JP2008136233A - Data transfer device, method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a virtual private network (VPN) over a plurality of Internet service providers (ISPs). <P>SOLUTION: In the interwork gateway of the network connection part of both Internet service providers, when determining the lines of respective packets, the lines are determined using the information of the region of an encapsulated header introduced to configure the VPN and the region of both IP headers, and the encapsulated header in an output side network is also constituted of the information further. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a virtual private network (VPN) on the Internet.
ork) relates to a construction method and an interwork router for connecting Internet service providers.

Applications such as e-mail and WWW (World Wide Web) can be used on the Internet protocol (IP) network. IP networks are also cheaper to build than traditional telephone-based switching networks. For this reason, the Internet has become popular in recent years. Under such circumstances, an intra-company network (intranet) constructed with IP has become indispensable for corporate activities.

Companies are often unevenly distributed in multiple regions. In this case, it is necessary to interconnect the corporate networks in each region to construct a single corporate network. When building a corporate network across multiple regions, the following two methods can be considered.

The first is to interconnect the local corporate networks with dedicated lines. By constructing in this way, the corporate network can be isolated from the external network and security can be ensured.

Second, the terminal is provided with a function for identifying packets of its own network by IPsec (IP security protocol) technology, and is transferred as an IP packet based on a global address in the Internet. A VPN can be realized by countering an attack from a malicious user with this identification function and encryption.

However, the use of a dedicated line increases the network cost, and in the VPN using the IPsec method, malicious users can be intruded by attack and decryption, and encryption processing becomes a bottleneck for the speed of high-speed networks. There is a problem that the terminal cost increases.

For this reason, as the Internet becomes widespread and can be used at a low price, a dedicated network is virtually constructed on the Internet using the IP lower layer functions provided by the network, the cost is reduced, and There has been a growing demand for safe and some quality assurance that is isolated from external networks.

The following VPN is considered as a network that satisfies this requirement. V
Internet Service Pro that provides PN (Internet Service Pro
vider: Encapsulation at the entrance of the ISP network. On the ISP network, transfer is performed based on the encapsulated header, and the capsule header is removed at the exit of the network. In this VPN configuration method, by using a VPN-specific encapsulation header, it is isolated from an external network and security is ensured. In addition, as a specific protocol of this encapsulation, IP encapsulation,
MPOA (Multi Protocol over ATM), MPLS (Multi Protocol Layer Switch)
ching), etc., and as of February 1999, it is being studied by standardization organizations such as ITU-T SG13 and IETF. Also, in ITU-T SG13, a study is being conducted on Core Protocol (also called GMN-CL) that encapsulates and transfers the inside of a network with an E.164 address.

NTT R & D vol.47 No.4 1998 (published on April 10, 1998) proposes a configuration method for access systems and edge nodes that interwork user networks and core networks in GMN-CL.
NTT R & D vol.47 No.4 1998 (issued April 10, 1998)

Business activities in recent years are extensive. For this reason, for example, there is a need to have bases in Japan, the United States, and Europe, build an intranet at each base, and connect them with each other by VPN.

On the other hand, since ISPs generally provide services in a specific area, a plurality of ISs are required to connect networks of each base as described above using VPN.
It is necessary to construct a VPN across P.

When multiple ISPs are connected to each other, an interworking gateway is provided for mutual connection. In this interwork router, interworking is realized by transferring packets destined for the partner network coming from both networks to the partner network according to the IP header. In addition, Nikkei Communication December 15, 1997
As described on page 146 of the Japanese edition, for mutual interworking of multiple networks, each other's networks are connected using a device called IX (Internet Exchange), and this IX transfers between each other's networks. Packet transfer may be performed. In such IX, there is a method using “Layer 3 forwarding” that identifies and forwards an IP packet, or “Layer 2 forwarding” that identifies and forwards a lower layer header in an ATM communication device or the like. .

The inventors of the present application have examined a problem when attempting to configure a VPN across a plurality of ISP networks. First, in order to construct a VPN in each Internet service provider's network, encapsulation is performed in each network. The encapsulation protocol for each network will generally be different. In this case, the interwork router needs to search the IP header information of the IP packet, which is a common protocol of both networks, determine the destination route, and search whether the packet is for another network. .

