JP2980049B2 - ATM address management device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM (Asyn)
An IP (Internet P) is used in a chronological transfer mode asynchronous transfer mode network.
The present invention relates to a protocol address and ATM address management device for performing data transfer between terminal devices using a protocol address such as a protocol address, and particularly applied to a communication service for connectionless data transfer.

[0002]

2. Description of the Related Art FIG. 17 shows a configuration of a conventional address management device described in, for example, IEICE technical report SSE95-100 "ATM Internet Management System: ATOMVIEW-Logical IP Subnet Management and Connection Management". FIG. Also, FIG.
2 is a signal sequence diagram of the conventional address management device shown in FIG. FIG. 19 is a configuration diagram showing a configuration example of an address management server for performing address resolution by the signal sequence shown in FIG.

In FIG. 17, reference numerals 1a to 1f denote ATM switching devices; 2a to 2f, terminal devices accommodated in an ATM network;
Reference numerals a to 3b denote address management servers connected to the ATM network for managing protocol addresses such as IP addresses;
Is a network management device that is connected to the ATM network and manages and controls the ATM network; 5 is a logical subnet A accommodated on the ATM network; 6 is a logical subnet B accommodated on the ATM network
It is.

In FIG. 18, reference numeral 61a denotes an address inquiry signal transmitted from the transmitting terminal 2a to the address management server 3a, 61b an address inquiry request signal transferred between the address management servers, and 62a an address inquiry server. An address inquiry response signal 62b transferred between the address management server 3a and an address inquiry response signal 63 sent from the address management server 3a to the terminal device 2a on the transmission side.
Is the AT from the terminal device 2a on the transmission side to the destination terminal device 2f.
A connection setting request signal transmitted via an M switching device (not shown), 64 is a connection setting response signal transmitted from the destination terminal device 2f to the transmitting terminal device 2a via the ATM switching device, and 65 is a transmission signal. Side terminal device 2a
This is a data transfer performed from the ATM switching device to the destination terminal device 2f.

In FIG. 19, reference numeral 91 denotes an apparatus management function for managing the entire apparatus of the address management server 3, 92 denotes an address response function for including an address solution result for an address inquiry in an address inquiry response signal, and 93 denotes an address response function between the address servers. The A of the destination terminal device which is periodically performed and is not in the address management terminal table of the address server itself.
A routing information exchange function for exchanging information such as to which address management server the TM address should be transferred to; a routing table 94 for storing information obtained by the routing information exchange function;
Is A of the terminal device in charge of the address management server itself.
An address management table for storing information on TM addresses and protocol addresses,

FIG. 20 is a configuration diagram showing an example of the configuration of an ATM communication network for executing conventional connectionless data communication. FIG. 21 is a signal sequence diagram of conventional connectionless data communication executed in the ATM communication network configuration shown in FIG. FIG. 22 is a signal sequence diagram of conventional multicast data communication executed in the ATM communication network configuration shown in FIG.

In FIG. 20, the same reference numerals as those in FIG. 17 indicate the same or corresponding parts. 7a and 7b are connectionless servers that are connected to the ATM network and provide connectionless services to the terminal device 2, and 8a and 8b are multicast servers that are connected to the ATM network and provide multicast communication services to the terminal device 2. In FIG. 21, reference numeral 75 denotes the terminal device 2a on the transmission side to the destination terminal device 2f.
Up to this point, data transfer is performed via the CLS and the ATM switching device 1. In FIG. 22, reference numeral 85 denotes data transfer from the terminal device 2a on the transmission side to the destination terminal device 2f via the MCS 8 and the ATM switching device 1.

Next, an address conversion operation by a conventional address management device for converting a protocol address such as an IP address on an ATM network into an ATM address will be described with reference to FIGS. For example, when the terminal device 2a on the transmission side transmits a user cell to the destination terminal device 2f and the ATM address of the destination terminal device 2f is unknown, the terminal device 2a on the transmission side will be described with reference to FIG.
As shown in FIG. 8, the address management server 3a that manages the logical subnet A5 (FIG. 17) to which the terminal device 2a on the transmitting side belongs, including the address inquiry signal request signal 61a including the protocol address of the destination terminal device 2f as the destination protocol address. Send to

When the address management server 3a receives the address inquiry request signal 61a from the terminal device 2a on the transmitting side, the address management server 3a refers to the address management table 95 (FIG. 19) held by the address management server 3a itself and refers to the destination terminal device. It is checked whether the IP address of 2f and the ATM address are registered.

If the IP address and the ATM address of the destination terminal device 2f are not registered in the address management table 95 held by the address management server 3a, the address management server 3a determines whether the logical subnet of the destination terminal device 2f belongs to. Using the B6 as a key, the routing table 94 held by the address management server 3a itself is searched to obtain an ATM address "3b" as an address management server to which an address inquiry request signal should be sent.

Next, the address management server 3a sends this AT
An address inquiry request signal 61b is sent to the address management server 3b based on the M address "3b". The address management server 3b, which has received the address inquiry request signal 61b, determines whether the IP address and the ATM address of the destination terminal device 2f are registered with reference to the address management table 95 held by the address management server 3b itself. The destination terminal device 2f is stored in the address management table 95.
When the ATM address of the destination terminal device 2f is registered,
An address inquiry response signal 62a including 2f "is sent to the address management server 3a.

The address management server 3a, having received the address inquiry response signal 62a, sends an address inquiry response signal 62b to the terminal device 2a on the transmitting side. The terminal device 2 on the transmitting side that has received the address inquiry response signal 62a
“a” obtains the ATM address “2f” of the destination terminal device 2f from the address inquiry response signal 62a.

The address inquiry response signal 62a
Is transmitted from the address management server 3b to the terminal device 2a on the transmission side.
It may be sent directly to.

Next, based on the acquired ATM address "2f" of the destination terminal device 2f, the terminal device 2a on the transmission side sets a connection between the terminal devices directly to the destination terminal device 2f. Request signal 63
Is sent. The terminal device 2a on the transmission side is the destination terminal device 2f.
When the connection setting response signal 64 indicating that the connection was successful is received from the
Thereafter, the data transfer 65 is directly performed between the terminal devices.

The address management table 95 held by the address management server 3 is set by the network management device 4 shown in FIG. 17 or by an address registration request signal from the terminal device 2. There are a case where the setting is made by the data of the address inquiry signal transferred between the address management servers when transferring the signal, and a case where the setting is made from the control console directly connected to each address management server 3.

The routing table 94 held by the address management server 3 is set from the network management device 4 or set by exchanging routing information between the address management servers 3 by the routing information exchange function 93. And the address management server 3
May be set from the control console connected to the server.

