JPH098817A - ATM communication system - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the number of broadcast messages and improve the network efficiency in the address resolution method in the ATM communication network from the transmitting terminal to the receiving terminal. [Structure] One or more address resolution devices are arranged in a network, and an address resolution request message is not transferred to all connected destination terminals, but is transferred to the address resolution device and processed there. When the address resolution device recognizes that the received message is the address resolution request message, the address resolution device searches for a physical address corresponding to the logical address that requires the address resolution requested by the address resolution request message, and determines the destination of the message. The address is given to the physical address and returned to the sending terminal, and when it is searched for and cannot be found, it is transferred to another address resolution device.

Description

Detailed Description of the Invention

The present invention relates to an ATM (Asynchronous Trunk).
The present invention relates to an ansfer mode) communication system, and more particularly to a system for resolving addresses for high speed data communication in an ATM communication network.

With the recent increase in speed of computer systems and widening of private networks, high-speed data communication in public networks is required.

Therefore, the ATM generated from the transmitting terminal
In addition to connection-type data that has been set up by VCI (Virtual Connection Interface) in a cell, a predetermined address (destination physical address or physical address of the local station)
Connectionless data communication is provided with a unique header containing a.

When performing such data communication, the transmitting terminal needs to know (solve) the physical address of the other party.

[0004]

2. Description of the Related Art FIG. 16 conceptually shows a conventional ATM communication system. When a communication is performed from a transmitting terminal 6 to a receiving terminal (generally designated by a symbol T) via an ATM communication network NW, an address Address Resolution Protoc (ARP)
ol), the transmitting terminal 6 broadcasts to all the terminals T to which its own terminal is directly connected via the network NW.

That is, as shown in FIG. 17, an upper layer address resolution request (ARP) message (packet)
In order to generate a connectionless message from an ATM cell that further passes through a transmission line,
In the address resolution request message having the header format as shown in 8, the physical address of the own terminal (source) (eg 1C-044-777-1111), the logical address of the own terminal (eg 123.123.111.111), the reception The logical address (for example, 122.133.100.111) of the terminal (destination terminal) and "1" indicating the address resolution request are inserted in the operation code.

Next, the hexadecimal "0806" designating that it is an address resolution request message is assigned to the Ethernet type of the header format as shown in FIG.

Then, a connectionless type message in which, for example, 1E-044-888-1111 (E designates a plurality of destinations) is specified in the destination physical address of the header format shown in FIG. 20 is generated.

Further, the connectionless message is transferred to the lower layer ATM as shown in the protocol of FIG.
It mapped to a cell and broadcasted an address resolution request message.

[0009]

In the conventional ATM communication system shown in FIG. 16, address resolution is performed by broadcasting a message to all the terminals directly addressed to the own terminal. This address resolution has caused a problem that unnecessary messages increase on the network.

Therefore, it is an object of the present invention to reduce broadcast messages and improve network efficiency in an address resolution system in an ATM communication network from a transmitting terminal to a receiving terminal.

[0011]

In order to achieve the above object, the ATM communication system according to the present invention uses a message received from a transmission terminal 6 via an ATM switch SW as shown in principle in FIG. An address resolution request recognition unit 1 for recognizing whether or not the address resolution request message, and the address resolution request message when the address resolution request recognition unit 1 recognizes that the received message is the address resolution request message. An address resolution memory unit 2 for assigning a search result to the destination physical address of the message only when a physical address corresponding to a logical address required for the requested address resolution is searched and exists, and the address resolution memory unit 2 Addresses the message only when the search result is attached to the destination physical address An address resolution device including an address resolution response message generation unit 3 that transfers the address resolution response message and a message routing unit 4 that transfers the address resolution response message from the address resolution response message generation unit 3 to the transmission terminal. At least 5
One of them is provided, and when the message routing unit 4 receives the address resolution request message from the address resolution response message generation unit 3, it transfers the address resolution request message to another address resolution device 5.

When the address resolution request recognition unit 1 recognizes the received message as not the address resolution request message, it transfers the received message to the message routing unit 4, and the message routing unit 4 sends the received message. It can be transferred to another address resolution device 5.

Further, when the transmitting terminal 6 sets one or more fixed VCIs to the address resolving apparatus 5, the transmitting terminal 6 sends the address resolving request message as a connection type message. It is possible to recognize whether or not the message is the address resolution request message by transmitting by the ATM cell to which the fixed VCI is added, the address resolution request recognition unit 1 receiving the ATM cell and identifying the VCI. .