However, since the interwork router terminates the protocol lower than the IP layer at the interface, the interwork router searches for the IP address by removing the encapsulation header attached to configure the VPN in the previous network. Hop information is determined, and a capsule header for constructing a VPN in the subsequent network is generated and attached to the packet. Therefore, inside the interwork apparatus, packets in the VPN and packets in networks other than the VPN are mixed.
Therefore, there is a problem that intrusion into the VPN becomes possible with the interwork router as a base point due to the addition of an illegal header by a malicious user.

Further, some companies may configure a VPN using an internal address without using a global address. In this case, once the encapsulated header is removed by the interwork router, the internal ISP uses the internal address for each of the multiple VPNs on the receiving ISP side. I can't. For this reason, the transfer destination of the packet cannot be determined. When configuring a VPN on the Internet across multiple ISPs,
There is a problem as described above (first problem).

Furthermore, services in each ISP are not uniform. For example, communication quality will be described as an example. In some ISP, each VP is created by establishing a path using an ATM VC.
N guarantees quality, and another ISP uses Diffserv (Differenciated Services)
When the quality is guaranteed by the above, it is difficult to define the communication quality end-to-end when the VPNs configured on both sides are connected to each other. (Second problem).

As described above, it is difficult to construct a VPN on the Internet across a plurality of ISPs at a practical level.

Accordingly, the present invention provides a method for constructing a VPN across a plurality of ISPs, and an interwork router for connecting the ISPs when constructing a VPN across a plurality of ISPs.

In order to solve the first problem, the function for determining the output route and generating the encapsulation header in the output side ISP network using the information of both the encapsulation header and the IP header, which are VPN identification numbers, is provided. Provided in work router equipment. ATM in the lower layer
An example of connecting ISPs that operate MPLS networks using ATM will be described below. ATM VPI and VC, which are encapsulation headers used for VPN identification, are described below.
Search using header information such as I and IP address as a key, generate header information such as ATM VPI and VCI to be used for VPN identification in the next route and the next network, and send it to the subsequent network The header information generated at the time is added and sent.

As a result, VPN interworking can be realized, and a VPN configuration on the Internet can be configured for an area spanning a plurality of ISPs.

In order to solve the second problem, the field value representing the QoS of the encapsulation header area on the input side is mapped to the value of the field representing the QoS of the encapsulation header area on the output side. Thereby, the quality information of both networks can be transferred transparently.

According to the present invention, a VPN network spanning a plurality of ISPs can be constructed. In addition, QoS information can be interworked between a plurality of VPN networks.

  Embodiments of the present invention will be described below with reference to the drawings.

A configuration method of a VPN separated by a lower layer extending over a plurality of ISPs according to the present invention and the role of the interwork router will be described with reference to FIGS. Here, the lower layer refers to a protocol for encapsulating IP packets, and I
Even when a P packet is encapsulated with an IP header, the capsule header is expressed as a lower layer header.

First, referring to FIG. 2, a problem when a VPN that spans a plurality of ISPs is configured using a conventional router will be described. In FIG. 2, ISP1 (2-1) and ISP2 (2-2) realizing VPN by encapsulating in the lower layer are interworked by the existing router (9). The ISP 1 is developing services in the A district, and accommodates LAN1 (1-1), LAN2 (1-2), and LANa (1-a). ISP2 is developing services in B area, LAN3 (1-3)
, LAN4 (1-4) and LANb (1-b) are accommodated. LAN1,
LAN2, LAN3, and LAN4 are LANs of the same company and want to configure a VPN. LANa and LANb are also LANs of the same company, and they want to configure a VPN. In such a case, in the same ISP, by establishing a capsule channel at the entrance of the network and the entrance of the network, it can be separated from the packets of other users, so that a network with high security can be constructed. However, when setting up VPN over ISP1 and ISP2, the existing router terminates the lower layer at the interface section on the input side, merges at the IP level, and then performs ring processing at the packet forward. There is a problem that user packets are mixed. In other words, packets in the VPN and other packets are mixed. Therefore, it is possible for a malicious user to intrude into the network with a false IP address. Furthermore, when two companies try to construct an in-house LAN using private addresses, the same IP address may be assigned because each company assigns an address independently. In this case, the existing router cannot correctly transfer the packet because of address batting.

