JP3156231B2 - Address resolution server - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plurality of LANs (Local Area) using different communication protocols.
The present invention relates to an address resolution server for performing address resolution when performing communication on a network to which a network is connected, and in particular, a LAN segment composed of a broadcast type network using Ethernet or the like, and a non-broadcast using an ATM network or the like. Technology that is effective when applied to an address resolution server that performs address resolution when transferring data via a segment with a different communication protocol in a single subnet in which a LAN segment configured with a type network is mixed. Things.

[0002]

2. Description of the Related Art In a conventional network in which a plurality of computers are connected, a broadcast network capable of simultaneously communicating with a plurality of computers connected to the network and a broadcast network capable of performing simultaneous communication, and individual computers connected to the network are provided. It can be classified as a non-broadcast network that performs one-to-one communication.

[0003] As a conventional broadcast network, a plurality of computers are connected to Ethernet, and TCP / IP is used.
(Transmission Control Pro
2. Description of the Related Art There is a network in which communication is performed using a frame in which a hardware address or the like is added to a packet created according to a communication protocol such as a communication protocol (tocol / Internet Protocol).

In the conventional broadcast type network,
A frame transmitted by a specific computer is transmitted to all computers connected to the broadcast network, and a computer connected to the broadcast network receives a frame transmitted by the specific computer. Checking the address indicating the transmission destination of the frame, and if the address indicating the transmission destination is its own address, reads the data in the frame, and the address indicating the transmission destination is not its own address In such a case, communication is performed by discarding the frame.

[0005] For example, in a conventional broadcast network using the Ethernet, software having a TCP / IP communication protocol is used to identify a plurality of computers on the broadcast network when the computers start up. Protocol)
Set an address and add the IP
An IP packet is created by adding header information including an address, and the destination MAC (Media Access C) is created.
A MAC frame is created by adding an Ethernet address or the like, which is an (control) address, to the created IP packet, and the created MAC frame is transmitted over Ethernet.

Here, the MAC address is a unique hardware assigned to the network card for identifying a plurality of computers connected to the conventional broadcast network on the broadcast network. In a network using Ethernet, an address having a length of 6 bytes is used.

As described above, in a conventional broadcast network using Ethernet, when an IP packet created by adding an IP address or the like according to a TCP / IP communication protocol is transmitted to a transmission destination computer, the transmission is performed. The MAC address of the transmission destination is obtained from the previous IP address and added to the IP packet.

As described above, in a network in which a plurality of computers are connected, a MAC address which is a hardware address set in a network card is obtained from an address set by software having an upper communication protocol such as an IP address. This is called address resolution.

On the other hand, the conventional non-broadcast network includes an ATM (Asynchronous Tran).
sfer Mode).
The conventional non-broadcast network using the ATM network has excellent functions such as scalable transmission speed and communication quality setting for each destination as compared with the conventional broadcast network using the Ethernet. It is known to have

When a conventional non-broadcast type network using the ATM network is newly installed, the existing broadcast type network using the Ethernet is already widely used. In some cases, a non-broadcast type network using an ATM network is connected to the broadcast type network.

As described above, when communication is performed between a plurality of networks by connecting a non-broadcast type network using an ATM network to an existing broadcast type network using Ethernet, the Ethernet is usually used. LAN emulation for emulating the MAC protocol used in the broadcast network on a non-broadcast network using an ATM network has been performed.

That is, a conventional non-broadcast type network using the ATM network includes an address resolution server having an address management table in which ATM addresses corresponding to MAC addresses of a plurality of computers connected to the network are registered. Sent from a broadcast network using Ethernet
With reference to a header portion of the C frame, an address resolution of an ATM address corresponding to the MAC address added to the MAC frame is performed, and an ATM cell is created from the MAC frame based on information such as an ATM address; The created ATM cell is transmitted on the ATM network.

[0013]

The present inventor has found the following problems as a result of studying the above prior art.

That is, in the conventional broadcast network or non-broadcast network, a plurality of types of L
In the case where the AN segments are connected to each other to form a single subnet, L having only different communication protocols
Since communication cannot be performed between AN segments, connection cannot be established unless LAN segments having the same type of communication protocol are used.

Therefore, in a conventional broadcast network having a MAC protocol and a non-broadcast network having an ATM protocol, when a LAN segment having an ATM protocol is to be combined with a LAN segment having a MAC protocol, Since it is necessary to emulate the MAC protocol on a computer connected to the LAN segment having the ATM protocol, the communication between the computers connected to the LAN segment having the ATM protocol requires not only the ATM protocol but also the necessary communication. There is a problem that communication must be performed using a MAC protocol that does not exist.

Further, in a conventional broadcast network having a MAC protocol and a non-broadcast network having an ATM protocol, an L network having an ATM protocol is used.
When the MAC protocol is emulated on a computer connected to the AN segment, the communication quality cannot be set when setting the ATM connection from the MAC frame because the MAC protocol does not have information on the communication quality. However, there is a problem that high-quality communication cannot be performed.

An object of the present invention is to provide a technique capable of reducing the processing load of communication in a network in which a plurality of segments using different communication protocols are connected and realizing an environment for performing communication with specified quality. Is to do.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0019]

SUMMARY OF THE INVENTION Among the inventions disclosed by the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, in an address resolution server for performing an address resolution for converting an address set by software having a higher communication protocol into a hardware address in a network connecting a plurality of segments using different communication protocols, An address management table in which a plurality of types of hardware addresses corresponding to the different communication protocols are registered for one address set by software having a higher-level communication protocol for each of the plurality of connected computers. Address resolution request receiving means for receiving an address resolution request packet transmitted from a plurality of computers connected to the network; and address resolution received by the address resolution request receiving means. Address resolution processing means for obtaining a specific type of hardware address in the address management table in accordance with the contents of the request packet; and an address resolution response packet storing the specific type of hardware address obtained by the address resolution processing means. And an address resolution response unit for returning the address resolution response packet to the transmission source of the address resolution request packet.

