JPH09139742A - Address management system in atm-lan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the operating efficiency of a network by learning and registering a source address with respect to an ATM address inquiry from a terminal equipment so as to reduce the probability of address analysis through a broadcast. SOLUTION: When an ATM address of an opposite terminal equipment 12 is not clear, an outgoing terminal equipment 11 inquires about it of a server 21. The server 21 registers cross reference between a protocol address and an ATM address of the outgoing terminal equipment 11 to an ATM address table 21a. Then an ATM address of the opposite terminal equipment 12 is retrieved from an ATM address table 21a. When the ATM address is in existence, it is informed to the outgoing terminal equipment 11, and when not, the inquiry is broadcast to all terminal equipments via an ATM exchange 31. Upon the reception of the inquiry transferred from a server 21, the opposite terminal equipment 12 informs an ATM address of its own terminal equipment to the server 21 when the address is coincident with a protocol address of its own terminal equipment. Then the server 21 informs it to the outgoing terminal equipment 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN (ATM-LAN) using an ATM communication system, and particularly to a plurality of terminals and an ATM address table for storing a correspondence relationship between a protocol address of each terminal and an ATM address. ATM-LAN equipped with a server and an ATM exchange accommodating each terminal and server, and such ATM-L
The present invention relates to an address management system in AN.

With the improvement in performance of personal computers and workstations, applications that handle high-speed data and multimedia are rapidly spreading. Also, LAN
Technologies such as remote file access via the Internet and distributed computing have been established, and recently, expectations for a higher-speed LAN compatible with multimedia are increasing.

In response to such expectations, research and development of a LAN (ATM-LAN) using the ATM communication system has been activated. The ATM-LAN is a switching LAN in which each terminal is connected in a star shape to a device having an ATM switching function (for example, an ATM switch), and each terminal is
To the destination terminal, a virtual channel (Virtual Channel: V
C) is set and a fixed length packet (ATM cell) consisting of a 5-byte header and 48-byte data
Data transfer is performed. Therefore, a large number of VCs (the number of which can be represented by VPI / VCI) can be set on the terminal interface, and the terminal can simultaneously communicate with a plurality of partner terminals via the set VCs.

In such an ATM-LAN, address management (mapping from a protocol address to an ATM address) for connectionless communication, which is performed in a conventional LAN, can be efficiently performed. Are required to do so.

[0005]

2. Description of the Related Art Generally, when performing communication on a LAN, the calling terminal needs to know the physical address of the other terminal. This corresponds to the MAC address in the conventional LAN, and in the conventional LAN, each terminal has an address resolution protocol (AR).
In P), the MAC address is analyzed from the upper protocol address, and the MAC address acquired by this is used to frame the upper packet for communication.

On the other hand, in the ATM-LAN based on the connectionless type communication, a VC is set between the terminals and the upper packet is made into cells for communication. Therefore, the physical address at this time is the address of the ATM layer. (VP
I / VCI). Since this is determined by the SETUP sequence using the ATM address (terminal address), the ATM-LAN requires a method of analyzing the ATM address from the higher protocol address.

Conventionally, as a method of analyzing an ATM address from a higher-order protocol address, there are known a method of broadcasting by all terminals and a method of providing an address server in the ATM-LAN and inquiring about it to know the ATM address. Has been.

FIG. 7 shows an AT based on the broadcast method.
It is a sequence diagram which shows M address analysis. In the broadcast method, if the ATM address of the other terminal is unknown at the time of the communication request, broadcasting is performed in the network and the terminal is directly inquired. It is not necessary to create a database and it is easy to implement.

However, in the case of the broadcast method, when frequent communication is performed with an unspecified terminal, the AR by broadcast is generated every time a communication request is generated.
Since P is performed, there is a problem that control traffic based on this is increased. In particular, this problem becomes remarkable due to the increase in the number of terminals and the expansion of the network scale.

FIG. 8 is a sequence diagram showing ATM address analysis by the server system. In the server method, if the ATM address of the other terminal is unknown at the time of the communication request, it simply queries the server having the ATM address table, so this control traffic is not broadcast, and therefore the control traffic is minimized. It is possible to limit it.

