here, the IP transmission / reception means 2 does not receive this Hello message.

Next, a case where the IPv6 multicast client 104 is not joined to the IPv6 multicast group (ff1e :: 238.0.0. 1) in the communication network system 100 will be described.
First, processing in the conversion apparatus 1 that has received an IPv4 multicast packet (addressed to 238.0.0.1) sent from the IPv4 multicast server 101 to the IPv4 network 111 will be described.
FIG. 14 is a communication sequence diagram for the processes 205 to 207.

(Processing 205)
Upon receiving an IPv4 multicast packet (addressed to 238.0.0.1) from the IPv4 network 111, the IP transmission / reception means 2 receives an IPv4 end point address (= IP multicast address = 238.0.0.1) of the IPv4 multicast packet, Using the IPv4 start point address (= IP multicast server address = 133.144.93.2) as a search key, the relay destination (IPv4 output information and IPv6 output information) to which this IPv4 multicast packet is to be relayed is IP multicast route control information. The management unit 6 is inquired.

(About processing 206)
The IP multicast route control information management means 6 inquires of the IP address translation information holding means 4 about the IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address.

(About processing 207)
First, the IP address translation information holding unit 4 checks whether the IPv4 end point address is registered in the IP address translation table 41, and inquires whether the corresponding IPv6 address is registered or unregistered (in this case, an IP multicast route) Report to the control information management means 6). If not registered, an IPv4 end point address and an IPv6 address (ff1e :: 238.0.0.1) obtained by adding fixed data (IPv6 multicast prefix = eg ff1e :: / 96) to the IPv4 end point address Are registered in the IP address conversion table 41, and this IPv6 address (ff1e :: 238.0.0.1) is reported to the IP multicast routing information management means 6.

Also, the IP address translation information holding unit 4 checks whether the IPv4 start point address is registered in the IP address translation table 41, and inquires whether the corresponding IPv6 address is registered or unregistered (in this case, an IP multicast route) Report to the control information management means 6). If not registered, an IPv6 unicast address is obtained from the translation IP address holding means 3 and registered in the IP address translation table 41 in association with the IPv4 start address, and then this IPv6 unicast address is assigned to the IP multicast routing information. Report to management means 6. Here, since the IPv4 start point address (133.144.93.2) is not registered in the IP address conversion table 41, the IPv6 unicast address (4 :: 100) is obtained from the conversion IP address holding means 3. After obtaining and registering in the IP address conversion table 41, this IPv6 unicast address is reported.
FIG. 15 is a communication sequence diagram for the processes 208 and 209.

(About processing 208)
Next, the IP multicast route control information management unit 6 sends the IPv4 end point address (IP multicast address; 238.0.0.1) given from the IP transmission / reception unit 2 and the IPv4 start point address (IP multicast server address; 133. 144.93.2) is used as a search key to search the IP multicast route information table 51. When there is a corresponding entry in the IP multicast route information table 51, the IP transmission / reception means 2 is notified of output information (information indicating the interface and protocol to be output). On the other hand, if there is no corresponding entry, entries for the IP multicast address (238.0.0.1) and the IP multicast server address (133.144.93.2) are created as described above.

  Here, the entry output information set (setting) when notifying the IP transmission / reception means 2 of the output information (information indicating the output interface and protocol) of the entry of the IP multicast route information table 51 will be described.

  The IPv4 output information of the interface whose neighboring router information is set to ON in the IPv4 neighboring router information table 71 is set to ON. The IPv6 output information of the interface whose neighboring router information is set to ON in the IPv6 neighboring router information table 72 is set to ON. In the IPv4 multicast member information table 61, the IPv4 output information of the interface whose IPv4 address is (238.0.0.1) and whose member enrollment information interface is set to ON is set to ON. In the IPv6 multicast member information table 62, the IPv6 address is (ff1e :: 238.0.0.1), and the IPv6 output information of the interface whose member enrollment information interface is set to ON is set to ON. The IPv4 output information of the interface that has received the IPv4 multicast packet is set to OFF. Also, IPv4 output information and IPv6 output information not corresponding to any of the above are set to OFF. Here, the output information of IPv4 output information = OFF for all interfaces and IPv6 output information = OFF for all interfaces is notified from the IP multicast route control information management means 6 to the IP transmission / reception means 2.

(About processing 209)
The IP transmission / reception means 2 sends out an IPv4 multicast packet to the IPv4 network corresponding to the interface whose IPv4 output information is set to ON. Here, since the IPv4 output information of all interfaces is set to OFF, the IPv4 multicast packet is not sent to any IPv4 network.
FIG. 16 is a communication sequence diagram for the processes 210 to 214.

(About processing 210)
The IP transmission / reception unit 2 passes the IPv4 multicast packet to the IP header conversion unit 5.