Next, the solution of the problem according to the present invention will be described with reference to FIG. For example, a case where communication is performed from LAN 1 of company A to LAN 3 of company A will be described. In this embodiment, ISP1 realizes VPN by IP encapsulation, and ISP2 is MPLS.
VPN is realized by encapsulation (by ATM). When a packet arriving from the LAN 1 enters the ISP 1 (2-1), the ISP 1 performs IP encapsulation, and the packet arrives at the interwork router through the IP encapsulation logical channel (5-1). In the interwork router (9), the packet has been loaded.
The output route is searched from both the IP encapsulation header indicating the P-encapsulated logical channel and the original packet header, and the encapsulation header in ISP 2 is created. In this embodiment, ISP2 is providing services using MPLS, so ATM.
Create a header for. The packet encapsulated by ATM is sent to the LAN 3 through the ATM logical channel (5-3). In the interwork router, the search is performed using the capsule header and the IP header, so that the company A and the company B can use the private addresses and transfer them to the correct destinations even when the IP addresses are batting. .

In the present embodiment, as the encapsulation protocol, the IP encapsulation which is the IP layer encapsulation method and the method of performing the encapsulation using ATM have been described. Of course, encapsulation may be performed using a frame relay or HDLC protocol.

FIG. 3 illustrates an embodiment of a VPN configuration method across a plurality of ISPs according to the present invention, using a network configuration and a protocol stack. Here, the encapsulation protocol is not limited. ISP1 (2-1) is an edge node (3-1, 3-2)
LAN1 (1-1) and LAN2 (1-2) are accommodated through the network. Similarly, ISP2 (2-2) is set to L through edge nodes (3-3, 3-4), respectively.
A plurality of networks such as AN3 (1-3) and LAN4 (1-4) are accommodated. Further, each ISP transfers IP packets by encapsulating them with headers used in the network from the entrance to the exit of the own network. A capsule header is uniquely assigned to the VPN, so that VPN traffic is identified from other traffic in the network, and a closed network related to VPN is configured. ISP1 (2-1)
And ISP2 (2-2) are interworked by the interwork router (10), and traffic destined for the partner network is transferred to the partner network via the interwork router.

For example, a description will be given of a case of configuring a VPN connecting LAN1 and LAN3 (referred to as VPN1). An IP packet addressed to LAN3 sent from LAN1 is searched by an IP address at an edge node (3-1).
The packet is addressed to the interwork router belonging to, and a capsule header (103a in the layer diagram) destined for the interwork router (10) of VPN1 is given to reach the interwork router (10). The interwork router (10) is searched by the capsule header (103a in the layer diagram) and the IP address, searches for the packet addressed to the edge node (3-3) belonging to the VPN1, and the V2 in the ISP2
A capsule header (103b in the layer diagram) addressed to the edge node (3-3) is assigned by PN1, and the inside of ISP2 is transferred to the edge node (3-3) according to the capsule header. The edge node (3-3) removes the capsule header and transfers the IP packet to the LAN 3. As a result, it is possible to transfer the VPN IP packet extending over both networks without being mixed with other traffic.

Note that IP packets using global addresses are not dependent on lower layer information, but are determined as a whole by determining the transfer destination and capsule header (when using the capsule header) as a whole. You can make a transfer to.

The operation of the interwork router (10) will be described with reference to FIGS.
FIG. 4 is a processing flow of the conventional router device, and FIGS. 5 and 6 are processing flows of the interwork router (10) according to the present invention. In the conventional router, when a packet arrives, the physical layer used for forwarding in ISP1 (2-1) is terminated (201).
), And remove (202) the capsule header used for the transfer in ISP1,
A route search is performed based on the value of the IP header (203), and the route is transferred to a desired route via a switch (204). Thereafter, a capsule header used for transfer in ISP 2 is added (205), and then the physical layer is processed (206) and sent out from the transmission path. In this flow, since the capsule header of ISP1 is removed and the route is determined only by the IP header, traffics of a plurality of VPNs are merged once.
According to the interwork router of the present invention, such a problem can be avoided.

