JP3808471B2 - Network and router apparatus and address notification method used therefor - Google Patents

Description

  The present invention relates to a network and a router device, and an address notification method used therefor, and more particularly, to a NAT (Network Address Translation) router with a UPnP (Universal Plug and Play) function.

  Conventionally, in this type of NAT router with UPnP function, as shown in FIG. 6, a NAT processing unit 81, a WAN side logical port group 82 composed of WAN (Wide Area Network) side logical ports 821 to 823, a LAN ( (Local Area Network) port 83 and WAN port 84 are provided.

  The WAN-side logical ports 821 to 823 communicate with a plurality of connection destinations (not shown) via the WAN port 84. The NAT processing unit 81 performs NAT (address conversion) between a LAN and a WAN (not shown) (see, for example, Non-Patent Document 1), and transmits a UPnP notification message from the LAN port 83.

  The NAT router 8 can notify the WAN side IP (Internet Protocol) address of the NAT router 8 by becoming a UPnP device (device) to the LAN side host, and the LAN side host can pass through the NAT router 8. It is possible to easily operate an application that was difficult to connect to.

  However, in recent years, broadband services have diversified, and each carrier and ISP (Internet Service Provider) provides users with their own closed network (not shown) in addition to the Internet connection network (not shown). There is a tendency to develop original services.

  The NAT router 8 holds two connections of an Internet connection network and a closed network, and has a function of determining the transfer destination of each packet by routing or the like based on the destination IP address.

  However, in the UPnP device function, a template for notifying the correspondence relationship between the destination host and the connection destination network is not prepared, and any connection destination among a plurality of connection destinations from the UPnP control point (Control Point) of the LAN side host is prepared. There is no way to determine what to use.

“Traditional IP Network Address Translator (Traditional NAT) [RFC (Request for Comments) 3022, January 2001]

  However, since the conventional NAT router with UPnP function does not have a function of notifying destination information to UPnP, it is impossible to determine which WAN interface is used in actual communication from the UPnP control point. There is a problem.

  Further, in the conventional NAT router with UPnP function, there are many implementations in which the WAN connection destination using the UPnP function is fixedly set, and therefore, a different connection destination cannot be targeted for UPnP at each UPnP control point. There is.

  That is, the UPnP control point acquires the WAN side IP address using UPnP, cannot issue a request for port mapping or the like to the UPnP device, and can use UPnP only in one of the networks. Can not.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems and provide a network and router apparatus that can simultaneously use the UPnP function for a plurality of connection destinations, and an address notification method used for them.

The network according to the present invention performs a UPnP (Universal Plug and Play) device function that holds a plurality of connection destinations on a WAN (Wide Area Network) side, and performs address conversion between the WAN side and a LAN (Local Area Network) side. A network including a router device having a NAT (Network Address Translation) function to perform,
A plurality of WAN logical ports for receiving packets received by the WAN interface according to their contents;
LAN logical ports arranged corresponding to the plurality of WAN logical ports;
The router apparatus includes means for associating the WAN side logical port with the LAN side logical port and notifying each LAN side logical port as an independent UPnP device.

The router device according to the present invention includes a UPnP (Universal Plug and Play) device function that holds a plurality of connection destinations on a WAN (Wide Area Network) side, and address conversion between the WAN side and a LAN (Local Area Network) side A router device having a NAT (Network Address Translation) function for performing
A plurality of WAN logical ports for receiving packets received by the WAN interface according to their contents;
LAN logical ports arranged corresponding to the plurality of WAN logical ports;
And a means for associating the WAN side logical port with the LAN side logical port and notifying each LAN side logical port as an independent UPnP device.

An address notification method according to the present invention includes a UPnP (Universal Plug and Play) device function that holds a plurality of connection destinations on a WAN (Wide Area Network) side, and an address between the WAN side and a LAN (Local Area Network) side. An address notification method for notifying an address of the UPnP device in a network including a router device having a NAT (Network Address Translation) function for performing conversion,
A plurality of WAN logical ports that receive packets received by the WAN interface according to their contents are associated with LAN logical ports arranged corresponding to the plurality of WAN logical ports, and are independent for each LAN-side logical port. Notification as a UPnP device.

