JP2004180023A - Data relay method, data relay device, and data relay system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent troubles in a unicast relay at the time of relay content distribution by utilizing multicast data relay together with unicast data relay. <P>SOLUTION: A content distribution server 66 which stores the data of the contents of a plurality of specific users is provided in a data center 65 of a backbone network 1 of a communication enterpriser, and each of PE routers 10 to 40 is provided with a function of discriminating the classifications of the packets, a function of performing multicast relay using the IP, and a function of performing unicast relay using the MPLS, and content multicast distribution and unicast data relay between LANs 60, 61, and 63 or LANs 62 and 64 of specific users are performed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a data relay method, a data relay device, and a data relay system using the MPLS (Multi Protocol Label Switching) for performing data relay by tunneling over a network and distributing multicast contents, and a data relay device using the device. Things.
[0002]
[Prior art]
In a conventional data relay method, a tunnel using an LSP (Label Switched Path) is set using a backbone network provided by a communication carrier, for example, using the MPLS technology as described in Patent Document 1 described below, and a VPN number is set. Some provide an Internet Protocol (IP) -Virtual Private Network (VPN) service that logically multiplexes and transmits data with a label corresponding to. As shown in the system of FIG. 20, for example, such an IP-VPN service is provided to each company (in the figure, company A and company B), and is provided to a physical line such as a network line or a router. The connection uses a common facility, and the communication between the different enterprise users A and B is separated, so that the service cost can be reduced as compared with the related art.
[0003]
That is, in FIG. 20, a plurality of PE (provider edge) routers 10 to 30 provided on the IP-VPN backbone network 1 are connected to the same VPN of a specific user via CE (customer edge) routers 50 to 54. It may be used for a system in which the LANs 60 to 64 of Company B and Company B are connected. In the PE routers 10 to 30, routers belonging to the same VPN form a mesh and exchange route information via a core router (not shown) in the network 1. The route information exchanged here is stored in the unicast forwarding table, and these PE routers select the optimal route based on the route information and relay the data of the unicast packet.
[0004]
In such a system, among the PE routers 10 to 30 provided in the IP-VPN backbone network 1, a site common to the same PE routers 20 and 30 is used in order to reduce the number of parts and improve the efficiency of the system configuration. A plurality of LANs of company A and a plurality of LANs 62 of company B are connected to a plurality of specific users belonging to a VPN having no VPN, that is, a PE router 20 shown in FIG. And a plurality of LANs 64 of Company B are connected. In such a case, the PE routers 20 and 30 hold a unicast forwarding table for each VPN, and use a relay control IP protocol corresponding to each VPN to use a client PC (personal computer) connected to each LAN. Computer) to relay data of unicast packets sent from the computer.
[0005]
However, in recent years, there has been a movement to distribute the contents of stream data including images and audio data between LANs belonging to the same VPN of a specific user. For example, servers for the contents distribution have been installed in the LANs of the head offices of the companies A and B, respectively. Some devices are installed to relay data of stream data.
[0006]
[Patent Document 1]
JP-A-2002-247086 (pages 1 to 12, FIGS. 6, 7, 12, and 13)
[0007]
[Problems to be solved by the invention]
However, since the stream data to be distributed has a large data capacity, if this content distribution is performed from the server in the LAN of the specific user via the PE router as in the above-described conventional example, the communication between the CE router and the PE router may occur. If the transmission rate of the stream is low, the router is occupied by the stream data relay, and the unicast data relay from the same LAN to the backbone network cannot be performed, which may hinder the unicast data relay. There was a problem.