(About processing 211)
The IP header conversion unit 5 inquires the IP address conversion information holding unit 4 about IPv6 addresses corresponding to the IPv4 end point address and the IPv4 start point address of the IPv4 multicast packet.

(About processing 212)
The IP address translation information holding unit 4 acquires IPv6 addresses corresponding to the IPv4 end point address and the IPv4 start point address from the IP address translation table 41 in accordance with (Processing 207), and the inquiry source (here, the IP header translation unit 5). )

(About processing 213)
The IP header conversion means 5 converts the IPv4 multicast address into the IPv6 end point address using the IPv6 address corresponding to the IPv4 end point address, and converts the IPv4 multicast address into the IPv6 start point address using the IPv6 address corresponding to the IPv4 start point address. An IPv6 multicast packet is created from the packet, and the created IPv6 multicast packet is returned to the IP transmission / reception means 2.

(Processing 214)
The IP transmission / reception unit 2 sends out an IPv6 multicast packet to the IPv6 network corresponding to the interface set to IPv6 output information = ON notified from the IP multicast route control information management unit 6 in (Processing 208). Here, since IPv6 output information of all interfaces is set to OFF, the IPv6 multicast packet is not transmitted to any IPv6 network.

Next, a case where the IPv6 multicast client 104 joins the IPv6 multicast group (ff1e :: 238.0.0.1) will be described.
The IPv6 multicast client 104 creates an MLD Report message for joining the IPv6 multicast group (ff1e :: 238.0.0.1) according to the MLD protocol, and sends it to the IPv6 network 122. Processing of the conversion apparatus 1 that has received this MLD Report message from the IPv6 network 122 will be described.
FIG. 17 is a communication sequence diagram for the process 215.

(About processing 215)
The IP transmission / reception means 2 passes the MLD message to the IP multicast membership information management means 7. The IP multicast membership information management means 7 analyzes the MLD message according to the MLD protocol to create an IPv6 multicast member information table 62, and uses the information obtained by the analysis of the MLD message as the IP multicast routing information management means 6 Notify The IP multicast route control information management means 6 creates the IP multicast route information table 51 according to the information obtained by analyzing the MLD message.

  Here, since it has been found that the subscriber of the IPv6 multicast group (ff1e :: 238.0.0.1) is in the IPv6 network 122 by receiving the MLD message, the IPv6 address of the IPv6 multicast member information table 62 is used. The interface 11 of (ff1e :: 238.0.0. 1) is set to ON, and the interface 11 of the IPv6 address (ff1e :: 238.0.0.1) in the IP multicast route information table 51 is set to ON. Further, in the IP multicast route information table 51, there may be a plurality of entries of IPv6 address (ff1e :: 238.0.0.1) depending on the value of the IP multicast server address. The interface 11 of the plurality of entries to be set is set to ON.

  Next, the processing of the conversion apparatus 1 that has received the IPv4 multicast packet (addressed to 238.0.0.1) sent from the IPv4 multicast server 101 to the IPv4 network 111 will be described. However, the process of the conversion apparatus 1 after the process 215 repeats the above-described processes 205 to 214 again. Details will be described below.

  The IP transmission / reception means 2 performs (Process 205) and inquires the IP multicast route control information management means 6 about the relay destination (IPv4 output information and IPv6 output information) of the IPv4 multicast packet. The IP multicast route control information management means 6 performs (Process 206) and inquires the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address to the IP address translation information holding means 4.

  The IP address translation information holding unit 4 performs (Processing 207) and inquires about the IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address of the IPv4 multicast packet (here, the IP multicast route control information management unit 6). To report to. In this example, the IPv6 address (ff1e: 238.0.0.1) corresponding to the IPv4 end point address (238.0.0.1) and the IPv6 corresponding to the IPv4 start point address (133.144.93.2) are used. The address (4 :: 100) is reported.

  Further, the IP multicast route control information management means 6 performs (Processing 208) and notifies the IP transmission / reception means 2 of the output information (information indicating the output interface and protocol) of the IPv4 multicast packet. Here, the output information of IPv4 output information of all interfaces = OFF, IPv6 output information of the interface 11 = ON, and IPv6 output information = OFF of the other interfaces is sent from the IP multicast route control information management means 6 to the IP transmission / reception means 2. Be notified.

  The IP transmission / reception means 2 performs (Process 209), and sends out an IPv4 multicast packet to the IPv4 network corresponding to the interface set to IPv4 output information = ON. Here, since the IPv4 output information of all interfaces is set to OFF, the IPv4 multicast packet is not transmitted to any IPv4 network.