However, in the server system, ATM-L
Since it is necessary to register information on all terminals connected to the AN in advance, not only this kind of setting work is required at the time of initial installation, but database updating work is also performed each time terminals are added or relocated. Is required. In addition, there is a problem that a large-capacity database is required as the number of terminals increases and the network scale expands, and the hardware scale of the server increases.

[0012] On the other hand, Japanese Patent Application No.
In 153381, the broadcast method and the server method are used together to manage the ATM address, thereby suppressing the increase of the control traffic, and
An address management system is disclosed that can eliminate the need for initializing the contents of the TM address table.

FIG. 9 shows the configuration of an address management system in the conventional ATM-LAN to which the present invention is applied. In the figure, 11, 12, 13, ...
21 is a server, 31 is A for accommodating each terminal and server
It is a TM exchange.

In each terminal 11-13, 11a-
Reference numeral 13a is an ATM address inquiry request generating means, which sends out an inquiry request for the ATM address to the server 21 when the ATM address of the partner terminal is unknown during communication. 11b to 13b are communication means,
A notified from the server 21 in response to the inquiry request
The TM address is used to communicate with the partner terminal via the ATM exchange 31. Reference numerals 11c to 13c are ATM address response means, which are ATs transferred from the server 21.
If the protocol address included in the M address inquiry request matches the protocol address of the own terminal,
It responds to the server 21 with the ATM address of its own terminal.

In the server 21, 21a is an ATM address table, which stores the correspondence between the protocol address of each terminal and the ATM address by learning.
Reference numeral 21b is a search means, which searches the ATM address table 21a for an ATM address corresponding to the protocol address included in the ATM address inquiry request from the terminal. Reference numeral 21c denotes an ATM address inquiry request transfer means, which sends an ATM address inquiry request to the ATM switch 31 when the inquired ATM address cannot be obtained from the ATM address table 21a.
Broadcast to all terminals via. 21d is AT
The M address responding means responds the inquired ATM address to the terminal which issued the inquiry request.

The operation of the conventional system in the configuration shown in FIG. 9 is as follows. The calling terminal 11 sends out an ATM address inquiry request to the server 21 by an ATM-ARP request message when the ATM address of the partner terminal 12 is unknown during communication.

FIG. 10 shows the format of the ATM-ARP request message / response message. In the figure, 100 is a protocol type, which indicates a higher protocol type (IP or the like). Reference numeral 101 is an ATM address length, which indicates the address length of the ATM address used in the ATM network. Reference numeral 102 denotes a protocol address length, which indicates the address length of a higher level protocol (IP
Is 4 bytes). 103 is an operation
It is a code (1: request, 2: response). Reference numeral 104 is an ATM address (source address) of the request source terminal. Reference numeral 105 is a protocol address (source address) of the request source terminal. 106 is the ATM address of the target terminal. 107 is the protocol address of the target terminal.

When the server 21 receives the ATM address inquiry request from the terminal 11, the server 21 corresponds to the protocol address of the terminal 12 included in the inquiry request.
The TM address is searched by referring to the ATM address table 21a.

If the ATM address corresponding to the protocol address is registered in the ATM address table 21a, the server 21 notifies the terminal 11 of this ATM address. If AT corresponding to protocol address
If the M address is not registered in the ATM address table 21a, the server 21 transfers (broadcasts) an ATM address inquiry request including this protocol address to all the terminals 12, 13, ... Through the ATM switch 31. .

When the terminals 12, 13, ... Receive the ATM address inquiry request transferred from the server 21, it is determined whether or not the protocol address included in the inquiry request matches the protocol address of the own terminal. To check.

The terminal 12 notifies the server 21 of the ATM address of its own terminal because the protocol address contained in the inquiry request matches the protocol address of its own terminal. The server 21 notifies the calling terminal 11 of the notified ATM address. As a result, the calling terminal 11 uses the ATM address notified by the server 21
A path is set and communication is performed with the partner terminal 12 via the exchange 31.

Thus, in response to an ATM address inquiry request, this ATM address is the ATM of the server.
When registered in the address table, the target ATM address can be obtained by operating in the same manner as the conventional server system. If the ATM address is not registered in the ATM address table, the ATM address inquiry request can be broadcast to obtain the desired ATM address.

