JP2000101648A - Network connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network connector capable of reducing the quantity of communication through a network to become the toll charging object of a public line or the like when solving the name of a computer. SOLUTION: When the lines of routers 361 and 362 are connected through an ISDN 5, the name solution table of a work group 341 stored in the router 361 is transmitted and stored into the router 362, and the name solution table of a work group 342 stored in the router 362 is transmitted and stored into the router 361. Besides, the inquiry packets of IP addresses of computers 333 and 334 from computers 331 and 332 are not defined as the trigger of line connection between the routers 361 and 362.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a network connection device such as a router for connecting a plurality of networks.

[0002]

2. Description of the Related Art In the Internet, TCP / IP (Transport C) is a protocol for communication between computers.
ontrol Protocol / Internet Protocol) and identify each host computer by assigning a fixed 4-byte unique length IP address to each of a plurality of host computers (primary master name servers) existing on the network. I have. This IP address is a series of numbers, which is inconvenient for humans to remember.
Instead of an address, a hierarchical domain name (host computer name) that is convenient for humans to remember is used, and the correspondence between the domain name and the IP address is defined by a name resolution system called DNS (Domain Name Server). We have solved it. Domain names are determined to be unique throughout the Internet.

In recent years, many personal computers have, for example, NetBIOS (Network Basic Input Out), which is a basic protocol for a small LAN.
OS (Opera such as Microsoft's Windows 95 (trade name) and Windows NT (trade name) that adopts putSystem: network basic input / output system)
application program running on the ting system). These OSs are, as shown in FIG.
NetBIOS is realized on TCP / IP. That is, as shown in FIGS. 9A and 9B, the OSI (Op
en Systems Inerconnection
n) The network layer and the transport layer of the reference model are realized by TCP / IP, and the session layer is NetBI.
It is realized by OS. Note that, as shown in FIG.
NetBIOS operating at the session layer is NetBT
(NetBIOS over TCP / IP).

A computer using an OS adopting NetBT as described above is not a DNS, but a computer.
A name server called a WINS (Windows Internet Name Service) server is used. The name server, when defining a group consisting of a plurality of computers having shared resources connected via a network, assigns a computer belonging to the group a NetBIOS computer name unique within the group, and Register and inquire the correspondence between the computer name and the IP address. WINS is a dynamic host configuration (DHCP) that automatically assigns an IP address to a computer in a group each time the computer is started.
Protocol) can be used. By using DHCP, a user can use a complicated I / O when starting up a computer.
There is no need to set the P address.

The NetBIOS computer name and I
As a method of resolving a name with a P address, in addition to a name server, a method of inquiring each computer using a broadcast packet, or a method in which each computer uses a NetBIOS computer name and an IP address of another computer having a shared resource. LMHOS correspondence
There is a method of statically saving in a TS file. However, these methods cannot realize the aforementioned DHCP.

Hereinafter, the name server (WINS) will be described in detail. The name server stores a name resolution table indicating the correspondence between the NetBIOS computer names and the IP addresses of the computers in the group in the memory, and upon receiving an inquiry packet including the NetBIOS computer name, stores the entry corresponding to the NetBIOS computer name. Search and find the I
Returns a response packet containing the P address.

Here, the name resolution table of the name server is generated as described below. That is, when a new computer joins the group, the name server receives a registration packet from the computer and adds the NetBIOS computer name and the IP address included in the registration packet to the name resolution table.

Further, the name server periodically receives an update packet from a computer belonging to the group, searches the name resolution table for an entry corresponding to the NetBIOS computer name and the IP address included in the update packet, and It is determined whether or not the content should be updated. If the content needs to be updated, the content of the entry is added to the NetBIO included in the update packet.
Update with S computer name and IP address. The update packet is periodically transmitted from the computer to the name server, for example, every three days. Also, the name server is
When the computer belonging to the group is removed, the release packet is received from the computer, and the entry in the name resolution table corresponding to the NetBIOS computer name and the IP address included in the release packet is deleted. The above-described registration packet, update packet, and release packet are transmitted from computers belonging to the group by explicitly specifying the address of the name server.

[0009]

By the way, for example, I
When a plurality of networks are connected via a public line employing a charging system such as SDN, one name server is provided for the plurality of networks as a method of arranging the above-mentioned name servers. And one in which one name server is provided for each network.

[0010] In the former case, for example, even when communication is performed between computers in one network where no name server is provided, communication with the name server via a public line is required. In other words, there is a problem that billing due to use of a public line increases.

In the latter case, conventionally, for example, the name server of each network regularly exchanges the name resolution table via the public line, and the use of the public line increases the billing. There is a problem.

