JP5224418B2 - Data relay method, apparatus thereof, and data relay system using the apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data relay method for constructing a virtual network and relaying data, an apparatus thereof, and a data relay system using the apparatus, and more particularly, an ISP (Internet Service Provider) IP-VPN (Internet Protocol-Virtual Private Network). The present invention relates to a data relay method for relaying data using a service, its apparatus, and a data relay system using the apparatus.

  In such a conventional data relay method, for example, a logical tunnel is constructed in an ISP backbone IP network, and a service using IP-VPN, which is a service equivalent to a service using a dedicated line, is provided. For example, an intranet such as an in-house network that has been conventionally constructed using a dedicated line has been constructed using the IP-VPN service of this ISP.

  In such an IP-VPN service, an ISP backbone IP network is shared in a network constructed by terminal devices (host devices) such as personal computers of a plurality of users. For this reason, the IP-VPN service has an advantage that a network can be constructed at a lower cost than a dedicated line service exclusively used by a single user. In addition, the IP-VPN service is a relay service at the layer 3 (network layer) level, whereas an inter-LAN connection service that relays and connects user LANs at the layer 2 (data link layer) level. Is provided.

  In addition, a technique called PPPoE (Point to Point Protocol over Ethernet (registered trademark)) is used in an ADSL (Asymmetric Digital Subscriber Line) and an optical fiber access network that are spreading in the Internet access network, and the user host The device and the ISP are connected via a network (hereinafter referred to as “access network”) constructed by an access network service provider. At this time, in order to provide one-to-one communication in the access network, a tunneling technique called L2TP (Layer 2 Tunneling Protocol) or MPLS (Multiprotocol Label Switching) has been used. In this tunneling technology, new data is added to the data communicated between the host device of the user and the ISP in the access network to encapsulate the data, and then relayed in the access network.

  FIG. 20 is a configuration diagram showing an outline of a system configuration of a conventional Internet connection network that relays data via ADSL. In the figure, an access network 20 is constructed from a network termination device 21 and a BAS (Broadband Access Server) 22 installed inside, and a logical tunnel 23 is constructed between the network termination device 21 and the BAS 22. Yes. The ISP IP network 10 is connected to the network terminating device 21 via a line L, and the host devices 27 to 29 of the users A to C are connected to the BAS 22 via the ADSL (telephone lines) 24 to 26, respectively. It is connected. Here, for example, data transmitted from the ISP IP network 10 is input to the network terminating device 21 via the line L, where it is relayed, and further transferred to the BAS 22 via the logical tunnel 23. After that, it was distributed to each of the host devices 27-29.

  That is, when data is distributed to each user from the ISP IP network 10, the data transmitted from the ISP IP network 10 is taken into the network termination device 21 in a packet configuration including an IP header and data. This packet is sent to the BAS 22 with a tunnel header (IP network header in the operator network) and a PPP (Point-to-Point Protocol) header in the access network 20 added to the network termination device 21, and is tunneled by the BAS 22. Only the header is deleted and transmitted to the host devices 27 to 29 via the ADSL 24 to 26 as PPP data.

  However, since the IP-VPN of the above-described conventional example provides a layer 3 level relay service, it is necessary to store the user's layer 3 route information in the ISP. In such a case, it is necessary to notify the ISP side each time, change the setting of the relay device in the ISP, or operate the control software for exchanging the route information to exchange the route information. For this reason, it is necessary to exchange route information with each other within the same virtual network even with a slight change. As the virtual network size increases, more information is exchanged and the amount of data to be transmitted increases and the exchange time increases. However, there is a problem that a large load is applied.

  In the case of a layer 2 level relay service, it is necessary to relay a broadcast frame. When this broadcast frame is received by a relay device on the ISP side, the data is copied to all other sites and relayed. There is a need to. In addition, in the case of layer 2 relay, a connection service is provided only between the same data links. For this reason, for example, when an Ethernet (registered trademark) frame is relayed, the relay destination must also be an Ethernet (registered trademark) LAN, and a network connected by an ATM leased line. There was a problem that could not be connected.

Further, in a system with an access network interposed, there are the following problems when broadcast data called multicast distribution technology is distributed.
That is, the multicast distribution technique is used for broadcast data, for example, and distributes the same broadcast data to a plurality of users at the same time. However, in the conventional technique, the ISP and each user communicate with each other one-to-one. Even when using, it is necessary to distribute data to each user, and as with normal unicast communication, data for the number of users is copied and distributed, so a very large transmission bandwidth is required. There was a problem of becoming.