[0021] The address resolution server may be configured such that, in the address management table, one address set by software having a higher-level communication protocol for each of the plurality of computers connected to the network is different. A plurality of types of hardware addresses corresponding to the communication protocol are registered.

When a specific computer connected to the network performs communication for transmitting specific data to another computer on the network, the specific computer transmits an address resolution request packet to the address resolution server. Then, a request for performing an address solution for obtaining a hardware address of the destination computer from an address of the destination computer set by software having a higher-level communication protocol is issued.

The address resolution request receiving means of the address resolution server receives an address resolution request packet transmitted from the specific computer.

The address resolution processing means of the address resolution server acquires a specific type of hardware address in the address management table according to the contents of the address resolution request packet received by the address resolution request receiving means.

The address resolution response means of the address resolution server generates an address resolution response packet storing the specific type of hardware address obtained by the address resolution processing means, and sends the address resolution response packet to the source of the address resolution request packet. The address resolution response packet is returned.

For example, when a broadcast network using an Ethernet and a non-broadcast network using an ATM network are connected via an interworking unit such as a bridge, and communication is performed using a TCP / IP communication protocol. Performs address resolution as shown below.

First, the address resolution server stores a TCP / IP address in the address management table for each of a plurality of computers connected to the network.
For one IP address set by software having an IP communication protocol, a MAC address of a broadcast network using Ethernet and an ATM
ATM of non-broadcast network using network
The address is registered as a hardware address.

Here, when registering the MAC address corresponding to the IP address of the computer connected to the non-broadcast type network using the ATM network in the address management table of the address resolution server, it is necessary to register the MAC address using the Ethernet. A virtual MAC address that does not overlap with the MAC address used in the broadcast network is assigned to the M of the computer connected to the ATM network.
It is set as an AC address and registered in the entry of the address management table.

In the case where an ATM address corresponding to the IP address of a computer connected to a broadcast network using Ethernet is registered in the address management table of the address resolution server, the broadcast to which the computer is connected is registered. Address of the interworking unit that connects the type network and the non-broadcast type network using the ATM network is set as the ATM address of the computer connected to the broadcast type network using the Ethernet. Register in the entry.

A specific computer connected to the broadcast network using Ethernet, which performs communication using a MAC address, transmits specific data to another computer via the non-broadcast network using the ATM network. When performing the communication to transmit the, the specific computer using a MAC address transmits an address resolution request packet to the address resolution server,
A request for address resolution for obtaining the hardware address of the destination computer from the IP address of the destination computer is issued.

[0031] The address resolution request receiving means of the address resolution server transmits the MA via the interworking unit.
An address resolution request packet transmitted from the specific computer using the C address is received, and the address resolution processing means of the address resolution server, according to the content of the address resolution request packet received by the address resolution request receiving means, The MAC address of the destination computer in the address management table is obtained.

That is, when the destination computer is a computer connected to a broadcast network using Ethernet, the address resolution processing means of the address resolution server uses the IP address of the destination to execute the address management table. To obtain the MAC address of the transmission destination registered in the address management table.

In the case where the destination computer is a computer connected to a non-broadcast network using an ATM network, the address resolution processing means of the address resolution server uses the IP address of the destination to transmit the address. A management table is searched, and a virtual MA of a destination registered in the address management table is searched.
Get the C address.

Next, the address resolution response means of the address resolution server generates an address resolution response packet storing the MAC address obtained by the address resolution processing means, and transmits the address resolution response packet to the address resolution request packet via the interworking unit. The address resolution response packet is returned to the transmission source.

Further, a specific computer connected to a non-broadcast type network using an ATM network for performing communication using an ATM address is connected to another computer via a broadcast type network using the Ethernet. When performing communication for transmitting data, AT
The specific computer using the M address transmits an address resolution request packet to the address resolution server, and performs a request for performing an address resolution to obtain a hardware address of the destination computer from an IP address of the destination computer. Put out.

The address resolution request receiving means of the address resolution server receives an address resolution request packet transmitted from the specific computer using an ATM address, and the address resolution processing means of the address resolution server transmits the address resolution request packet to the address resolution server. According to the content of the address resolution request packet received by the resolution request receiving means, the ATM of the destination computer in the address management table
Get the address.

That is, when the destination computer is a computer connected to a non-broadcast network using an ATM network, the address resolution processing means of the address resolution server uses the IP address of the destination to transmit the address. The management table is searched to obtain the ATM address of the transmission destination registered in the address management table.

In the case where the destination computer is a computer connected to a broadcast network using Ethernet, the address resolution processing means of the address resolution server uses the IP address of the destination to execute the address management table. To obtain the ATM address of the interworking unit to the broadcast network using the Ethernet connected to the destination computer registered in the address management table.

Next, the address resolution response means of the address resolution server generates an address resolution response packet storing the ATM address obtained by the address resolution processing means, and sends the address resolution response packet to the source of the address resolution request packet. Returns a response packet.

As described above, in the address resolution server, when the computer that has transmitted the address resolution request packet is a computer that uses a MAC protocol that creates a MAC frame by adding a MAC address or the like to an IP packet, The MAC address of the transmission destination is obtained from the IP address of the transmission destination to perform address resolution.

In the address resolution server, the computer that has transmitted the address resolution request packet is an ATM.
AT that creates ATM cells based on information such as addresses
If the computer uses the M protocol,
The transmission destination ATM address is obtained from the transmission destination IP address to perform address resolution.