[0008]
Also, there is a case where a server is set up in a data center operated by a telecommunications carrier instead of a server at a specific user site, and management of content distribution is outsourced. However, in a telecommunications carrier, relay of unicast data is separated by VPN. Therefore, it is necessary to prepare a server individually for each user, and there is a problem that the equipment cost and the operation cost of the server increase.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a content distribution server that stores data of a plurality of specific user contents in a data center of a communication carrier, and performs multicast data relay using IP and MPLS. Provided are a data relay method, a data relay device, and a data relay system using the device, which can use a unicast data relay that is used together to prevent a problem that occurs in the unicast relay when relaying content distribution. Aim.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, in the data relay method according to the first aspect, tunneling of MPLS is performed between networks of specific users via a data relay device provided in a backbone network constructed by VPN, and unicast is performed. In the data relay method for relaying data of a packet, a server that stores data of content preset for each specific user is provided in the backbone network, and a request for content distribution from the specific user is provided using a multicast routing protocol. Transferring the content stored in the server by multicasting; transmitting the content stored in the server by multicast; and transmitting data input from the backbone network to a unicast packet or a multicast key. Determining whether the packet is a multicast packet, and in the case of the multicast packet, a data transfer step of transferring the multicast packet to a specific user who has requested the content distribution. .
[0011]
According to the present invention, for example, a content distribution server that stores data of a plurality of specific user contents is provided in a data center of a communication carrier on a backbone network, and a content distribution request using a multicast routing protocol such as IGMP is provided. By relaying the stream data of the corresponding content in the content distribution server by multicast, it is possible to distribute the content without affecting the unicast relay performed between the networks of the specific user.
[0012]
Further, the data relay method according to claim 2, further comprising an authentication step of authenticating the specific user with respect to the content distribution request, wherein the request transfer step includes the step of: The distribution request is transferred to the backbone network.
[0013]
According to the present invention, in response to a content distribution request, it is authenticated whether or not the user who made the request is a specific user constituting a VPN, and when the user is authenticated, the server of the backbone network issues the content distribution request. By transferring the content to the connected PE router, it is possible to distribute the content only to a preset specific user.
[0014]
In the data relay method according to claim 3, in the data transfer step, if the data is a unicast packet, the unicast packet is transferred by tunneling the MPLS, and the data is multicast. In the case of a packet, the multicast packet is transferred to a specific user who has requested the content distribution using IP.
[0015]
According to the present invention, a content distribution server is provided in a data center of a communication carrier, and content distribution from this data center is transmitted by multicast using normal IP, and unicast data relay between specific users is performed by: By transferring the encapsulated packet using MPLS, it is possible to use both multicast data relay using IP and unicast data relay using MPLS.
[0016]
Further, in the data relay device according to the present invention, the data relay device is provided in a backbone network constructed by VPN, and performs MPLS tunneling between networks of specific users to relay data of packets. A distribution request transfer unit for transferring a content distribution request from a user to the backbone network using a multicast routing protocol, a determination unit for determining whether the received packet is a unicast packet or a multicast packet, and the determination result. Control means for performing a unicast control process or a multicast control process of the packet, and a transfer of the unicast packet subjected to the control process, and a context provided in the backbone network. The multicast packet from Tsu distribution server, characterized by comprising a packet transfer means for transferring to the particular user that a request for the content distribution.
[0017]
According to the present invention, a request for content distribution from a specific user is transferred to another PE router in the backbone network using a multicast routing protocol, and the type of a received packet is determined. After performing unicast control processing or multicast control processing, transfer of unicast packets using MPLS and transfer of content stream data by multicast without using MPLS allow unicast data transmission at the time of multicast data relay. Prevent problems that occur in relaying.
[0018]
The data relay device according to claim 5, further comprising an authentication unit that authenticates the specific user in response to a content distribution request from the specific user, wherein the distribution request transfer unit includes a specific user Is authenticated, the content distribution request is transferred to the backbone network.
[0019]
According to the present invention, a specific user is authenticated in response to a content distribution request from a user, and when the user is authenticated as a specific user who is permitted to receive content distribution, the content distribution request is transmitted to, for example, a backbone network. By transferring the content to the PE router to which the server is connected, it is possible to deliver the content only to a preset specific user.
[0020]
Further, in the data relay device according to claim 6, the packet transfer means transfers the multicast packet using IP without setting up tunneling of MPLS.
[0021]
According to the present invention, unicast packets use MPLS to perform tunneling to relay data between specific users, and multicast packets use IP to relay data such as stream data through another path, thereby achieving multicast communication. Enables simultaneous use of unicast data relay.