  That is, as shown in FIG. 21, when the same data is transmitted from a certain content server 11 in the ISP IP network 10 to each of the host devices 27 to 29 of the users A to C, the network termination device 21 including a router and each Since the host devices 27 to 29 communicate one-to-one, the content server 11 (or the network termination device 21) needs to copy and transmit data to each of the host devices 27 to 29. For this reason, the conventional technology has a problem in that the content server and the network are required to have transmission bandwidth and processing capacity corresponding to transmission data × the number of received users.

  Further, it is considered that there are a plurality of relay devices between the normal content server and the network terminal device of the access network operator. In order to use the multicast distribution technology under such circumstances, it is necessary to change the software and setting information of these relay devices already in operation to support the multicast distribution technology. There was a problem that it was expensive and time consuming.

  The present invention has been made in view of the above problems, and there is no need to perform data copying, and a data relay method, apparatus, and apparatus that can perform efficient data distribution using existing equipment are used. The purpose is to provide a data relay system.

  In order to achieve the above object, in the data relay method according to the present invention, a logical tunnel is established in a predetermined backbone network interposed between networks, and data in a predetermined format is transmitted between the networks via the tunnel. In the data relay method for relaying, a determination step of determining a type of a destination address in a data link layer (layer 2 level) from the data fetched from the network into the backbone network, and the determined type individually In the case of a destination address, a transmission step of transmitting the data to the tunnel of the relay destination determined for each address, and in the case where the type is a broadcast destination address, corresponds to the destination address of the network layer And identify the tunnel of the relay destination from the data contents set in advance, and the identified relay destination Characterized in that it comprises an identification transmission step of transmitting the data to the tunnel.

  According to the present invention, the type of the destination address at the layer 2 level is determined from the data captured in the ISP backbone network, and if it is broadcast, it is set in correspondence with the destination address at the layer 3 level. By identifying the relay destination tunnel from the data contents and transmitting the data only to the relay destination tunnel, data copying is omitted and the data relay efficiency is increased.

  In the data relay method according to the present invention, in the above invention, when transmitting data to the relay destination tunnel, a determination step of determining whether the data relay method to the destination is a data link layer relay method, and the relay method includes: If the data link layer is not a relay method, a deletion step of deleting the data link layer header from the predetermined format, and when the data is received via the relay destination tunnel, the data link layer And an additional step of adding a header and relaying.

  According to the present invention, when data is transmitted to the relay destination tunnel, if the relay method is other than layer 2, the layer 2 level header is omitted and the data is transmitted from the relay destination tunnel after receiving the data. By adding a two-level header, the amount of data to be transmitted is reduced and the data transmission efficiency is increased.

  In the data relay method according to the present invention, a logical tunnel is established in a predetermined public network interposed between a predetermined backbone network and a host device, and data is transmitted between the backbone network and the host device via the tunnel. In the data relay method for relaying, the content of the data fetched from the host device is monitored, and a judgment step for judging whether the data is user data; and if the data is the user data, the data is routed through the tunnel And a relay process for relaying data and a control process for performing control processing without passing through the tunnel when the data is a predetermined control packet.

  According to the present invention, for example, when the data from the host device is unicast data, the data is relayed on a one-to-one basis with the host device via the tunnel, and the multicast data is multicast without passing through the tunnel. The distribution network is relayed to the user and distributed to the user, and the data copy for each user is unnecessary.

  In the data relay method according to the present invention, in the above invention, a second determination step of monitoring data fetched from the backbone network and determining whether the data is data for a single traffic, and the data In the case of data for a single traffic, a second relay step of relaying data via the tunnel, and in the case where the data is the predetermined control target data, A storage control step of storing control target data, wherein the control processing step performs control processing of the stored control target data.

  According to the present invention, for example, unicast data communicates with a host device on a one-to-one basis via a tunnel in a public network, and multicast data is relayed through a multicast distribution network without going through the tunnel. It is no longer necessary to copy data that is distributed to users and performed for each user.

  In the data relay method according to the present invention, in the data relay method for relaying data between the backbone network and the host device via the public network, the data transmitted from the backbone network to a specific IP address in the public network Address conversion step for converting the destination of the address to a broadcast address of a specific group set in advance, a transfer step of transferring the address-converted data into the multicast network of the public network, and the transfer A distribution step of distributing the processed data to the host device.