Therefore, by performing address resolution by the address resolution server, when performing communication between a plurality of computers using the ATM protocol on a non-broadcast type network using the ATM network, the MAC protocol is used. A communication environment in which communication is performed without emulation and communication is performed without emulating the ATM protocol when communication is performed between a plurality of computers using the MAC protocol on a broadcast network using Ethernet. Can be realized.

The communication between the broadcast network using the Ethernet and the non-broadcast network using the ATM network without emulating the MAC protocol makes it possible to transmit the TOS of the IP packet to the ATM connection. (Type Of Servi
ce) field describes the quality of service (QOS:
By setting Quality of Service, it is possible to realize a communication environment for performing high-quality communication, or performing communication with specified quality such as suppressing communication quality in accordance with communication contents. Become.

As described above, according to the address resolution server, the address resolution request packet from the computer connected to the network is the same type as the hardware address used by the computer that transmitted the address resolution request packet. Since the hardware address is returned, it is possible to reduce the processing load of communication in a network in which a plurality of segments using different communication protocols are connected, and to realize an environment for performing communication with specified quality.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings together with an embodiment.

Hereinafter, in the address resolution server of the present invention, different types of segments between a LAN segment formed by a broadcast network using Ethernet and a LAN segment formed by a non-broadcast network using an ATM network are described. An address resolution server according to an embodiment that performs address resolution when data is transferred through a segment having a different communication protocol in a single mixed subnet will be described.

FIG. 1 is a diagram showing a schematic configuration of a communication system having an address resolution server according to the present embodiment. FIG.
1A is a heterogeneous segment combined single IP subnet, 1B and 1C are broadcast LAN segments, 1D is a non-broadcast wide area network, 1E is a non-broadcast LAN segment,
F and 1G are interworking units, 1H is a transmitting terminal, 1I is a receiving terminal, 1J is a transmitting terminal, 1K is a receiving terminal, and 1L is an address resolution server.

As shown in FIG. 1, a heterogeneous segment combined single IP subnet 1A, which is a communication system having the address resolution server of the present embodiment, includes a broadcast LAN segment 1B and 1C and a non-broadcast type wide area network. 1D and non-broadcast type L
AN segment 1E and interworking unit 1F
1G, a transmitting terminal 1H, a receiving terminal 1I, a transmitting terminal 1J, a receiving terminal 1K, and an address resolution server 1L.

Further, as shown in FIG. 1, in the communication system having the address resolution server of the present embodiment, the broadcast LA
By connecting the N segment 1B and the non-broadcast type wide area network 1D via the interworking unit 1F, and connecting the broadcast type LAN segment 1C and the non-broadcast type wide area network 1D via the interworking unit 1G. , A heterogeneous segment composite single IP subnet 1A.

The apparatus that communicates on the heterogeneous segment combined single IP subnet 1A, which is a communication system having the address resolution server of the present embodiment, has an IP address, MA
C address or ATM address is set.

In the heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment, an interworking unit 1F for connecting the broadcast LAN segments 1B and 1C and the non-broadcast wide area network 1D. And 1G are devices such as bridges for connecting a broadcast network using Ethernet or the like and a non-broadcast network using an ATM network or the like, and transmitting frames or cells transmitted from mutual networks. Looking ahead, if the frame or cell is to be transmitted to the other network, convert the frame or cell to the data format of the other network, and then convert the converted frame or cell on the other network. To be sent.

The broadcast type LAN segment 1B of the heterogeneous segment composite type single IP subnet 1A having the address resolution server of the present embodiment has "I
P. 1.1. Is set, and the calling terminal 1H having the MAC address set to "MAC. 1." is connected, and the broadcast type LAN segment 1C is set to the IP address "IP.1.2." And MAC
The receiving terminal 1I to which "MAC. 4." is set as the address is connected.

Although not shown in FIG. 1, a heterogeneous segment composite type single I having the address resolution server of the present embodiment is provided.
The P subnet 1A has the IP address “IP.1.3.”
A sending terminal 1J in which an ATM address "ATM 3.1." Is set, a receiving terminal 1K in which an IP address "IP 1.4." And an ATM address "ATM 4.1." IP address "IP.1.5.", MAC
Address “MAC.2.” And ATM address “AT
M. 1.1. Is set, the IP address “IP.1.6.”, The MAC address “MAC.3.”, And the ATM address “ATM.
2.1. Interworking unit 1G with ""
And the virtual MAC address “MAC.9.” And AT
A non-broadcast type wide area network 1D is constituted by an ATM switch connecting the address resolution server 1L to which the M address "ATM.5.1." Is set.

The transmitting terminal 1J and the receiving terminal 1K are connected to the non-broadcast type LAN segment 1E by the ATM switch.
And not shown in FIG. 1, the non-broadcast type L
"MAC. 9." is set as a virtual MAC address for the transmission terminal 1J and the reception terminal 1K of the AN segment 1E.

FIG. 2 is a diagram showing a functional configuration of the address resolution server of the present embodiment. In FIG. 2, 2A is an address resolution processing unit, 2B is an address resolution request receiving unit, 2C
Is an address resolution response unit.

As shown in FIG. 2, the address resolution server of the present embodiment has an address resolution processing section 2A, an address resolution request receiving section 2B, and an address resolution response section 2C.

As shown in FIG. 2, in the address resolution server of the present embodiment, an address resolution request receiving means for receiving an address resolution request packet from a device connected to the heterogeneous segment combined single IP subnet 1A. An address resolution processing unit 2A, which is an address resolution processing means for performing address resolution, is connected to the address resolution request receiving unit 2B, and the address resolution response packet is sent to the address resolution processing unit 2A to the source of the address resolution request packet. Is connected to an address resolution response unit 2C which is an address resolution response means for returning a response.