If the address management server 3 does not have the routing table 94 and the routing information exchange function 93 and the address of the inquiry terminal is not registered in the address management table 95, the abnormal response signal is transmitted to the terminal 2a on the transmitting side. May be returned.

In the conventional example shown in FIG. 20, a connectionless server (CLS: Conn.)
The configuration example of the ATM communication network when an ATM address of CLS 7 is set in each terminal device 2 is shown in FIG. FIG. 21 shows a signal sequence in the ATM communication network shown in FIG. In this conventional example, there is no address management server.

Next, the operation of the conventional ATM address management device shown in FIG. 20 will be described with reference to FIG. By transmitting the data 75 to the CLS 7a, the terminal device 2a on the transmission side communicates with the destination terminal device 2f without knowing the ATM address of the destination terminal device 2f in advance. In this case, when the terminal device 2a on the transmission side generates the data transmission request signal, the data can be immediately transferred to the destination terminal device 2f without performing the address inquiry process.

That is, the CLS 7 is transmitted from the terminal device 2a on the transmitting side.
The IP address of the destination terminal device 2f is included in the first user cell of the packet which is the data transmitted to the CLS 7a. When the CLS 7a receives this user cell, the CLS 7a uses the IP address of the destination terminal device 2f as a key. A of the next-stage CLS 7b on the route from the routing table held by itself to the destination terminal device registered in advance
The TM address "7b" is read.

Next, the CLS 7a is connected to the next CLS 7b.
After establishing a connection with the CLS 7b based on the ATM address "7b", the user cell received from the terminal device 2a on the transmitting side is transmitted to the CLS 7b. Upon receiving the user cell, the CLS 7b uses the IP address in the header of the user cell as a key, and the ATM address “7c” of the next-stage CLS 7c on the route from its own routing table to the destination terminal device 2f registered in advance. (Not shown).

Next, the CLS 7b establishes a connection with the CLS 7c based on the ATM address "7c" of the CLS 7c at the next stage, and sends out the user cell received from the terminal device 2a on the transmission side to the CLS 7c. Hereinafter, the same operation is performed up to the last stage CLS7 in the above route. Assuming that the last-stage CLS 7 is, for example, 7b, the last-stage CLS 7
b receives the user cell from the preceding CLS 7 and
ATM address of destination terminal device 2f registered in advance from the address management table held by S7b itself "
2f "is read out, and the user cell is transmitted to the destination terminal device 2f.

A multicast server (MCS: MCS) for providing a multicast service to the ATM switching equipment 1
When a multi cast server (hereinafter referred to as MCS) 8 is connected and the ATM address of the MCS 8 that provides the multicast service is set to each of the terminal devices 2, the group of the destination terminal device in the terminal device 2 a on the transmission side is set. A certain multicast group 2
When a multicast data transmission request signal for b, 2c, 2d is generated, by transmitting data with a multicast address set to MCS 8a, data transfer 85 to destination terminal devices 2b, 2c, 2d may be performed. it can.

That is, the MCS 8 is transmitted from the transmitting terminal 2a.
The first user cell of the data packet transmitted to a includes a multicast IP address indicating the destination terminal device multicast group. When the MCS 8a receives the user cell, the MCS 8a owns the multicast cell using the multicast IP address as a key. The ATM address "2b", "2c", "2d" of the corresponding destination terminal device is read from the corresponding address management table, and the ATM addresses "2b", "2c", "2" of the destination terminal device are read out.
Based on d ″, the user cell is transmitted to the destination terminal device 2b, 2c, 2d.

[0025]

The conventional address management device is configured as described above. For example, in the address management device based on the signal sequence shown in FIG. 18, the address management device is based on the ATM address of the destination terminal device converted from the IP address. Since direct communication is performed between the terminal devices, QoS (Quality of S
service high-quality communication service). Therefore, QoS is guaranteed. However, in this address management device, even for communication for which QoS guarantee is not required, an ATM address inquiry request of the destination terminal device, an ATM address analysis / resolution, an AT
In order to execute the process of the M address inquiry response, an ATM connection between the terminal devices is required for each communication,
There has been a problem that the economy of resources in the ATM network is impaired.

Further, in the communication apparatus using the signal sequence shown in FIG. 21, since each CLS 7 has many other terminal devices 2 connected thereto, the user cells from these terminal devices 2 are also multiplexed in the communication between the CLS 7s. By transmitting the data to the CLS 7, a statistical multiplexing effect is expected, and the economy of resources in the network is improved. However, by multiplexing the user cells from other terminal devices 2 as well, the traffic of the user cells increases, and the cell loss rate increases accordingly. In addition, there is a problem that QoS required for communication cannot be guaranteed because connection setting with a destination is not performed.

Further, when the network configuration is changed, such as a change in the ATM address of the CLS 7 or MCS 8 that provides a service to each terminal device 2, the setting of all the terminal devices 2 must be changed one by one. was there.

The present invention has been made in order to solve such a problem. For communication that does not require QoS guarantee, the CLS ATM address is notified to effectively use resources in the network, and In the case where QoS guarantee is required, a communication service capable of guaranteeing communication quality by resolving and notifying the ATM address of the destination terminal device, and changing the address of a server such as CLS or MCS which provides the service to the terminal device For example, it is possible to flexibly cope with a change in the network configuration, and the transmitting-side terminal device does not depend on the service and the actual transmitting party (C
LS or destination terminal)
An object is to obtain a TM address management device.

[0029]

An ATM according to a first aspect of the present invention.
The address management device communicates with a plurality of connectionless servers (CLS) that provide connectionless services to a plurality of terminal devices, and communicates with the destination terminal device when the ATM address of the destination terminal device is unknown. A transmitting-side terminal device for transmitting an address inquiry request signal including QoS information indicating whether quality assurance is desired or not and a protocol address such as an IP address; and a protocol address of a plurality of terminal devices and an ATM address. Having an ATM address table for storing the correspondence and receiving an address inquiry request signal from the terminal device on the transmitting side, it is determined whether or not the QoS information is included in the address inquiry request signal. If it is included, the ATM address of the destination terminal device is notified, and the QoS information is If not rare, in which and an address management server to notify the ATM address of the CLS to the terminal device of the transmission side.