[0012] The present invention has been made in view of the above-mentioned problems of the related art, and is capable of reducing the amount of communication via a network to be charged such as a public line when performing name resolution of a computer using a name server. It is intended to provide a connection device.

[0013]

In order to solve the above-mentioned problems of the prior art and to achieve the above-mentioned object, a network connection device according to a first aspect of the present invention comprises a first network and a single or a single network. Network connection device that relays a message transmitted to and from a second network to which a plurality of first processing devices are connected and does not relay a message broadcast in the second network to the first network When the first network and a third network to which a second processing device is connected are connected via a remote network connection device, the name and address of the first processing device First storage means for storing first name resolution data indicating a correspondence relationship with the remote network via the first network When a line is connected to a connection device, a transmitting unit that transmits the first name resolution data to the remote network connection device; and when the line is connected, the remote network connection device Receiving means for receiving second name resolution data indicating the correspondence between the name and address of the second processing means, and second storage means for storing the second name resolution data received by the receiving means And

[0014] In the first network connection device of the present invention, due to some factor other than the inquiry message for the address of the second processing device received from the first processing device, the first network connection device may be connected via the first network. When a line is connected to the remote network connection device, the first name resolution data is transmitted from the transmission means to the remote network connection device, and the second name from the remote network connection device is transmitted. Solution data is received by the receiving means.

[0015] The network connection device according to the first aspect of the present invention, specifically, transmits the inquiry message for the address of the second processing device received from the first processing device to the first processing device. It does not trigger line connection to the remote network connection device via the network.

[0016] Preferably, the network connection device according to the first aspect of the present invention, upon receiving a network reference message requesting reference to the third network from the first processing device, A line is connected to the remote network connection device via the first network.

Further, in the network connection device according to the first aspect of the present invention, preferably, when the receiving means is capable of simultaneously connecting a plurality of lines via the first network, The storage means has an independent storage area for each line that can be simultaneously connected.

Further, in the network connection device according to the first aspect of the present invention, preferably, the names of the first processing device and the second processing device are in a group including a plurality of processing devices having shared resources. Is a name uniquely determined by

Further, the network connection device of the present invention comprises:
Preferably, the address is an address uniquely determined on the Internet.

Further, a network connection device according to a second aspect of the present invention is a device for transmitting a message transmitted between a first network and a second network to which one or more first processing devices are connected. Relay the message broadcast in the second network to the first network.
A network connection device that does not relay to the first network, wherein the first device is connected via a remote network connection device.
Is connected to a third network connected to the first network and one or more second processing apparatuses and a name server that stores name resolution data indicating the correspondence between the names and addresses of the second processing apparatuses. When a line is connected to the remote network connection device via the first network, an inquiry message for the address of the second processing device transmitted from the first processing device is sent to the remote network connection device. , Via the first network, to the name server, and the address received from the name server to the first processing device.

[0021]

Hereinafter, a network system according to an embodiment of the present invention will be described. FIG. 1 is a configuration diagram of a network system 1 according to the present embodiment. FIG.
As shown in FIG.
_1, 36 via the ₂ and 36 _3, respectively LAN (Loc
al Area Network) 32 ₁ , 32 ₂ and 32 ₃ are connected.

[0022] LAN32 connected routers 36 ₁ to _1,
Computers 33 ₁ and 33 ₂ are in workgroup 34
It belongs to _1. In workgroup 34 ₁ , router 3
6 ₁ functions as a name server. Here, as a master browser for generating and storing a browse list including the NetBIOS computer names of the computers in the work group 34 ₁ , the computer 33 ₁ or
33 ₂ functions. Computers 33 ₁ and 33 ₂ have “PC1” as the NetBIOS computer name.
And “PC2”.

[0023] In addition, the router 3, which is connected to LAN32 ₂
6 _2, the computer 33 ₃ and 33 ₄ in a workgroup 34 _2. In Workgroup 34 _2, the router 36 ₂ functions as a name server. The computer 33 ₃ and 33 _4, as NetBIOS computer name, "PC3" and "PC4" is assigned, respectively. The master browser workgroup 34 within ₂ computer 33 ₃ or 33 ₄ functions.

Furthermore, LAN 32 ₃ router connected 36 _3, the computer 33 ₅ and nameserver 33 ₆
Belongs to a workgroup 34 _3. In Workgroup 34 _3, nameserver 33 ₆ functions as a name server and master browser. The computer 33 ₅ and name server 33 _6, as NetBIOS computer name, "PC5" and "SV1" is attached, respectively. Incidentally, NetBIOS computer names are determined to be unique workgroup 34 _1, 34 _2, 34 within _3.

The function and configuration of each component shown in FIG. 1 will be described below. Computer 33 ₁ computer 33 _1, for example, was adopted NetBIOS, Microsoft's Windows95 (trademark name) and WindowsNT (trademark name) OS (Opera, such as
operating the application program on the ting system).