Further, when there is a call from the transmitting terminal 6 to the address resolving apparatus 5, the address resolving apparatus 5 regards the address resolving request message as a connection type message, and the transmitting terminal 6 and the address resolving apparatus. The address resolution request recognition unit 1 receives the ATM cell in which the exchange-type VCI is set after the establishment of the call setup between the five and recognizes the VCI by identifying the VCI, thereby recognizing whether or not the address resolution request message. You can

Further, at least the address resolution request recognition unit 1 of the address resolution device 5 is provided in a connectionless server capable of transferring a message from the transmission terminal 6 to the reception terminal, and the address resolution request message is transmitted. The address request recognition unit 1 in the connectionless server that has received the address resolution request message as a connectionless message sent from the sending terminal 6 by embedding recognizes whether or not the address resolution request message. can do.

Further, when the address resolution device part other than the address resolution request recognition part 1 exists outside the connectionless server, the address resolution device part performs both the connectionless type message and the connection type message. Can be processed.

Further, the address resolution request recognition unit 1 recognizes whether or not the address resolution request message is identified by identifying the destination physical address addressed to a specific individual or group in the header of the connectionless message. can do.

Further, the address resolution request recognition unit 1 can recognize whether or not it is the address resolution request message by identifying the higher layer protocol identifier (HLPI) in the header of the connectionless message. .

Further, by dividing the plurality of address resolution devices 5 into classes of the logical address and associating the specific physical addresses with the respective classes, the transmitting terminal 6 accommodates the logical address having the address resolution request. The address resolution request message can be sent only to the addressed address resolution device 5.

Further, by dividing the plurality of the address resolving devices 5 for each class of the logical address and associating the specific fixed VCI with each of them, the transmitting terminal 6 determines that the logical address for which the address resolving request is made. The address resolution request message can be transmitted only to the accommodated address resolution device 5.

Further, when a plurality of the address resolution devices 5 are connected in a ring shape and there is no physical address corresponding to the logical address required for the address resolution requested by the address resolution request message, the physical address It is also possible that the address resolution request message is transferred to the address resolution device 5 in which the address exists, the response is sent to the sending terminal 6, and the subsequent address resolution device 5 is not transferred.

Further, a plurality of the address resolution devices 5 are connected in a ring shape, the address resolution request message is processed, and at the same time, the message is transferred to another address resolution device 5 and requested by the address resolution request message. The address resolution device 5 having the physical address corresponding to the logical address that needs the address resolution can respond to the transmission terminal 6.

Further, among the plurality of address resolution devices 5,
When the first address resolution device 5 cannot process the address resolution request message, it can be broadcast from the first address resolution device 5 to other address resolution devices 5.

It is also possible for the transmission terminal 6 to broadcast to each address resolution device 5 by broadcasting with a destination address designating a specific group.

Further, the connectionless server sends the address resolution request message to the address resolution request recognition unit 1
It is also possible to broadcast to the address resolution device 5 other than the above.

[0026]

In the present invention, one or more address resolution devices 5 having the configuration shown in FIG. 1 are arranged in the network, and the address resolution request message is not transferred to all connected destination terminals, but the address resolution is performed. Transfer to the device,
By performing processing therefor, unnecessary broadcast packets in the network can be reduced.

First, in the case of performing address resolution for processing a connection type message, the transmitting terminal 6 has its own logical address and physical address in the address resolution header in the address resolution request message (packet) shown in FIG. Insert the operation code "1" that specifies the logical address and address resolution request, and then
An ATM cell in which a hexadecimal number "0806" is inserted to specify address resolution in the Ethernet type part of the LLC / SNAP header shown in 9, and the VCI to the address resolution device is set in the ATM cell header as shown in FIG. Is generated by mapping as shown in FIG. 6, and the address resolution request message is transferred to the address resolution device 5.

In this case, when the transmitting terminal 6 sets one or more fixed VCIs (PVC) for the address resolving apparatus 5, the transmitting terminal 6 sends the address resolving request message as a connection-oriented message. It is transmitted by an ATM cell to which a fixed VCI is added. Also, when a call is made from the sending terminal 6 to the address resolution device 5, the address resolution device 5 regards the address resolution request message as a connection type message, and the address resolution request message between the sending terminal 6 and the address resolution device 5 is considered. After the call setup is established, the ATM cell in which the switched VCI is set is received.