[0022]
Further, in the data relay system according to the present invention, in a data relay system for relaying unicast packet data by tunneling MPLS between a backbone network constructed by VPN and a specific user's network, A multicast packet comprising: a data relay device according to any one of claims 4 to 6; and a server for storing data of content preset for each specific user, wherein a multicast packet is transmitted to a specific user who has requested content distribution. Is performed.
[0023]
According to the present invention, the data relay device according to any one of claims 4 to 6 is connected to the backbone network of the communication carrier and the server that stores the data of the content to be distributed to the specific user. By transferring the corresponding content in the server to a specific user by multicast using IP, unicast data relay using MPLS and multicast data relay using IP are used in combination, and data relay of both is performed. Perform without any hindrance.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a data relay method, a data relay device, and a data relay system using the device according to the present invention will be described with reference to the accompanying drawings of FIGS. In the following drawings, the same components as those in FIG. 20 are denoted by the same reference numerals for convenience of explanation.
[0025]
(Embodiment)
FIG. 1 is a system configuration diagram showing an example of a schematic configuration of a data relay system according to the present invention. 20 differs from the configuration of FIG. 20 in that a data center 65 is connected via a CE router 55 to a PE router 40 provided on the IP-VPN backbone network 1, and a content distribution server is connected to the data center 65. This is the point that a function for performing multicast data relay to the PE routers 10 to 40 is added.
[0026]
As shown in FIG. 2, the content distribution server 66 stores contents of each specific user, for example, data of contents 1 to 4, and transmits the data to the IP-VPN backbone network 1 via the CE router 55. Sending out. Each specific user constitutes a multicast group, for example, multicast groups 1 to 6, and a group IP address and a group number 1 to 6 of a VPN are assigned by a communication carrier that provides this content distribution service. I have. By the way, in FIG. 1, since the specific users are the companies A and B, in this embodiment, the multicast groups are 1 and 2, and the data of the contents 1 and 2 are stored in the content distribution server 66. It is remembered.
[0027]
Each of the PE routers 10 to 40 has the same configuration. Here, the configuration of the PE router 20 will be representatively described with reference to the configuration diagram of FIG. In the figure, a PE router 20 includes a packet receiving unit 21 and a packet transmitting unit 22 which are connected to CE routers 51 and 52 on the downstream side and a core router (not shown) in the backbone network 1 via respective ports, respectively, and a layer 3 level. An IP relay control unit 23 that controls data relay, a multicast protocol control unit 24 that controls multicast routing using IGMP (Internet Group Management Protocol: RFC2236), and an authentication table 25 connected to the multicast protocol control unit 24. , A multicast forwarding table 26 connected to the IP relay controller 23 and the multicast protocol controller 24, and a unicast forwarding table connected to the IP relay controller 23. And Buru 27, the filtering table 28, and a MPLS label table 29..
[0028]
The IP relay control unit 23 determines the type of the packet received by the packet receiving unit 21, performs control processing of data relay of the multicast packet and the unicast packet, and sends the data to the packet transmitting unit 22. Further, the IP relay control unit 23 performs control processing of data relay of a PIM Join message input from a multicast protocol control unit 24 described later, and sends the data to the packet transmission unit 22. Further, the IP relay control unit 23 includes a table storing therein a packet receiving port and a VPN number to which a LAN (specific user) connected to the receiving port belongs.
[0029]
The multicast protocol control unit 24 performs authentication of an IGMP Join message input from the CE router and creation of a PIM (Protocol Independent Multicast: RFC2362) Join message. The created PIM Join message is sent to the IP relay control unit 23. Output.
[0030]
As shown in FIG. 4, the authentication table 25 includes a group IP address, a source IP address, and a group IP address set in advance for each specific user (Company A and Company B in this embodiment shown in FIG. 1) by the communication carrier. A VPN group number is stored. The multicast protocol control unit 24 extracts the group IP address and the source IP address from the IGMP membership report, searches the authentication table 25 from the group IP address and the source IP address, and performs authentication.
[0031]
As shown in FIG. 5, the multicast forwarding table 26 includes, for example, a group IP address of a multicast group indicating contents to be distributed, and a receiver port to which each host device (client PC) wishing to join the multicast group is connected. A list of numbers is stored.