The address resolution request receiving unit 2B of the address resolution server of the present embodiment is a
The address resolution processing unit 2A receives an address resolution request packet from the non-broadcast type wide area network 1D of the P subnet 1A,
A specific type of hardware address is obtained by searching the address management table according to the contents of the address resolution request packet received by the address resolution request receiving unit 2B, and the address resolution response unit 2C is obtained by the address resolution processing unit 2A. An address resolution response packet storing the specific type of hardware address is generated, and the address resolution response packet is returned to the transmission source of the address resolution request packet.

FIG. 3 is a diagram showing an example of the address management table of the address resolution server according to the present embodiment. In FIG. 3, 3A is an IP address description field, 3B is an ATM address description field, and 3C is a MAC address description field.

As shown in FIG. 3, the address management table of the address resolution server of the present embodiment has an IP address description column 3A, an ATM address description column 3B, and a MAC address description column 3C.

As shown in FIG. 3, in the address management table of the address resolution server according to the present embodiment, the IP address description field 3A, the ATM address description field 3B, and the MAC address
In the address description column 3C, the transmitting terminal 1H in the broadcast LAN segment 1B, the receiving terminal 1I in the broadcast LAN segment 1C, and the non-broadcast LAN segment 1E shown in FIG.
IP address, ATM of sending terminal 1J and receiving terminal 1K, and interworking units 1F and 1G within
The address and the MAC address are registered.

The address management table of the address resolution server according to the present embodiment corresponds to the address resolution server 1 shown in FIG.
L in the IP address description field 3A of the address management table, as key information for searching the address management table, all the IP addresses in the heterogeneous segment composite single IP subnet 1A are provided. The IP addresses assigned to the terminal and the interworking units 1F and 1G are registered.

In the address management table of the address resolution server of the present embodiment, the interworking units 1F and 1G on the non-broadcast type wide area network 1D, the transmitting terminal 1J in the non-broadcast type LAN segment 1E, and the non-broadcast type Type LA
The ATM address of each device is registered in the ATM address description field 3B corresponding to the IP address of the receiving terminal 1K in the N segment 1E.

Further, in the address management table of the address resolution server of the present embodiment, the AT corresponding to the IP address of the calling terminal 1H in the broadcast type LAN segment 1B.
In the M address description column 3B, the broadcast LAN segment 1
B and the non-broadcast type wide area network 1D are registered with the ATM address of the interworking unit 1F. The ATM address description field 3B corresponding to the IP address of the receiving terminal 1I in the broadcast type LAN segment 1C is registered in the ATM address description field 3B. , Broadcast type L
The ATM address of the interworking unit 1G that connects the AN segment 1C and the non-broadcast wide area network 1D is registered.

Further, in the address management table of the address resolution server of the present embodiment, the originating terminal 1H in the broadcast LAN segment 1B, the broadcast LAN segment 1
The MAC address of each device is registered in the MAC address description column 3C corresponding to the IP address of the receiving terminal 1I, the interworking units 1F, and 1G in C.

In the address management table of the address resolution server according to the present embodiment, the originating terminal 1J in the non-broadcast type LAN segment 1E on the non-broadcast type wide area network 1D and the receiving terminal in the non-broadcast type LAN segment 1E. One “MAC.9.” Is set as a single virtual MAC address in the MAC address description column 3C corresponding to the IP address of the terminal 1K, and this value is registered.

Hereinafter, a heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment will be described.
, The transmitting terminal 1J in the non-broadcast type LAN segment 1E to the receiving terminal 1I in the broadcast type LAN segment 1C
A description will be given of a procedure for address resolution when an IP packet is transmitted to a server.

First, the transmitting terminal 1J in the non-broadcast type LAN segment 1E of the heterogeneous segment combined type single IP subnet 1A having the address resolution server of the present embodiment is connected to the receiving terminal 1I in the broadcast type LAN segment 1C. An address resolution request packet storing the IP address “IP.1.2.” Is created, and the created address resolution request packet is transmitted to the address resolution server 1L connected to the non-broadcast type wide area network 1D.

Here, the address resolution request packet created by the transmitting terminal 1J in the non-broadcast type LAN segment 1E is, for example, RFC1577 (Request For
Comment: 1577)
This is a packet requesting to resolve an ATM address from an address, and is a control packet different from a normal IP packet.

The address resolution request receiving unit 2B of the address resolution server 1L connected to the non-broadcast type wide area network 1D of the heterogeneous segment compound type single IP subnet 1A having the address resolution server of the present embodiment has a non-broadcast type. An address resolution request packet from the originating terminal 1J in the LAN segment 1E is received, and the received address resolution request packet is passed to the address resolution processing unit 2A.

The address resolution processing unit 2A of the address resolution server 1L of the present embodiment comprises an address resolution request receiving unit 2B
The IP address "IP.1.2." Of the receiving terminal 1I stored in the address resolution request packet received from the server is read.

Next, the address resolution server 1 of this embodiment
L of the receiving terminal 1
Using the IP address “IP.1.2.” Of I as a key, the address management table is searched, and the hardware address of the receiving terminal 1I is read from the address management table.

Here, the hardware address of the receiving terminal 1I read from the address management table by the address resolution processing unit 2A of the address resolution server 1L of the present embodiment is:
The address resolution request packet received from the address resolution request receiving unit 2B is an IP address defined by RFC1577.
Since it is a packet requesting to resolve the ATM address from the address, as shown in FIG. 3, the ATM address "ATM.2.1.1." Of the receiving terminal 1I described in the ATM address description column 3B of the address management table. ".