In the address resolution device 5, the address resolution request recognition unit 1 identifies whether or not the VCI of the received ATM cell is the address resolution request message. 1, and otherwise outputs it to the message routing unit 4 as it is.

The address resolution request recognition unit 1 preferably identifies, as shown in FIG. 4, whether the received ATM cell is an address resolution request message (step S).
1) VCI identification unit or destination physical address identification unit or HL
It has one of the configurations of the PI identification unit. When identifying by VCI, if the VCI of the received ATM cell is the VCI for the address resolution request message, it is transferred to the address resolution memory unit 2.

The address resolution memory unit 2 retrieves a physical address (eg, 1C-045-777-2222) corresponding to the destination logical address of the address resolution header unit shown in FIG. 18 of the address resolution request message.

That is, the address resolution memory unit 2 is shown in FIG.
As shown in FIG. 18, it comprises a memory 20 for associating a logical address with a physical address, and an address assigning unit 21 for inserting the retrieved physical address in the destination physical address part of the address resolution header part shown in FIG.

Here, it is judged whether or not the destination physical address requested by the address resolution request message exists (step S2), and when it is found that it exists, a search result is added to the destination physical address (step S3). ),
When it is determined that the address does not exist, the address resolution request message is passed as it is (step S4).

In the address resolution response message generation section 3, the operation code is rewritten to "2" which designates the address resolution response.

That is, the address resolution response message generator 3 converts the operation code into "2" if the destination physical address of the address resolution header has a search result as shown in FIG. 6 (steps S5, S).
However, if the search result is not added, the operation code is not changed (step S7).

Further, in the case of a connectionless type message, the source physical address of the address resolution header is added to the destination address of the connectionless type message. Here, an address resolution response message is generated from the address resolution request message.

The message routing unit 4 converts this address resolution response message into ATM cells, adds the set VCI to the transmission terminal 6, and returns the message.

That is, as shown in FIG. 7, the message routing unit converts the address resolution response message or the address resolution request message that could not be resolved into an ATM cell as usual in accordance with the operation code (step S8).

Here, the ATM cells are converted into A cells,
The address resolution request / response message is transferred to the TM network, and if it is the address resolution response message (code “2”), it is returned to the transmitting terminal 6, and the address resolution request message (code “1”) is sent to another address resolution device. Can be transferred.

As a result, address resolution can be performed without broadcasting the address resolution request message to all connected terminals.

On the other hand, when address resolution for processing a connectionless type message is performed, the transmitting terminal 6 has its own logical address and physical address in the address resolution header shown in FIG. The logical address of the called terminal and the operation code "1" designating the address resolution request are inserted, and then FIG.
Insert the hexadecimal number "0806" to specify the address resolution in the Ethernet type part of the LLC / SNAP header shown in
Further, as the destination physical address of the connectionless message header shown in FIG. 19, the physical address for the address resolution device (for example, 1C-043-222-1111) or HLPI is used.
And insert your physical address (eg 1C-044-777-1111).

Then, an ATM cell header as shown in FIG. 2 is added to form an ATM cell, and an address resolution request message is sent to the connectionless server.

The connectionless server checks the destination physical address of the received address resolution request message, HLPI, or the received VCI in the built-in address resolution request recognition section 1, and if the message is the address resolution request message, The data is transferred to the address resolution memory unit 2 of the address resolution device connected to the connectionless server or to the outside.

The address resolution memory unit 2 searches for a physical address corresponding to the destination logical address in the address resolution request message.

The address resolution response message generator 3
Rewrite the operation code to "2" and send terminal 6
The physical address of is inserted into the destination address of the connectionless message header.

The message routing unit 4 converts this address resolution response message into ATM cells, adds VCI, and transfers it to the transmission terminal 6.

As a result, address resolution can be performed without broadcasting to all terminals.

Here, when the entire address resolving apparatus 5 is in the connectionless server, the logical address is made to correspond to the address management table that the connectionless server has for routing the message, thereby externally resolving the address. The amount of hardware can be reduced as compared with the case where the device 5 is installed.