[0032]
The unicast forwarding table 27 is composed of VPN tables for each VPN set for each specific user. Each VPN table has a destination of a unicast packet as shown in the VPN1 table of FIG. , A destination IP address indicating the recipient host device, data of the subsequent subnet mask, an IP address of a Next Hop router indicating the next downstream router to reach the recipient host device, and the downstream router and the LSP (Label Switched Path) and an MPLS label index for setting a tunnel.
[0033]
As shown in FIG. 7, the filtering table 28 includes a group IP address of a multicast group, data of a subsequent subnet mask, a list of recipient port numbers, and a processing state of the content of the multicast group in its own device (for example, (Information indicating whether the process is a discard process or a relay process). The IP relay control unit 23 searches the filtering table 28 and the multicast forwarding table 26 from the destination IP address (group IP address) of the multicast packet, and if the multicast packet is a relay target and the receiver can be confirmed, the multicast packet is The receiver is outputting to the connected port.
[0034]
As shown in FIG. 8, the MPLS label table 29 includes an MPLS label index, a label to be added when transmitting from a PE router, a label included in a packet when receiving, and a corresponding VPN group number. Is stored. For the received unicast packet, the IP relay control unit 23 specifies the source VPN from the reception port, and further searches the unicast forwarding table (the VPN table of the corresponding VPN) 27 for the destination address, After labeling the packet, the unicast packet is transferred to the Next Hop router.
[0035]
FIG. 9 is a diagram illustrating a frame configuration of the PIM message packet. In the figure, a PIM message packet includes a MAC header, an IP header, and fields of a PIM message. The MAC header includes a destination including a MAC address, a source address, and the like. As shown in FIG. 10, the IP header includes a version, a header length (HLEN), a service type, a bucket length (Total Length), an identifier, a flag, a fragment offset value, a lifetime, a protocol field, a header checksum, and a source IP address. (Unicast), destination IP address (multicast), and data such as a data part. Note that “103” data indicating the PIM is stored in the protocol field in the IP header.
[0036]
The IP relay control unit 23 searches the protocol field in the IP header, and if the value is “103”, determines that the packet is a PIM message packet and outputs the packet to the multicast protocol control unit 24.
[0037]
The field of the PIM message shown in FIG. 9 includes, as shown in FIG. 11, a PIM version, a type indicating a specific PIM control message, a reserve, a checksum, an option type, an option length, an option value, and the like. Have been. The types of the PIM include Hello, Register, Register-Stop, Join / Prune, Bootstrap, Assert, and the like.
[0038]
As shown in FIG. 12, the format of the Join / Prune message packet of the PIM indicates the version of the PIM, the type of the message, the reserve, the checksum, the Encoded Unicast Upstream Neighbor Address indicating the address of the upstream neighbor, and the number of multicast groups. Shows the number of groups, the hold time, the address of the set multicast group, the number of join source addresses, the number of prune source addresses, a field indicating the encoded join source address, and the encoded prune source address. Field and consists of: A plurality of fields below the address of the set multicast group are provided for each set group.
[0039]
As shown in FIG. 13, the IGMP message packet transmitted from the client PC of each LAN includes a MAC address, an IP address, and fields of the IGMP message.
[0040]
As shown in FIG. 14, the fields of the IGMP message include Type indicating the type of the IGMP message, Max Resp Time indicating the maximum response time, Checksum indicating the checksum value of the IGMP message, and the receiver who wants to participate. And a group IP address (multicast address). The IP relay control unit 23 searches the type field in the IGMP message, and if the value is “0x16”, determines that the report is an IGMP membership report and outputs the report to the multicast protocol control unit 24.
[0041]
FIG. 15 is a diagram showing a packet flow in multicast data relay in the data relay system shown in FIG. Here, an example in which the client PC of the LAN 61 makes a content distribution request will be described.
[0042]
In the figure, a specific user requesting content distribution transmits a message packet of an IGMP membership report using a client PC 61 in a LAN, and a CE router 51 that has received this message packet sends a message to a PE router. 20 and relay the data.
[0043]
When the PE router 20 captures this message packet, it performs an authentication procedure described later, creates a Join / Prune message packet of the PIM, designates the next core router in the backbone network 1, and transmits the Join / Prune message packet. I do.