Computer 33₁OK, WINS server
Router 36 as the IP address of ₁IP address
keeping. Here, the IP address is
This address is uniquely determined on the Internet.

Computer 33₁Is workgroup 3
4₁When I belong to my NetBIOS computer,
The registration packet containing the data name and the IP address
36 ₁Specify the IP address of LAN32₁Through
Router 36₁Send to The computer 33₁
Is not registered, for example, every three days.
Update packet containing IOS computer name and IP address
To the router 36₁Specify the IP address of the LAN
32₁Through the router 36₁Send to Also, compilation
Computer 33₁Is, for example, a work group 34₁Removed from
When deleted, your NetBIOS computer name
The release packet containing the IP address and the
₁Specify the IP address of LAN32₁Through le
Data 36₁Send to

Further, the computer 33 _1, in response to operation of the user, and transmits when network reference of the remote LAN workgroup 34 ₂ or 34 _3, the network reference packet to the router 36 _1, the router 36
Through _1, it receives the browse list from the master browser workgroup 34 ₂ and 34 _3, and displays the NetBIOS computer name included in the browse list that the received display.

The computer 33₁Is, for example, on
While executing the network reference described,
Workgroup 34 connected by reference_TwoOr 34
_ThreeAccess to a computer belonging to LA
N32₁Through the router 36 ₁Perform the access
Question including the computer's NetBIOS computer name
Send a matching packet. And computer 3
3₁Is the router 36₁Perform the access received from
Via ISDN5 using the IP address of the computer
Then, the computer is accessed. At this time,
Router 36₁And the computer making the access
Work group 34_TwoOr 34_ThreeRouter 36_Two
Or 36_ThreeIs already known by referring to the network
And no new line connection is required.

[0030] The functions of the computer 33 ₂ is the same as the function of the computer 33 ₁ described above.

Router 36 ₁ Router 36 ₁ is, in principle, an L which is a local LAN.
AN32 ₁ and is relaying messages (packets) between the ISDN5, LAN32 ₁ computer 33 ₁
And 33 ₂ broadcast from the message (packet) is not relayed to the filtering to ISDN5. Also, the router 36 ₁ is connected to the LAN 3 from the ISDN 5.
Among the messages sent to the 2 _1, is not relay should be excluded from a security perspective.

The router 36 ₁ is a remote LAN L
AN32 ₂ and 32 workgroups 34 ₂ and 34 ₃ of the workgroup name on the ₃ "WG2" and "WG
3 "holds, periodically broadcasts a workgroup announcement packet including the workgroup name on LAN 32 _1.

The router 36₁Is the WINS server mentioned above
Function as the computer 33 ₁And 33_TwoN
Correspondence between etBIOS computer name and IP address
Name resolution table (name resolution data) indicating the person in charge, for example
For example, the local LAN storage area of the DRAM 49 shown in FIG.
50_ThreeI remember.

The router 36 ₁ receives the registration packet described above, NetBIO included in the registration packet
Add the S computer name and IP address to the name resolution table. The router 36 ₁ receives the update packet, included in the update packet NetBI
An entry corresponding to the OS computer name and the IP address is searched from the name resolution table, and it is determined whether or not the content of the entry should be updated. When the entry needs to be updated, the content of the entry is transmitted to the update packet. Is updated with the NetBIOS computer name and the IP address included in. The router 36 ₁ receives the open packet, included in the open packet NetBIO
S Delete the entry in the name resolution table corresponding to the computer name and the IP address.

The router 36 _1, the computer 33 ₁ or 33 _2, upon receiving an inquiry packet IP address for the computer in LAN32 _1, from the entry of the name resolution table that corresponds to the NetBIOS name included in the query packet, An IP address is obtained, and a response packet including the IP address is transmitted to the computer that transmitted the inquiry packet.

[0036] In addition, the router 36 _1, computer 33
From ₁ or 33 _2, upon receiving a network reference packet that instructs to refer to workgroups 34 _2, connected to the router 36 ₂ via the ISDN5, workgroup 3 from the master browser workgroup 34 ₂
42. The browse list of ₂ is received, and the received browse list is transmitted to the computer that transmitted the network reference packet. Router 36 _1, when connected to the router 36 ₂ via the ISDN5, through ISDN5, stores receives a name resolution table workgroup 34 ₂ from the router 36 _2, workgroups 3
4 to send ₁ of the name resolution table to the router 36 _2. The router 36 ₁ is connected to the computer 33 ₁ or 33
_2, when receiving the inquiry packet IP address of the computer that belongs to a workgroup 34 _2, by referring to the name resolution table workgroup 34 ₂ described above stores, contained in the inquiry packet NetBI
Obtaining an IP address corresponding to the OS computer name, a response packet including the IP address, transmits through the ₁ LAN 32 to the computer that sent the inquiry packet.