  According to the present invention, for example, when data is transmitted to a multicast delivery proxy device in the public network, the destination address of the data is converted into a preset multicast address, transferred to the multicast network in the public network, and the user Using the multicast distribution network installed independently in the public network without using the conventional relay device between the backbone network and the public network for multicast distribution. Broadcast distribution.

  The data relay device according to the present invention is provided in a predetermined backbone network interposed between networks, and relays data in a predetermined format from the network via a logical tunnel constructed in the backbone network. In the data relay device to be performed, a storage means for storing information on the relay destination tunnel in correspondence with the destination address of the data network layer, and a type determination for determining the type of destination address in the data link layer of the data fetched from the network And a transmission means for transmitting the data to the relay destination tunnel corresponding to the network layer destination address stored in the storage means when the destination address type is a broadcast address. It is characterized by.

  According to the present invention, the information of the relay destination tunnel is stored in the storage means in correspondence with the IP address, and the type of the layer 2 level destination address is determined from the data taken into the ISP backbone network. In the case of broadcast, copying of data is omitted by identifying the relay destination tunnel corresponding to the destination address of the layer 3 level from the data content stored in the storage means, and transmitting the data only to this relay destination tunnel. To improve data relay efficiency.

  In the data relay device according to the present invention, in the above invention, the storage means further stores information on a hierarchy of a relay system together with information on a relay destination tunnel in association with a destination address of the network layer of the data, and the data relay The apparatus includes: a method determining unit that determines a data relay method to a transmission destination from data contents stored in the storage unit when transmitting data to the relay destination tunnel; and the determined relay method. If the data link layer is not a relay method, a deletion unit that deletes the header of the data link layer from the predetermined format, and when the data is received via the relay destination tunnel, the data link layer An additional means for adding a header and relaying is further provided.

  According to the present invention, when the data is transmitted to the relay destination tunnel, if the relay method is other than layer 2, the deletion means omits the layer 2 level header and sends the data. By adding the layer 2 level header, the amount of data to be transmitted is reduced and the data transmission efficiency is increased.

  The data relay device according to the present invention is provided in a predetermined public network interposed between a predetermined backbone network and a host device, and passes through a logical tunnel constructed in the public network, In a data relay device that relays data between host devices, a first type determination unit that monitors the content of data fetched from the host device and determines the type of the data, and a traffic with a single data type In the case of data intended for the data, the first relay means for relaying data via the tunnel, and in the case where the data is a predetermined control packet, control processing is performed without going through the tunnel. And a control processing means for performing the above.

  According to the present invention, for example, when the data from the host device is unicast data, the first relay means relays the data one-to-one with the host device via the tunnel, and the multicast data is: It was distributed to users via a multicast distribution network without going through a tunnel, making it unnecessary to copy data for each user.

  The data relay device according to the present invention is provided in a predetermined public network interposed between a predetermined backbone network and a host device, and passes through a logical tunnel constructed in the public network, In a data relay device that relays data between host devices, a second type determination unit that monitors the content of data fetched from the backbone network and determines the type of the data, and a traffic that has a single data type In the case of data intended for data, the second relay means for relaying data via the tunnel, and in the case where the data type is data intended for simultaneous broadcasting of a specific group, the data Storage control means for storing.

  According to the present invention, for example, unicast data communicates with the host device one-to-one via the tunnel in the public network by the second relay means, and multicast data is stored in the storage means. In addition, it is distributed after waiting for a multicast reception request from a user, and copying of data performed for each user is unnecessary.

  The data relay device according to the present invention is provided in a predetermined public network interposed between a predetermined backbone network and a host device, and passes through a logical tunnel constructed in the public network, Address conversion for changing a destination of data transmitted to a specific IP address in the public network to a preset broadcast address of a specific group in a data relay device that relays data between host devices Means for transferring the address-converted data to a multicast network logically constructed in the public network, and distribution means for distributing the transferred data to a host device. And

  According to the present invention, for example, when data is transmitted to a multicast distribution agency in the public network, the address conversion unit converts the destination address of the data into a preset multicast address, and the transfer unit converts the data in the public network. Transfer to the multicast network, broadcast distribution to the user by the distribution means, and the relay device that has been operated in the past between the backbone network and the public network, without having to support multicast distribution, independently in the public network Broadcast distribution using the installed multicast distribution network.

  In the data relay system according to the present invention, the data relay has a logical tunnel constructed in a predetermined backbone network interposed between networks, and relays data in a predetermined format between the networks via the tunnel In the system, the data relay device according to the above invention is provided in the backbone network, and the relay tunnel corresponding to the address addressed to the broadcast in the data link layer of the data fetched from the network to the data relay device, It is characterized by transmitting data.