  That is, the router device of the present invention includes a UPnP device in a NAT (Network Address Translation) router having a UPnP (Universal Plug and Play) device (device) function that holds a plurality of connection destinations on a WAN (Wide Area Network) side. A host having a UPnP control point (Control Point) function to be managed can select a connection destination using UPnP.

  More specifically, the router device of the present invention receives a packet received by the WAN logical port at the WAN interface according to the content of each packet. Also, the router device of the present invention transmits a packet requested to be transmitted from the NAT processing unit using the WAN side interface.

  The router device of the present invention has the same number of LAN (Local Area Network) side logical ports as the WAN side logical port, the LAN side logical port holds the IP address of the same subnet, and performs NAT processing on packets transmitted and received by the LAN interface Send and receive.

  The NAT processing unit has a one-to-one correspondence with the LAN side logical ports prepared for the same number of WAN side logical ports held on the WAN side, and whether there is one logical port at the connection destination of each LAN side logical port. Behave as if there are a plurality of UPnP devices with respect to the UPnP control point on the LAN side.

  As described above, in the router device of the present invention, a LAN interface is prepared for each logical port of the WAN side interface, and the LAN side acts as if it is a plurality of UPnP devices. Since the UPnP control point existing in the local host has a routing table in its own host, it is possible to select the UPnP to be used from the local host.

  The plurality of connection destinations connected to the WAN side logical port are an Internet connection network or a closed network provided by a carrier or ISP (Internet Service Provider).

  The LAN side logical port has a one-to-one correspondence with the WAN side logical port, but holds one IP address of the LAN side IP subnet. The NAT processing unit notifies the LAN side network of the UPnP device. However, since the notification is performed using the IP address of each LAN side logical port, the UPnP control point detects a plurality of UPnP devices and determines the next hop. It becomes possible to obtain a plurality of IP addresses.

  Generally, an IP host maintains a routing table and manages a destination address and a next-hop IP address in combination, and can use different next-hop routers. That is, the UPnP control point can determine which UPnP device should be used by the routing table.

  Thus, in the router device of the present invention, UPnP devices are notified for each WAN connection destination, so that the host of the UPnP control point on the LAN side can use a plurality of connection destination UPnP devices.

  In addition, since the router apparatus of the present invention notifies a plurality of UPnP devices for each WAN side connection destination, each PC (personal computer) is different when there are a plurality of UPnP control points on the LAN side. The UPnP function can be used at the connection destination.

  Further, since the router device of the present invention constantly notifies the UPnP device for each of the plurality of WAN side connection destinations, even when the UPnP function can be used only by one connection destination, the setting of the NAT router is possible. Can be selected on the PC side without changing.

  With the configuration and operation described below, the present invention provides an effect that the UPnP function can be used simultaneously for a plurality of connection destinations.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a router device according to an embodiment of the present invention. Referring to FIG. 1, a router apparatus according to an embodiment of the present invention includes a NAT (Network Address Translation) having a UPnP (Universal Plug and Play) device (device) function that holds a plurality of connection destinations on a WAN (Wide Area Network) side. Router 1.

  The NAT router 1 includes a NAT processing unit 2, a LAN side logical port group 3 including LAN (Local Area Network) logical ports 31 to 33, a WAN side logical port group 4 including WAN logical ports 41 to 43, and a LAN port 5. And a WAN port 6.

  The WAN logical ports 41 to 43 receive the packets received at the WAN port 6 at the respective ports according to the contents. Further, the WAN side logical ports 41 to 43 use the WAN port 6 to transmit the packet requested to be transmitted from the NAT processing unit 2.

  The same number of LAN side logical ports 31 to 33 as the WAN side logical ports 41 to 43 exist, and hold IP (Internet Protocol) addresses of the same subnet. Further, the LAN side logical ports 31 to 33 transmit / receive packets transmitted / received by the LAN port 5 to / from the NAT processing unit 2.