When there are a plurality of address resolution devices 5,
Connect them in a ring. Then, each address resolution device makes its own determination from the logical address in the address resolution memory unit 2 in response to the address resolution request.

If the corresponding physical address does not exist in its own address resolution memory unit 2, it is transferred to the next address resolution device 5.

When there are a plurality of address resolution devices 5,
To enable the sending terminal 6 to simultaneously transfer to the destination physical address to all the address resolution devices 5 (for example, 1E-044-222-555
5, E: Specify multicast) It is also possible to perform multicast.

As a result, the delay until the address resolution response message returns to the transmitting terminal 6 can be suppressed as compared with the ring form.

When the message is identified by the destination physical address identification unit or the HLPI identification unit, the BO of the ATM cell
The destination address or HLPI included in M is identified, and if it is the address resolution request message, the message is transferred to the address resolution memory unit 2.

[0054]

FIG. 8 shows an embodiment of an ATM communication system according to the present invention. In this embodiment, four address resolution devices 11 to 14 are installed for the transmission terminal 6, and the address resolution memory unit 2 of each address resolution device 11 to 14 has logical addresses divided into classes A to D, respectively. ing.

Therefore, when the sending terminal 6 knows the specific physical address for each class from the class of the destination logical address, the sending terminal 6 designates the class of the logical address, and Even if there are a plurality of resolution devices, the address resolution request message can be transferred only to the device that can resolve the logical address.

FIG. 9 shows another embodiment of the ATM communication system according to the present invention. In this embodiment, eight address resolution devices 211 to 241 are installed for the transmission terminal 6, and the address resolution memory unit 2 of each address resolution device 211 to 241 has a logical address as in the embodiment of FIG. Are divided into classes A to D, but address resolution devices 211 and 212, address resolution device 221
And 222, the address resolving devices 231 and 232, and the address resolving devices 241 and 242 are set to the same logical address class, and the address resolving memory unit 2 is distributed to a plurality of devices for each logical address class. Has been done.

Therefore, when the transmitting terminal 6 can set a specific multicast physical address from the class of the logical address of the destination for each of a plurality of address resolution devices that support the class, the transmitting terminal 6 determines the logical address of the logical address. Even if there are a plurality of address resolution devices, the address resolution request message can be transferred only to the address resolution device that supports the logical address class.

For example, with respect to the address resolution devices 221 and 22 having the common logical address class B, the transmitting terminal 6 simultaneously transfers the same address resolution request message to both.

FIG. 10 shows another embodiment of the ATM communication system according to the present invention. In this embodiment, as in the embodiment of FIG. 8, four address resolution devices 31 to 34 are installed for the transmission terminal 6, and the address resolution memory unit 2 of each address resolution device 31 to 34 has a logical address. Are divided into classes A to D.

If the sending terminal 6 can set a specific VCI for each class from the class of the destination logical address, the sending terminal 6 has a plurality of address resolution devices based on the class of the logical address. However, the address resolution request message can be transferred only to the device that can resolve the logical address.

For example, when the logical address of the address resolution device 34 is class D and it is known that this corresponds to a specific VCI-4, the transmitting terminal 6 sends the specific VCI-4 to the address resolution request message. If it is included and transferred, the above-mentioned search is automatically performed in the address resolution memory unit 2 of the address resolution device 34.

FIG. 11 shows another embodiment of the ATM communication system according to the present invention. In this embodiment, when there are a plurality of address resolution devices 41 to 43, these address resolution devices 41 to 43 are connected in a ring shape.

Then, the terminal 6 which sends the address resolution request message sends the message to a certain address resolution device 41. If the address resolving device 41 can resolve the address, the address resolving device 41 returns a response message to the transmitting terminal 6 and does not transfer the message to the subsequent address resolving devices 42 and 43. The address resolution request message is transferred to the next device 42 only when the address cannot be resolved.

As a result, unnecessary address resolution request messages can be reduced, and the network can be effectively used.

FIG. 12 shows another embodiment of the ATM communication system according to the present invention. Also in this embodiment, when there are a plurality of address resolution devices 51 to 53, these address resolution devices 51 to 53 are connected in a ring shape.

Then, the transmission terminal 6 transfers the address resolution request message to a certain address resolution device 51. The address resolution device 51 performs the address resolution processing, and at the same time, transfers the address resolution request message to the next device 52 regardless of the address resolution device 51 being unable to resolve the address.