3, when a packet that is an algorithm executed by the interwork router (10) of the present invention arrives, the physical layer used for the transfer in the ISP 1 (2-1) is terminated (211), and the transfer in the ISP 1 is performed. The route search and the encapsulation header in ISP2 are generated based on the values of the capsule header and the IP header used (212).
). Thereafter, the ISP1 capsule header is removed (213), a capsule header used for transfer in ISP2 is added (214), and the capsule header is transmitted to the switch. Then, it is transferred (215) to a desired route by the switch. Thereafter, the physical layer is processed (216) and sent out from the transmission path. As a result, traffic from another network can be separated. Also, bare IP with the capsule header removed
Since the packet does not flow, another person cannot insert it into the VPN from this part. That is, an I to which an internal header used in ISP2 is not added
The P packet is lost and the packet does not flow into the VPN in ISP 2. Therefore, safety is also increased.

FIG. 6 will be described as another embodiment. The interwork router of this example is
Table of correspondence between capsule header and IP header value used for transfer in ISP 1 and capsule header index, capsule header index and ISP
2 has a correspondence table with the capsule header used for the transfer in 2. When the packet arrives, the physical layer used for forwarding in ISP1 (2-1) is terminated (2
21) Then, a route search and a capsule header index are generated based on the values of the capsule header and the IP header used for the transfer in the ISP 1 (222). Thereafter, the IP packet ISP1 capsule header is removed (223), and the removed IP
The generated capsule header index is added to the packet and transmitted to the switch, and the packet is transferred to a desired route by the switch (224). And capsule header
Capsule header used for ISP2 transfer from Index is generated and attached (225
) Thereafter, the physical layer is processed (226) and sent out from the transmission path. Also with this configuration, a highly secure closed network can be configured as in the case of FIG. That is, an IP packet to which no capsule header Index is assigned is not mixed in.

Next, with reference to FIG. 7 to FIG. 10, a description will be given of a VPN implementation method and a packet configuration example spanning ISP 1 that supports VPN by MPLS and ISP 2 that supports VPN using IP capsule.

FIG. 7 shows a network configuration and a protocol stack. Although FIG. 3 has been described without specifying an encapsulation method, FIG. 7 shows an example in which MPLS is adopted for ISP1 and IP encapsulation is adopted for ISP2. In the interwork router (10), FIG.
Similarly to the above, forwarding is performed by a combination of the ATM layer (104a) and IP layer (101), the IP capsule layer (104b), and the IP layer (101) corresponding to the encapsulation header. Accordingly, since each VPN uses a private address, it is possible to forward correctly even if the addresses overlap.

A method of encapsulating IP packets with ATM will be described with reference to FIG. This encapsulation is a method standardized by RFC 1483 of IETF. LLC / SN in IP packet consisting of IP header (250) and IP payload (251)
AP (253) is added, AAL5 header (252) and AAL5 trailer (2
55) is added to construct an AAL5 frame. PAD (254) inserts an AAL5 frame to make it a constant multiple of 48 octets, which is the payload (257) length of the ATM cell. The AAL5 trailer is divided into 48 octets, an ATM header (256) is added, and transfer is performed as one or a plurality of ATM cells.

FIG. 9 shows an IPv4 packet format indicated by RFC791.
When performing IP encapsulation, an IPv4 header is used as it is as a protocol for encapsulation, and an existing IPv4 router can be used as a router in the network.

FIG. 10 shows an encapsulation method using an IP tunnel. An IP packet composed of an IP header (260) and an IP payload (261) transmitted by the user is encapsulated by an encapsulation header (264). The encapsulation header includes an IP header (262) and a tunnel header (263). Consists of This encapsulation header is used in the ISP 2 and can be uniquely identified in the network. Therefore, even when the user uses a private address, routing can be performed by the capsule header in the network, and the packet can be carried to a desired edge. In this example, an example of a tunnel header according to RFC 1583 is shown.
P encapsulation includes GRE encapsulation (RFC1792) and IP mobile.