Further, the ATM address management device according to the second invention comprises a plurality of connectionless servers (CLS) for providing connectionless services to a plurality of terminal devices.
And if the ATM address of the destination terminal device is unknown,
When a transmitting terminal transmitting a TM address inquiry request signal and a correspondence table of a plurality of application types and QoS information suitable for the application type are held, and an ATM address inquiry request signal is received from the transmitting terminal, By referring to the correspondence table between the application type and the QoS information, the QoS of the connection used in the communication performed by the address inquiry request signal is determined, and when it is determined that the QoS guarantee is necessary, the terminal of the destination is determined. An address management server for notifying the ATM address of the device and notifying the transmitting terminal device of the ATM address of the CLS when QoS guarantee is not necessary.

Further, in the ATM address management device according to the third invention, while the address management server is detecting congestion of the ATM switching device, the QoS guarantee is required for the address inquiry signal from the terminal device on the transmission side. In this case, an abnormal response signal indicating that connection is not possible is notified, and if QoS guarantee is not required, the ATM address of the CLS is notified to the terminal device on the transmission side.

Further, the ATM address management device according to the fourth aspect of the present invention is arranged such that, while the address management server detects the congestion of CLS, the QoS management is required in response to an address inquiry from the terminal device on the transmission side. AT of destination terminal
The M address is notified, and if there is no need to guarantee the QoS, the ATM address of another CLS that is not congested is notified.

An ATM address management device according to a fifth aspect of the present invention includes a plurality of multicast servers (hereinafter, referred to as MCS) for providing a multicast service to a plurality of terminal devices, and a case where an ATM address of a destination terminal device is unknown. Describes a terminal device on the transmitting side that transmits an address inquiry request signal including a protocol address such as an IP address for communication with a destination terminal device, and a correspondence relationship between the protocol addresses of a plurality of terminal devices and the ATM address. It has an ATM address table to be stored and a control console, and when the protocol address of the address inquiry request signal received from the transmitting terminal is a multicast address, the transmitting terminal has the AT of the MCS.
And an address management server for notifying the M address.

Further, in the ATM address management device according to the sixth invention, the address management server is not congested in response to an address inquiry addressed to the multicast address from the terminal device on the transmission side while the congestion of the MCS is being detected. Another MC
It notifies the ATM address of S.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a configuration diagram showing an embodiment of an ATM address management device according to the present invention. FIG. 2 is a signal sequence diagram showing the operation of the ATM address management device shown in FIG. 1, and shows an address inquiry sequence. FIG. 3 is a detailed sequence diagram of the signal sequence shown in FIG. 2, which is an address inquiry sequence in the case of accompanying QoS information. FIG. 4 is a detailed sequence diagram of the signal sequence shown in FIG. 2, and shows an address inquiry sequence when no QoS information is involved. Also,
FIG. 5 is a configuration diagram showing a configuration example of an address management server for executing the signal sequences shown in FIGS.

In FIG. 1, 1a to 1f are ATM switching devices, 2a to 2f are terminal devices accommodated in an ATM network, 3a
3b are address management servers that are connected to the ATM network and manage IP addresses as an example of protocol addresses;
4 is a network management device connected to the ATM network and managing and controlling the ATM network. 5 is a logical subnet A accommodated on the ATM network. 6 is a logical subnet B accommodated on the ATM network. 7a and 7b are ATMs. Connectionless servers (CLS) 8a and 8b are connected to the network and provide a connectionless service to the terminal device 2, and 8a and 8b are multicast servers (MCS) connected to the ATM network and providing a multicast communication service to the terminal device 2. The ATM switching device 1 may hereinafter be referred to as the ATM switching device 1.

In FIG. 5, reference numeral 91 denotes an apparatus management function for managing the entire apparatus of the address management server 3; 92, an address response function for including an address solution result for an address inquiry in an address inquiry response signal; The AT of the destination terminal device that is periodically performed and is not in the address management terminal table of the address server itself.
A routing information exchange function for exchanging information such as which address management server should be transferred to resolve the M address, a routing table 94 for storing information obtained by the routing information exchange function, and a reference numeral 95 for address management AT of the terminal device in charge of the server itself
An address management table for storing information of the M address and the IP address; 96, a QoS information determining function for determining whether or not QoS information is included in an address inquiry request signal from the terminal device 2a on the transmitting side; IP
6 is a CLS address management table for storing correspondence between addresses, ATM addresses, and congestion states.

Next, the operation of the address management device according to the present embodiment will be described with reference to FIGS. Address management table 9 of address management server 3a in advance
5 (FIG. 5), a subordinate terminal device (terminal device on the transmission side) 2a
And the corresponding ATM address are registered. For this purpose, an address registration request signal including the IP address of the transmitting terminal device 2a and the corresponding ATM address is transmitted from the transmitting terminal device 2a to the address management server 3a. Upon receiving the address registration request signal from the transmitting terminal device 2a, the address management server 3a stores the IP address and the ATM address of the transmitting terminal device 2a in the address management table 95 stored in the address management server 3a itself. sign up.

The IP address of the subordinate terminal (destination terminal) 2f and the corresponding ATM address are registered in the address management table 95 (FIG. 5) of the address management server 3b in advance. For this purpose, an address registration request signal including the IP address of the destination terminal device 2f and the corresponding ATM address is transmitted from the destination terminal device 2f to the address management server 3b. When receiving the address registration request signal from the destination terminal device 2f, the address management server 3b registers the IP address and the ATM address of the destination terminal device 2f in the address management table 95 held by the address management server 3b itself.

On the other hand, the subnet address and the ATM address of the logical subnet managed by the address management server 3 are automatically and regularly exchanged between the address management servers 3 as routing information, and the routing table 94 of each address management server 3 (as routing information). It is registered in FIG. For example, the logical subnet address "A" and the ATM address "3a" of the address management server 3a are periodically exchanged with the logical subnet address "B" and the ATM address "3b" of the address management server 3b. In the routing table 94, the logical subnet address “B” and the ATM address “3b” of the address management server 3b are registered. Similarly, the logical subnet address “A” and the ATM address “3a” of the address management server 3a are registered in the routing table 94 of the address management server 3a.

Under the conditions in which the above settings are made, for example, when the transmitting-side terminal device 2a attempts to transmit a user cell to the destination terminal device 2f, QoS is secured by the connection used for the communication. If this is desired, the terminal device 2a on the transmitting side is connected to the destination terminal device 2 as shown in FIG.
An address inquiry request signal 61a containing the IP address of f and the QoS information is sent to the address management server 3a that manages the logical subnet A5 (FIG. 1) to which the terminal device 2a on the transmitting side belongs.