As a result, in the address resolution response message, the processing delay of whether or not each address resolution device can resolve the address does not affect other devices, and the transmission terminal 6
It is possible to suppress the delay before returning to.

FIG. 13 shows another embodiment of the ATM communication system according to the present invention. In this embodiment, when there are a plurality of address resolution devices 61 to 63, the address resolution device 61 as the first server which receives the address resolution request message directly from the transmitting terminal 6 sends the address resolution request message If it cannot be processed, it is broadcast to the other address resolution devices 62 and 63.

This makes it possible to avoid unnecessary broadcast of the address resolution request message.

FIG. 14 shows another embodiment of the ATM communication system according to the present invention. In this embodiment, when there are a plurality of address resolving devices 71 to 73, the transmitting terminal 6 determines all the address resolving devices 7 in the network.
The address resolution request message is multicast to 1 to 73.

As a result, the delay until the address resolution response message returns to the transmitting terminal 6 can be suppressed.

FIG. 15 shows another embodiment of the ATM communication system according to the present invention. In this embodiment, the connectionless server 10 and the plurality of address resolution devices 81,
When there is 82, the connectionless server 10 that has received the address resolution request message broadcasts the address resolution request message.

This makes it possible to suppress the delay for address resolution as low as possible.

[0074]

As described above, the ATM according to the present invention
According to the communication method, one or more address resolution devices are arranged in the network, and the address resolution request message is transferred to all the connected destination terminals instead of being transferred to the address resolution device and processed there. Since it is configured as described above, unnecessary broadcast packets in the network are reduced to contribute to effective use of the network.

The present invention is not limited to address resolution for connectionless data communication, but is widely applied to address resolution for data communication in a public network.

[Brief description of drawings]

FIG. 1 is a block diagram showing a principle configuration of an address resolution device used in an ATM communication system according to the present invention.

FIG. 2 is a diagram showing a general ATM cell header format.

FIG. 3 is a diagram showing general mapping of connection-oriented messages.

FIG. 4 is a diagram conceptually showing the configuration of an address resolution request recognition unit in the address resolution device used in the ATM communication system according to the present invention.

FIG. 5 is a diagram conceptually showing the structure of an address resolution memory unit in the address resolution device used in the ATM communication system according to the present invention.

FIG. 6 is a diagram conceptually showing the structure of an address resolution response message generation unit in the address resolution device used in the ATM communication system according to the present invention.

FIG. 7 is a diagram conceptually showing the configuration of a message routing unit in the address resolution device used in the ATM communication system according to the present invention.

FIG. 8 is a block diagram showing an embodiment (1) of an ATM communication system according to the present invention.

FIG. 9 is a block diagram showing an embodiment (2) of the ATM communication system according to the present invention.

FIG. 10 is an embodiment (3) of the ATM communication system according to the present invention.
FIG.

FIG. 11 is an embodiment (4) of the ATM communication system according to the present invention.
FIG.

FIG. 12 is an embodiment (5) of the ATM communication system according to the present invention.
FIG.

FIG. 13 is an embodiment (6) of the ATM communication system according to the present invention.
FIG.

FIG. 14 is an embodiment (7) of the ATM communication system according to the present invention.
FIG.

FIG. 15 is an embodiment (8) of the ATM communication system according to the present invention.
FIG.

FIG. 16 is a block diagram conceptually showing the structure of a conventional ATM communication system.

FIG. 17 is a diagram showing a general mapping of connectionless type messages.

FIG. 18 is a diagram showing an address resolution header format.

FIG. 19 is a diagram showing an LLC / SNAP header format.

FIG. 20 is a diagram showing a header format of a connectionless type message.