The interwork router (10) performs forwarding processing by combining the capsule header shown in FIG. 8 and FIG. 10 and the user's IP address,
Secure VPNs can be configured across ISPs, and users can build VPNs using private addresses.

An embodiment of the interwork router (10) will be described with reference to FIGS.

FIG. 11 shows an example of the configuration of the interwork router (10). The control unit (50) performs control of the entire apparatus and routing processing with other nodes. The core switch (51) is a switch that transfers packets between the packet layer processing units (52). The lower layer processing unit (ATM) (53) is an interface that accommodates the MPLS network of ISP1, and the lower layer processing unit (IP capsule) (54) is an interface that accommodates the IP capsule network of ISP2. The packet layer processing unit (52) receives lower layer information and I from the lower layer processing units (53, 54).
A P packet is received, and a packet transfer destination is determined based on a combination of lower layer information and IP packet header information.

First, the processing flow in the reception direction will be described. FIG. 12 shows a lower layer processing unit (ATM
) (53) shows a block configuration. A signal arriving from the ISP1 network is first terminated at the physical layer processing unit (150), and then the ATM layer processing unit (151).
The ATM layer is terminated at At this time, together with the reconfigured IP packet, the ATM header that performs the VPN identification function on the receiving side is also the VPN number assigning unit (
152). The VPN number assigning unit (152) generates a VPN number used for identifying the VPN in the apparatus from the ATM header. At this time, the receiving side VPN number table (153) is used. The VPN number and the IP packet are transferred to the packet layer processing unit via the packet processing unit IF (154).

FIG. 13 shows a configuration example of the receiving side VPN number table (153). This table is composed of a pair of an input side ATM header (300) and an input side VPN number (303), and the input side ATM header serves as an input key to output the input side VPN number (303). As an input side ATM header that serves as an input key, VPI
/ LPI (Cell of Priori) indicating packet transfer priority in addition to / VCI (301)
ty) bit (302) may be used as a key. In addition to the in-device VPN number (304), the input side VPN number for general use in the device is QoS (Quality of Ser
A field (305) indicating vice) may be provided. Further, a table for mapping CLP and QoS may be provided independently of this table for VPN identification.

FIG. 14 shows an embodiment of the lower layer processing unit (IP capsule) (54). ISP
2 terminates the physical layer in the physical layer processing unit (170), and then terminates the capsule header in the capsule layer reception processing unit (171). At this time, the terminated capsule header is sent to the VPN number assigning unit (172) together with the IP bucket. The VPN number assigning unit (172) uses the V used for identifying the VPN in the device.
A PN number is generated from the ATM header. At this time, the receiving side VPN number table (17
3) is used. And this VPN number and IP packet are the packet processing part IF
It is transferred to the packet layer processing unit via (154).

FIG. 15 shows a configuration example of the receiving side VPN number table (173). This table is composed of a pair of an input side capsule header (310) and an input side VPN number (303). The input side ATM header serves as an input key and the input side VPN.
The number (303) is output. As an input side IP capsule header serving as an input key, in addition to the source address (311) of the capsule header, a TOS (Type of Service) field (302) indicating a packet transfer priority may be used as a key. And the VPN number on the input side that is used for general purposes in the device is the VPN number in the device (304)
In addition, a field (305) indicating QoS may be provided.

Further, a table for mapping ToS and QoS may be provided independently of this table for VPN identification.

The VPN number on the input side (303) by the method described with reference to FIGS.
The processing when the IP packet reaches the packet layer processing unit (52) will be described with reference to FIG. Via the lower layer processing unit (180), the input side VPN number (30
4) When the route search / VPN processing unit (181) receives the IP packet, the IP header and the input side VP are used here using the route search / VPN table (182).
Route search and output side VPN number are determined using both N numbers as keys. As a result, the output route, the output side VPN number, and the IP packet are sent to the core switch via the core switch IF and reach the desired packet layer processing unit.

FIG. 17 shows a configuration example of the route search / VPN table. A search is performed using the input side VPN number (320) and the IP header (323) as input keys, and the output route number (325) and the output side capsule number (326) are output. The output route number (326) is an in-device identifier for transferring a packet to a desired interface by the core switch and others, and the output side capsule number (326) is assigned a capsule header in the lower layer processing unit on the output side It is an in-device identifier for the capsule header for The output side capsule number (326) may be provided with QoS (328) in addition to the capsule number (327) to perform priority control.