  According to the present invention, the type of the layer 2 level destination address is determined from the data captured in the ISP backbone network, and if it is broadcast, the content of the layer 3 level is determined from the data content stored in the storage means. The relay destination tunnel corresponding to the destination address is identified, and data is transmitted only to this relay destination tunnel. At this time, if the relay method is other than layer 2, the deletion means omits the layer 2 level header. After the data is received, the layer 2 level header is added by the adding means, thereby omitting data copying and reducing the amount of data to be transmitted, thereby increasing the data transmission efficiency.

  The data relay system according to the present invention has a logical tunnel constructed in a predetermined public network interposed between a predetermined backbone network and a host device, and passes through the tunnel between the backbone network and the host device. In the data relay system for relaying data, the data relay device according to the invention is provided in the public network, and when the data fetched from the host device is a predetermined control packet, the data is routed through the tunnel. It is characterized by performing control processing without doing so.

  According to the present invention, when the data fetched from the host device is, for example, multicast data, it is relayed to the multicast distribution network without passing through the tunnel and distributed to the user, so that it is not necessary to copy the data for each user. .

  In the data relay system according to the present invention, in the above invention, the data relay system further includes the data relay device according to the above invention, and the control processing means of the data relay device according to the above invention is the above invention. The control processing of relaying the data to be controlled stored by the storage control means of the data relay device described in the above to the host device that has made a predetermined reception request is performed.

  According to this invention, for example, in response to a multicast reception request from the host device, the control processing means described in the above invention relays the multicast data stored by the storage control means described in the above invention to the host device. As a result, the multicast distribution network is relayed to the user without passing through the tunnel, and the copy of data performed for each user is unnecessary.

  The data relay system according to the present invention has a logical tunnel constructed in a predetermined public network interposed between a predetermined backbone network and a host device, and passes through the tunnel between the backbone network and the host device. In the data relay system for relaying data, the public network includes the data relay device according to the invention described above, and distributes the address-converted data to a host device.

  According to the present invention, for example, when data is transmitted to a multicast delivery proxy device in the public network, the destination address of the data is converted into a preset multicast address, transferred to the multicast network in the public network, and the user Using the multicast distribution network installed independently in the public network without using the conventional relay device between the backbone network and the public network for multicast distribution. Broadcast distribution.

  In the present invention, the type of the destination MAC address at the data link layer level is determined from the data fetched into the IP backbone network, and if it is broadcast, tunnel control is performed in correspondence with the target IP address at the network layer level. The relay destination tunnel number is identified from the data contents set in the table, and data is transmitted only to this relay destination tunnel, so there is no need to copy data and efficient data using existing equipment. Distribution can be performed.

  In addition, according to the present invention, when the data fetched from the host device is data intended for a single traffic, the data is relayed one-to-one with the host device via the tunnel, and the specific group is simultaneously broadcast. In the case of data targeted for information, since it is distributed to the host device via the multicast distribution network without going through the tunnel, it is not necessary to copy data for each user, and efficient data distribution can be performed. .

  Further, according to the present invention, when data is transmitted to a proxy device in the public network, the destination address of the data is converted into a preset multicast address, transferred to the multicast network in the public network, and the same as the user. Data distribution, so there is no need to copy data, efficient data distribution can be performed using existing equipment, and a conventional relay device between the backbone network and the public network can be multicast Broadcast distribution can be performed using a multicast distribution network installed independently in the public network without corresponding to distribution, and the cost and time for changing the distribution can be greatly reduced.

