JP2002185538A - System for switching connection between closed area networks - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for switching closed area networks capable of effectively connecting between the closed area networks by dynamically switching a correspondence between the closed area networks in an access server and the closed area networks in a backbone. SOLUTION: This system comprises an access server 13 and a backbone 17 having one or more closed area networks; a closed area networks connector 31 for connecting and disconnecting between the closed area network of the access server 13 and the closed area network of the backbone 17; and a closed area network group control server 16 in which an enable or disable of connection is determined based on a connection request from an access user 11, and when the connection is possible, a closed area network connector 31 is controlled to connect to a predetermined closed area network, and an enable or disable of disconnection is determined based on a disconnection request from the access user 11. When the disconnection is possible, the closed area network connector 31 is controlled to disconnect between the closed area networks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet network capable of forming a plurality of closed networks in computer communication for packetizing and transmitting data. The present invention also relates to a closed network connection switching method for connecting closed networks, which is present in each packet network.

[0002]

2. Description of the Related Art In recent years, IP (Internet Pro
Tocol), a closed network is constructed using a packet communication method, and while reducing the cost, virtual closed area network technology that guarantees the communication quality required for intra-enterprise communication such as security such as communication confidentiality is required. Is attracting attention. When interconnecting each closed network (group) between multiple carriers,
Fixed networks are fixedly interconnected in advance. Also, an access server (NAS: Network Access S) that accommodates a packet communication host using access means such as dial-up or xDSL.
server), a device capable of accommodating a plurality of closed networks is installed in the apparatus, and the closed network existing in the backbone and the closed network existing in the access server are interconnected, so that the access can be shared by the plurality of closed networks. The server may provide remote access services.

[0003] As a prior art example, Fig. 4 shows a configuration of an implementation example using an access server capable of accommodating this closed area network.

In FIG. 4, reference numeral 11 denotes an access user (PC),
12 is an access network (Access) such as POTS, ISDN or xDSL, 13 is an access server (NAS),
14 is a closed network (VPN # 1 to 4) in the access server,
15 is a control unit (C) in the access server, 16 is a closed network group control server (AAS), and 17 is a backbone (BB).
N) and 18 are closed networks in the backbone (VPN @ a to
d) and 19 show a control unit (C) in the backbone.

[0005] A connection / disconnection sequence will be described with reference to FIG.

[0006] When the access user 11 initiates a connection, the access user 11 exchanges PPP (Po) with the access server 13 before transmitting / receiving data to / from the closed network 18 in the backbone 17.
A session is established by, for example, an int-to-point protocol. At this time, the access user 11 transmits an authentication request including a user identifier, a closed network identifier, a password, and the like to the closed network group control server 16 via the access server 13. Closed network group control server 1
6 performs an authentication process based on the authentication information.

[0007] When the connection is not permitted, the closed network group control server 16 sends the access user 1 via the access server 13.
1 returns an authentication rejection response, and the establishment of this session fails (connection failure).

When the connection is permitted, the closed network group control server 16 sets new route information relating to this session in the backbone 17, and further, based on a setting response from the backbone 17 to the closed network group control server 16, the closed network group control server 16 The control server 16 returns an authentication acceptance response to the access user 11 via the access server 13. The authentication acceptance response includes information such as a closed network identifier and an address used by the access user 11. As a result, communication from the access user 11 to the closed networks 14 and 18 in the access server 13 and the backbone 17 becomes possible, and communication is started.

When the access user 11 starts disconnection,
A disconnection request is transmitted to the closed network group control server 16 via the access server 13. The closed network group control server 16 deletes the route information for the session set in the closed network 18 in the backbone, and sends a deletion response from the backbone 17 to the closed network group control server 16. The disconnection response is returned to the access user 11 via the access server 13. The access server 13 deletes information on this session from the closed network 14 within the access server. As a result, the disconnection of this session is completed.

In this system, the access server 13 and the closed networks 14 and 18 inside the backbone 17 are fixedly associated with each other and connected, so that the access user 11 without direct access means to the backbone 17 is provided.
Is the closed network 1 in the backbone via the access server 13
8 can be communicated with. However, this closed network 1
Since the correspondence between 4 and 18 is fixed, the same number of closed networks as in the backbone 17 or the same number as the number of closed networks in the backbone 17 permitted to connect via the access server 13 are provided in the access server 13. It is necessary to keep it.

[0011]

As described above, when the closed network in the access server 13 and the closed network in the backbone 17 are fixedly connected, it is necessary to match the numbers of the respective internal closed networks. Becomes Alternatively, it is necessary to provide the same number of closed networks in the access server 13 as the number of closed networks in the backbone 17 for which connection is permitted via the access server 13. For example, the access server 13
When the number of closed networks that can be held inside is smaller than the number of closed networks that can be held inside the backbone 17, the number of closed networks that simultaneously establish sessions between the access server 13 and the backbone 17 is small, and the access server must be installed more than necessary. There was a problem.