[0044]
This Join / Prune message packet is relayed by some core routers and then relayed to the next designated PE router 40. Similarly, when the PE router 40 captures the Join / Prune message packet, the PE router 40 designates the next CE router 55 and relays the data of the Join / Prune message packet.
[0045]
The CE router 55 distributes the content of the stream data from the content distribution server 66 in the form of a multicast packet. When the CE router 55 captures the PIM Join / Prune message packet, the CE router 55 searches the multicast forwarding table and searches for the multicast forwarding table. The content distribution of the corresponding stream data of the multicast group to which the specific user belongs is performed.
[0046]
Contrary to the flow of the IGMP membership packet and the Join / Prune message packet of the PIM, the stream data is sequentially relayed through each corresponding router, and is transmitted to the client PC of the LAN 61 that has made the content distribution request. Will be sent. At this time, each router searches the multicast forwarding table in its own device and sends out this stream data to the port of the receiver corresponding to the group IP address.
[0047]
Next, the packet discriminating operation and the forwarding process operation by the PE router according to the present invention will be described based on the flowcharts of FIGS. First, FIG. 16 is a flowchart for explaining the packet discriminating operation by the PE router. In the figure, when a packet is received by the packet receiving unit 21 (step 101), the packet is input to the IP relay control unit 23. The IP relay control unit 23 performs a control process for relaying the received packet (step 102). Here, the IP relay control unit 23 determines whether the received packet is an IGMP membership report. (Step 103).
[0048]
Here, the IP relay control unit 23 searches the type field in the received packet, and if the value is “0x16”, determines that the report is an IGMP membership report, and sends the message to the multicast protocol control unit 24. Is output, and the flow shifts to the processing flow by the multicast protocol control unit 24 (step 104). If the received packet is not an IGMP membership report, it is determined whether the received packet is a multicast packet (step 105).
[0049]
Here, if the received packet is not a multicast packet, the IP relay control unit 23 proceeds to a unicast forwarding processing flow (step 106). If the received packet is a multicast packet, the IP relay control unit 23 proceeds to the multicast forwarding processing flow (step 107).
[0050]
Next, the processing operation by the multicast protocol control unit 24 will be described based on the flowchart of FIG. In the figure, the multicast protocol control unit 24 extracts the source IP address and the group IP address in the received IGMP membership report message and performs authentication for accepting IGMP (step 201). Specifically, based on the extracted source IP address and group IP address, the authentication table shown in FIG. 4 is searched to detect a corresponding VPN group, and the sender of the received IGMP membership report is It is checked whether it belongs to the detected VPN group, and it is determined whether the specific user has been authenticated (step 202).
[0051]
If the authentication fails, the received IGMP membership report is discarded (step 203). If the authentication is successful, it is searched for an entry in the multicast forwarding table shown in the figure (step 204).
[0052]
If there is an entry in the multicast forwarding table, the entry is held (step 205). If this entry does not exist, a PIM Join message is transmitted to the upstream router (step 206).
[0053]
Next, the unicast forwarding processing operation by the IP relay control unit 23 will be described based on the flowchart of FIG. In the figure, the IP relay control unit 23 determines whether the received packet is a packet labeled by MPLS (step 301).
[0054]
Here, the unicast packet received from the core router on the upstream side of the PE router is a labeled packet, and the unicast packet received from the CE router on the downstream side is an unlabeled packet. First, if the received packet is not labeled, the internal table is searched to extract the VPN number to which the transmission source belongs from the reception port, and this VPN table is selected from the unicast forwarding table. (Step 302).
[0055]
Next, the destination address of the received unicast packet is searched from the selected VPN table (step 303), and it is determined whether or not this entry exists (step 304).
[0056]
If there is no entry, the received packet is discarded (step 305). If there is an entry, it adds an MPLS label and sends it to the Nexthop router (step 306).
[0057]
Next, when the received packet is labeled, the MPLS label table is searched, the corresponding VPN is extracted from the MPLS label of the packet, the VPN table is selected, and the label of the packet is removed ( Step 307).
[0058]
Then, the destination address of the packet is searched in the selected VPN table (step 308), and it is determined whether or not this entry exists (step 309).