Next, the IP transmission / reception means 2, the IP address translation information holding means 4 and the IP header translation means 5 perform (processing 210 to 213) to create an IPv6 multicast packet from the IPv4 multicast packet.
The IP transmission / reception means 2 performs (Process 214), and for the IPv6 network corresponding to the interface set to IPv6 output information = ON notified from the IP multicast route control information management means 6 in (Process 208). Send IPv6 multicast packet. Here, since the IPv6 output information of the interface 11 is set to ON, the IPv6 multicast packet is sent to the IPv6 network 122. The IPv6 multicast client 104 receives an IPv6 multicast packet from the IPv6 network 122.

As a result, the multicast packet broadcast by the IPv4 multicast server 101 can be received by the IPv6 multicast client 104.
Next, a case where the IPv6 multicast client 104 leaves the IPv6 multicast group (ff1e :: 238.0.0.1) will be described.

The IPv6 multicast client 104 creates an MLD Done message for leaving the IPv6 multicast group of ff1e :: 238.0.0.1 according to the MLD protocol, and sends it to the IPv6 network 122.
Here, processing of the conversion apparatus 1 that has received the MLD Done message from the IPv6 network 122 will be described.
FIG. 18 is a communication sequence diagram for the process 217.

(About processing 217)
The IP transmitting / receiving unit 2 passes the MLD Done message to the IP multicast membership information managing unit 7. Upon receiving the MLD Done message, the IP multicast membership information management means 7 creates an MLD Query message for confirming the existence of an IPv6 multicast group subscriber, and sends the IP transmission / reception means 2 to the IPv6 network 122. Instruct. The IP transmission / reception means 2 sends an MLD Query message to the IPv6 network 122.

  When there are other IPv6 multicast group subscribers, the MLD Report message indicating the subscription to the IPv6 multicast group is sent to the network 122 within a predetermined time by the subscriber, so that the IP transmitting / receiving means 2 sends the MLD Report message. Pass to IP multicast membership information management means 7. The IP multicast membership information management means 7 discards the MLD Report and MLD Done messages and ends the subsequent processing.

  If there are no other IPv6 multicast group subscribers, an MLD Report message indicating participation in the IPv6 multicast group is not sent to the IPv6 network 122 even after a predetermined time has elapsed. The IPv6 multicast member information table 62 is created in accordance with the MLD Done message, and information obtained by analyzing the MLD Done message is notified to the IP multicast route control information management means 6. The IP multicast route control information management means 6 creates the IP multicast route information table 51 according to the information obtained by analyzing the MLD Done message.

  In addition, here, it is found that the subscriber of the IPv6 multicast group (ff1e :: 238.0.0.1) has disappeared from the IPv6 network 122 by the reception of the MLD Done message and a series of subsequent processes. The interface 11 of the IPv6 address (ff1e :: 238.0.0.1) in the IPv6 multicast member information table 62 is OFF, and the interface of the IPv6 address (ff1e :: 238.0.0.1) in the IP multicast route information table 51 11 is set to OFF. Further, there may be a plurality of IPv6 address (ff1e :: 238.0.0.1) entries in the IP multicast route information table 51 depending on the value of the IP multicast server address. The interface 11 of the plurality of entries to be set is set to OFF.

  Next, the processing of the conversion apparatus 1 that has received the IPv4 multicast packet (addressed to 238.0.0.1) sent from the IPv4 multicast server 101 to the IPv4 network 111 will be described. However, the process of the conversion apparatus 1 after the process 217 repeats the above-described processes 205 to 214 again. Details will be described below.

  The IP transmission / reception means 2 performs (Process 205) and inquires of the IP multicast route control information management means 6 about the relay destination (IPv4 output information and IPv6 output information) of the IPv4 multicast packet. The IP multicast route control information management means 6 performs (Process 206) and inquires the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address to the IP address translation information holding means 4.

  The IP address translation information holding unit 4 performs (Processing 207) and inquires about the IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address of the IPv4 multicast packet (here, the IP multicast route control information management unit 6). To report to. Here, it corresponds to the IPv6 address (ff1e: 238.0.0.1) corresponding to the IPv4 end point address (238.0.0.1) and the IPv4 start point address (133.144.93.2). IPv6 address (4 :: 100) is reported.

  Further, the IP multicast route control information management means 6 performs (Processing 208) and notifies the IP transmission / reception means 2 of the output information (information indicating the output interface and protocol) of the IPv4 multicast packet. Here, the output information of IPv4 output information = OFF for all interfaces and IPv6 output information = OFF for all interfaces is notified from the IP multicast route control information management means 6 to the IP transmission / reception means 2.

  The IP transmission / reception means 2 performs (Process 209), and sends out an IPv4 multicast packet to the IPv4 network corresponding to the interface set to IPv4 output information = ON. Here, since the IPv4 output information of all interfaces is set to OFF, the IPv4 multicast packet is not transmitted to any IPv4 network.

  Next, the IP transmission / reception means 2, the IP address translation information holding means 4 and the IP header translation means 5 perform (processing 210 to 213) to create an IPv6 multicast packet from the IPv4 multicast packet.