The router 36₁Is a computer 33
₁Or 33_TwoFrom workgroup 34_ThreeNetwork
Receiving the network reference packet, the
TA 36_ThreeConnect with workgroup 34_ThreeMaster bra
Name server 33 which is a user ₆Receive browse list from
The browse list and the network reference
And send it to the computer that sent it. In this example
Is the router 36₁And 36_ThreeIs connected via ISDN5
Even if the router 36_ThreeRemembers the name resolution table
Router 36₁Is the router 36_ThreeFrom
Workgroup 34_ThreeDoes not receive the name resolution table.

Next, the router 36 _1, computer 33
IP from ₁ or 33 _2, upon receiving an inquiry packet IP address of the computer that belongs to a workgroup 34 _3, the name server 33 ₆ via ISDN5
It transmits an inquiry packet address, receiving a response packet including the IP address from the name server 33 _6. In this case, the inquiry packet of the IP address is not a trigger (opportunity) which connects the router 36 ₁ and 36 ₃ through ISDN5, by treatment in accordance with the network reference packet workgroup 34 ₃ described above, because it is already connected to the router 36 ₁ and 36 _3, no new line connection is needed. Thus, the router 36 _1, IP address, of the reception of the inquiry packet because it does not trigger the line connection ISDN5, suppress line connection ISDN5 by inquiry packet inadvertent such as computer 33 ₁ and 33 ₂ misconfiguration it can.

The router 36 _1, as described above, when receiving the response packet from the nameserver 33 _6, the response packet is transmitted via the LAN 32 ₁ to the computer that sent the inquiry packet.

As shown in FIG. 1, the router 36 ₁
A router that connects N5 and LAN 32 ₁
For relaying or holding data transmitted via the DN5, as shown in FIG. 2, the DRAM49, in addition to a workgroup 34 ₁ name resolution local LAN memory area 50 for storing data _3, the ISDN5 B channel storage area 5 corresponding to each of 2B channels
And a 0 _1, 50 _2. Therefore, it is possible to prevent data stored in one channel of the ISDN 5 from erasing stored contents of data communicated through another channel.

The computer 33 _3, 33 ₄ and a router
36 ₂ Computer 33 _3, 33 ₄ has except that LAN 32 ₂ is locally LAN, and the same function as the basic computer 33 ₁ described above. Computer 33 ₃ ,
33 _4, as the IP address of the WINS server, and holds the IP address of the router 36 _2. The router 36 ₂ will have except that LAN 32 ₂ is locally LAN, and the same function as essentially the router 36 ₁ described above.

[0042] Computer 33 ₅ computer 33 _5, in the same manner as the computer 33 _1,
For example, Microsoft's Windows 95 (trade name) or Windows NT using NetBIOS
An application program is operated on an OS such as (trade name). Computer 33 _5, as the IP address of the WINS server, and holds the IP address of the name server 33 _6.

[0043] The computer 33 _5, like the computer 33 ₁ described above, and transmits the registration packet, the update packet and open the packet to a name server 33 _6.

[0044] The computer 33 _5, in response to a user operation transmitted when network reference workgroup 34 ₁ or 34 ₂ of the remote LAN, and the network reference packet to the router _363, the router 36
₃ through receives the browse list from the master browser workgroup 34 ₁ or 34 _2, displays NetBIOS computer names included in the browse list received on a display.

The computer 33_FiveIs, for example, on
While executing the network reference described,
Workgroup 34 connected by reference₁Or 34
_TwoAccess to a computer belonging to LA
N32_ThreeVia the name server 33₆The access
NetBIOS computer name of the computer that performs
A query packet of the IP address including the IP address is transmitted. This
, The name server 33₆Is a workgroup 34₁
And 34_TwoDid not remember the name resolution table for
Computer 33_FiveIs a name server 33₆From d
Receive an error signal. Computer 33_FiveIs a name
Server 33₆When an error signal is received from the
NetBIOS computer of the computer trying to be
Broadcast inquiry packet of IP address including name
Cast and router 36_ThreeFrom the NetBIOS core
The IP address corresponding to the computer name is received. Soshi
And computer 33_FiveIs the received IP address
Using the workgroup 34 ₁Or 34_TwoBelongs to
Access the computer.

The name server 33 ₆ Name Server 33 _6, name resolution table (the name that shows the correspondence between the function as a WINS server and the master browser described above, NetBIOS computer name and IP address of the computer 33 ₅ and the name server 33 ₆ and resolution data), and stores the browse list containing computer 33 ₅ and NetBIOS computer name of the name server 33 ₆ such as a DRAM.