When the address management server 3a receives the address inquiry request signal 61a from the terminal device 2a on the transmitting side, the QoS information determination function 9 of the address management server 3a
6 (FIG. 5) indicates that the address inquiry request signal 61a has Q
It is checked whether oS information is included (step S321 in FIG. 3). If it is determined that QoS information is included, the address management server 3a itself refers to the address management table 95 shown in FIG. 5 to determine whether or not the ATM address is registered in the IP address of the destination terminal device 2f. Check (step S322 in FIG. 3).

If no ATM address information is registered in the address management table 95 for the IP address of the destination terminal device 2f, the address management server 3a sets the subnet address "B" of the logical subnet B6 to which the destination terminal device 2f belongs to. As a key, the routing table 94 held by the address management server 3a itself is searched, and the ATM of the address management server 3b to which the inquiry signal should be sent is sent.
The address "3b" is obtained (step S323 in FIG. 3).

Next, the address management server 3a retrieves the ATM address of the address management server 3b obtained as a result of the search.
3b ", sends an address inquiry request signal 61b including the QoS information to the address management server 3b (FIG. 2). When the address management server 3b receives the address inquiry signal 61b from the address management server 3a,
It is checked whether or not QoS information is included in the address inquiry request signal 61b. (Step S32 in FIG. 3)
4).

If it is determined that QoS information is included,
Referring to the address management table 95 held by the address management server 3b itself (step S325 in FIG. 3), it is determined whether an ATM address is registered in the IP address of the destination terminal device 2f. When the ATM address of the destination terminal device 2f is registered in the address management table 95, the address inquiry response signal 62a including the ATM address "2f" of the destination terminal device 2f is sent to the address management server 3a, so that the destination address is registered. The ATM address "2f" of the terminal device 2f is notified to the address management server 3a (FIG. 2).

Next, when the address management server 3a receives the address inquiry response signal 62a including the ATM address "2f" of the destination terminal device 2f from the address management server 3b, the address inquiry response signal 62b is sent to the transmitting terminal device 2a. Notice. The terminal device 2a on the transmission side sends an address inquiry response signal 6 from the address management server 3b.
2a, the ATM address "2f" of the destination terminal 2f is extracted from the address inquiry response signal 62a, and the ATM address "2f" of the destination terminal 2f is extracted.
The connection setting request signal 63 including the QoS information is transmitted to the destination terminal device 2f based on the.

When the connection setting response signal 64 is received from the destination terminal device 2f, the connection setting between the transmitting terminal device 2a and the destination terminal device 2f is completed, and thereafter, the connection between the transmitting terminal device 2a and the destination terminal device 2f is established. Data transfer 65 is performed between the two.

If the address management server 3 does not have the routing table 94 and the routing information exchange function 93 and the address of the destination terminal device is not registered in the address management table 95, the abnormal response signal is transmitted to the terminal device 2a on the transmission side. May be returned to

When the terminal device 2a on the transmitting side tries to transmit a user cell to the destination terminal device 2f, for example, if QoS guarantee is not necessary for the connection used for the communication, the terminal device on the transmitting side The device 2a sends an address inquiry request signal 66a that includes the IP address of the destination terminal device 2f and does not include the QoS information to the address management server 3a that manages the logical subnet A5 to which the terminal device 2a on the transmitting side belongs.

When the address management server 3a receives the address inquiry request signal 66a from the terminal device 2a on the transmitting side, the QoS information determination function 9 of the address management server 3a
6 (FIG. 5) shows that the address inquiry request signal 66a has Q
It is checked whether oS information is included (step S321 in FIG. 4). If it is determined that no QoS information is included, the CLS address management table 97 held by the address management server 3a itself is searched using the IP address of the destination terminal device 2f as a key, and a search is made for the destination terminal device 2f registered in advance. The ATM address "7a" of the nearest CLS 7a on the route is read (step S422 in FIG. 4).

Next, an address inquiry response signal 66b including the ATM address "7a" of the CLS 7a is returned to the terminal device 2a on the transmission side (FIG. 2). The terminal device 2a on the transmission side acquires the ATM address "7a" of the CLS 7a from the address inquiry response signal 66b received from the address management server 3a.

Next, the terminal device 2a on the transmission side acquires the acquired C
Based on the ATM address “7a” of LS7a, CLS7
A user cell including the IP address of the destination terminal device 2f in the first cell is transmitted to the communication device a (data transfer 6 in FIG.
7). When the CLS 7a receives the data transfer 67 from the transmitting-side terminal device 2a, the CLS 7a obtains the IP address of the destination terminal device 2f from the header of the received user cell, and uses the IP address of the destination terminal device 2f as a key. The ATM address “7b” of the next-stage CLS 7b on the route to the destination terminal device 2f registered in advance by searching its own CLS routing table.
Read out.

Next, the CLS 7a obtains the next-stage CLS
The user cell including the IP address of the destination terminal device 2f as the first cell is transferred to the CLS 7b based on the ATM address "7b" of the 7b (data transfer 67 in FIG. 2). C
When the LS 7b receives the data transfer 67 from the terminal device 2a on the transmission side, the LS 7b obtains the IP address of the destination terminal device 2f from the header of the received user cell, and acquires the IP address of the destination terminal device 2f.
Using the IP address of the CLS 7b as a key, the CLS routing table held by the CLS 7b itself is searched, and the next-stage CLS 7 on the route to the destination terminal device 2f registered in advance is searched.
Read the ATM address "7c" of c.

Next, the CLS 7b obtains the acquired next-stage CLS.
The user cell including the IP address of the destination terminal device 2f as the first cell is transferred to the CLS 7c based on the ATM address "7c" of the 7c. Hereinafter, the same operation is performed, and the user cell reaches the final stage CLS7.

Assuming that the last-stage CLS is, for example, the CLS 7b, the last-stage CLS 7b stores the user cell in the previous-stage CLS.
When receiving from S7, the destination terminal device 2f in the user cell
Using the IP address of the CLS 7b as a key, an address management table of the CLS 7b itself is searched to read out the ATM address “2f” of the destination terminal device 2f registered in advance, and data is transferred to the destination based on the ATM address “2f”. The data is transferred to the terminal device 2f (data transfer 67 in FIG. 2).

A multicast server (MCS) 8 for providing a multicast service to the ATM switching device 1
Is connected, and the AT of the MCS 8 that provides a multicast service to each of the destination terminal devices 2b, 2c, 2d
When the M address is set, the terminal device 2 on the transmitting side
a is a destination terminal device 2b which is a multicast group,
When a multicast data transmission request signal is generated in 2c, 2d, a user cell in which a multicast address is set is transmitted to the MCS 8a, so that data can be transferred to the destination terminal devices 2b, 2c, 2d.