FIG. 1 is a configuration diagram showing a configuration of a first embodiment of a data relay system according to the present invention. FIG. 2 is a block diagram showing a configuration of the router shown in FIG. FIG. 3 is a diagram showing data contents of the tunnel control table of the target IP address possessed by the ARP broadcast processing unit shown in FIG. FIG. 4 is a diagram illustrating data contents of the MAC address learning table included in the ARP processing unit illustrated in FIG. FIG. 5 is a diagram showing a data format of data transmitted between the host apparatus and the router shown in FIG. FIG. 6 is a diagram showing a data format of data transmitted between the routers shown in FIG. FIG. 7 is a diagram showing a data format of the MAC header shown in FIG. FIG. 8 is a flowchart for explaining the data relay operation of the router. FIG. 9 is a flowchart for explaining a normal data relay processing operation by the MPLS processing unit shown in FIG. FIG. 10 is a diagram illustrating a data format of the MAC header of the ARP request packet. FIG. 11 is a diagram showing a data format of the ARP data shown in FIG. FIG. 12 is a block diagram showing the configuration of Embodiment 2 of the data relay system using the data relay method according to the present invention. FIG. 13 is a block diagram showing the configuration of the router function of the BAS shown in FIG. FIG. 14 is a flowchart for explaining the packet distribution operation of the network terminating device shown in FIG. FIG. 15 is a flowchart for explaining the packet delivery operation of the BAS shown in FIG. FIG. 16 is a block diagram showing the configuration of Embodiment 3 of the data relay system using the data relay method according to the present invention. FIG. 17 is a block diagram showing a configuration of the proxy device shown in FIG. FIG. 18 is a diagram of a table in which unicast addresses and corresponding multicast addresses are stored. FIG. 19 is a flowchart for explaining the proxy processing operation of the proxy device shown in FIG. FIG. 20 is a configuration diagram showing an outline of a system configuration of a conventional Internet connection network that relays data via ADSL. FIG. 21 is also a configuration diagram showing an outline of a system configuration of a conventional Internet connection network for explaining the problem.

  Exemplary embodiments of a data relay method, an apparatus thereof, and a data relay system using the apparatus according to the present invention will be described below with reference to the accompanying drawings. In the present invention, layer 2 data relay is basically performed to solve the problem of broadcast (broadcast communication). In the following, the same components as those in FIG. 20 are denoted by the same reference numerals for convenience of explanation.

Example 1
FIG. 1 is a configuration diagram showing the configuration of Embodiment 1 of a data relay system using the data relay method according to the present invention. In the figure, an ISP IP network 10 is provided with a plurality of relay devices, in this embodiment, three routers 12 to 14, and a logical connection between these routers 12 to 14 using MPLS technology. Tunnels 16-18 are constructed. The routers 12 to 14 are connected to the host devices 30 to 35 of the user on the network (Ethernet (registered trademark)) side through ports to be described later, and the router 12 is connected to another router 15 via another router 15. For example, it is connected to user host devices 36 and 37 in the tenant building. This system uses the IP-VPN service of ISP. The routers 12 to 14 perform layer 2 level data relay for the host devices 30, 32, 34 and 36, and layer 3 level data for the host devices 31, 33, 35 and 37. It shall be relayed.

  Numbers are set in advance in each of the routers 12 to 14 and each tunnel. For example, the routers 12, 13, and 14 have numbers * 1, * 2, * 3, and the tunnels 16 to 18 have a number # 1. , # 2 and # 3 are set. The tunnels 16 and 18 using the MPLS technology are paths between the routers 12 and 14, and this indicates, for example, that a physical line (signal line) is logically shared. There may be one or more lines. Similarly, the tunnel 17 can share physical lines with other routes.

  Since the routers 12 to 14 have the same configuration, the configuration of the router 12 is shown in FIG. 2 as a representative here. In the figure, the router 12 has an input port 12a for inputting data, an L2 relay processing unit 12b for relaying this data at the layer 2 level, and a normal ARP (Address Resolution Protocol) packet. An ARP processing unit 12c that performs ARP processing, an ARP broadcast processing unit 12d that performs broadcast processing when this data is a broadcast ARP packet, and the IP-VPN of the ISP using the tunneling technique It comprises an MPLS processing unit 12e for making the service available, and an output port 12f for outputting MPLS processed data.

  As shown in FIG. 3, the ARP broadcast processing unit 12d has a tunnel control table for target IP addresses. In this tunnel control table, a target IP address indicating a transmission destination, a tunnel number and a router number of a relay destination corresponding to the IP address, and a layer 2 or 3 relay method are registered. The tunnel control table can be set in advance for each router, or can be set by notification such as broadcast.

  The L2 relay processing unit 12b has a MAC address learning table as shown in FIG. In this learning table, the destination MAC address, the tunnel number of the relay destination corresponding to the destination MAC address, and the number of the relay device (router) are registered in advance.

  As shown in FIG. 5, the data format of data transmitted between the host device and the router includes a layer 2 level MAC header, a layer 3 level IP header, and data. Further, as shown in FIG. 6, the data format of data transmitted between routers includes a MAC header, a label header, an IP header, and data. As shown in FIG. 7, the MAC header includes a destination MAC address, a transmission source MAC address, and an Ethernet (registered trademark) type value.