Next, the address resolution server 1 of this embodiment
L of the receiving terminal 1I read from the address management table.
M. 2.1. Is passed to the address resolution response unit 2C.

The address resolution response unit 2C of the address resolution server 1L of the present embodiment uses the ATM address “ATM.
2.1. Is generated and returned to the originating terminal 1J in the non-broadcast type LAN segment 1E.

Using the contents of the address resolution response packet responded as described above, the non-broadcast type LAN segment 1 is used.
The transmitting terminal 1J in E transmits an IP packet to the receiving terminal 1I in the broadcast type LAN segment 1C as follows.

That is, first, the transmitting terminal 1J in the non-broadcast type LAN segment 1E receives the address resolution response packet returned from the address resolution server 1L, and the ATM of the receiving terminal 1I in the broadcast type LAN segment 1C. Read the address "ATM.2.1."

Next, the transmitting terminal 1J in the non-broadcast type LAN segment 1E transmits the IP address “IP.1.2.” Of the receiving terminal 1I in the broadcast type LAN segment 1C, data to be transmitted, and the like. From the stored IP packet, the ATM address “ATM.2.
1. ATM cell is created based on information such as "ATM 2.1." In the non-broadcast type wide area network 1D.
Send to

The transmitting terminal 1J in the non-broadcast type LAN segment 1E creates an ATM cell on the assumption that the ATM address "ATM.2.1." Is the ATM address of the receiving terminal 1I, and transmits the created ATM cell. However, since the ATM address "ATM.2.1." Is actually the ATM address of the interworking unit 1G, the ATM cell transmitted by the calling terminal 1J transmits the broadcast type LAN segment 1C to the non-broadcast type. It is transmitted to the interworking unit 1G connected to the wide area network 1D.

The interworking unit 1G of the non-broadcast type wide area network 1D receives the ATM cell sent from the originating terminal 1J in the non-broadcast type LAN segment 1E and stores it in the received ATM cell. I of the IP packet
The P address is checked, and the IP address stored inside the ATM cell is the IP address "IP.1.2." Of the receiving terminal 1I in the broadcast LAN segment 1C.
In the IP packet, the MAC address “M
AC. 4. And the like are added, and the created MAC frame is transmitted to the broadcast type LAN segment 1.
Send on C.

The receiving terminal 1I in the broadcast-type LAN segment 1C receives the MAC frame transmitted on the broadcast-type LAN segment 1C by the interworking unit 1G, thereby receiving the non-broadcast-type LAN segment 1C.
The data transmitted from the transmitting terminal 1J in E is received.

As described above, the address resolution server of the present embodiment responds to the address resolution request packet from the transmission terminal 1J in the non-broadcast type LAN segment 1E by the reception terminal 1I in the broadcast type LAN segment 1C. A set to
Since the TM address is responded, the transmitting terminal 1J in the non-broadcast type LAN segment 1E transmits the broadcast type LAN segment 1C.
The IP packet to be transmitted to the receiving terminal 1I in the
After creating a MAC frame by adding an AC address or the like, emulation of a MAC protocol such as creating an ATM cell after adding a header created based on information such as an ATM address to the created MAC frame. Without performing this, it is possible to transmit data from the transmitting terminal 1J in the non-broadcast type LAN segment 1E to the receiving terminal 1I in the broadcast type LAN segment 1C.

Hereinafter, a heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment will be described.
, The transmitting terminal 1J in the non-broadcast type LAN segment 1E to the receiving terminal 1 in the non-broadcast type LAN segment 1E
The processing procedure of address resolution when transmitting an IP packet to K will be described.

First, the originating terminal 1J in the non-broadcast LAN segment 1E of the heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment is the receiving terminal 1K in the non-broadcast type LAN segment 1E. An address resolution request packet storing the IP address “IP.1.4.” Is generated, and the generated address resolution request packet is transmitted to the address resolution server 1L connected to the non-broadcast type wide area network 1D.

Here, the address resolution request packet created by the transmitting terminal 1J in the non-broadcast type LAN segment 1E is a control packet for requesting to resolve an ATM address from an IP address specified by RFC1577. .

The address resolution request receiving unit 2B of the address resolution server 1L of the present embodiment receives an address resolution request packet from the originating terminal 1J in the non-broadcast type LAN segment 1E, and converts the received address resolution request packet. The address is passed to the address resolution processing unit 2A.

The address resolution processing unit 2A of the address resolution server 1L of the present embodiment comprises an address resolution request receiving unit 2B
The IP address “IP.1.4.” Of the receiving terminal 1K stored in the address resolution request packet received from the server is read.

Next, the address resolution server 1 of this embodiment
L of the receiving terminal 1
Using the IP address “IP.1.4.” Of K as a key, an address management table is searched, and the hardware address of the receiving terminal 1K is read from the address management table.

Here, the hardware address of the receiving terminal 1K read from the address management table by the address resolution processing unit 2A of the address resolution server 1L of the present embodiment is:
The address resolution request packet received from the address resolution request receiving unit 2B is an IP address defined by RFC1577.
Since it is a packet requesting that the ATM address be resolved from the address, as shown in FIG. 3, the ATM address "ATM.4.1.1." Of the receiving terminal 1K described in the ATM address description field 3B of the address management table. ".

Next, the address resolution server 1 of this embodiment
The address resolution processing unit 2A of L receives the ATM address “AT” of the receiving terminal 1K read from the address management table.
M. 4.1. Is passed to the address resolution response unit 2C.

The address resolution response section 2C of the address resolution server 1L of the present embodiment transmits the ATM address "ATM.
4.1. Is generated and returned to the originating terminal 1J in the non-broadcast type LAN segment 1E.