  The NAT processing unit 2 has a plurality of WAN side logical ports 41 to 43 held on the WAN side corresponding to the LAN side logical ports 31 to 33 prepared in the same number as the LAN side logical ports 31 to 33. Whether there are multiple UPnP devices for the LAN side UPnP control point (Control Point) (not shown) that manages UPnP devices. Behave like

  As described above, in this embodiment, the LAN side logical ports 31 to 33 are prepared for the WAN side logical ports 41 to 43, and the LAN side behaves as if it is a plurality of UPnP devices. Since the UPnP control point existing on the LAN side has a routing table in its own host, UPnP to be used can be selected from the own host.

  A plurality of connection destinations connected to the WAN side logical ports 41 to 43 are an Internet connection network (not shown) or a closed network (not shown) provided by a carrier or ISP (Internet Service Provider). The LAN side logical ports 31 to 33 correspond to the WAN side logical ports 41 to 43 on a one-to-one basis, but each holds one IP address of a LAN side IP subnet (not shown).

  The NAT processing unit 2 notifies the LAN side network of UPnP devices. However, since the notification is performed using the IP addresses of the LAN side logical ports 31 to 33, the UPnP control point detects a plurality of UPnP devices. A plurality of next-hop IP addresses can be obtained.

  In general, an IP host can maintain a routing table and manage a destination address and a next-hop IP address in combination, and can use different next-hop routers. That is, the UPnP control point can determine which UPnP device should be used by the routing table.

  FIG. 2 is a block diagram for explaining the operation of the router device according to the embodiment of the present invention. In FIG. 2, the NAT processing unit 2 associates the WAN side logical ports 41 to 43 with the LAN side logical ports 31 to 33 on a one-to-one basis, and notifies UPnP notification to the LAN side network (not shown) for each combination. Against.

  The WAN side logical ports 41 to 43 hold IP addresses of different subnets, respectively, and serve as an interface for packet transmission / reception performed by the NAT processing unit 2.

  Each of the LAN side logical ports 31 to 33 holds an IP address of the same subnet and serves as an interface for packet transmission / reception performed by the NAT processing unit 2.

  The NAT processing unit 2 transmits and receives packets via the WAN side logical ports 41 to 43 and the LAN side logical ports 31 to 33 existing for each connection destination. The NAT processing unit 2 associates the WAN side logical ports 41 to 43 with the LAN side logical ports 31 to 33, and notifies the logical ports of the LAN side logical ports 31 to 33 as independent UPnP devices. The connections of the WAN side logical ports 41 to 43 are associated with the LAN side logical ports 31 to 33.

  The UPnP notification messages transmitted from the LAN side logical ports 31 to 33 describe the connections of the associated WAN side logical ports 41 to 43, respectively.

  In the above description, the NAT processing unit 2 is well known to those skilled in the art and is not directly related to the present invention. In the above description, the WAN side logical ports 41 to 43 and the LAN side logical ports 31 to 33 do not have to be three, and any number of configurations can be used as long as there are two or more. Moreover, although there is only one LAN side port 5 and WAN side port 6, there may be a plurality of each.

  FIG. 3 is a flowchart showing an initial operation of the NAT router 1 of FIG. The initial operation of the NAT router 1 according to an embodiment of the present invention will be described with reference to FIGS.

  The NAT router 1 holds the WAN side logical ports 41 to 43 (step S1 in FIG. 3), and automatically generates the same number of LAN side logical ports 31 to 33 corresponding thereto (step S2 in FIG. 3). The IP addresses of the WAN side logical ports 41 to 43 are dynamically assigned from the WAN side, or predetermined addresses are assigned. The IP addresses of the LAN side logical ports 31 to 33 are the same IP subnet, and any IP addresses that do not overlap with other hosts may be set by the user.

  The NAT processing unit 2 associates the WAN side logical ports 41 to 43 with the LAN side logical ports 31 to 33 one-to-one, and transmits a UPnP device notification message (step S3 in FIG. 3). This notification message uses different UPnP device IDs for the respective LAN side logical ports 31 to 33, and UPnP sequences of UPnP Discovery, Description, Control, and Eventing are executed with the IP addresses of the respective ports (FIG. 3). Step S4).