  In the above configuration, the routers 12 to 14 in the system perform the data relay operation shown in the flowchart of FIG. That is, in FIG. 8, when a packet is received by the L2 relay processing unit 12b (see FIG. 2) via the input port 12a (step 101), the L2 relay processing unit 12b uses Ethernet (registered trademark) in the MAC header. It is determined whether the type (see FIGS. 5 and 7) is ARP (step 102).

  Here, when the type is not ARP, the routine proceeds to normal relay processing by the MPLS processing unit 12e described later (step 103). When the type is ARP, the destination MAC address in the MAC header is referred to. It is then determined whether this MAC address is addressed to broadcast (broadcast) (step 104). Specifically, when the value of the destination MAC address is “FFFFFFFFFFFF” (hexadecimal number) or the least significant bit of the first byte is “1”, it is a broadcast address, and the least significant bit of the first byte is “ In the case of “0”, it is an individual address.

  Here, when the destination MAC address is an individual destination address, the process proceeds to normal ARP processing by the ARP processing unit 12c, and the transmission corresponding to the destination MAC address is performed with reference to the MAC address learning table shown in FIG. Identify the destination (tunnel and router). In this MAC address learning table, for example, when the destination MAC address is “00: 01: 01: 01: 01: 01”, the number tunnel # 1 is used to transmit to the router * 3 (step 105).

  In the case of addressing to the broadcast, the process shifts to the ARP broadcast processing unit 12d and further checks the upper layer. That is, here, for example, the case of an ARP request packet that resolves the MAC address for the IP address will be described based on the data format of the MAC header of the ARP request packet shown in FIG. 10 and the contents of the ARP data in FIG.

  When the router receives the ARP request packet shown in FIG. 10 from the host device on the user side, the router first refers to the Ethernet (registered trademark) type value, determines the ARP packet from “0x0806”, and then determines the destination MAC address. Referring to this MAC address for broadcasting, the upper layer (network layer) is checked. In this upper layer check, the request packet for the IP address is determined from the protocol address space and the operation code, and then the target protocol address is referred to. Since this target protocol address is the target IP address “192.168.1.2” of the host device 34 connected to the router 14 with the number * 3, the tunnel control table of FIG. The relay destination tunnel, in this case, the tunnel 16 of number # 1 is determined (step 106).

  Next, it is determined from this control table whether the relay method is L2 (layer 2 level) (step 107). In this embodiment, since the relay method is L2, the ARP request packet is transmitted to the corresponding relay destination tunnel 16 (step 109). If the relay method is not L2, the MAC header that is the L2 header is deleted from the ARP request packet (step 108), and then the ARP request packet is transmitted to the corresponding relay destination tunnel (step 109).

  In step 102, if the Ethernet (registered trademark) type in the MAC header is not ARP, the process proceeds to the normal relay process shown in FIG. 9 by the MPLS processing unit 12e. In this process, first, the destination IP address is referred to, the tunnel control table of the target IP address in FIG. 3 is searched, and the relay destination tunnel is determined from the contents (step 201).

  Next, the relay method is searched from the table to determine whether the relay method is L2 (step 202). If the relay method is not L2, the L2 header is deleted from the packet (step 203), and the packet is transmitted to the corresponding relay tunnel (step 204).

  As described above, in the data relay system shown in the first embodiment, the type of the destination MAC address at the layer 2 level is determined from the data fetched in the ISP network. Since the relay destination tunnel number is identified from the data contents set in the tunnel control table in correspondence with the target IP address of the level and the data is transmitted only to this relay destination tunnel, the data copy is omitted. Can improve the relay efficiency.

  In the first embodiment, when the relay method of data to the transmission destination is layer 3, data relay is performed by deleting the MAC header of layer 2 from the data packet and performing data relay. The data transmission efficiency can be increased.

(Example 2)
FIG. 12 is a block diagram showing the configuration of Embodiment 2 of the data relay system using the data relay method according to the present invention. In the figure, in this system, in addition to the access network 20 constructed by the network termination device 21, the BAS 22 and the tunnel 23, a multicast distribution network 40 is logically constructed. The multicast distribution network 40 is constructed by a network termination device 41, a BAS 42, and a multicast path 43, and the BASs 22 and 42 are logically connected.

  Here, the network termination devices 21 and 41 connected to the IP network 10 of a specific ISP logically group the ports of one network termination device 21 and virtually terminate the two network terminations. The apparatus is configured to exist, and the BASs 22 and 42 are similarly configured so that one BAS 22 virtually includes two BASs, thereby reducing the manufacturing cost. In addition, the tunnel 23 and the multicast route 43 also logically share one physical line. The network termination devices 21 and 41 and the BASs 22 and 42 can be physically configured as separate units.