Using the content of the address resolution response packet responded as described above, the non-broadcast type LAN segment 1 is used.
The transmitting terminal 1J in E transmits an IP packet to the receiving terminal 1K in the non-broadcast type LAN segment 1E as follows.

That is, first, the transmitting terminal 1J in the non-broadcast type LAN segment 1E receives the address resolution response packet returned from the address resolution server 1L, and transmits the address to the receiving terminal 1K in the non-broadcast type LAN segment 1E. The ATM address "ATM. 4.1." Is read.

Next, the transmitting terminal 1J in the non-broadcast type LAN segment 1E transmits the IP address “IP.1.4.” Of the receiving terminal 1K in the non-broadcast type LAN segment 1E, data to be transmitted, and the like. From the IP packet storing the ATM address “ATM.
4.1. ATM cell is created on the basis of information such as ".ATM.4." In the non-broadcast type wide area network 1D.
1. To ".

The receiving terminal 1K in the non-broadcast type LAN segment 1E receives the ATM cell transmitted from the calling terminal 1J in the non-broadcast type LAN segment 1E, and thereby transmits the ATM cell from the calling terminal 1J. Receive data.

As described above, the address resolution server of this embodiment responds to the address resolution request packet from the transmitting terminal 1J in the non-broadcast type LAN segment 1E by the receiving terminal in the non-broadcast type LAN segment 1E. Since the 1K ATM address is responded, the transmitting terminal 1J in the non-broadcast type LAN segment 1E adds a MAC address or the like to the IP packet to be transmitted to the receiving terminal 1K in the non-broadcast type LAN segment 1E and transmits the MAC address. After the frame is created, the non-broadcast type L is used without emulating a MAC protocol such as creating an ATM cell from the created MAC frame based on information such as an ATM address.
Non-broadcast LA from originating terminal 1J in AN segment 1E
It is possible to transmit data to the receiving terminal 1K in the N segment 1E. In the following, in the heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment, the transmission in the broadcast LAN segment 1B is performed. A description will be given of a processing procedure of address resolution when an IP packet is transmitted from the terminal 1H to the receiving terminal 1I in the broadcast type LAN segment 1C.

First, the originating terminal 1H in the broadcast type LAN segment 1B of the heterogeneous segment combined type single IP subnet 1A having the address resolution server of the present embodiment is connected to the IP address of the receiving terminal 1I in the broadcast type LAN segment 1C. By creating an address resolution request packet storing the address “IP.1.2.” And broadcasting the created address resolution request packet in the broadcast type LAN segment 1B, the created address resolution request packet is transmitted. The address is transmitted to the address resolution server 1L connected to the non-broadcast type wide area network 1D via the interworking unit 1F.

Here, the address resolution request packet created by the calling terminal 1H in the broadcast type LAN segment 1B is:
For example, the packet is a request for resolving a MAC address from an IP address as specified in RFC 826, and is a control packet different from a normal IP packet.

The address resolution request receiving unit 2B of the address resolution server 1L connected to the non-broadcast type wide area network 1D of the heterogeneous segment compound type single IP subnet 1A having the address resolution server of the present embodiment comprises a broadcast type LAN. An address resolution request packet from the originating terminal 1H in the segment 1B is received, and the received address resolution request packet is passed to the address resolution processing unit 2A.

The address resolution processing unit 2A of the address resolution server 1L of the present embodiment comprises an address resolution request receiving unit 2B
The IP address "IP.1.2." Of the receiving terminal 1I stored in the address resolution request packet received from the server is read.

Next, the address resolution server 1 of this embodiment
L of the receiving terminal 1
Using the IP address “IP.1.2.” Of I as a key, the address management table is searched, and the hardware address of the receiving terminal 1I is read from the address management table.

Here, the hardware address of the receiving terminal 1I read from the address management table by the address resolution processing unit 2A of the address resolution server 1L of the present embodiment is:
Since the address resolution request packet received from the address resolution request receiving unit 2B is a packet requesting to resolve a MAC address from an IP address as defined in RFC 826, as shown in FIG. The MAC address of the receiving terminal 1I described in the address description column 3C is “MAC.4.”.

Next, the address resolution server 1 of this embodiment
The address resolution processing unit 2A of L receives the MAC address “MA” of the receiving terminal 1I read from the address management table.
C. 4. Is passed to the address resolution response unit 2C.

The address resolution response unit 2C of the address resolution server 1L of the present embodiment transmits the MAC address “MAC. MAC” of the receiving terminal 1I received from the address resolution processing unit 2A.
4. To create an address resolution response packet containing
It returns to the originating terminal 1H in the broadcast type LAN segment 1B.

Using the contents of the address resolution response packet responded as described above, the broadcast type LAN segment 1B
The transmitting terminal 1H transmits an IP packet to the receiving terminal 1I in the broadcast LAN segment 1C as follows.

That is, first, the transmitting terminal 1H in the broadcast type LAN segment 1B receives the address resolution response packet returned from the address resolution server 1L, and the MAC address of the receiving terminal 1I in the broadcast type LAN segment 1C. "MAC. 4." is read.

Next, the transmitting terminal 1H in the broadcast LAN segment 1B stores the IP address “IP.1.2.” Of the receiving terminal 1I in the broadcast LAN segment 1C, data to be transmitted, and the like. A MAC frame is created by adding the read-out MAC address “MAC.4.” Of the receiving terminal 1I to the IP packet thus read, and is transmitted to the broadcast LAN segment 1B.

Interworking unit 1F for connecting broadcast type LAN segment 1B and non-broadcast type wide area network 1D
Receives the MAC frame transmitted by the calling terminal 1H in the broadcast type LAN segment 1B, and sets the MAC address of the received MAC frame to the broadcast type LAN segment 1B.
When detecting that it is not the above MAC address, the IP address of the IP packet stored inside the received MAC frame is checked, and the address resolution request storing the IP address “IP.1.2.” Of the IP packet is stored. The packet is sent to the address resolution server 1L, and the ATM address “AT” of the receiving terminal 1I in the broadcast type LAN segment 1C is sent.
M. 2.1. To get.