The name server 33 _6, computer 33
_5, when receiving the inquiry packet of IP addresses for Workgroups 34 ₁ and 34 ₂ belonging computers on a remote LAN, and transmits an error signal to the computer 33 _5.

[0048] In addition, the name server 33 _6, remote L
From AN routers 36 ₁ or 36 _2, upon receiving an inquiry packet IP address, workgroup 34
₃ with reference to the name resolution table to obtain a corresponding IP address, the response packet including the IP address, the router 36 ₁ or 3 which has transmitted the inquiry packet
To send to the 6 _2.

The router 36 ₃ routers 36 _3, via the ISDN5, when connected to the router 36 ₁ or 36 _2, router 36 ₁ or 3
6 ₂ workgroups stored in 34 ₁ or 34
Receive and store the _second name resolution table. Then, the router _363, when inquiry packet of IP addresses for Workgroups 34 ₁ or 34 ₂ belonging computers are broadcast by the computer 33 _5, contained in the inquiry packet NetBIOS
To send the IP address that corresponds to the computer name in the computer 33 _5. The router ₃₆₃ also, as shown in FIG. 2, the storage area 50 ₁ for each channel of ISDN5,
It has a 50 _2, because as the name server does not work, without using the storage area 50 ₃ for the local LAN is.

Hereinafter, the operation of the network system 1 will be described. First operation example The following describes the operation of the network system 1 when performing access from the computer ₃₃₁ to the computer 33 _3. Figure 3 is a diagram for explaining a screen displayed on computer 33 ₁ display. FIG.
Is a diagram for explaining the operation of the network system 1 when performing access from the computer ₃₃₁ to the computer 33 _3.

[0051] The computer 33 ₁ of the display,
Based on the work group 34 ₁ browse list received from Masutaburaza, the initial screen 60 shown in FIG. 3 (A)
Is displayed. The initial screen 60 includes the work group 34
_The icons 61a and 61b indicating the NetBIOS computer names "PC1" and "PC2" of the computers belonging to ₁ respectively, and the icon 61c for displaying the workgroup on the network are displayed.

[0052] Then, the icon 61c of the initial screen 60 When the user double-clicks, the computer 33 _first display screen 62 shown in FIG. 3 (B) is displayed. The screen 62, the local LAN and the remote LAN workgroup are registered in the router 36 ₁ 3
4 _1, 34 _2, 34 _3, which is a workgroup name "WG
Icon 63 indicating “1”, “WG2” and “WG3”
a, 63b and 63c are displayed.

When the user double-clicks the icon 63b on the screen 62, the computer 33
From ₁ to router 36 _1, the network reference packet workgroup 34 ₂ is transmitted (FIG. 4 (A)). When the network reference packet is received by the router 36 _1, it is connected to the router 36 ₁ and 36 ₂ via ISDN5 (FIG. 4 (B)), the router from the router 36 ₂ 36
Browse list Workgroup 34 ₂ is transmitted to ₁ (FIG. 4 (C)). Browse list is transmitted from the router 36 ₁ via the LAN 32 ₁ to the computer 33 ₁ (FIG. 4 (D)), the screen 64 shown in FIG. 3 (C) to the computer 33 ₁ of the display is displayed. The screen 64 shows the Ne of the computer belonging to the work group 34 _2.
tBIOS computer names "PC3" and "PC4"
65a and 65b, respectively, and an icon 6 for displaying a workgroup on the network.
5c is displayed.

[0054] Also, when the router 36 ₁ and 36 ₂ via the ISDN5 is connected, via a ISDN5, name resolution table workgroup 34 _2, router 36
Transmitted from the ₂ to the router 36 ₁ (FIG. 4 (E)), is the name resolution table for example stored in the B channel storage area 50 ₁ of the router 36 ₁ shown in FIG. Also, name resolution table workgroup 34 ₁ is transmitted from the router 36 ₁ to the router 36 ₂ (FIG. 4 (E)), the name resolution table B channel storage area 50 ₁ shown in FIG. 2 of the router 36 ₂ Is stored.

Next, when the user double-clicks the icon 65a on the screen 64 shown in FIG.
AN32 ₁ router 36 from the computer 33 ₁ via the
₁ , an IP address inquiry packet including the NetBIOS computer name “PC3” is transmitted (FIG. 4).
(F)). The router at 36 _1, reference is already name resolution table workgroup 34 ₂ stored therein, NetBIOS computer name "PC included in the query packet received from the computer 33 ₁
The IP address is obtained from the entry corresponding to “3”, and a response packet including the IP address is
₁ (FIG. 4 (G)).