Next, processing in the transmission direction will be described. A processing example of the packet layer processing unit (52) will be described with reference to FIG. When the output side capsule number (326) and the IP packet are received via the core switch IF (184), these pieces of information are transferred to the lower layer processing units (53, 54) via the lower layer processing unit IF.

The operation of the lower layer processing unit (ATM) (53) will be described with reference to FIG. In the lower layer processing unit (ATM) (53), the output side capsule number (326) and I are sent from the packet layer processing unit (52) via the packet layer processing unit IF (159).
P packet is received. Next, the ATM header determination unit (157) generates an ATM header corresponding to the capsule header from the output side capsule number (326) using the header generation table (158). The ATM header and IP packet generated in this way are transformed into ATM cells by the ATM layer transmission processing unit (156) and transmitted to the ISP1 network through the physical layer transmission processing unit (155).

FIG. 18 shows the configuration of the header generation table. The output side ATM header is output using the output side capsule number as a key. Thereby, the output side ATM header can be obtained from the output side capsule number.

Similarly, the operation of the lower layer processing unit (IP capsule) (54) will be described with reference to FIG. The lower layer processing unit (IP capsule) (54) receives the output side capsule number (326) and the IP packet from the packet layer processing unit (52) via the packet layer processing unit IF (159). Next, a capsule header determination unit (177)
Generates an IP capsule header and an output MAC address corresponding to the capsule header from the output capsule number (326) using the header generation table (178). The IP capsule header, the output side MAC address, and the IP packet generated in this way are encapsulated by the capsule layer transmission processing unit (176) and transmitted to the ISP1 network through the physical layer transmission processing unit (175).

FIG. 19 shows the configuration of the header generation table. The output-side IP capsule header and the output-side MAC address are output using the output-side capsule number as a key.

An example of the configuration of the interwork router device has been described above. In this embodiment, the input side,
An example in which the input-side VPN number (320) and the output-side capsule number (326) that are unified internally is used for each process on the output side is shown. However, the input key of the route search / VPN table may be an input side capsule header, or an output side capsule header may be directly generated as an output.

The table shown in this embodiment is a logical table, and as a table search method, an address is output using a search algorithm typified by a tree structure,
A method of obtaining a desired output may be employed, or a configuration using CAM or a method of sequentially searching a table may be employed.

FIG. 23 shows an interface for issuing an instruction from the NMS to the apparatus for setting the table of this embodiment. The agent is installed in the control unit 50.
(gement Information Base) An example of composition is shown. Input capsule header Entry (
500) is an MIB for setting the receiving side VPN table shown in FIG.
Similarly, the VPN cross-connect entry (501) is the route search / V shown in FIG.
This is an MIB for setting the PN table (182). Similarly, the output side capsule header Entry (502) is an example of the configuration of the header generation table. These MI
The information set in B is set from the NMS to the control unit (50), and the control unit (
50) sets a table in each part in the interwork router.

Up to this point, the VPN interworking has been described focusing on the device configuration.
An application example of the interwork router in the network will be described with reference to FIGS.

FIG. 20 shows an example in which two ISPs are connected via two interwork routers owned by each ISP. Encapsulation between two interwork routers (10
Each VPN is identified by 3b). In each interwork router (10a, 10b), as explained in FIG.
Routing processing is performed by a combination of the capsule header (103a, 103b, 103c) and the IP address.

FIG. 21 shows an example in which two ISPs have their own interwork routers and are connected via IX that performs layer 3 processing. Each interwork router and IX are configured to identify each VPN by encapsulation (103b). In the interwork router (10a), IX (10c), and the interwork router (10b), as described up to FIG. 19, forwarding processing is performed by the combination of the capsule header (103a, 103b, 103c) and the IP address.