  The IP transmission / reception means 2 performs (Process 214), and for the IPv6 network corresponding to the interface set to IPv6 output information = ON notified from the IP multicast route control information management means 6 in (Process 208). Send IPv6 multicast packet. Here, since IPv6 output information of all interfaces is set to OFF, the IPv6 multicast packet is not transmitted to any IPv6 network.

(Second Embodiment)
FIG. 11 is a configuration diagram of a communication network system 200 using the conversion device 1 according to the present invention.
The communication network system 200 includes, for example, the conversion device 1 (IPv4 addresses; 133.1444.97.1 and 133.144.98.1, IPv6 addresses; 7 :: 1 and 8 :: 1 are assigned). The IPv4 networks 111 and 112 are connected to the IPv6 networks 121 and 122 via the IPv4 networks, and the IPv4 multicast routers 105 and 106 and the IPv6 multicast routers 107 and 108 are used to connect the IPv4 networks 113 and 114 and the IPv6 networks 123 and 124. The IPv4 network 113 includes an IPv4 multicast server 101 (IPv4 address; 133.144.93.2) that broadcasts multicast packets in IPv4, and the IPv4 network 11 Includes an IPv4 multicast client 102 (IPv4 address; 133.144.95.2) that receives multicast packets by IPv4, and an IPv6 multicast server 103 (IPv6 address that broadcasts multicast packets by IPv6) is included in the IPv6 network 123. 1 :: 2), and the IPv6 network 124 includes an IPv6 multicast client 104 (IPv6 address; 2 :: 2) that receives multicast packets in IPv6.

  The IPv4 multicast server 101 broadcasts an IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 113, and the IPv6 multicast server 103 sends an IPv6 multicast packet (IPv6 address; ff1e: : 238.0.0.2).

  Next, in this communication network system 200, the IPv4 multicast server 101 broadcasts the IPv4 multicast packet (IPv4 address; 238.0.0.1) to the IPv4 network 113, and sends the IPv4 multicast packet to the IPv6 multicast client. A case of receiving at 104 will be described. However, portions overlapping with the communication network system 100 according to the first embodiment are omitted to the extent that the description is not redundant.

First, processing (processing 201 to 204) performed periodically by the conversion apparatus 1 according to the IGMP protocol, the MLD protocol, and the PIM-DM protocol will be described.
The IP multicast membership information management means 7 performs (Processing 201) and creates the IPv4 multicast member information table 61. However, since there is no IPv4 multicast group subscriber here, the IGMP Report message is not received. The IP multicast membership information management means 7 performs (Process 202) and creates an IPv6 multicast member information table 62. However, since there is no IPv6 multicast group subscriber here, the MLD Report message is not received.

  The IP multicast route control information management means 6 performs (Process 203) and creates an IPv4 neighboring router information table 71. Here, the IPv4 neighboring router information table 71 is created based on the information of the Hello message received from the IPv4 multicast routers 105 and 106. The IP multicast route control information management means 6 performs (Process 204) and creates the IPv6 neighboring router information table 72. Here, the IPv6 neighboring router information table 72 is created based on the information of the Hello message received from the IPv6 multicast routers 107 and 108.

Next, a case where the IPv6 multicast client 104 has not joined the IPv6 multicast group (ff1e :: 238.0.0. 1) will be described.
First, the IPv4 multicast server 101 sends out an IPv4 multicast packet (addressed to 238.0.0.1) to the IPv4 network 113. The IPv4 multicast router 105 relays the IPv4 multicast packet to the IPv4 network 111.

Here, processing in the conversion apparatus 1 that has received the IPv4 multicast packet will be described.
The IP transmission / reception means 2 performs (Process 205) and inquires of the IP multicast route control information management means 6 about the relay destination (IPv4 output information and IPv6 output information) of the IPv4 multicast packet. The IP multicast route control information management means 6 performs (Process 206) and inquires the IPv6 address corresponding to each of the IPv4 end address and the IPv4 start address to the IP address translation information holding means 4.

  The IP address translation information holding unit 4 performs (Process 207), and inquires about the IPv6 address corresponding to each of the IPv4 end point address and the IPv4 start point address of the IPv4 multicast packet (in this case, the IP multicast route control information management unit) Report to 6). Here, it corresponds to the IPv6 address (ff1e: 238.0.0.1) corresponding to the IPv4 end point address (238.0.0.1) and the IPv4 start point address (133.144.93.2). IPv6 address (4 :: 100) is reported.

  The IP multicast route control information management means 6 performs (Processing 208) and notifies the IP transmission / reception means 2 of the output information (information indicating the output interface and protocol) of the IPv4 multicast packet. Here, the IPv4 output information of the interface 9 = ON and the output information of IPv6 output information = ON of the interfaces 10 and 11 are notified from the IP multicast route control information management means 6 to the IP transmission / reception means 2.