Then, the computer 33₁By le
Data 36₁Computer 33 received from_ThreeIP ad
Computer via ISDN5
33 _ThreeIs accessed (FIG. 4H). This and
Come, router 36₁And router 36 _TwoIs the network
Already connected by network reference, and a new line connection
No need to do.

[0057] The second operation example The following describes the operation of the network system 1 when performing access from the computer ₃₃₁ to the computer 33 _5. Figure 5 is a diagram for explaining a screen displayed on computer 33 ₁ display. FIG.
Is a diagram for explaining the operation of the network system 1 when performing access from the computer ₃₃₁ to the computer 33 _5.

[0058] The computer 33 ₁ of the display,
As in the case of the first operation example described above, a screen 62 shown in FIG. 5B is displayed following the initial screen 60 shown in FIG.

When the user double-clicks the icon 63c on the screen 62, the computer 33
From ₁ to router 36 _1, the network reference packet workgroup 34 ₃ is transmitted (FIG. 6 (A)). When the network reference packet is received by the router 36 _1, the router 36 ₁ through ISDN5 and router 36
₃ and is connected (FIG. 6 (B)), the router ₃₆₃ a packet for inquiring the browse list name server 33 ₆ is transmitted from the browse list of name servers 33 ₆ Workgroup 34 ₃ transmitted to the router 36 ₃ But,
Is sent to the router 36 ₁ through ISDN5 (Figure 6
(C), (D)). Then, the browse list is L
AN32 ₁ computer 33 from the router 36 ₁ via the
Sent to ₁ (FIG. 6 (E)), the screen 66 shown in FIG. 3 (C) to the computer 33 ₁ of the display is displayed.
The screen 66, icons 67a and 67b shows NetBIOS computer name of the computer that belongs to a workgroup 34 ₃ "SV1", and "PC5", respectively
And an icon 67c for displaying a workgroup on the network.

[0060] In addition, because the router 36 _3, the name resolution table of the work group 34 ₃ is not stored, I
When the router 36 ₁ and 36 ₃ through SDN5 is connected, the router 36 ₁ does not receive the name resolution table workgroup 34 ₃ from the router 36 _3.

Next, when the user double-clicks the icon 67b on the screen 66 shown in FIG.
AN32 ₁ router 36 from the computer 33 ₁ via the
₁ transmits an IP address inquiry packet including the NetBIOS computer name “PC5” (FIG. 6).
(F)). At this time, the router 36 _1, the name resolution data workgroup 34 ₃ is not stored, I
Through the SDN5, name server 33 from the router 36 _1
6 , an inquiry packet of the IP address including the NetBIOS computer name “PC5” is transmitted (FIG. 6).
(G)). The inquiry packet is sent to the name server 3
3 ₆ Once received, in the name server 33 _6, reference name resolution table workgroup 34 _3, the entry corresponding to the NetBIOS computer names contained in the inquiry packet "PC5" is searched, IP of the entry The response packet containing the address is
Is sent to the router 36 ₁ through DN5 (Figure 6
(H)).

[0062] The response packet is received by the router 36 ₁ is transmitted from the router 36 ₁ to the computer 33 ₁ (FIG. 6 (I)). Then, the computer 33 _1, using the IP address included in the response packet received via the ISDN5, access is made to the computer 33 ₅ (FIG. 6 (J)). In this case, the process corresponding to the network reference packet workgroup 34 ₃ described above, since it is already connected to the router 36 ₁ and 36 _3, a new line connection is not performed.

[0063] The third operation example of the following describes the operation of the network system 1 when performing access from the computer 33 ₅ to the computer 33 _1. Figure 7 is a diagram for explaining a screen displayed on the display of computer 33 _5. FIG.
Is a diagram for explaining the operation of the network system 1 when performing access from the computer 33 ₅ to the computer 33 _1.

[0064] The display of the computer 33 _5,
Workgroup received from the name server 33 ₆ 34 ₃
The initial screen 68 shown in FIG. 7A is displayed based on the browse list. The initial screen 68 is displayed and icons 69a and 69b shows NetBIOS computer name of the computer that belongs to a workgroup 34 ₃ "PC5" and "SV1", respectively, and icons 69c for displaying the workgroup on the network .

[0065] Then, the icon 69c of the initial screen 68 the user double-clicks, the display of the computer 33 _5, a screen 70 shown in FIG. 7 (B) is displayed. The screen 70, the local LAN and the remote LAN workgroup are registered in the router 36 ₃ 3
4 _1, 34 _2, 34 _3, which is a workgroup name "WG
Icons 71 indicating "1", "WG2" and "WG3"
a, 71b and 71c are displayed.