  Therefore, a UPnP control point such as a PC (personal computer) (not shown) on the LAN 100 side detects a plurality of UPnP devices.

  FIG. 4 is a block diagram showing a network configuration according to an embodiment of the present invention. In FIG. 4, a network according to an embodiment of the present invention is configured by connecting a LAN 100, a LAN 200, a closed network A 300, and a closed network B 400 to a NAT router 1, and the LAN 100 is connected to the LAN side of the NAT router 1 on the Internet 200 side. The closed network A300 and the closed network B400 are connected to the WAN side of the NAT router 1, respectively.

  Further, a UPnP control point such as a PC 7 is connected to the LAN 100, and the PC 7 holds a routing table 7a. The routing table 7a includes IP addresses (“172.16.1.0/24”, “172.16.2.0/24”, “default”) of the WAN side network (Internet 200, closed network A300, closed network B400). ) And the next hop IP address ("IP address 1", "IP address 2", "IP address 3").

  Further, since the PC 7 generally has a function of selecting a transmission destination based on the routing table 7a, if the registration is performed in advance using this function, the UPnP operating at the UPnP control point (PC 7). The application can easily determine the UPnP device to be used, and the user can save the trouble of selecting the UPnP device. Further, UPnP applications can communicate using UPnP devices that are desired to be used.

  For example, when a UPnP application that communicates with the closed network A300 in FIG. 3 is executed on the PC 7, the PC 7 that is the UPnP control point looks at the routing table 7a and uses the UPnP device of “IP address 2”. Since it is understood that it is good, it is possible to acquire the WAN side IP address from the UPnP device of “IP address 2” by using the UPnP function or to execute the port mapping function for the closed network A300.

  The specific sequence of UPnP, the NAT, and the port mapping technique are techniques well known to those skilled in the art, and a detailed description thereof will be omitted.

  In this way, in this embodiment, since the UPnP device is notified for each WAN connection destination, the host (PC 7) of the UPnP control point on the LAN 100 side can use a plurality of connection destination UPnP devices. .

  In this embodiment, since a plurality of UPnP devices are notified for each WAN-side connection destination, when there are a plurality of UPnP control points on the LAN side, each of the PCs 7 as UPnP control points is connected separately. The UPnP function can be used first.

  Further, in this embodiment, since a plurality of UPnP devices for each WAN-side connection destination are constantly notified, even when the UPnP function can be used only by one connection destination, the NAT router 1 is set. It can be selected on the PC 7 side without changing.

  FIG. 5 is a block diagram showing a network configuration according to another embodiment of the present invention. The operation of the network according to another embodiment of the present invention will be described with reference to FIG. The basic configuration of the NAT router 1 according to another embodiment of the present invention is the same as that of the NAT router 1 according to the embodiment of the present invention described above. Devised.

  In FIG. 5, the NAT router 1 notifies the route information of the WAN side network (Internet 200, closed network A300, closed network B400) using a routing protocol such as RIP (Route Information Protocol).

  The NAT processing unit (not shown) of the NAT router 1 has a function of notifying route information of the WAN side network (Internet 200, closed network A300, closed network B400) using a routing protocol. On the PC 7 side, for example, there are many hosts having a function capable of obtaining a routing table by a routing protocol such as RIP.

  As described above, in this embodiment, it is not necessary to set the routing table that needs to be set on the PC 7 side, and an effect that the dynamic routing table can be changed is obtained.

  As another embodiment of the present invention, a user manually sets an IP address to be assigned to a LAN side logical port by performing address management using a DHCP (Dynamic Host Configuration Protocol) server on the LAN side. It becomes possible to set automatically without doing.

  The network configuration according to another embodiment of the present invention is equivalent to the configuration shown in FIG. 2, but the NAT processing unit of the NAT router 1 automatically sets the DHCP server function and the IP address of the LAN side logical port. It has a function.