  The IP transmission / reception means 2 performs (Process 209), and sends out an IPv4 multicast packet to the IPv4 network corresponding to the interface set to IPv4 output information = ON. Here, since the IPv4 output information of the interface 9 is set to ON, the IPv4 multicast packet is sent to the IPv4 network 112.

  The IPv4 multicast router 106 receives the IPv4 multicast packet relayed to the IPv4 network 112, but does not relay the IPv4 multicast packet to the IPv4 network 102 because there is no IPv4 multicast group subscriber in the IPv4 network 102. Discard.

  Next, the IP transmission / reception means 2, the IP address translation information holding means 4 and the IP header translation means 5 perform (processing 210 to 213) to create an IPv6 multicast packet from the IPv4 multicast packet.

  The IP transmission / reception means 2 performs (Process 214), and for the IPv6 network corresponding to the interface set to IPv6 output information = ON notified from the IP multicast route control information management means 6 in (Process 208). Send IPv6 multicast packet. Here, since the IPv6 output information of the interfaces 10 and 11 is set to ON, the IPv6 multicast packet is sent to the IPv6 networks 121 and 122.

  The IPv6 multicast router 107 receives the IPv6 multicast packet relayed to the IPv6 network 121, but does not relay the IPv6 multicast packet to the IPv6 network 123 because there is no IPv6 multicast group subscriber in the IPv6 network 123. Discard.

  Similarly, the IPv6 multicast router 108 receives the IPv6 multicast packet relayed to the IPv6 network 122, but since there is no IPv6 multicast group subscriber in the IPv6 network 124, the IPv6 multicast packet is sent to the IPv6 network 124. Discard without relaying.

Next, the conversion apparatus 1 that has received a PIM-Prune message requesting to cancel the relay of the IPv6 multicast packet (ff1e :: 238.0.0.1) to the IPv6 network 122 from the IPv6 multicast router 108. Processing will be described.
FIG. 19 is a communication sequence diagram for the processes 231 to 233.

(About processing 231)
The IP transmitting / receiving unit 2 passes the PIM-Prune message to the IP multicast route control information managing unit 6. The IP multicast route control information management means 6 is adapted to store the IPv4 address corresponding to each of the IPv6 multicast address and the IPv6 multicast server address requested not to be relayed to the IPv6 network 122 by the PIM-Prune message. 4 is inquired.

(About processing 232)
First, the IP address translation information holding unit 4 determines whether the IPv6 multicast address (ff1e :: 238.0.0.1) requested not to be relayed to the IPv6 network 122 is registered in the IP address translation table 41. It checks and reports whether the corresponding IPv4 address is registered or unregistered to the inquiry source (IP multicast route control information management means 6 in this case). If not registered, the IPv6 multicast address corresponds to the IPv4 address (238.0.0.1) that can be obtained by deleting fixed data (IPv6 multicast prefix, eg, ff1e :: / 96) from the IPv6 multicast address. At the same time, it is registered in the IP address conversion table 41, and this IPv4 address is reported.

  Next, the IP address translation information holding unit 4 checks whether or not the IPv6 multicast server address (4 :: 100) requested not to be relayed to the IPv6 network 122 is registered in the IP address translation table 41 and responds to it. Whether the IPv4 address to be registered is registered or unregistered is reported to the inquiry source (IP multicast route control information management means 6 in this case). If not registered, an IPv4 unicast address is obtained from the translation IP address holding means 3 and registered in the IP address translation table 41 in association with the IPv6 multicast server address, and then this IPv4 unicast address is reported. Here, since the IPv6 multicast server address (4 :: 100) is associated with the IPv4 address (133.144.93.2) and registered in the IP address conversion table 41, (133.144. 93.2) IPv4 address will be reported.

(About processing 233)
The IP multicast route control information management means 6 is the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) in the IP multicast route information table 51 and the corresponding IPv6 multicast server address “4 :: 100”. The IPv6 output of the interface that has received the PIM-Prune message is set to OFF, and the IPv4 address (238.0. 23) corresponding to the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) is set. 0.1) and the IPv6 output of the interface that is the IPv4 address (133.144.93.2) corresponding to the corresponding IPv6 multicast server address (4 :: 100) and that has received the PIM-Prune message. Set to OFF To. Here, the IPv4 address corresponding to the IPv6 multicast address “ff1e :: 238.0.0.1” is “238.0.0.1”, and the IPv6 multicast server address “4 :: 100” is supported. The IPv6 output of the interface 11 whose IPv4 address is “133.144.93.2” is set to OFF.
FIG. 20 is a communication sequence diagram for the process 234.