  The network termination device 21 and the BAS 22 have a function as a router, and relay input data. FIG. 13 illustrates the router function of the BAS 22 as a representative. In FIG. 13, the BAS 22 includes an input port 22a for inputting data from each of the host devices 27 to 29 on the user side connected via the ADSLs 24 to 26, a multicast distribution unit 22b for distributing received data, and a single traffic. A unicast relay processing unit 22c that performs unicast data relay processing for the target, a multicast relay processing unit 22d that performs multicast data relay processing for simultaneous broadcasts to a specific group, and an output port 22e. And a multicast output port 22f.

  The router function of the network termination device 21 has the same configuration, and it monitors whether the data content received from the IP network 10 of the ISP is user data (unicast) or multicast, and depends on the data content. The data is sorted and output after relay processing.

  The packet distribution operation of the system having such a configuration will be described with reference to FIGS. In FIG. 14, when a packet is input from the ISP IP network 10 (step 301), the network terminating device 21 determines whether the data content of the received packet is multicast data (step 302). That is, since the IP address range of the IP header is different between multicast and unicast data, the multicast distribution unit can easily determine whether or not the data is multicast data based on the value of this IP address.

  Here, when the data content is unicast, the unicast relay processing unit relays the packet to the BAS 22 via the relay destination tunnel 23 of the access network (step 303). The processing unit relays the packet to the BAS 42 via the multicast route 43 of the multicast distribution network (step 304).

  When the unicast data is input from the network terminating device 21, the BAS 22 identifies a specific user host device based on the individual destination address by the unicast relay processing unit, and the unicast is one-on-one with the host device. Send the data. Further, when multicast data is input from the network termination device 21 (logically the network termination device 41), the BAS 42 stores the multicast data in the storage means.

  Next, in FIG. 15, when the BAS 22 fetches data from a certain host device (step 401), the multicast distribution unit determines whether the data content of the received packet is a multicast reception request packet (step 402).

  Here, when the data content is unicast, the conventional unicast relay processing unit relays the packet to the network terminating device 21 via the relay destination tunnel 23 of the access network (step 403). In the case of a multicast reception request, the multicast relay processing unit relays the packet to the BAS 42 of the multicast distribution network (step 404).

  When the BAS 42 receives the multicast reception request packet, the BAS 42 transmits the data of the corresponding destination address from the stored multicast data to the BAS 22. When the BAS 22 captures the multicast data, the BAS 22 distributes the data to the host apparatus that has requested multicast reception.

  As described above, in the second embodiment, for conventional unicast data, one-to-one data relay is performed with the host device via a relay destination tunnel of the access network operator, and for multicast data. Since it distributes to the host device via the multicast distribution network, it is not necessary to copy data for each user, and efficient data distribution can be performed using existing equipment.

(Example 3)
FIG. 16 is a block diagram showing the configuration of Embodiment 3 of the data relay system using the data relay method according to the present invention. In this figure, in this system, in addition to the configuration of the second embodiment, a multicast proxy device 45 that performs multicast distribution on the multicast distribution network 40 is provided, and this multicast proxy device 45 is connected to the ISP IP network 10 and BAS 42 And a multicast path 46 for logical connection. In the third embodiment, data to be broadcast from the content server 11 to a plurality of host devices is transmitted to the multicast proxy device 45 (to a specific unicast address set in the multicast proxy device 45).

  As shown in FIG. 17, the multicast proxy device 45 includes an input port 45 a connected to the ISP IP network 10, a multicast proxy processing unit 45 b that performs proxy processing of received multicast data, and relay processing of multicast data. A multicast relay processing unit 45c that performs the above and a multicast output port 45d.

  The multicast proxy processing unit 45b has a conversion table in which the unicast address shown in FIG. 18 and the multicast address corresponding to the unicast address are set in advance, and the destination address of the received unicast data is set to the above-described destination address. The multicast address is converted into a corresponding multicast address according to the table, and the multicast relay processing unit 45c performs the relay process of the converted multicast data and transfers it to the BAS 42 via the multicast output port.

  Next, the multicast delivery proxy operation by the multicast proxy device 45 will be described based on the flowchart of FIG. First, when data is received from the input port 45a (step 501), the multicast proxy processing unit 45b recognizes the destination address of the data and determines whether this destination address is in the table shown in FIG. 502).