Next, the interworking unit 1F
After removing header information such as a MAC address from the MAC frame transmitted by the calling terminal 1H in the broadcast type LAN segment 1B to form an IP packet, based on information such as the ATM address "ATM.2.1." To create an ATM cell, and transfer the created ATM cell to the non-broadcast type wide area network 1.
The ATM address on D sends to "ATM.2.1."

The interworking unit 1F is an ATM
The address "ATM.2.1." Is the ATM of the receiving terminal 1I.
An ATM cell is created as an address, and the created ATM cell is transmitted. Actually, the ATM address "ATM.2.1."
Since the ATM address is G, the ATM cell transmitted by the interworking unit 1F is transmitted to the interworking unit 1G that connects the broadcast LAN segment 1C to the non-broadcast wide area network 1D.

The interworking unit 1G of the non-broadcast type wide area network 1D receives the ATM cell sent from the interworking unit 1F and changes the IP address of the IP packet stored inside the received ATM cell. It is checked that the IP address stored inside the ATM cell is the IP address "IP.1.2." Of the receiving terminal 1I in the broadcast type LAN segment 1C. A MAC frame is created by adding "MAC.4."
The C frame is sent out on the broadcast type LAN segment 1C.

The receiving terminal 1I in the broadcast-type LAN segment 1C receives the MAC frame transmitted on the broadcast-type LAN segment 1C by the interworking unit 1G, thereby receiving the non-broadcast-type LAN segment 1C.
The data transmitted from the transmitting terminal 1J in E is received.

As described above, in the address resolution server of the present embodiment, the originating terminal 1 in the broadcast type LAN segment 1B
H to address resolution request packet from H
MAC set to receiving terminal 1I in N segment 1C
Address, and an ATM address set to the receiving terminal 1I in the broadcast LAN segment 1C in response to an address resolution request packet from the interworking unit 1F in the non-broadcast type wide area network 1D. Without emulating an ATM protocol in the broadcast LAN segment 1B or emulating a MAC protocol in the non-broadcast wide area network 1D, via the non-broadcast wide area network 1D. Calling terminal 1H in segment 1B
Can transmit data to the receiving terminal 1I in the broadcast type LAN segment 1C.

Hereinafter, a heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment will be described.
, The transmitting terminal 1 in the broadcast type LAN segment 1B
H to receiving terminal 1K in non-broadcast LAN segment 1E
A description will be given of a procedure for address resolution when an IP packet is transmitted to a server.

First, the originating terminal 1H in the broadcast type LAN segment 1B of the heterogeneous segment combined type single IP subnet 1A having the address resolution server of the present embodiment is connected to the receiving terminal 1K in the non-broadcast type LAN segment 1E. By creating an address resolution request packet storing the IP address “IP.1.4.” And broadcasting the created address resolution request packet in the broadcast type LAN segment 1B, the created address resolution request packet To the address resolution server 1L connected to the non-broadcast type wide area network 1D via the interworking unit 1F.

Here, the address resolution request packet created by the calling terminal 1H in the broadcast type LAN segment 1B is:
For example, it is a control packet requesting resolution of a MAC address from an IP address, as specified in RFC826.

The address resolution request receiving unit 2B of the address resolution server 1L of the present embodiment receives an address resolution request packet from the originating terminal 1H in the broadcast type LAN segment 1B, and converts the received address resolution request packet into an address. It is passed to the solution processing unit 2A.

The address resolution processing unit 2A of the address resolution server 1L of the present embodiment comprises an address resolution request receiving unit 2B
The IP address “IP.1.4.” Of the receiving terminal 1K stored in the address resolution request packet received from the server is read.

Next, the address resolution server 1 of this embodiment
L of the receiving terminal 1
Using the IP address “IP.1.4.” Of K as a key, an address management table is searched, and the hardware address of the receiving terminal 1K is read from the address management table.

Here, the hardware address of the receiving terminal 1K read from the address management table by the address resolution processing unit 2A of the address resolution server 1L of the present embodiment is:
Since the address resolution request packet received from the address resolution request receiving unit 2B is a packet requesting to resolve a MAC address from an IP address as defined in RFC 826, as shown in FIG. The MAC address of the receiving terminal 1K described in the address description field 3C is “MAC.9.”.

Next, the address resolution server 1 of the present embodiment
The address resolution processing unit 2A of L receives the MAC address “MA” of the receiving terminal 1K read from the address management table.
C. 9. Is passed to the address resolution response unit 2C.

The address resolution response unit 2C of the address resolution server 1L of the present embodiment transmits the MAC address “MAC. MAC” of the receiving terminal 1K received from the address resolution processing unit 2A.
9. To create an address resolution response packet containing
It returns to the originating terminal 1H in the broadcast type LAN segment 1B.

Using the contents of the address resolution response packet responded as described above, the broadcast type LAN segment 1B
The transmitting terminal 1H transmits an IP packet to the receiving terminal 1K in the non-broadcast type LAN segment 1E as follows.

That is, first, the originating terminal 1H in the broadcast type LAN segment 1B receives the address resolution response packet returned from the address resolution server 1L, and sets the MAC address of the receiving terminal 1K in the non-broadcast type LAN segment 1E. The address “MAC.9.” Is read.