When the user double-clicks the icon 71a on the screen 70, the computer 33
₅ to the router _363, the network reference packet workgroup 34 ₁ is transmitted (FIG. 8 (A)). When the network reference packet is received by the router _363, connected router 36 ₃ and 36 ₁ and via the ISDN5 (FIG 8 (B)), the router from the router 36 ₁ 36
₃ browse list workgroup 34 ₁ is transmitted (FIG. 8 (C)). Then, the browse list is L
AN32 ₃ computer 33 from the router 36 ₃ via a
₅ to be transmitted (FIG. 8 (D)), the screen 72 shown in FIG. 7 (C) is displayed on the display of the computer 33 _5.
The screen 72, icons 73a and 73b shows NetBIOS computer name of the computer that belongs to a workgroup 34 ₁ "PC1" and "PC2", respectively
And an icon 73c for displaying a work group on the network.

Also, the router 36 via the ISDN 5_ThreeWhen
36₁Is connected via ISDN5.
Workgroup 34₁Is stored in the router 36
₁To router 36_Three(FIG. 8 (E)), and the name
Pre-resolution table is router 36 _ThreeFor example, in FIG.
Channel storage area 50₁Is stored.

Next, when the user double-clicks the icon 73a on the screen 72 shown in FIG.
AN32 ₃ in the name server 33 ₆ from the computer 33 ₅ through, NetBIOS computer name "PC1"
Is transmitted (FIG. 8F). At this time, the name server 33 _6,
Because workgroup 34 ₁ of the name resolution table is not stored, the computer 33 from the nameserver 33 _6
An error signal is transmitted to ₅ (FIG. 8 (G)).

[0069] error signal from the name server 33 _6,
When received by the computer 33 ₅ , the computer 33
₅ on the LAN 32 _3, inquiry packet of IP addresses, including the NetBIOS computer name "PC1" is broadcast (FIG. 8 (H)). The inquiry packet is received by the router 363 and the router 36 _3
3 name resolution table workgroup 34 ₁ stored is referred to, the entry corresponding to the NetBIOS computer names contained in the inquiry packet "PC1" is searched, IP address, of the entry is obtained. Then, the response packet including the obtained IP address, via the LAN 32 _3, is transmitted from the router 36 ₃ to the computer 33 ₅ (FIG. 8 (I)).

[0070] When the response packet is received by the computer 33 _5, using the IP address included in the response packet via the ISDN5, computer 33 ₅
Access is made to the computer ₃₃₁ (FIG. 8
(J)). This time, the router ₃₆₃ and the router 36 ₁ are already connected by treatment according to the network reference packet workgroup 34 ₁ described above, it is not necessary to perform new channel connection.

As described above, the network system
According to system 1, as shown in FIG.₁and
36_TwoTo have a function as a name server
So, for example, workgroup 34₁Computer belonging to
TA33₁Is workgroup 34 _TwoNetwork reference
When performing, the router 36₁And 36_TwoIs connected to
Is detected, and by the detection, the router 36 is detected.₁And 36_TwoWith
Workgroup 34₁And 34_TwoName resolution
Cables can be interchanged. Therefore, the network
According to the system 1, the name servers can communicate with each other via the ISDN.
There is no need to periodically send and receive name resolution data.
According to the network system 1, for example, FIG.
As shown in FIG.₁But workgroup
34_TwoComputer belonging to_ThreeOr 33 _FourAccess
The process is performed by the workgroup 34 described above._TwoNet
Network access,
Is workgroup 34_TwoName resolution table is router 3
6₁Has already been stored. Therefore, computer 3
3₁Is the router 36₁All connections that may be
Computer that attempts the access to the
There is no need to query the IP address of the data. Also,
When performing the access, the router 36₁And 36_TwoWhat is
It is already connected and there is no need to make a new line connection.
No.

[0072] According to the network system 1, the computer 33 from _1, the router 36 ₃ even when accessing the computer 33 ₅ belonging to a workgroup 34 ₃ which does not have a function as a name server, a work group from the computer 33 ₁ 34 in the middle of performing a network reference to _3, already with ISDN5 line connected, from the name server 33 ₆ to obtain an IP address, by performing the access by using the IP address, the new There is no need to make a simple line connection.

According to the network system 1,
Router 36 _1, 36 ₂ and 36 _3, the reception of the inquiry packet IP address since it does not trigger line connection ISDN5, the line connection ISDN5 by inquiry packet erroneous due misconfigured computers in the local LAN Can be suppressed.

According to the network system 1,
Router 36 _1, 36 ₂ and 36 _3, as shown in FIG. 2, the storage area 50 corresponding to each channel of ISDN5 ₁
By providing the 50 _3, can be avoided by the data to be communicated via one of the channels, the stored contents of the data communicated via the other channel is erased.