[0059]
If the entry does not exist, the received packet is discarded (step 310). If the entry exists, the IP address of the next hop router is extracted, and the unicast packet is sent to this router. It transmits (step 311).
[0060]
Next, the multicast forwarding processing operation by the IP relay control unit 23 will be described based on the flowchart of FIG. In the figure, the IP relay control unit 23 first extracts a destination IP address of a received multicast packet, searches a filtering table (step 401), and determines whether or not a hit has been made as a discard target (step 402).
[0061]
Here, if the destination IP address is hit as a discard target, the received packet is discarded (step 403). If the destination IP address is not hit as a discard target, the multicast forwarding table is searched with the destination address (including the mask) of the received multicast packet (step 404), and the multicast packet joins the multicast group. It is determined from the recipient port list whether there is a recipient present (step 405).
[0062]
If there is no receiver participating in the multicast group, the received multicast packet is discarded (step 406). If there is a receiver participating in the multicast group, the multicast packet is transferred to the port where the receiver is located (step 407), and the packet is transmitted from the packet transmitting unit to the downstream CE router (step 407). Step 408).
[0063]
As described above, in this embodiment, a content distribution server that stores content data is provided in the data center of the backbone network, and multicast packets from this server to the PC relay data using IP, and Since a unicast packet between the two relays data using MPLS, even when a unicast relay performed between networks of a specific user is performed when a multicast packet is relayed from a server, the unicast relay affects this unicast relay. Without data relay, it can be used together.
[0064]
Further, in this embodiment, a common content distribution server that stores data of content for each VPN to which a specific user belongs is provided in a data center of the backbone network, and stream data is transmitted by multicast transmitted from the content distribution server. Since the relay is performed, it is not necessary to separately provide a large-capacity content distribution server for each specific user, and it is possible to reduce the LAN construction cost.
[0065]
Further, in this embodiment, in the case of multicast content distribution, there is no restriction on the address of the subscriber side (specific user), and content distribution can be received while using a private IP address. Even if the addresses are duplicated, the data can be relayed without any problem.
[0066]
The present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, for unicast data relay between specific users, relay may be performed on the IP-VPN network, and for multicast content distribution from the server, relay may be performed on the IP network. It is also possible to separate the core network into an IP-VPN network and an IP network, and to connect two ports to the core network separately in the PE router.
[0067]
【The invention's effect】
As described above, according to the present invention, in a data relay device that is provided in a backbone network constructed by a VPN and performs MPLS tunneling between networks of a specific user and relays data of a packet, The content distribution request is forwarded to the backbone network using a multicast routing protocol, and the type of the received packet is determined. If the received packet is a unicast packet, data relay using MPLS is performed. Also, when this packet is a multicast packet, data relay is performed without using MPLS, so that it is possible to prevent a trouble occurring in unicast relay when relaying content distribution.
[0068]
In addition, in the present invention, a specific user is authenticated in response to a content distribution request, and the content distribution from the content distribution server is performed only to the authenticated user. Can be delivered.
[0069]
Further, in the present invention, the content distribution from the data center is transmitted by multicast using normal IP, and the unicast data relay between specific users transmits the encapsulated data using MPLS. By using both the multicast data relay using IP and the unicast data relay using MPLS, it is possible to prevent troubles occurring in the unicast relay when relaying the content distribution.
[0070]
Further, in the present invention, a data relay system is provided with a common content distribution server storing content data for each specific user, and the data relay device according to any one of claims 4 to 6, wherein multicast data using IP is provided. Since the relay and the unicast data relay using the MPLS can be used together, it is possible to reduce the equipment cost and the operating cost of the server by sharing the distribution server among the users.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an example of a schematic configuration of a data relay system according to the present invention.
FIG. 2 is a diagram showing a data configuration of a content distribution server according to the present invention.
FIG. 3 is a configuration diagram illustrating an example of a configuration of a PE router illustrated in FIG. 1;
FIG. 4 is a table configuration diagram showing a configuration of an authentication table shown in FIG. 3;
FIG. 5 is also a table configuration diagram showing a configuration of a multicast forwarding table.