Further, when the server receives the response notification of the ATM address from the predetermined terminal, the server newly registers the correspondence between the protocol address of this terminal and the notified ATM address in the ATM address table. In this way, if there is an inquiry about this ATM address after registration, it is not necessary to broadcast this inquiry request, and the AT address can be easily obtained from the ATM address table.
The M address can be obtained.

That is, it is possible to manage the ATM address by using both the broadcast method and the server method, and further, by sequentially registering the correspondence relationships obtained by the broadcast method in the ATM address table, The ATM address table can be enhanced, and the initialization work of the ATM address table can be eliminated.

[0025]

In the conventional address management system, when the server receives an ATM address inquiry request, this inquiry message (ATM-ARP) is issued.
The source address (ATM address and protocol address) of the request message can be further enhanced by registering it in the server, but the conventional address management method does not perform such processing. .

When a terminal is added / relocated, the terminal issues an ATM address inquiry request addressed to itself, so that the source address learning described above can be used to broadcast the address in the server without broadcasting. Can be registered and changed, but the conventional method has not performed such processing.

The present invention is intended to solve such a problem of the prior art, and in the address management system in the ATM-LAN, the ATM-ARP from the terminal is used.
By performing learning registration for the source address of the request as well, it is possible to reduce the probability that address analysis will be performed by broadcasting, thus reducing control traffic and enabling more efficient network operation. The purpose is to do so.

[0028]

Means for solving the problems of the present invention will be described below.

(1) A plurality of terminals 11, 12, 13, ...
A server 21 having an ATM address table that registers the correspondence between the protocol address and ATM address of each terminal, and an ATM that accommodates each terminal and address server
In the address management system in the ATM-LAN provided with the exchange 31, the calling terminal uses the A
If the TM address is unknown, ATM is sent to the server 21.
Send an address inquiry request.

When the server 21 receives the ATM address inquiry request from the calling terminal, the server 21 registers the correspondence between the protocol address and the ATM address of the calling terminal included in this inquiry request in the ATM address table and includes it in the inquiry request. The ATM address corresponding to the protocol address of the partner terminal is searched from the ATM address table, and if the ATM address corresponding to this protocol address is obtained from the ATM address table, this ATM address is notified to the calling terminal.
When the TM address cannot be obtained from the ATM address table, an ATM address inquiry request including the protocol address is broadcast to all terminals via the ATM exchange 31.

The other terminal is the AT transferred from the server 21.
When the M address inquiry request is received, if the protocol address included in this inquiry request matches the protocol address of the own terminal, the ATM address of the own terminal is notified to the server 21.

The server 21 sends the AT of the notified terminal
Notify the calling terminal of the M address.

(2) In the case of (1), when a terminal is added or relocated, the terminal sends an ATM address inquiry request addressed to itself to register or change the address in the server 21. .

(3) A plurality of terminals 11, 12, 13, ...
In the address management system in the ATM-LAN provided with the server 21 having the ATM address table 21a for registering the correspondence between the protocol address of each terminal and the ATM address, and the ATM switch 31 which accommodates each terminal and the server, Configure the server as follows:

The terminals 11, 12, 13, ... If the ATM address of the other terminal is unknown during communication, the server 21
To send an ATM address inquiry request to the AT
M address inquiry request generation means 11a, 12a, 1
3a, ..., And the ATM switch 31 using the ATM address notified from the server 21 in response to this inquiry request.
Communication means 11b, 12b for communicating with the other terminal via
, And the protocol address included in the ATM address inquiry request transferred from the server 21 match the protocol address of the own terminal, the ATM address responding means 11c for responding the ATM address of the own terminal to the server 21. 12c, 13c, ...

The server 21 searches the ATM address table for the ATM address corresponding to the protocol address included in the ATM address inquiry request from the terminal, and the ATM address corresponding to this protocol address in the ATM address table. If not registered, AT containing this protocol address
The ATM address inquiry request transfer means 21c for broadcasting the M address inquiry request to all terminals via the ATM switch 31 and the ATM address obtained from the ATM address table or the ATM address obtained by the response from the terminal are used as the inquiry request. And an ATM address responding means 21d for notifying the terminal which has sent the request, and when the ATM address inquiry request from the calling terminal is received, the correspondence relation between the protocol address and the ATM address of the calling terminal included in the inquiry request is sent to the ATM address. Register in the table.