That is, the MCS 8 is transmitted from the terminal device 2a on the transmitting side.
The header of the data sent to the MCS 8a includes an IP address indicating the multicast group. When the data is received by the MCS 8a, the corresponding destination terminal device 2b, It reads the ATM addresses "2b", "2c" and "2d" of 2c and 2d and sends out the user cells to the terminal devices 2b, 2c and 2d.

According to the present embodiment, the connection or CLS directly performed between the terminal devices according to the required quality of communication.
Since the data communication is performed by selectively using the connection relayed in step 7, the resources in the network can be made economical by the statistical multiplexing effect between CLSs, and communication capable of guaranteeing QoS can be performed between the terminal devices.

Further, compared to the case where the ATM address of the CLS 7 is set in advance in all the terminal devices 2 on the transmitting side, the network configuration can be changed more flexibly, and
Has the effect that communication can be performed by the same address inquiry operation without regard to whether the transmission destination is the destination terminal device or the CLS.

Further, it is possible to provide communication capable of guaranteeing QoS without making the transmitting side terminal device aware of the transmission partner.
In the communication that does not require the oS guarantee, the resources in the network can be effectively used, and the network configuration can be easily changed such as the CLS address.

Embodiment 2 FIG. 6 shows an ATM according to the present invention.
It is a lineblock diagram showing the example of composition of the address management server which shows another embodiment of an address management device. 6, the same reference numerals as those in FIG. 5 denote the same or corresponding parts. Reference numeral 98 denotes a QoS information management table showing a correspondence between the type of application and QoS information indicating whether this application needs to secure QoS. FIG. 7 shows FIG.
QoS information management table 9 of the address management server shown in FIG.
8 is a table structure diagram showing a structure example of FIG.

FIG. 8 is an explanatory diagram for explaining the operation of the address management server 3 when there is an address inquiry request signal containing the application type and the QoS information from the terminal device 2a on the transmitting side. FIG. 9 is an explanatory diagram for explaining the operation of the address management server 3 when there is an address inquiry request signal not including the application type or including the application type but not including the QoS information from the terminal device 2a on the transmission side. is there.

Next, the operation of this embodiment will be described with reference to FIGS.
This will be described with reference to FIG. The type of application used for communication and whether each application needs to secure QoS (1 if necessary, 1 if unnecessary) from the network management device 4 or a control console connected to the address management server 3a in advance A QoS information management table 98 is prepared in which the correspondence with the QoS information indicating 0) is made in a table.

When an address inquiry request signal including the application type is received from the terminal device 2a on the transmitting side, the QoS information determination function 96 of the address management server 3a
Checks whether there is an application type (step S821 in FIG. 8). If there is an application type,
The address management server 3a stores the QoS information management table 98
, It is determined whether QoS guarantee is required for each application type (step S822 in FIG. 8). If QoS guarantee is required, the address management table 95 is referred to (step S823 in FIG. 8).

If the ATM address is registered in the address management table 95, this ATM address is included in the address inquiry response signal and notified to the terminal device 2a on the transmitting side. If the ATM address is not registered in the address management table 95, the address management server 3a refers to the routing table 94 (step S82 in FIG. 8).
4) Transmit an address inquiry request signal including the application type to the next-stage address management server 3b.

When the address management server 3b at the next stage receives the address inquiry request signal from the address management server 3a, the QoS information judgment function 96 of the address management server 3b checks whether there is an application type (FIG. 8).
Step S825). If there is an application type, the QoS information determination function 96 of the address management server 3b
Refers to the QoS information management table 98 and checks whether QoS guarantee is necessary for each application type (step S826 in FIG. 8).

If QoS guarantee is required, the address management table 95 is referred to (step S827 in FIG. 8).
The ATM of the destination terminal device 2f is stored in the address management table 95.
If the address is registered, the address management server 3a is notified by including the ATM address "2f" of the destination terminal device 2f in the address inquiry response signal. The address management server 3a includes the ATM address "2f" of the destination terminal device 2f received from the address management server 3b in the address inquiry response signal and notifies the transmitting terminal device 2a.

When an address inquiry request signal that does not include the application type is received from the transmitting terminal device 2a, the QoS information determination function 96 of the address management server 3a checks whether or not there is an application type (see FIG. 8). Step S821). If there is no application type, the address management server 3a refers to the CLS address management table 97 (step S90 in FIG. 9).
2) AT of CLS7 in charge of terminal device 2a on the transmitting side
The M address is included in the address inquiry response signal and notified to the terminal device 2a on the transmission side. The terminal device 2a on the transmission side acquires the ATM address of the CLS 7 from the address inquiry response signal, and performs data transfer with the destination terminal device 2f via the CLS 7 based on the ATM address of the CLS 7 in the same manner as in the first embodiment. be able to.

When an address inquiry request signal including the application type is received from the transmitting terminal device 2a, the QoS information determination function 96 of the address management server 3a checks whether there is an application type (FIG. 8).
Step S821). If there is an application type, the address management server 3a refers to the QoS information management table 98 and checks whether QoS guarantee is necessary for each application type (step S901 in FIG. 9). Qo
If the S guarantee is unnecessary, the address management server 3a
With reference to the S address management table 97 (step S902 in FIG. 9), the CLS 7 in charge of the terminal device 2a on the transmitting side.
Is included in the address inquiry response signal to notify the terminal device 2a on the transmitting side.

The terminal device 2a on the transmitting side obtains the ATM address of the CLS 7 from the address inquiry response signal and, based on the ATM address of the CLS 7, transmits data to the destination terminal device 2f via the CLS 7 in the same manner as in the first embodiment. Transfer can be performed.

According to this embodiment, when the address management server receives the ATM address inquiry request signal including the application type from the terminal device on the transmitting side, the address management server reads out the QoS information corresponding to the application type from the table, and guarantees the QoS. If it is determined that QoS is necessary, the ATM terminal of the destination terminal device is notified to the transmitting side terminal device. If it is determined that QoS guarantee is not necessary, C is determined.
Since the LS ATM address is notified, it is possible to provide detailed effects for each application.

Embodiment 3 In Embodiments 1 and 2, CLS 7 used in communication without QoS guarantee
Has a problem that congestion may occur because the connectionless service is provided to a plurality of terminal devices 2.
Here, an example of an address management device that solves such a problem will be described.