FIG. 6 is a table configuration diagram showing a configuration of a unicast forwarding table.
FIG. 7 is a table configuration diagram showing the configuration of a filtering table.
FIG. 8 is a table configuration diagram showing the configuration of an MPLS label table.
FIG. 9 is a diagram showing a frame configuration of a PIM message packet transmitted and received by the system of FIG. 1;
FIG. 10 is a diagram showing a frame configuration of an IP header shown in FIG. 9;
11 is a diagram showing a frame configuration of the PIM message shown in FIG. 9;
12 is a diagram illustrating a frame configuration of a Join / Prune message packet of the PIM illustrated in FIG. 11;
FIG. 13 is a diagram showing a frame configuration of an IGMP packet transmitted and received in the system of FIG. 1;
FIG. 14 is a diagram showing a frame configuration of the IGMP message shown in FIG.
FIG. 15 is a diagram showing a flow of a packet in multicast data relay in the data relay system shown in FIG. 1;
FIG. 16 is a flowchart for explaining a packet discriminating operation by the PE router shown in FIG. 3;
FIG. 17 is a flowchart illustrating a processing operation by the multicast protocol control unit illustrated in FIG. 3;
FIG. 18 is a flowchart for explaining a unicast forwarding processing operation by the IP relay control unit.
FIG. 19 is a flowchart illustrating a multicast forwarding processing operation by an IP relay control unit.
FIG. 20 is a system configuration diagram showing a schematic configuration of a conventional data relay system.
[Explanation of symbols]
1 backbone network
10-40 PE router
21 Packet receiver
22 Packet transmitter
23 IP relay control unit
24 Multicast Protocol Control Unit
25 Authentication table
26 Multicast forwarding table
27 Unicast forwarding table
28 Filtering table
29 MPLS label table
50-55 CE router
60-65 LAN
65 Data Center
66 Content Distribution Server

Claims (7)

A data relay method for relaying unicast packet data by tunneling MPLS between specific user networks via a data relay device provided in a backbone network constructed by VPN,
A request transfer step of providing a server for storing data of content preset for each specific user in the backbone network, and transferring a content distribution request from the specific user to the backbone network using a multicast routing protocol. ,
A delivery step of delivering content stored in the server by multicast,
A data transfer step of determining whether data input from the backbone network is a unicast packet or a multicast packet, and in the case of the multicast packet, transferring the multicast packet to a specific user who has requested the content distribution;
A data relay method comprising: In the data relay method, an authentication step of authenticating the specific user with respect to the content distribution request,
2. The data relay method according to claim 1, further comprising, in the request transfer step, transferring the content distribution request to the backbone network when the specific user is authenticated. In the data transfer step, if the data is a unicast packet, the MPLS tunneling is performed to transfer the unicast packet. If the data is a multicast packet, the content is transmitted using IP. 3. The data relay method according to claim 1, wherein the multicast packet is transferred to a specific user who has requested distribution. In a data relay device that is provided in a backbone network constructed by VPN and that performs MPLS tunneling between specific user networks and relays data of packets,
A distribution request transfer unit that transfers a request for content distribution from the specific user to the backbone network using a multicast routing protocol,
Determining means for determining whether the received packet is a unicast packet or a multicast packet;
Control means for performing a unicast control process or a multicast control process of the packet according to the determination result,
A packet transfer unit that transfers the control-processed unicast packet, and transfers the multicast packet from a content distribution server provided in the backbone network to a specific user who has requested the content distribution.
A data relay device comprising: The data relay device, in response to a content distribution request from the specific user, an authentication unit that authenticates the specific user,
5. The data relay device according to claim 4, further comprising: when the specific user is authenticated by the authentication unit, the distribution request transfer unit transfers the content distribution request to the backbone network. The data relay device according to claim 4, wherein the packet transfer unit transfers the multicast packet using IP without using MPLS tunneling. In a data relay system that relays unicast packet data by tunneling MPLS between a backbone network constructed by VPN and a specific user network,
The data relay device according to any one of claims 4 to 6, wherein the data relay device is provided in the backbone network.
A server for storing data of content set in advance for each specific user,
And transmitting a multicast packet to a specific user who has requested content distribution.

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