Next, the transmitting terminal 1H in the broadcast type LAN segment 1B transmits the IP address “IP.1.4.” Of the receiving terminal 1K in the non-broadcast type LAN segment 1E, data to be transmitted, and the like. In the stored IP packet, the read MAC address “MAC.9.” Of the receiving terminal 1K is added.
A MAC frame is created by adding the above information and transmitted to the broadcast type LAN segment 1B.

Interworking unit 1F for connecting broadcast type LAN segment 1B and non-broadcast type wide area network 1D
Receives the MAC frame transmitted by the calling terminal 1H in the broadcast type LAN segment 1B, and sets the MAC address of the received MAC frame to the broadcast type LAN segment 1B.
When detecting that it is not the above MAC address, the IP address of the IP packet stored inside the received MAC frame is checked, and the address resolution request storing the IP address “IP.1.4.” Of the IP packet is stored. The packet is sent to the address resolution server 1L, and the non-broadcast type LAN is sent.
The ATM address “A” of the receiving terminal 1K in the segment 1E
TM. 4.1. To get.

Next, the interworking unit 1F
After removing the header information such as the MAC address from the MAC frame transmitted by the transmitting terminal 1H in the broadcast type LAN segment 1B to form an IP packet, the IP packet is formed based on the information such as the ATM address "ATM. 4.1." Then, the ATM cell is created, and the created ATM cell is transmitted to the receiving terminal K in the non-broadcast type LAN segment 1E.

The receiving terminal 1K in the non-broadcast type LAN segment 1E receives the ATM cell sent from the interworking unit 1F, thereby transmitting the ATM cell from the transmitting terminal 1H in the broadcast type LAN segment 1B. Receive data.

As described above, in the address resolution server of the present embodiment, the originating terminal 1 in the broadcast type LAN segment 1B
Non-broadcast type L for address resolution request packet from H
MA set in receiving terminal 1K in AN segment 1E
C address, and an ATM address set in the receiving terminal 1K in the non-broadcast type LAN segment 1E in response to an address resolution request packet from the interworking unit 1F in the non-broadcast type wide area network 1D. So
Without emulating the ATM protocol in the broadcast type LAN segment 1B or emulating the MAC protocol in the non-broadcast type wide area network 1D, the non-broadcast type is transmitted from the originating terminal 1H in the broadcast type LAN segment 1B. It is possible to transmit data to the receiving terminal 1K in the LAN segment 1E.

As described above, by using the address resolution server of this embodiment, the ATM protocol and the MAC
It is possible to construct a heterogeneous segment composite type single IP subnet 1A composed of a plurality of LAN segments having heterogeneous LAN protocols, such as
Further, the ATM terminal accommodated in the LAN segment having the ATM protocol uses the A
The MAC terminal that communicates using only the TM protocol and is accommodated in the LAN segment having the MAC protocol is A
It is possible to realize a communication environment in which communication is performed using only the MAC protocol without using the TM protocol.

In the heterogeneous segment combined single IP subnet 1A having the address resolution server of the present embodiment, a MAC is used between a broadcast network using Ethernet and a non-broadcast network using ATM network. By performing communication without emulating the protocol, the quality of service (QOS: Qualified) described in the TOS (Type Of Service) field of the IP packet is established in the ATM connection.
By setting (ty of service), it is possible to realize a communication environment for performing high-quality communication or performing communication with specified quality such as suppressing communication quality in accordance with communication contents. Become.

As described above, according to the address resolution server of the present embodiment, the hardware address used by the computer that has transmitted the address resolution request packet is different from the address resolution request packet from the computer connected to the network. Responds to the same type of hardware address, reducing the processing load of communication in a network that combines multiple segments using different communication protocols and realizing an environment that performs quality-specified communication. It is.

Although the present invention has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the scope of the invention. It is.

[0134]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

That is, the same type of hardware address as the hardware address used by the computer that transmitted the address resolution request packet is responded to the address resolution request packet from the computer connected to the network, so that different communication is performed. It is possible to reduce the processing load of communication in a network in which a plurality of segments using a protocol are connected, and to realize an environment for performing communication with specified quality.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a communication system having an address resolution server according to an embodiment.

FIG. 2 is a diagram illustrating a functional configuration of an address resolution server according to the embodiment;

FIG. 3 is a diagram illustrating an example of an address management table of the address resolution server according to the embodiment;

[Explanation of symbols]

1A ... heterogeneous segment compound single IP subnet, 1B
And 1C: Broadcast LAN segment, 1D: Non-broadcast wide area network, 1E: Non-broadcast LAN segment, 1F and 1G
... Interworking unit, 1H ... Calling terminal, 1I ...
Receiving terminal, 1J originating terminal, 1K receiving terminal, 1L address resolution server, 2A address resolution processing unit, 2B ...
Address resolution request receiving unit, 2C ... Address resolution response unit,
3A: IP address description field, 3B: ATM address description field, 3C: MAC address description field.

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 12/56 H04L 12/28 H04L 12/46

Claims (1)

(57) [Claims] 1. An address resolution server for performing an address resolution for converting an address set by software having a higher-level communication protocol into a hardware address in a network connecting a plurality of segments using different communication protocols. An address management table in which a plurality of types of hardware addresses corresponding to the different communication protocols are registered for one address set by software having a higher-level communication protocol for each of the plurality of connected computers. Address resolution request receiving means for receiving an address resolution request packet transmitted from a plurality of computers connected to the network, and an address resolution request packet received by the address resolution request receiving means. Stored in the door
Corresponding to the address of the higher communication protocol
Among multiple types of hardware addresses, the address
Address resolution request packet
Address resolution processing means for obtaining the same type of hardware address from the address management table as
Characterized in that it comprises an address resolution response means for returning said address resolution process generates an address resolution response packet storing the hard ware address acquired by the means, the address resolution response packet to the sender of the address resolution request packet Address resolution server.