FIG. 10 is a configuration diagram of an address management server showing another embodiment of the address management device according to the present invention. 5, the same reference numerals as those in FIG. 5 indicate the same or corresponding parts.
Reference numeral 99 denotes an ATM network state monitoring function for monitoring the congestion state of the ATM exchange 1, and 100 denotes a C for monitoring the congestion state of the CLS 7.
This is an LS state monitoring function. FIG. 11 shows a case where the QoS is transmitted from the terminal device 2a on the transmission side while the ATM exchange 1 is congested.
FIG. 9 is an explanatory diagram showing an operation of the address management server when an address inquiry request signal including information is received. FIG. 12 shows an address management server 3 when an address inquiry request signal not including QoS information is received from the terminal device 2a on the transmission side while the ATM exchange 1 is congested.
It is an explanatory view showing the operation of.

Next, the operation of this embodiment will be described with reference to FIG. 10, FIG. 11, and FIG. Address management server 3
a detects congestion of the ATM switch 1 by receiving congestion information of the ATM switch 1 from the control console connected to the address management server 3a, the remote network management device 4 or the ATM switch 1.

Alternatively, for example, IETF (Intern
et Engineering Task Forc
e) RIP (Routing In) standardized in
formation Protocol) and OSPF
(Open ShortestPath First)
The congestion information of the ATM exchange 1 is periodically exchanged between the address management server 3 and the ATM exchange 1 according to the same procedure as described above, so that the ATM status monitoring function 99 of the address management server 3a has the ATM exchange 1 congested. Is detected (step S1101 in FIG. 11 or FIG. 12).

When an address inquiry request signal including QoS information is received from the terminal device 2a on the transmission side while the ATM state monitoring function 99 detects congestion of the exchange 1,
The address management server 3a notifies the terminal device 2a on the transmission side of an address inquiry response signal including a message indicating that the ATM exchange 1 is congested and "connection is impossible".

The ATM status monitoring function 99 is provided for the exchange 1
While the terminal device 2a on the transmitting side detects Q
When an address inquiry request signal that does not include the QoS information is received, the address management server 3a checks whether or not the QoS information is included, and if it determines that the QoS information is not included, the CLS address management table 97 (see FIG. 1
CLS in charge of terminal device 2a on the transmitting side with reference to 5)
Then, an address inquiry response signal including the ATM address 7 is notified to the terminal device 2a on the transmission side.

The terminal device 2a on the transmitting side acquires the ATM address of the CLS 7 from the address inquiry response signal, and performs data transfer with the destination terminal device 2f via the CLS 7 based on the ATM address of the CLS 7 in the same manner as in the first embodiment. It can be performed.

According to this embodiment, the address management server 3a transmits the congestion information of the ATM network to the address management server 3a.
a from the control console or remote network management device 4 or the ATM switch 1 connected to the
During the detection of the congestion of the ATM network, an abnormal response signal of "connection unreachable" is notified in response to an address inquiry requiring a QoS guarantee from the terminal device 2a on the transmission side, and the QoS guarantee is performed. For an unnecessary address inquiry, the ATM address of CLS7 is notified.
By taking appropriate countermeasures against the congestion state of the ATM network in accordance with the necessity of the oS guarantee, there is an effect that data discard does not occur and high-quality data transfer can be secured.

The address management server periodically exchanges congestion information of the ATM network with each of the ATM exchanges 1 so that the address management server can exchange data with the ATM exchanges 1.
When the ATM exchange 1 is congested and the QoS between the terminal devices needs to be guaranteed when the ATM exchange 1 is congested, the address management server sends an abnormal response signal indicating that connection with the destination terminal device is impossible. When QoS guarantee is not required, the ATM address of CLS is notified.
By taking appropriate countermeasures against the congestion state of the ATM switching apparatus according to the necessity of S guarantee, it is possible to ensure the high-quality data transfer without data discard.

Embodiment 4 When communication requiring QoS guarantee is performed intensively, a large number of connections may be set and the CLS 7 may become congested. FIG. 13 shows CLS7
FIG. 9 is an explanatory diagram for explaining the operation of the address management server 3 when an address inquiry request signal not including QoS guarantee is received from the terminal device 2a on the transmission side during the time when is congested.

Next, the operation of the address management server 3a in the present embodiment will be described. Address management server 3a
Is transmitted from the control console connected to the address management server 3a or the remote network management device 4 or the CLS 7 to the C
By receiving the congestion information of the LS 7, the address management server 3 is notified that the CLS 7 is congested.

Alternatively, the congestion information is periodically exchanged between the address management server 3 and the CLS 7 according to the same procedure as RIP or OSPF standardized by IETF, for example, so that the CLS status monitoring function 100 of the address management server 3a can be performed. Detects that the CLS 7 is congested (step S1301 in FIG. 13). When the CLS status monitoring function 100 detects the congestion of CLS # 1, the status “N” is added to the address of CLS # 1 in the CLS address management table 97.
Record "G". If there is no congestion, “OK” is recorded.

The address management server 3 a
When an address inquiry request signal including the QoS guarantee together with the IP address addressed to f is received from the terminal device on the transmission side,
When the QoS information is included, the address management server 3a follows the address management server 3 at the next and subsequent stages to obtain the ATM address "2f" of the destination terminal device 2f in the same manner as in the first embodiment. The ATM terminal “2f” of the destination terminal device is included in the address inquiry response signal and is notified to the terminal device 2a on the transmission side.

The terminal device 2a on the transmission side acquires the ATM address "2f" of the destination terminal device from the address inquiry response signal, and based on the ATM address "2f" of the destination terminal device, does not pass through the CLS 7 to the destination terminal device 2f. It is possible to transfer data by establishing a direct connection.

When the address management server 3a receives from the transmitting terminal 2a an address inquiry request signal that does not include the QoS information together with the IP address of the destination terminal 2f, the address managing server 3a transmits the IP address of the destination terminal 2f to the transmitting terminal 2a. The CLS address management table 97 in charge is searched to check the congestion state and the ATM address of the CLS 7, and
When the CLS 7 is congested, referring to the CLS address management table 97 (FIG. 10), the ATM address of another CLS # 2 without congestion is included in the address inquiry response signal, and the transmitting-side terminal device 2a (See FIG. 13)
Step S1303). The terminal device 2a on the transmission side acquires the ATM address of CLS # 2 from the address inquiry response signal, and based on the ATM address of CLS # 2, as in the first embodiment, the destination terminal device via CLS # 2. Data transfer with 2f can be performed.

According to this embodiment, the address management server 3a transmits the CLS congestion information to the address management server 3a.
While the congestion of the CLS is being detected by notifying the address management server 3 from the control console or the network management device 4 or the CLS 7 connected to the Notifies the ATM address of the destination terminal device 2f,
For an address inquiry that does not require S, an ATM address of another CLS that is not congested is notified, so that there is an effect that data discard does not occur and high-quality data transfer can be secured.