According to the network system 1,
Since name resolution is performed using the name server, each computer does not need to have an LMHOSTS file or the like, and it can cope with dynamic IP address assignment by DHCP or the like.

Further, according to the network system 1, since a name server is provided for each work group, it is necessary to perform communication via the ISDN 5 when performing name resolution within each work group. And the billing amount can be reduced. As described above, the network system 1
According to this, the number of times of communication via the ISDN 5 and the communication time can be reduced, and the billing amount can be reduced.

The present invention is not limited to the above embodiment. In the embodiment described above, as shown in FIG.
As a component of a workgroup 34 _1, 34 ₂ and 34 _3, it has been illustrated computer, in addition to or in a printer of a computer.

In the above-described embodiment, for example, FIG.
(G), as shown in (H), "P from the router 36 ₁
In response to the inquiry packet of "C5", the name server 3
3 ₆ has been exemplified a case returning the IP address corresponding to "PC5", rather than the IP address, workgroup 3
4 ₃ may be to return the name resolution table.

[0079]

As described above, according to the network connection device of the present invention, when performing the name resolution of the second processing device, the communication amount via the first network can be reduced. If one network is a communication line to be charged, the amount of charging can be reduced. Further, according to the network connection device of the present invention, by storing name resolution data and exhibiting a function as a name server, it is possible to cope with dynamic address allocation by DHCP or the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a network system according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a storage area of a router in the network system shown in FIG. 1;

FIG. 3 is a diagram for explaining a screen displayed on a display of a computer in a first operation of the network system shown in FIG. 1;

FIG. 4 is a diagram for explaining a first operation of the network system shown in FIG. 1;

FIG. 5 is a diagram for explaining a screen displayed on a display of a computer in the second operation of the network system shown in FIG. 1;

FIG. 6 is a diagram for explaining a second operation of the network system shown in FIG. 1;

FIG. 7 is an exemplary view for explaining a screen displayed on a display of a computer in the third operation of the network system shown in FIG. 1;

FIG. 8 is a diagram for explaining a third operation of the network system shown in FIG. 1;

FIG. 9 is a diagram for explaining WindowsNT.

[Explanation of symbols]

1: Network system, 5: ISDN, 32 ₁ , 3
2 ₂ , 32 ₃ ... LAN, 33 ₁ , 33 ₂ , 33 ₃ , 33
_4, 33 ₅ ... computer, 33 ₆ ... name server, 3
6 ₁ , 36 ₂ , 36 ₃ ... router

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 12/66 H04L 11/20 B H04M 3/00

Claims (6)

[Claims] 1. A method for relaying a message transmitted between a first network and a second network to which one or more first processing devices are connected, wherein the message is broadcast in the second network. The message
A network connection device that does not relay to the first network, wherein the first network and the third network to which the second processing device is connected are connected via a remote network connection device; A first storage unit for storing first name resolution data indicating a correspondence relationship between a name and an address of the processing device, and a line connected to the remote network connection device via the first network Sending means for sending the first name resolution data to the remote network connection device; and, when the line is connected, the name and address of the second processing device from the remote network connection device. Receiving means for receiving second name resolution data indicating a correspondence relationship between the second name resolution data received by the receiving means; Network connection device and a second storage means for storing. 2. When the receiving means is capable of simultaneously connecting a plurality of lines via the first network, the second storage means stores independent data for each of the simultaneously connectable lines. The network connection device according to claim 1 having an area. 3. A message relayed between a first network and a second network to which one or more first processing devices are connected, and is broadcast in the second network. The message
A network connection device that does not relay to one of the networks, wherein one or more second processing devices and one or more second processing devices are connected to a third network connected to the first network via a remote network connection device. When a name server that stores name resolution data indicating a correspondence relationship between a name and an address is connected, when the line is connected to the remote network connection device via the first network, An address inquiry message transmitted from the first processing device for the address of the second processing device is transmitted to the name server via the first network, and the address received from the name server is transmitted to the first processing device. Network connection device to send to. 4. A storage means for storing first name resolution data indicating a correspondence between a name and an address of the first processing device, and wherein the receiving means comprises a plurality of lines via the first network. 4. The network connection device according to claim 3, further comprising: a second storage unit having an independent storage area for each of the lines that can be simultaneously connected when the simultaneous connection is possible. 5. A method according to claim 1, further comprising: receiving an inquiry message for an address of said second processing device received from said first processing device, as a trigger for a line connection with said remote network connection device via said first network. The network connection device according to any one of claims 1 to 4, wherein the connection is not performed. 6. When a network reference message requesting reference to the third network is received from the first processing device, a line between the first processing device and the remote network connection device via the first network. The network connection device according to any one of claims 1 to 5, wherein