  Here, if there is no destination address in this table, it is determined that the data is not data for proxy delivery, and the packet is discarded (step 503). If there is a destination address in this table, it is determined that the data is to be distributed, and after the process of converting the destination address of the data to the corresponding multicast address is performed, the data is output to the multicast relay processing unit 45c (step) 504). The multicast relay processing unit 45c transfers the above data to the BAS 42 via the multicast output port after relaying the input multicast data. As shown in the second embodiment, when there is a multicast reception request from the host device, the BAS 42 broadcasts the corresponding multicast data to the host device.

  As described above, in this third embodiment, a proxy device that performs multicast distribution proxy is provided in the multicast distribution network of the access provider, and a unicast address that is a destination of data transmitted from the ISP is converted into a multicast address. Since the broadcast distribution is performed, there is no need to perform data copying, and efficient data distribution can be performed using existing equipment.

Further, in the third embodiment, an independent multicast distribution network installed in the access network operator is used without making the relay device that has been operated in the past between the content server and the access network operator compatible with multicast distribution. Since broadcast distribution can be performed, the cost and time for changing the distribution can be greatly reduced.
The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.

10 ISP IP network 11 Content server 12-14 Relay device (router)
12a, 22a, 45a Input port 12b Relay processing unit 12c ARP processing unit 12d Broadcast processing unit 12e MPLS processing unit 12f, 22e Output port 16, 17, 18, 23 Tunnel 20 Access network operator network 21, 41 Network termination device 22, 42 BAS
22b Multicast distribution unit 22c Unicast relay processing unit 22d Multicast relay processing unit 22f, 45d Multicast output port 24-26 ADSL
27 to 37 Host device 40 Multicast distribution network 43 and 46 Multicast route 45 Multicast proxy device 45b Multicast proxy processing unit 45c Multicast relay processing unit A to C User L line

Claims (9)

A logical tunnel is established in a predetermined public network that is interposed between a predetermined backbone network and a host device, and a multicast distribution network that does not pass through the tunnel is configured to relay data between the backbone network and the host device. In the data relay method to be performed,
A determination step in which a type determination unit connected to the host device side in the public network monitors the content of data fetched from the host device and determines the type of the data;
When the data type is data targeted for a single traffic, data relay control is performed via the tunnel, and when the data is a predetermined packet to be controlled, the multicast distribution is performed. A control processing step for performing data relay control via a network;
A data relay method comprising: The control processing step further includes a storage control step of storing the control target data when the data is the predetermined control target data.
The control processing step, when receiving a broadcast reception request from the host device, relays the data stored by the storage control step to the host device that has made the broadcast reception request. The data relay method according to claim 1.   The data relay method according to claim 1 or 2, wherein the multicast distribution network is a virtual circuit physically shared with the tunnel. The multicast distribution network is:
An address conversion step of changing a destination of data transmitted to a specific IP address in the public network to a preset address of a specific group broadcast;
A transfer step of transferring the address-converted data to a multicast network logically constructed in the public network;
A distribution step of distributing the transferred data to a host device;
The data relay method according to claim 1, further comprising: Data that is provided in a predetermined public network interposed between a predetermined backbone network and a host device, and relays data between the backbone network and the host device via a logical tunnel constructed in the public network In the relay device,
A type determination means connected to the host device side, monitoring the content of data fetched from the host device and determining the type of the data;
First relay means for relaying data via the tunnel;
Second relay means for relaying data via a multicast distribution network without going through the tunnel;
When the data type is data targeted for a single traffic, data relay control is performed via the first relay means, and when the data is a predetermined packet to be controlled. Control processing means for performing data relay control via the second relay means;
A data relay device comprising: The second relay means includes storage control means for storing the data when the data type is data intended for simultaneous broadcasting of a specific group,
The control processing means relays the data stored in the storage control means to the host apparatus that has made the simultaneous broadcast reception request when receiving the simultaneous broadcast reception request from the host apparatus. The data relay device according to claim 5.   7. The data relay apparatus according to claim 5, wherein the second relay unit is a virtual relay unit that is physically shared with the first relay unit. The second relay means includes
Address conversion means for changing a destination of data transmitted to a specific IP address in the public network to a preset address of a simultaneous broadcast of a specific group;
Transfer means for transferring the address-converted data to a multicast network logically constructed in the public network;
Distribution means for distributing the transferred data to a host device;
The data relay apparatus according to claim 5, further comprising: Input means for connecting the host device and the type determination means;
First output means for connecting the tunnel and the first relay means;
Second output means for connecting the multicast distribution network and the second relay means;
The data relay device according to any one of claims 5 to 8 , further comprising:

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