(4) In the case of (3), when a terminal is added or relocated, the terminal sends an ATM address inquiry request addressed to itself to register or change the address in the server 21. .

(5) A plurality of terminals 11, 12, 13, ...
In the address management system in the ATM-LAN provided with the server 21 that manages the correspondence between the protocol address of each terminal and the ATM address, and the ATM switch 31 that accommodates each terminal and server, the server is configured as follows. .

ATM address table 2 for storing the correspondence between the protocol address and ATM address of each terminal
1a and a search means 21b for searching the ATM address table for an ATM address corresponding to the protocol address included in the ATM address inquiry request from the terminal.
And an ATM for inquiring the terminal of the ATM address corresponding to this protocol address via the ATM switch 31.
The address inquiry request transfer means 21c and the ATM address obtained from the ATM address table or the ATM address obtained from the response from the terminal are transferred to the ATM.
AT for notifying the terminal that sent the address inquiry request
M address response means 21d.

Upon receipt of the ATM inquiry request from the calling terminal, the AT corresponding to the protocol address of the calling terminal included in the ATM address inquiry request is received.
The M address is registered in the ATM address table 21a, and the ATM address corresponding to the protocol address of the partner terminal included in the ATM address inquiry request is searched from the ATM address table 21a. If this ATM address is not registered, the broadcast is performed. AT responded by inquiring ATM address by
Notify the calling terminal of the M address.

As described above, according to the present invention, the learning registration is performed for the source address of the ATM-ARP request from the terminal, so that the probability of address analysis by broadcast is reduced. Therefore, the control traffic can be reduced, and more efficient network operation can be performed.

[0042]

1 and 2 show a first embodiment (1), (2) of the present invention, in which an ATM-LAN is used.
2 shows an example of the communication sequence and its entire communication sequence. Further, FIG. 3 is a flowchart showing a first operation example of the terminal according to the first embodiment, showing a case where a communication request is generated. FIG.
6 is a flowchart showing a second operation example of the terminal according to the first embodiment, showing the time when ATM-ARP is received. FIG. 5 is a flowchart showing an operation example of the server according to the first embodiment. In addition, in FIGS. 1 and 2, A,
B, C, D indicate protocol addresses, and a, b, c,
d indicates an ATM address.

The terminal that has made the communication request refers to the cache (memory) of its own terminal to refer to the ATM of the communication partner.
Whether or not the address is registered is checked (normally, the information of the other party to communicate with after the power is turned on is not registered in this cache). If registered, this A
Using the TM address, SETUP is executed to set a path for communication, but if it is not registered, an ATM-ARP request is sent to the server to inquire the ATM address for the protocol address of the communication partner. In the examples of FIGS. 1 and 2, the case where the terminal A communicates with the terminal D and then the communication request from the terminal C to the terminal A occurs.

At the server, the ATM-ARP is sent from the terminal.
When the request is received, the correspondence between the protocol address of the source address and the ATM address shown therein is registered in the ATM address table. For target address, AT for protocol address
It is checked whether or not the M address is registered in the ATM address table. If registered, the information (AT
(M address) is returned to the terminal as an ATM-ARP response.

On the other hand, if not registered, this ATM
-Transfer the ARP request to all terminals using the broadcast function of the switch. In the examples of FIGS. 1 and 2, the information of the terminal D is not registered in response to the inquiry from the terminal A, and the subsequent inquiry from the terminal C occurs in the terminal A. It shows a case where the information is registered by the source address learning of the ATM-ARP equest that was previously performed.

ATM-ARP transferred from the server
When each terminal receives the request, each terminal determines whether or not it is addressed to itself, based on the protocol address shown therein, as shown in FIG. If it is addressed to its own terminal, that terminal generates an ATM-ARP response indicating the ATM address of its own terminal,
Send it back to the server.

At the server, the ATM-ARP is sent from the terminal.
By receiving the response, the ATM of the target terminal
Get the address. Information obtained here (ATM address)
Are registered in the ATM address table. 1 and 2
In the above example, the ATM-ARP response from the terminal D is
An example of the case of transferring to the terminal A is shown.