[Description of Reference Signs] 1 Address resolution request recognition unit 2 Address resolution memory unit 3 Address resolution response message generation unit 4 Message routing unit 5 Address resolution device 6 Transmission terminal SW ATM switch In the drawings, the same reference numerals indicate the same or corresponding portions.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Watanabe ▼ Miwako 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Yutaka Esaki 1015 Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Stock In the company

Claims (15)

[Claims] 1. An address resolution request recognition unit for recognizing whether a message received from a transmitting terminal via an ATM switch is an address resolution request message, and the received message is said address resolution request message. When it is recognized by the resolution request recognition unit, the physical address corresponding to the logical address that requires the address resolution requested by the address resolution request message is searched and the search result is added to the destination physical address of the message only when it exists. And an address resolution response message generation unit that transfers the message as an address resolution response message only when a search result is attached to the destination physical address in the message from the address resolution memory unit, From the address resolution response message generator, At least Kosonae and message routing unit transfers the address resolution response message to the transmitting terminal in the configured address resolution device,
An ATM communication system, wherein the message routing unit transfers the address resolution request message to another address resolution device when receiving the address resolution request message from the address resolution response message generation unit. 2. The address routing request recognition unit according to claim 1, when the received message is recognized as not the address resolution request message, the received message is transferred to the message routing unit, and the message routing unit receives the received message. An ATM communication system characterized by transferring a message to another address resolution device. 3. The address resolution request as a connection type message according to claim 1 or 2, when the transmission terminal sets one or more fixed VCIs to the address resolution device. Send the message to the fixed VCI
ATM communication characterized in that the address resolution request recognition unit recognizes whether or not the address resolution request message is received by receiving the ATM cell and identifying the VCI. method. 4. The address resolving apparatus according to claim 1, wherein when the transmitting terminal makes a call to the address resolving apparatus, the address resolving apparatus considers the address resolving request message as a connection type message, and The address resolution request recognition unit receives the ATM cell in which the exchange-type VCI is set after the call setup between the address resolution devices is established, and identifies the VCI by identifying the VCI, thereby recognizing whether the message is the address resolution request message or not. An ATM communication method characterized by: 5. The address resolution request recognition unit according to claim 1 or 2, wherein at least the address resolution request recognition unit is provided in a connectionless server capable of transferring a message from the sending terminal to the receiving terminal, Whether the address request recognition unit in the connectionless server that has received the address resolution request message as a connectionless message sent from the sending terminal by embedding the address resolution request message is the address resolution request message ATM communication method characterized by recognizing whether or not. 6. The address resolving device part according to claim 5, wherein the address resolving device part other than the address resolving request recognition part exists outside the connectionless server. ATM characterized by being able to process both messages
Communication method. 7. The address resolution request message according to claim 5, wherein the address resolution request recognition unit identifies the destination physical address addressed to a specific individual or group in the header of the connectionless message. An ATM communication system characterized by recognizing whether or not. 8. The address resolution request recognition unit according to claim 5, wherein the address resolution request message is recognized by identifying a higher layer protocol identifier in the header of the connectionless message. ATM communication system characterized by. 9. The transmission terminal according to claim 1 or 5, wherein a plurality of address resolution devices are divided into classes of the logical address, and the specific physical address is associated with each of the classes, so that the transmission terminal can respond to the address resolution request. An ATM communication system characterized in that the address resolution request message is sent only to the address resolution device accommodating a certain logical address. 10. The transmission terminal according to claim 2, wherein the plurality of address resolution devices are divided into classes of the logical address, and the specific fixed VCI is associated with each of them, so that the transmission terminal has the address resolution request. An ATM communication system characterized in that the address resolution request message is sent only to the address resolution device that accommodates a logical address. 11. The method according to any one of claims 1 to 10,
When a plurality of the address resolution devices are connected in a ring shape and there is no physical address corresponding to the logical address requiring the address resolution requested by the address resolution request message, the physical address exists An ATM communication system characterized in that the address resolution request message is transferred to a resolution device, responds to the transmission terminal, and is not transferred to the address resolution device thereafter. 12. The method according to any one of claims 1 to 10,
A logic that connects a plurality of the address resolution devices in a ring shape, processes the address resolution request message, transfers the message to another address resolution device at the same time, and requires the address resolution requested by the address resolution request message. An AT characterized in that the address resolution device having a physical address corresponding to the address responds to the transmission terminal.
M communication method. 13. The method according to claim 1, wherein
An ATM characterized by broadcasting the address resolution request message from the first address resolution device to another address resolution device when the first address resolution device cannot process the address resolution request message among the plurality of address resolution devices.
Communication method. 14. The method according to any one of claims 1 to 10,
An ATM communication system characterized in that the transmission terminal broadcasts to a destination group designating a specific group and transfers the broadcast address to each address resolution device. 15. The ATM communication system according to claim 5, wherein the connectionless server broadcasts the address resolution request message to the address resolution device other than the address resolution request recognition section.