  As described above, in this embodiment, since the setting of the IP address that had to be set on the PC 7 side is automated, there is an effect that the setting on the PC 7 side is simplified. The DHCP server function according to the present embodiment may be any means as long as it is a means for assigning an address to the PC 7 from the NAT router 1 side, such as bootp (bootstrap protocol) or PPPoE (Point to Point Protocol over Ethernet (R)). May be used.

It is a block diagram which shows the structure of the router apparatus by one Example of this invention. It is a block diagram for demonstrating operation | movement of the router apparatus by one Example of this invention. 3 is a flowchart showing an initial operation of the NAT router of FIG. 2. It is a block diagram which shows the structure of the network by one Example of this invention. It is a block diagram which shows the structure of the network by the other Example of this invention. It is a block diagram which shows the structure of the router apparatus by a prior art example.

Explanation of symbols

1 NAT router
2 NAT processing section
3 LAN side logical port group
4 WAN side logical port group
5 LAN port
6 WAN port 31-33 LAN logical port 41-43 WAN logical port 100 LAN
200 Internet 300 Closed network A
400 Closed network B

Claims (15)

A UPnP (Universal Plug and Play) device function that holds a plurality of connection destinations on a WAN (Wide Area Network) side, and a NAT (Network Address Transport Trunk) that performs address conversion between the WAN side and a LAN (Local Area Network) side ) A network including a router device having a function,
A plurality of WAN logical ports for receiving packets received by the WAN interface according to their contents;
LAN logical ports arranged corresponding to the plurality of WAN logical ports;
A network characterized in that the router device has means for associating the WAN side logical port with the LAN side logical port and notifying each LAN side logical port as an independent UPnP device.   The network according to claim 1, wherein the notification unit generates a UPnP message for each corresponding logical port.   3. The network according to claim 1, wherein the WAN logical port connection is associated with the LAN logical port.   4. The network according to claim 1, wherein a host having the UPnP control point function can freely select a connection destination using UPnP.   2. The WAN logical port holds an IP (Internet Protocol) address of a different subnet on the WAN side, and the LAN logical port holds an IP address of the same subnet on the LAN side. 4. The network according to any one of 4. A UPnP (Universal Plug and Play) device function that holds a plurality of connection destinations on a WAN (Wide Area Network) side, and a NAT (Network Address Transport Trunk) that performs address conversion between the WAN side and a LAN (Local Area Network) side A router device with a function,
A plurality of WAN logical ports for receiving packets received by the WAN interface according to their contents;
LAN logical ports arranged corresponding to the plurality of WAN logical ports;
A router device comprising: means for associating the WAN side logical port with the LAN side logical port and notifying each LAN side logical port as an independent UPnP device.   The router device according to claim 6, wherein the notification unit generates a UPnP message for each corresponding logical port.   8. The router device according to claim 6, wherein the WAN logical port connection is associated with the LAN logical port.   9. The router device according to claim 6, wherein a host having the UPnP control point function can freely select a connection destination using UPnP.   7. The WAN logical port holds an IP (Internet Protocol) address of a different subnet on the WAN side, and the LAN logical port holds an IP address of the same subnet on the LAN side. The router device according to any one of 9. A UPnP (Universal Plug and Play) device function that holds a plurality of connection destinations on a WAN (Wide Area Network) side, and a NAT (Network Address Transport Trunk) that performs address conversion between the WAN side and a LAN (Local Area Network) side An address notification method for notifying the address of the UPnP device in a network including a router device having a function;
A plurality of WAN logical ports that receive packets received by the WAN interface according to the contents thereof are associated with LAN logical ports arranged corresponding to the plurality of WAN logical ports, and independent for each LAN side logical port. An address notification method characterized by performing notification as a UPnP device.   12. The address notification method according to claim 11, wherein when performing the notification, a UPnP message is generated for each corresponding logical port.   13. The address notification method according to claim 11, wherein the connection of the WAN side logical port is associated with the LAN side logical port.   14. The address notification method according to claim 11, wherein a host having the UPnP control point function can freely select a connection destination using UPnP. 12. The WAN logical port holds an IP (Internet Protocol) address of a different subnet on the WAN side, and the LAN logical port holds an IP address of the same subnet on the LAN side. 14. The address notification method according to any one of 14.

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