The present invention has been made in view of the above circumstances, and dynamically switches the correspondence between the closed network in the access server and the closed network in the backbone (changes the correspondence between the closed network in the access server and the closed network in the backbone). It is an object of the present invention to provide a connection switching method between closed networks that can efficiently connect closed networks.

[0013]

In order to achieve the above object, a connection switching system between closed networks according to the present invention comprises a plurality of closed networks having at least one closed network, and a closed network of one of the closed networks. And a closed network connection device for connecting and disconnecting the closed network of the other closed network group, and a connection request is determined based on a connection request from the closed network or the closed network user, and if the connection is possible, the closed network connection is performed. By controlling the device, connected to a predetermined closed network, based on a disconnection request from a closed network or a closed network user, determine whether disconnection is possible, if disconnectable, controlling the closed network connection device, And a closed network group control server for disconnecting the connection between the closed networks.

The present invention also relates to the closed-network connection switching method, wherein the connection or disconnection is performed by a closed network of one closed network group and a closed network of the other closed network group in response to a request from a closed network or a closed network user. It is characterized in that the correspondence can be dynamically switched and performed.

Further, the present invention is characterized in that, in the connection switching method between closed networks, a plurality of closed networks or closed networks are accommodated in one device.

Further, according to the present invention, in the above-mentioned connection switching system between closed networks, one of the closed networks is dial-up or xD.
It is a session connection type access server such as SL, and the other closed network group is a backbone.

Further, in the present invention, in the closed network connection switching method, the closed network group control server includes means for counting the number of connected sessions of each closed network in the session connection type access server, whereby the closed network is provided. It is characterized in that the closed network group control server automatically determines the connection / disconnection trigger of the inter-connection.

The present invention also relates to the closed-area network connection switching method, wherein the closed-area network in the backbone having the connected session is provided as means for counting the number of connected sessions of each closed network in the session connection type access server.
Correspondence of the closed network in the session connection type access server,
A management table for recording the number of connected sessions is provided in the closed network group control server.

According to the present invention, a closed network group control server and a closed network connection device are provided to enable dynamic connection of the closed networks, and a connection between the closed networks in each closed network group. Is performed dynamically, the number of closed networks does not need to be the same, and if one closed network group is accommodated in the access server, the number of sessions is counted by the closed network group control server. This is different from the prior art in that the closed network group control server can automatically determine and establish / disconnect the interconnected network between the closed networks.

[0020]

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

(First Embodiment) FIG. 1 shows a system configuration of an embodiment according to the present invention. In FIG. 1, reference numeral 11 denotes an access user (PC), and 12 denotes an access network such as POTS, ISDN, or xDSL. (Access), 13 is an access server (NAS), 14 is a closed network (VPN # 1 to 4) in the access server, 15 is a control unit (C) in the access server, and 16 is a closed network group control server (AAS) , 17
Is a backbone (BBN), 18 is a closed network (VPN # a-d) in the backbone, 19 is a control unit (C) in the backbone, 31 is a closed network connection device (SW), and 32 is a closed network connection device. The control unit (C) is shown. FIG. 2 shows an example of an embodiment of the present invention, in which the closed network group control server 16 determines the interconnection relationship between the closed networks 14 and 18 in the access server 13 and the backbone 17 and the existing connection as shown below. 9 shows a management table used for counting the number of sessions.

The connection / disconnection sequence will be described with reference to FIG.

When starting access, the access user 11 establishes a session with the access server 13 by PPP or the like before transmitting / receiving data to / from the closed network 18 in the backbone 17. At this time, the access user 11 transmits an authentication request including a user identifier, a closed network identifier, a password, and the like to the closed network group control server 16 via the access server 13. Closed network group control server 1
6 performs an authentication process based on the authentication information.

If the connection is not permitted, the closed network group control server 16 sends the access user 1 via the access server 13.
1 returns an authentication rejection response, and the establishment of this session fails (connection failure).

When permitting the connection, the closed network 18 in the backbone for permitting the connection is already connected to the closed network group control server 1.
It is checked whether or not it is registered in the management table as shown in FIG. If it exists, the number of sessions connected to the corresponding closed network in the management table is increased. If it does not exist, the closed network group control server 16 adds the corresponding closed network entry to the management table, and interconnects the closed network 14 in the access server and the closed network 18 in the backbone to the closed network connection device 31. The setting is performed, and the closed network connection device 31 returns a setting response to the closed network group control server 16.

After that, the closed network group control server 16 sets new route information on this session in the backbone 17, and from the backbone 17, the closed network group control server 16
When the setting response is received, the closed network group control server 16 returns an authentication acceptance response to the access user 11 via the access server 13. The authentication acceptance response includes information such as a closed network identifier and an address used by the access user 11. As a result, communication from the access user 11 to the closed networks 14 and 18 in the access server 13 and the backbone 17 becomes possible, and communication starts.