Further, the server transfers the ATM-ARP response received from the terminal to the terminal that transmitted the ATM-ARP request. In the example of FIGS. 1 and 2,
An example of transferring an ATM-ARP response from the terminal D to the terminal A is shown.

The terminal which has issued the ATM-ARP request in (1) recognizes the ATM address of the communication partner by receiving the ATM-ARP response, and stores it in the cache of its own terminal. Also,
SETUP is executed using the ATM address obtained here, a path is set, and communication is performed. In the example of FIGS. 1 and 2,
The terminal A shows an example in which the ATM address (d) of the terminal D is known from the ATM-ARP response received from the server, registered in the cache, and SETUP is performed.

In the examples of FIGS. 1 and 2, subsequently, an example is shown in which the terminal C, which does not have a valid entry in its own cache, communicates with the terminal A. Terminal C is terminal A
ATM-AR to inquire the ATM address of the
Send P request to server.

At the server, the ATM-AR is sent from the terminal C.
When the P request is received, the correspondence between the protocol address of the source address and the ATM address shown therein is registered in the ATM address table. As for the target address, it is checked whether the ATM address corresponding to the protocol address is registered in the ATM address table. Here, the previous terminal A-terminal D
Since the information of the terminal A is already registered by the communication between the terminals, the information (ATM address) is returned to the terminal C as an ATM-ARP response.

Terminal C uses ATM-ARP
By receiving the response, the ATM of the communication partner terminal A
It recognizes the address and saves it in its own cache. Also, using the ATM address obtained here, SET
Execute UP to set a path and communicate.

By learning the source address in this way, the probability of address analysis by broadcast is further reduced.

FIG. 6 shows a second embodiment of the present invention, which shows a communication sequence in the case of changing the terminal, and when the protocol address is changed due to relocation of the terminal or the like, the communication sequence of the server is changed. The case of registering (changing) in the ATM address table is illustrated.

The terminal creates an ATM-ARP request for inquiring about the ATM address of the terminal itself and sends it to the server.

At the server, the ATM-ARP is sent from the terminal.
When the request is received, the correspondence between the protocol address of the source address and the ATM address shown therein is registered in the ATM address table. For target address, AT for protocol address
It is checked whether or not the M address is registered in the ATM address table. In this case, since the source protocol address and the target protocol address are the same, the ATM address registered immediately before is searched and the A
The TM address is returned to the terminal as an ATM-ARP response.

As described above, even when the terminal is relocated, the registration (change) to the server is possible without broadcasting.

[0058]

As described above, according to the present invention, A
In the address management system in the TM-LAN, learning registration is performed for the source address of the ATM-ARP request from the terminal. Therefore, in the case of the system of managing the ATM address by using both the broadcast system and the server system. , The probability that address analysis by broadcast is performed can be reduced. Therefore, control traffic is reduced, which is more efficient,
Network operation is possible and AT
Initialization work of the M address table becomes unnecessary.

Further, according to the present invention, when the terminals are relocated,
By issuing an ATM-ARP request addressed to its own terminal, the server can register and change the address.
No need to update the address table.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment (1) of the present invention.

FIG. 2 is a diagram showing a first embodiment (2) of the present invention.

FIG. 3 is a flowchart showing a first operation example of the terminal according to the first embodiment.

FIG. 4 is a flowchart showing a second operation example of the terminal according to the first embodiment.

FIG. 5 is a flowchart showing an operation example of the server according to the first embodiment.

FIG. 6 is a diagram showing a second embodiment of the present invention.

FIG. 7 is a sequence diagram showing ATM address analysis by a broadcast method.

FIG. 8 is a sequence diagram showing ATM address analysis by the server method.

FIG. 9 is a conventional ATM-LA to which the present invention is applied.
It is a figure which shows the structure of the address management system in N.

FIG. 10 is a diagram showing a format of an ATM-ARP request message / response message.