(About processing 234)
When there is a route in which IPv4 output of all interfaces = OFF and IPv6 output of all interfaces = OFF by (Processing 233), the IP multicast route control information management unit 6 A PIM-Prune message requesting not to relay is created and the IP transmission / reception means 2 is instructed to send it to the corresponding network. The IP transmission / reception means 2 outputs the PIM-Prune message to the instructed network.

  Here, since there is no path in which IPv4 output of all interfaces = OFF and IPv6 output of all interfaces = OFF by (Processing 233), the PIM-Prune message is not transmitted. In addition, when a PIM-Prune message requesting to stop relaying an IPv6 multicast packet (ff1e :: 238.0.0.1) to the IPv6 network 121 is received from the IPv6 multicast router 107, or IPv4 multicast When the PIM-Prune message requesting the cancellation of the relay of the packet (addressed to 238.0.0.1) to the IPv4 network 112 is received from the IPv4 multicast router 106, the conversion apparatus 1 (Processes 231 to 234) In this case, the IPv4 output of all interfaces having the IP multicast address (238.0.0.1) and the IP multicast server address (133.144.93.2) is performed by (Process 233). And IPv A PIM-Prune message requesting that the output is turned OFF and the IP multicast packet of the route is not relayed is created, and the PIM-Prune message is sent to an upstream router (for example, an IP multicast server) This is the next hop router of the address, and here, it is sent to the IPv4 network 111 where the IPv4 multicast router 105) is located.

  The PIM-Prune message is received by the IPv4 multicast router 105. Thereafter, the IPv4 multicast router 105 has the corresponding IPv4 multicast address (238.0.0.1) and the corresponding IPv4 multicast server address (133.144.93). .2) is not relayed to the IPv4 network 111.

Next, a case where the IPv6 multicast client 104 joins the IPv6 multicast group (ff1e :: 238.0.0.1) will be described.
The IPv6 multicast client 104 creates an MLD Report message for joining the IPv6 multicast group (ff1e :: 238.0.0.1) according to the MLD protocol, and sends the MLD Report message to the network 124. When receiving the MLD Report message from the network 124, the IPv6 multicast router 108 relays the IPv6 multicast packet (addressed to ff1e :: 238.0.0.1) to the IPv6 network 124 according to the MLD protocol and the PIM-DM protocol. A PIM Graph message requesting this is created and sent to the IPv6 network 122.

Here, the processing of the conversion apparatus 1 that has received this PIM Graph message from the IPv6 network 122 will be described.
FIG. 21 is a communication sequence diagram for the processes 235 to 237.

(About processing 235)
The IP transmission / reception means 2 passes the PIM Graft message to the IP multicast route control information management means 6. The IP multicast route control information management means 6 sets the IPv4 address corresponding to each of the IPv6 multicast address and the IP multicast server address requested to be relayed to the IPv6 network 122 by the PIM Graft message as the IP address translation information holding means 4. Contact

(About processing 236)
First, the IP address translation information holding unit 4 determines whether the IPv6 multicast address (ff1e :: 238.0.0.1) requested to be relayed to the IPv6 network 122 is registered in the IP address translation table 41. It checks and reports whether the corresponding IPv4 address is registered or unregistered to the inquiry source (IP multicast route control information management means 6 in this case). If not registered, the IPv6 multicast address corresponds to the IPv4 address (238.0.0.1) that can be obtained by deleting fixed data (IPv6 multicast prefix, eg, ff1e :: / 96) from the IPv6 multicast address. At the same time, it is registered in the IP address conversion table 41 and an IPv4 address is reported.

  Next, the IP address translation information holding unit 4 checks whether the IPv6 multicast server address (4 :: 100) requested to be relayed to the IPv6 network 122 is registered in the IP address translation table 41 and responds to it. The IPv4 address to be reported is reported to the inquiry source (in this case, the IP multicast routing information management means 6). If not registered, an IPv4 unicast address is obtained from the translation IP address holding means 3 and registered in the IP address translation table 41 in association with the IPv6 multicast server address, and then the IPv4 unicast address is reported. Here, since the IPv6 multicast server address (4 :: 100) is associated with the IPv4 address (133.144.93.2) and registered in the IP address conversion table 41, the IPv4 address (133.100) is registered. 144.93.2) will be reported.

(About processing 237)
The IP multicast route control information management means 6 uses the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) in the IP multicast route information table 51 and the corresponding IPv6 multicast server address (4 :: 100). The IPv6 output of the interface that has received the PIM Graft message is set to ON, and the IPv4 address (238.0.23) corresponding to the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) is set. 0.1) and the IPv6 output of the interface that is the IPv4 address (133.144.93.2) corresponding to the corresponding IPv6 multicast server address (4 :: 100) and that has received the PIM Graft message. Set to ON To.

Here, the IPv4 address corresponding to the IPv6 multicast address “ff1e :: 238.0.0.1” is “238.0.0.1”, and the IPv4 address corresponding to the IPv6 multicast server address “4 :: 100” is The IPv6 output of the interface 11 which is “133.144.93.2” is set to ON.
FIG. 22 is a communication sequence diagram for the process 238.