FIG. 22 shows that two ISPs have their respective interwork routers and two ISs.
An example is shown in which P is connected via IX. Here, IX is composed of a layer 2 device that does not perform layer 3 processing. Also in this case, each VPN is identified between each interwork router and IX by encapsulation (103b). Interwork router (10a) and interwork router (10b)
), As described up to FIG. 19, the capsule headers (103a, 103b,
103c) and the IP address are used for forwarding processing. IX performs forwarding by layer 2 forwarding.

In the present invention, the VPN connection method between a plurality of ISPs has been described. However, even when there are a plurality of encapsulation areas in the same ISP,
It is necessary to connect the PN. Even in that case, the VPN can be connected by the method described in the present invention.

It is a conceptual diagram of the interwork router operation | movement by this invention. It is the figure explaining the interwork system between several ISP in the case of using the conventional router. It is the figure explaining operation | movement of the interwork router by this invention using the protocol stack. It is a flowchart explaining the ISP interwork processing system by the conventional router. It is a flowchart explaining the operation | movement of the interwork router by this invention. It is a flowchart explaining the operation | movement of the interwork router by this invention. It is the figure explaining the connection form of the MPLS network by this invention and an IP encapsulation network using a protocol stack. It is a figure explaining ATM cell conversion of the IP packet by RFC1483. It is a figure explaining the IP packet format by RFC791. It is a figure explaining the structure of the IP tunnel packet by RFC1853. It is a figure explaining one structural example of the interwork router by this invention. It is a figure explaining 1 structural example of the lower layer process part of the interwork router by this invention. It is a figure explaining the structural example of the receiving side VPN number table in the lower layer process part by this invention. It is a figure explaining 1 structural example of the lower layer process part of the interwork router by this invention. It is a figure explaining the structural example of the receiving side VPN number table in the lower layer process part by this invention. It is a figure explaining 1 structural example of the packet layer process part of the interwork router by this invention. It is a figure explaining the structural example of the route search VPN table in the packet layer process part by this invention. It is a figure explaining the structural example of the header production | generation table in the lower layer process part by this invention. It is a figure explaining the structural example of the header production | generation table in the lower layer process part by this invention. It is a figure explaining the example of 1 application in the network of the interwork router by this invention. It is a figure explaining the example of 1 application in the network of the interwork router by this invention. It is a figure explaining the example of 1 application in the network of the interwork router by this invention. This is an interface for issuing an instruction from the NMS to the apparatus for setting the table of this embodiment.

Explanation of symbols

2 ... ISP network, 3 ... edge node, 10 ... interwork router device, 50 ...
Control unit 51 ... Core switch 52 ... Packet layer processing unit 53 ... Lower layer processing unit (ATM) 54 ... Lower layer processing unit (IP capsule) 152 ... VPN
Number assignment unit, 153... Reception side VPN number table, 157... ATM header determination unit, 158... Header generation table, 172... VPN number assignment unit, 173.
PN number table, 177 ... capsule header determination unit, 178 ... header generation table.

Claims (22)