[Explanation of symbols]

Terminals 11a, 12a, 13a, ... ATM address inquiry request generation means 11b, 12b, 13b, ... Communication means 11c, 12c, 13c, ... ATM address response means 21 Server 21a ATM address table 21b Search means 21c ATM address inquiry request transfer means 21d ATM address response means 31 ATM switch

Claims (5)

[Claims] 1. An ATM for registering a plurality of terminals and a correspondence relationship between a protocol address and an ATM address of each terminal.
An AT having a server having an address table and an ATM exchange accommodating the terminals and the address server
In the address management method on the M-LAN, if the calling terminal does not know the ATM address of the other terminal during communication, it sends an ATM address inquiry request to the server, and the server receives the ATM address inquiry request from the calling terminal. At this time, the correspondence relationship between the protocol address and the ATM address of the calling terminal included in the inquiry request is AT
While registering in the M address table, the ATM address corresponding to the protocol address of the partner terminal included in the inquiry request is searched from the ATM address table, and if the ATM address corresponding to the protocol address is obtained from the ATM address table, The ATM address is notified to the calling terminal, and when the ATM address cannot be obtained from the ATM address table, the AT address inquiry request including the protocol address is sent.
When the other terminal broadcasts to all terminals via the M switch and the other terminal receives the ATM address inquiry request transferred from the server, if the protocol address included in the inquiry request matches the protocol address of the own terminal, Address management system in the ATM-LAN, wherein the server notifies the ATM address of the other terminal to the server, and the server notifies the calling terminal of the notified ATM address of the other terminal. 2. The address management system for an ATM-LAN according to claim 1, wherein when a terminal is added or relocated, the terminal sends an ATM address inquiry request addressed to itself, thereby the server. An address management system in an ATM-LAN characterized by registering or changing an address in. 3. An ATM for registering a plurality of terminals and a correspondence relationship between a protocol address and an ATM address of each terminal.
ATM-LA equipped with a server having an address table and an ATM exchange accommodating the terminals and the server
In the address management system in N, the terminal sends an ATM address inquiry request to the server when the ATM address of the other terminal is unknown during communication, and an ATM address inquiry request generating means,
ATM notified from the server in response to the inquiry request
If the protocol means included in the communication means for communicating with the other terminal via the ATM switch using the address and the ATM address inquiry request transferred from the server match the protocol address of the own terminal, the ATM address of the own terminal To the server, and the server responds to the protocol address included in the ATM address inquiry request from the terminal by searching the ATM address table for the ATM address corresponding to the protocol address and the protocol address. If the ATM address to be registered is not registered in the ATM address table, an ATM address inquiry request transfer means for broadcasting an ATM address inquiry request including the protocol address to all terminals via the ATM switch, and an ATM address. The ATM address response means for notifying the ATM address obtained from the table or the ATM address obtained by the response from the terminal to the terminal that has sent the inquiry request is provided, and the ATM address inquiry request from the calling terminal is received. At this time, the ATM-LAN is characterized in that the correspondence between the protocol address of the calling terminal and the ATM address included in the inquiry request is registered in the ATM address table. 4. In the ATM-LAN according to claim 3, when a terminal is added or relocated, the terminal issues an ATM address inquiry request addressed to itself to register the address in the server. An ATM-LAN characterized by making changes. 5. An address management in an ATM-LAN including a plurality of terminals, a server that manages a correspondence relationship between a protocol address and an ATM address of each terminal, and an ATM switch that accommodates each terminal and the server. In the system, an ATM address table that stores the correspondence between the protocol address of each terminal and the ATM address in the server,
The ATM address corresponding to the protocol address included in the ATM address inquiry request from the terminal is sent to the AT.
By means of searching means for searching from the M address table, ATM address inquiry request transfer means for inquiring the terminal of the ATM address corresponding to the protocol address via the ATM switch, and ATM address obtained from the ATM address table or a response from the terminal. The ATM address response means for notifying the obtained ATM address to the terminal that has sent the inquiry request is provided, and upon receipt of the ATM inquiry request from the calling terminal, the protocol address of the calling terminal included in the ATM address inquiry request is set. The corresponding ATM address is the ATM
The ATM address is registered in the address table, and the ATM address corresponding to the protocol address of the other terminal included in the ATM address inquiry request is searched from the ATM address table. If the ATM address is not registered, the ATM address is inquired by broadcasting. A server that notifies the calling terminal of the responded ATM address.