When the access user 11 starts disconnection,
A disconnection request is transmitted to the closed network group control server 16 via the access server 13. The closed network group control server 16 determines whether this session is the last session connected to the closed network 18 of the corresponding backbone 17, that is, if this session is disconnected, there is no session connected to the corresponding closed network 18. Whether it is calculated using a management table as shown in FIG. 2 and checked. If it is the last session, the closed network group control server 16 deletes the entry of the corresponding closed network 18 from the management table and sets the closed network 14 in the access server and the closed network in the backbone set in the closed network connection device 31. Then, the interconnection between the network 18 is disconnected, and a disconnection response is returned from the closed network connection device 31 to the closed network group control server 16.

Thereafter, the closed network group control server 16 deletes the path information for this session set in the closed network 18 in the backbone, and a deletion response is returned from the backbone 17 to the closed network group control server 16. The closed network group control server 16 returns a disconnection response to the access user 11 via the access server 13. The access server 13 deletes information on this session from the closed network 14 within the access server. As a result, the disconnection of this session is completed.

Thus, the number of sessions connected to each closed network is counted, and when establishing the first connection session to a certain closed network, the access server 13 and the closed network of the backbone 17 are interconnected, and the connection is established to a certain closed network. Access server 13 when disconnecting the last connection session of
The connection between the access server 13 and the backbone 17 is efficiently used by automatically switching the connection when the session is connected or disconnected, such as opening the connection between the access server 13 and the backbone 17. Becomes possible.

In the embodiment of the present invention, the access server 13, the closed network group control server 16, the closed network connecting device 31, and the backbone 17 are described as separate devices, but some of them are in the same device. Even if this is realized, it is possible to implement without losing generality. For example, the backbone and the access server are connected to a virtual circuit (V
C: When a technology that can use virtual connection is used, the access server and / or backbone (or both) and the input / output VC number information are set and changed to provide a closed network required in the embodiment of the present invention. It is possible to realize the connection device function.

[0031]

As described above, according to the present invention, it is possible to dynamically connect a closed network (change the correspondence relationship between the closed networks). It is possible to interconnect closed networks having different numbers of closed networks without adding unnecessary devices. In particular, regarding the connection between the closed network in the access server and the closed network in the backbone, the number of connection sessions to each closed network is counted, and when the first connection session to a certain closed network is established, the access server and the backbone are connected. When a closed network is interconnected and the last connection session to a closed network is disconnected, the connection between the access server and the backbone closed network is automatically opened and the session is disconnected and triggered. By switching the connection, the closed network of the access server and the backbone can be used efficiently.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing an embodiment of the present invention.

FIG. 2 is a sequence diagram showing a connection / disconnection operation in the embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a management table in the embodiment of the present invention.

FIG. 4 is a configuration explanatory view showing a conventional connection switching method between closed networks.

FIG. 5 is a sequence diagram showing a connection / disconnection operation in FIG. 4;

[Description of Signs] 11 Access User (PC) 12 Access Network (Access) such as POTS, ISDN, xDSL 13 Access Server (NAS) 14 Closed Network (VPN # 1 to 4) in Access Server 15 Control in Access Server Unit (C) 16 Closed network group control server (AAS) 17 Backbone (BBN) 18 Closed network in backbone (VPN #a to d) 19 Control unit in backbone (C) 31 Closed network connection device (SW) 32 Closed Control unit (C) in network connection device

Claims (6)

[Claims] 1. A closed network connection device for connecting / disconnecting a plurality of closed networks having one or more closed networks, a closed network of one closed network and a closed network of the other closed network, and a closed network. Or, based on a connection request from a closed network user, determine whether connection is possible, if the connection is possible, control the closed network connection device, connect to a predetermined closed network, from the closed network or from a closed network user A closed network group control server that determines whether or not disconnection is possible based on the disconnection request and, when disconnection is possible, controls the closed network connection device to disconnect the connection between the closed networks; Network connection switching method. 2. The closed network connection switching method according to claim 1, wherein the connection or disconnection is performed by a closed network or a closed network user in response to a request from a closed network or a closed network user, and the closed network of another closed network group. A method of switching connections between closed networks, characterized in that the correspondence can be dynamically switched. 3. The connection switching method between closed networks according to claim 1 or 2, wherein a plurality of closed networks or a group of closed networks and a closed network connection device are accommodated in one device. method. 4. The closed network connection switching system according to claim 1, wherein one closed network group is a session connection type access server and the other closed network group is a backbone. Connection switching method between closed networks. 5. The closed network connection switching method according to claim 4, wherein the closed network group control server is provided with means for counting the number of connected sessions of each closed network in the session connection type access server. A closed network connection switching method, characterized in that the closed network group control server automatically determines the connection / disconnection timing of the network connection. 6. The connection switching method between closed networks according to claim 5, wherein, as means for counting the number of connected sessions of each closed network in the session connection type access server,
A closed network in the backbone having a connected session, a closed network corresponding to the closed network in the session connection type access server, and a management table for recording the number of connected sessions in the closed network group control server. Connection switching method.