Further, the address management server 3 stores each CLS 7
The congestion information of the CLS 7 is periodically exchanged between the CLS 7 and the congestion information of the CLS 7 during the detection of the congestion of the CLS 7. Notify the ATM address of
For an address inquiry that does not require QoS, an ATM address of another CLS7 that is not congested is notified.
There is an effect that data discard does not occur and high-quality data transfer can be ensured.

Embodiment 5 When multicast communication is performed intensively, a large number of connections are set and MC
S8 may be congested. FIG. 14 is a signal sequence diagram showing an address inquiry sequence according to another embodiment of the present invention. FIG. 15 is a configuration diagram of the address management server 3 for executing the signal sequence shown in FIG. In the figure, the same reference numerals as those in FIG. 10 indicate the same or corresponding parts. An MCS address management table 101 stores the correspondence between the IP address of the MCS 8, the ATM address, and the congestion state, and an MCS state monitoring function 102 monitors the congestion state of the MCS 8. FIG. 16 is an explanatory diagram showing an operation of the address management server 3 when an address inquiry request signal not including QoS information is received from the terminal device 2a on the transmission side while the MCS 8 is congested.

Next, the operation of the address management server 3a according to the present embodiment will be described. Address management server 3a
Receives the congestion information of the MCS 8 from the control console connected to the address management server 3a, the remote network management device 4 or the MCS 8,
S8 detects that congestion has occurred.

Alternatively, the congestion information is periodically exchanged between the address management server 3 and the MCS 8 according to a procedure similar to RIP or OSPF standardized by IETF, for example. Detects that the MCS 8 is congested (step S1601 in FIG. 16). When the MCS status monitoring function 102 detects the congestion of MCS # 1, the status “NG” is recorded at the address of MCS # 1 in the MCS address management table 101. If there is no congestion, “OK” is recorded.

Since QoS is not guaranteed in communication using the MCS, the terminal device on the transmitting side can use the address management server 3
When making an address inquiry about a multicast address to a, there is no need to include QoS information.
When the address management server 3a receives an address inquiry request signal including the multicast address from the terminal device on the transmission side, the address management server 3a searches the MCS address management table 101 in charge of the terminal device 2a on the transmission side and searches the MCS # 1. The MCS # 1 is checked for congestion, and if the MCS # 1 is congested, the MCS # 1 is inquired with reference to the MCS address management table 101 (FIG. 10) for the ATM address of another MCS # 2 that is not congested. The transmission-side terminal device 2a is included in the response signal and notified (step S1602 in FIG. 16).

The terminal device 2a on the transmitting side obtains the ATM address of MCS # 2 from the address inquiry response signal, and performs the first embodiment based on the ATM address of MCS # 2.
In the same manner as described above, the destination terminal device 2b, 2
Data transfer with c and 2d can be performed.

According to this embodiment, the address management server 3a responds to the address inquiry addressed to the multicast address from the terminal device 2a on the transmission side by responding to the AT of the MCS 8.
Since the M address is notified, the terminal device is provided with the multicast communication service without being conscious of the transmission partner, and it is possible to easily change the network configuration such as changing the address of the MCS.

The address management server 3a has the MCS 8
Is notified from the control console connected to the address management server 3a or the network management device 4 or the MCS 8 to the address management server 3,
While detecting the congestion in S8, an ATM address of another non-congested MCS is notified in response to an address inquiry from the terminal device 2a on the transmission side. Is achieved.

The address management server 3 stores each MCS 8
By periodically exchanging the congestion information of the MCS 8 between the above, while detecting the congestion of the MCS 8, the address inquiry from the terminal device 2a on the transmitting side is not congested. Since the ATM address of another MCS is notified, there is an effect that data discard does not occur and high-quality data transfer can be secured.

[0097]

According to the first aspect of the present invention, when QoS information is included in the ATM address inquiry signal received from the terminal device on the transmitting side by the address management server, the address management server sends the address information to the destination terminal device. The ATM address is notified to the terminal device on the transmitting side, and when the QoS information is not included, the ATM address of the CLS is notified. Providing guaranteed communication and Qo
In communication that does not require S guarantee, it is possible to effectively use resources in the network by the statistical multiplexing effect, and to easily change the network configuration such as changing the address of the CLS.

According to the second aspect, when the address management server receives the ATM address inquiry request signal including the application type from the transmitting terminal, the address management server reads out the QoS information corresponding to the application type from the table, When it is determined that QoS guarantee is necessary, the ATM terminal of the destination terminal device is notified to the terminal device on the transmission side, and when it is determined that QoS guarantee is not required, the ATM address of CLS is notified. This has the effect that a detailed response can be made every time.

According to the third aspect of the present invention, the address management server detects the congestion of the ATM switching equipment, and if the QoS is required in the communication between the terminal equipments, the address management server sends the address management server to the destination terminal. Since an abnormal response signal indicating that connection with the device is not possible is notified, and if QoS guarantee is not required, the ATM address of the CLS is notified, so appropriate measures against the congestion state of the ATM switching device should be taken according to the necessity of QoS guarantee. By taking such an effect, it is possible to ensure that high-quality data transfer can be ensured without data discarding.

According to the fourth aspect of the present invention, the address management server, while detecting the CLS congestion, responds to an address inquiry requiring QoS from the terminal device on the transmission side by using the ATM address of the destination terminal device 2f. Notify, and for an address inquiry that does not require QoS, another C that is not congested
Since the LS ATM address is notified, there is an effect that data discard does not occur and high-quality data transfer can be secured.

Further, according to the fifth aspect, the address management server notifies the ATM address of the MCS in response to an address inquiry addressed to the multicast address from the terminal device on the transmitting side, so that the terminal device is made aware of the transmission partner. Without providing multicast communication service, MCS
This makes it easy to change the network configuration such as changing the address of the network.

Further, according to the sixth aspect, the address management server, while detecting the congestion of the MCS, receives another address that is not congested in response to an address inquiry addressed to the multicast address from the transmitting terminal. Since the ATM address of the MCS is notified, there is an effect that data discard does not occur and high-quality data transfer can be secured.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an ATM address management device according to the present invention.

FIG. 2 is a signal sequence diagram showing an operation of the ATM address management device shown in FIG.

FIG. 3 is a detailed sequence diagram of the signal sequence shown in FIG. 2;

FIG. 4 is a detailed sequence diagram of the signal sequence shown in FIG. 2;

FIG. 5 is a configuration diagram showing a configuration example of an address management server for executing the signal sequences shown in FIGS. 2 and 3;

FIG. 6 is a configuration diagram showing a configuration example of an address management server showing another embodiment of the ATM address management device according to the present invention.