(About processing 238)
When there is a route with IPv4 output = ON or IPv6 output = ON by (Processing 237), the IP multicast route control information management unit 6 requests to relay the IP multicast packet of the route. While creating a Graph message, the IP transmission / reception means 2 is instructed to send it to the corresponding network. The IP transmission / reception means 2 outputs the PIM Graph message to the instructed network.

  Here, the IPv4 address (238.0.0.1) corresponding to the corresponding IPv6 multicast address (ff1e :: 238.0.0.1) and the corresponding IPv6 multicast server address (by processing 237) ( 4: 100), the IPv6 output of the interface 11 corresponding to the IPv4 address (133.144.93.2) is set to ON, so that the IPv4 multicast address is, for example, “238.0.0.1”, A PIM Graft message requesting that an IPv4 multicast packet with an IPv4 multicast server address of “133.144.93.2” be relayed to the IPv4 network 111 is created, and this PIM Graft message is sent to an upstream router ( For example, It is the next hop router of the IP multicast server address, and here it is sent to the IPv4 network 111 where the IPv4 multicast router 105) is located.

  The PIM Graft message is received by the IPv4 multicast router 105. Thereafter, the IPv4 multicast router 105 has an IPv4 multicast address of, for example, “238.0.0.1” and an IPv4 multicast server address of “133.144.93.2”. The IPv4 multicast packet is relayed to the IPv4 network 111.

Next, a case where the IPv6 multicast client 104 leaves the IPv6 multicast group (ff1e :: 238.0.0.1) will be described.
The IPv6 multicast client 104 creates an MLD Done message for leaving the IPv6 multicast group of ff1e :: 238.0.0.1 according to the MLD protocol, and sends it to the IPv6 network 124. When receiving the MLD Done message from the network 124, the IPv6 multicast router 108 does not relay the IPv6 multicast packet (addressed to ff1e :: 238.0.0.1) to the IPv6 network 124 according to the MLD protocol and the PIM-DM protocol. Is generated and sent to the IPv6 network 122.

  When the conversion apparatus 1 receives the PIM-Prune message from the IPv6 network 122, the conversion apparatus 1 performs (Processes 231 to 234), stops the relay of the route, and creates a PIM-Prune message requesting the stop of the relay of the route. The PIM-Prune message is sent to the upstream router (in this case, the IPv4 multicast router 105) of the route. As a result, the IPv4 multicast router 105 does not relay the IPv4 multicast packet of the route to the IPv4 network 111 thereafter.

  In the first and second embodiments described above, the case has been described in which the IPv6 multicast client 104 receives the IPv4 multicast packet broadcast by the IPv4 multicast server 101 using the IPv4 address '238.0.0.1'. However, the same applies to the case where the IPv4 multicast client 102 receives an IPv6 multicast packet broadcast by the IPv6 multicast server 103 at the IPv6 address (ff1e :: 238.0.0.2).

  In the first and second embodiments described above, when an IPv4 multicast packet broadcast by the IPv4 multicast server 101 is converted into an IPv6 multicast packet, the IPv4 end point address (238.0.0.1) is higher. The case of converting to a 128-bit IPv6 address (for example, ff1e :: ffff: 238.0.0.1) with a fixed pattern added has been described. For example, in addition to an IPv4 unicast address and an IPv6 unicast address, The IPv4 multicast address and the IPv6 multicast address used for the IP header translation are held in advance by the conversion IP address holding unit 3, and the IPv6 multicast address obtained from the conversion IP address holding unit 3 (for example, ff1e :: 1 0) may be converted.

  In the first and second embodiments described above, the conversion apparatus 1 reflects the IPv4 multicast route control information acquired by exchanging with the adjacent IPv4 multicast router in the IPv6 multicast route control information, and then adjoins it. By exchanging with the IPv6 multicast router, the IP multicast packet broadcast by the IPv6 multicast server 103 is relayed to the IPv4 multicast client 102, and the IPv6 multicast route control information obtained by exchanging with the adjacent IPv6 multicast router is further changed to IPv4. After reflecting in the multicast routing information, the IP multicast packet broadcast by the IPv4 multicast server 101 is changed to IP by exchanging with the adjacent IPv4 multicast router. In the above description, the IPv6 multicast route control information necessary for relaying the IP multicast packet broadcast by the IPv6 multicast server 103 to the IPv4 multicast client 102 is sent to the conversion apparatus 1 by the administrator. Even if the administrator sets the IPv4 multicast route control information necessary for relaying the IP multicast packet broadcasted by the IPv4 multicast server 101 to the IPv6 multicast client 104 in the conversion apparatus 1, the same applies. is there.