From the first network including the first virtual closed network to the second network including the plurality of second virtual closed networks, the upper layer header information indicating the destination and the first virtual closed network for configuring the first virtual closed network A data transfer apparatus for transferring data to which one lower layer header information is added,
A data processing unit for generating second lower layer header information for configuring one of the plurality of second virtual closed networks from the upper layer header information and the first lower layer header information;
A data transfer apparatus comprising a transmission unit that transmits the data by adding the second lower layer header information to the data. The data transfer device according to claim 1, wherein
A data transfer apparatus further comprising a processing unit that replaces the first lower layer header information with the second lower layer header information. The data transfer device according to claim 1, wherein
A data transfer apparatus further comprising a route determination unit that determines a transmission route of the data to the second network from the upper layer header information and the first lower layer header information. The data transfer device according to claim 1, wherein
A data transfer apparatus, wherein the data is an IP packet. From the first network including the first virtual closed network to the second network including the plurality of second virtual closed networks, the upper layer header information indicating the destination and the first virtual closed network for configuring the first virtual closed network A data transfer method for transferring data to which one lower layer header information is added,
Receiving the data;
Generating second lower layer header information for configuring one of the plurality of second virtual closed networks from the upper layer header information and the lower layer header information;
A data transfer method comprising a step of transmitting the data with the second lower layer header information added thereto. The data transfer method according to claim 5, wherein
A data transfer method further comprising the step of replacing the first lower layer header information with the second lower layer header information. The data transfer method according to claim 5, wherein
A data transfer method further comprising a step of determining a transmission route of the data to the second network from the upper layer header information and the first lower layer header information. The data transfer method according to claim 5, wherein
A data transfer method, wherein the data is an IP packet. A data transfer system,
A first network including a first virtual closed network;
A data transfer device for transferring data from the first network to the second network;
In the data, upper layer header information indicating a destination and first lower layer header information for constituting the first virtual closed network are added,
The data transfer device generates second lower layer header information for constituting one of the plurality of second virtual closed networks from the upper layer header information and the first lower layer header information. And transmitting the data with the second lower layer header information added thereto. The data transfer system according to claim 9, wherein
The data transfer system, wherein the first lower layer header information is replaced with the second lower layer header information. The data transfer system according to claim 9, wherein
The data transfer system, wherein the data transfer system determines a transmission route of the data to the second network from the upper layer header information and the first lower layer header information. From the first network including the first virtual closed network to the second network including the plurality of second virtual closed networks, the upper layer header information indicating the destination and the first virtual closed network for configuring the first virtual closed network A data transfer apparatus for transferring data to which one lower layer header information is added,
An index generation unit that generates an index from the upper layer header information and the first lower layer header information;
A data processing unit that generates second lower layer header information for configuring one of the plurality of second virtual closed networks from the index;
A data transfer apparatus comprising a transmission unit that transmits the data by adding the second lower layer header information to the data. The data transfer device according to claim 12, wherein
A data transfer apparatus further comprising a processing unit that replaces the first lower layer header information with the second lower layer header information. The data transfer device according to claim 12, wherein
A data transfer apparatus further comprising a route determination unit that determines a transmission route of the data to the second network from the upper layer header information and the first lower layer header information. The data transfer device according to claim 12, wherein
A data transfer apparatus, wherein the data is an IP packet. From the first network including the first virtual closed network to the second network including the plurality of second virtual closed networks, the upper layer header information indicating the destination and the first virtual closed network for configuring the first virtual closed network A data transfer method for transferring data to which one lower layer header information is added via first and second data transfer devices,
Receiving the data from the first network in the first data transfer device;
Generating an index from the upper layer header information and the first lower layer header information in the first data transfer device;
In the first data transfer device, adding the index to the data and transmitting to the second data transfer device;
Receiving the indexed data from the first data transfer device in the second data transfer device;
In the second data transfer device, generating second lower layer header information for configuring one of the plurality of second virtual closed networks from the index;
A data transfer method comprising the step of adding the second lower layer header information to the data and transmitting it to the second network in the second data transfer device. The data transfer method according to claim 16, comprising:
Replacing the first lower layer header information with the index in the first data transfer device;
The data transfer method further comprising the step of replacing the index with the second lower layer header information in the second data transfer device. The data transfer method according to claim 16, comprising:
The data transfer method further comprising the step of determining a transmission route of the data to the second network from the upper layer header information and the index in the second data transfer device. The data transfer method according to claim 16, comprising:
A data transfer method, wherein the data is an IP packet. A data transfer system,
A first network including a first virtual closed network;
A second network including a plurality of second virtual closed networks;
A first data transfer device for receiving data from the first network;
A second data transfer device for transferring the data to the second network;
In the data, upper layer header information indicating a destination and first lower layer header information for constituting the first virtual closed network are added,
The first data transfer device generates an index from the upper layer header information and the first lower layer header information, adds the index to the data, and transmits the data to the second data transfer device.
The second data transfer device generates second lower layer header information for configuring one of the plurality of second virtual closed networks from the upper layer header information and the index, A data transfer system, wherein the data is transmitted with the second lower layer header information added thereto. The data transfer system according to claim 20, wherein
The first data transfer device replaces the first lower layer header information with the index,
The data transfer system, wherein the second data transfer device replaces the index with the second lower layer header information. The data transfer system according to claim 21, wherein
The second data transfer apparatus determines a transmission route of the data to the second network from the higher layer header information and the index.

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