FIG. 7 is a table structure diagram showing a structure example of a QoS information management table 98 of the address management server shown in FIG. 6;

FIG. 8 is an explanatory diagram illustrating an operation of the address management server when an address inquiry request signal including an application type and including QoS information is received from the terminal device 2a on the transmission side.

FIG. 9 is an explanatory diagram for explaining the operation of the address management server when an address inquiry request signal that does not include an application type or includes an application type but does not include QoS information is received from the terminal device 2a on the transmission side.

FIG. 10 is a configuration diagram of an address management server showing another embodiment of the address management device according to the present invention.

FIG. 11 is an explanatory diagram showing an operation of the address management server when an address inquiry request signal including QoS information is received from the terminal device 2a on the transmission side while the exchange 1 of the ATM network is congested.

FIG. 12 is an explanatory diagram showing an operation of the address management server when an address inquiry request signal not including QoS information is received from the terminal device 2a on the transmission side while the exchange 1 of the ATM network is congested.

FIG. 13 is an explanatory diagram illustrating an operation of the address management server 3 when an address inquiry request signal not including a QoS guarantee is received from the terminal device 2a on the transmission side while the CLS 7 is congested.

FIG. 14 is a signal sequence diagram showing an address inquiry sequence according to another embodiment of the present invention.

15 is a configuration diagram of an address management server 3 for executing the signal sequence shown in FIG.

FIG. 16 is an explanatory diagram showing an operation of the address management server 3 when an address inquiry request signal not including QoS information is received from the terminal device 2a on the transmission side while the MCS 8 is congested.

FIG. 17 is a configuration diagram showing a configuration of a conventional address management device.

18 is a signal sequence diagram of the conventional address management device shown in FIG.

19 is a configuration diagram illustrating a configuration example of an address management server for performing address resolution according to the signal sequence illustrated in FIG. 18;

FIG. 20 is a configuration diagram showing a configuration example of an ATM communication network for executing conventional connectionless data communication.

21 is a signal sequence diagram of conventional connectionless data communication executed in the ATM communication network configuration shown in FIG.

FIG. 22 is a signal sequence diagram of conventional multicast data communication executed in the ATM communication network configuration shown in FIG.

[Explanation of symbols]

 1a-1e ATM switching device 2a-2f Terminal device 3a-3b Address management server 4 Network management device 5 Logical subnet 6 Logical subnet 7a-7b Connectionless server 8a-8b Multicast server 61a-61b Address inquiry request signal 62a-62b Address inquiry Response signal 63 Connection setting request signal 64 Connection setting response signal 65 Data transfer 91 Device management function 92 Address response function 93 Routing information exchange function 94 Routing table 95 Address management table 96 QoS information determination function 97 CLS address management table 98 QoS information management table 99 ATM network status monitoring function 100 CLS status monitoring function 101 MCS address management table 102 MCS status monitoring function

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-10-65704 (JP, A) JP-A-5-130268 (JP, A) JP-A-9-8817 (JP, A) 63161 (JP, B2) Hiroshi Shimizu et al. "ATM-LAN", Soft Research, P.90, 91 IEICE Technical Report SSE93-75 IEICE Technical Report SSE92-37 (58) Fields surveyed (Int. Cl. ⁶ , (DB name) H04L 12/28 H04L 12/46

Claims (6)

(57) [Claims] A plurality of connectionless servers (hereinafter referred to as C) that provide a connectionless service to a plurality of terminal devices.
LS), and when the ATM address of the destination terminal device is unknown, information as to whether or not to assure communication quality for communication with the destination terminal device (hereinafter referred to as QoS (Qual).
terminal device that transmits an inquiry request signal including an IP (Address of Service) information) and a protocol address such as an IP address, a plurality of terminal devices with protocol addresses and ATM (Asynchronous).
s Transfer mode), and has an ATM address table for storing a correspondence relationship with an address. When an address inquiry request signal is received from the transmitting terminal device, it is determined whether or not the QoS information is included in the inquiry request signal. If the QoS information is included, the ATM terminal of the destination terminal device is notified to the transmitting terminal device, and if the QoS information is not included, the ATM address of the CLS is notified. An ATM address management device, comprising: an address management server for notifying. 2. A plurality of connectionless servers (hereinafter C) for providing connectionless services to a plurality of terminal devices.
LS), when the ATM address of the destination terminal device is unknown, a transmitting terminal device that transmits an ATM address inquiry request signal including the type of application used for communication, and a plurality of application types. Having a correspondence table of QoS information suitable for this application type and receiving an ATM address inquiry request signal from the terminal device on the transmitting side, by referring to the correspondence table of the application type and QoS information,
The QoS of the connection used in the communication performed by the inquiry request signal is determined. If it is determined that the QoS is required, the ATM address of the destination terminal device is notified. If the QoS is not required, An ATM address management device, comprising: an address management server that notifies the transmitting terminal device of the ATM address of the CLS. 3. The address management server, when detecting congestion of the ATM switching device, notifies an address inquiry signal from the terminal device on the transmission side of an abnormal response signal indicating that connection is impossible when QoS guarantee is required. 3. The ATM address management device according to claim 1, wherein when QoS guarantee is not required, the ATM address of the CLS is notified to the terminal device on the transmission side. 4. The address management server, when detecting congestion of CLS, responds to an address inquiry from a terminal device on the transmitting side, if QoS guarantee is required, the address of the destination terminal device.
4. The method according to claim 1, wherein a notification of a TM address is provided, and if QoS guarantee is not necessary, an ATM address of another CLS that is not congested is notified.
TM address management device. 5. A plurality of multicast servers (hereinafter MCS) for providing a multicast service to a plurality of terminal devices.
When the ATM address of the destination terminal device is unknown, the terminal device on the transmitting side transmits an address inquiry request signal including a protocol address such as an IP address for communication with the destination terminal device. A control console and an ATM address table storing the correspondence between the protocol addresses and the ATM addresses of the plurality of terminal devices, and the protocol address of the address inquiry request signal received from the transmitting terminal device is a multicast address. The MCS of the MCS is transmitted to the transmitting side terminal device.
An ATM address management device, comprising: an address management server that notifies a TM address. 6. The address management server notifies an ATM address of another non-congested MCS in response to an address inquiry addressed to a multicast address from a terminal device on the transmission side while detecting congestion of the MCS. The ATM address management device according to claim 5, wherein