  Also, the IP address conversion information holding unit 4 deletes the correspondence between the held IPv4 address and the IPv6 address that is not referenced for a certain period of time, and the deleted IPv4 unicast address or IPv6 unicast address is used for conversion. It may be returned to the IP address holding means 3.

DESCRIPTION OF SYMBOLS 1 Conversion apparatus 2 IP transmission / reception means 3 Conversion IP address holding means 4 IP address conversion information holding means 5 IP header conversion means 6 IP multicast membership information management means 7 IP multicast route control information management means 31 IPv4 unicast address table 32 IPv6 Unicast address table 41 IP address conversion table 51 IP multicast route information table 61 IPv4 multicast member information table 62 IPv6 multicast member information table 71 IPv4 neighbor router information table 72 IPv6 neighbor router information table 101 IPv4 multicast server 102 IPv4 multicast client 103 IPv6 multicast Server 104 IPv6 multicast client 105, 106 Pv4 multicast routers 107 and 108 IPv6 multicast router 111 to 114 IPv4 network 121 to 124 IPv6 Network

Claims (8)

A communication device that relays multicast packets via a network between at least one first device that uses IPv4 as a communication protocol and at least one second device that uses IPv6 as a communication protocol,
Two or more interface units connected to either the at least one first device or the at least one second device via a network;
A transmission / reception unit that relays the multicast packet received from any one of the two or more interface units to any other interface unit;
When a message requesting reception of an IPv6 multicast packet including a first IPv6 multicast address as a destination address is received from one of the interface units from the at least one second device, the interface that has received the message is A storage unit for storing in association with the first IPv4 multicast address corresponding to the first IPv6 multicast address;
When the transmission / reception unit receives an IPv4 multicast packet including the first IPv4 multicast address as a destination address from the at least one first device, the first IPv4 multicast address included in the IPv4 multicast packet as a destination address is set. A converting unit that converts the corresponding first IPv6 multicast address into an IPv6 multicast packet that includes the first IPv6 multicast address as a destination address from the IPv4 multicast packet;
The transmission / reception unit transmits the created IPv6 multicast packet to an interface stored in the storage unit in association with the first IPv4 multicast address. The communication device according to claim 1,
The communication device, wherein the first IPv4 multicast address corresponding to the first IPv6 multicast address is an address obtained by deleting a fixed pattern from the first IPv6 multicast address. The communication device according to claim 1, further comprising:
A holding unit for holding at least one IPv6 multicast address;
The first IPv6 multicast address is a communication device in which one IPv6 multicast address of at least one IPv6 multicast address held by the holding unit is assigned to the first IPv4 multicast address. The communication device according to claim 1, further comprising:
A holding unit for holding at least one IPv6 unicast address;
The converting unit converts an IPv4 unicast address included in the IPv4 multicast packet as a source address into one IPv6 unicast address among at least one IPv6 unicast address held by the holding unit, and the converted A communication device that creates an IPv6 multicast packet including IPv6 unicast as a source address. A communication device that relays multicast packets via a network between at least one first device that uses IPv6 as a communication protocol and at least one second device that uses IPv4 as a communication protocol,
Two or more interface units connected to either the at least one first device or the at least one second device via a network;
A transmission / reception unit that relays the multicast packet received from any one of the two or more interface units to any other interface unit;
When a message requesting reception of an IPv4 multicast packet including the first IPv4 multicast address as a destination address is received from any of the interface units from the at least one second device, the interface that has received the message is A storage unit for storing in association with the first IPv6 multicast address corresponding to the first IPv4 multicast address;
When the transmission / reception unit receives an IPv6 multicast packet including the first IPv6 multicast address as a destination address from the at least one first device, the first IPv6 multicast address included in the IPv6 multicast packet as a destination address is set. A conversion unit that converts the corresponding first IPv4 multicast address into an IPv4 multicast packet that includes the first IPv4 multicast address as a destination address from the IPv6 multicast packet;
The transmission / reception unit transmits the created IPv4 multicast packet to an interface stored in the storage unit in association with the first IPv6 multicast address. The communication device according to claim 5,
The communication device, wherein the first IPv6 multicast address corresponding to the first IPv4 multicast address is an address obtained by adding a fixed pattern to the first IPv4 multicast address. The communication device according to claim 5, further comprising:
A holding unit for holding at least one IPv4 multicast address;
The first IPv4 multicast address is a communication device in which one IPv4 multicast address among at least one IPv4 multicast address held by the holding unit is assigned to the first IPv6 multicast address. The communication device according to claim 5, further comprising:
A holding unit for holding at least one IPv4 unicast address;
The conversion unit converts an IPv6 unicast address included in the IPv6 multicast packet as a transmission source address into one IPv4 unicast address among at least one IPv4 unicast address held by the holding unit, and the converted A communication device that creates an IPv4 multicast packet including IPv4 unicast as a source address.

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