JPH11275104A - Atm network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for combining the plural small-scale ATM (asynchronous transfer mode) exchanges by considering the property of the traffic amount of the data of subscribers and performing network housing. SOLUTION: The subscribers connected to this ATM network system are classified into first and second client groups 11 and 12 and a server 40. In this case, the first and second client groups 11 and 12 are connected to first and second ATM exchanges 21 and 22, the server 40 is connected to an ATM multiplexer/demultiplexer 30, the first and second ATM exchanges 21 and 22 are connected to each other and the first and second ATM exchanges 21 and 22 are connected to the ATM multiplexer/demultiplexer 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ATM network system, and more particularly to an ATM network system in which a client and a server are connected.

[0002]

2. Description of the Related Art The U.S. Department of Defense (DARPA: US.
Defence AdvancedResearch
AR supported by Projects Agency
PANET (Advanced Research P
The Internet (The Internet) originated from the Project Agency Network.
Although originally developed for academic and research purposes, in recent years, with the opening to commercial use and the spread of personal computers, the amount of data exchanged thereon has been increasing and becoming more diversified.

[0003] The Internet is for exchanging electronic mail (e-mail) between researchers, and for net news (NetN).
ews), since the network is mainly used for exchange and the like, there is no extreme difference between the amount of data transmitted by the user and the amount of data received, and it can be said that the amounts are almost equal.

However, in recent years, WWW (World W
As represented by the spread of ide Web), usage forms for distributing information in a broadcast manner are increasing.
In other words, if in principle two-way communication is substantially similar to one-way communication, for example, from one user, the amount of data received is enormous, but the amount of data transmitted is relatively small. is increasing. In addition, a distinction between a side that provides information and a side that is provided with information has become apparent. In this case, the amount of data transmitted and received between the sides that are provided with information is relatively small.

[0005] Since the Internet mainly exchanges data equally, it has been constructed by connecting packet switches called routers to each other. When the number of routers increases and the amount of data exchanged increases, the number of connections between routers increases.
Therefore, IXP (Internet eXchange)
ePoint), a connection mechanism between routers is increasingly used. In other words, instead of connecting the routers one by one and exchanging data between the routers, the idea is that the routers are first connected to the IXP and all data exchanges between the routers are performed via the IXP. IPX is usually configured by a large-scale router in many cases. In Japan, data exchange using IXP such as NSPIXP and NSPIXP2 is performed.

[0006] The concept of this network construction is equivalent to the concept used in a so-called telephone network. In other words, as the number of connections between routers on the Internet has increased, subscribers have become one-to-one on the Internet.
Rather than connecting to each other, a method similar to that of temporarily accommodating in a telephone exchange arranged at a telephone office and making all connections between subscribers using this telephone exchange is adopted. . It is also well known that the conventional public network also adopts a hierarchical connection type, but the data exchange that was performed by flat router connection on the Internet has been hierarchized. Attempts have been made to use such a connection configuration.

[0007] From such a background, a method has been considered in which a router is connected to the Internet by adopting a hierarchically-structured connection form as used in a public network as the connection form.

One solution is B-ISDN (Broa).
d Band ISDN) networking. In B-ISDN, ATM (Asyn
A data transfer method called a “chronous transfer mode” is employed. ATM can handle all data communication such as conventional circuit switching and packet communication by a single means. Therefore, not only a public network but also a LAN (Local Area Network) can be used.
rk) can be used in a private network, and standardization work is being carried out by an organization such as an ATM forum.

[0009]

The above-mentioned A
When configuring a network system using TM,
It is often the case that a single exchange is used or a plurality of exchanges are connected in a hierarchical manner so that each line interface can always communicate with another arbitrary line interface.

[0010] Here, in the case of data communication on the Internet, as described above, it can be considered to be divided into a side that provides information and a side that is provided with information. In the following description, the side that provides information is referred to as a server, and the side that is provided is referred to as a client. In other words, using this definition, the current state of data communication on the Internet is relatively small, and the amount of data transmitted and received between the client and the client is relatively small, and the amount of data transmitted and received between the client and the server is relatively large. .

As can be understood from the above, AT
In the conventional network configuration using M, if such current data communication is to be performed, unnecessary redundancy is given to the network equipment, so that the network equipment is effectively used. Was not possible.

Such a situation is not a problem when the size of the ATM switch is small. However, when a multi-line, large-capacity ATM switch is to be constructed, a large-scale hardware having unnecessary redundancy is required. Hardware is required, which leads to a problem that the cost required for introducing the exchange becomes enormous.

Here, prior arts related to the present invention are enumerated, and it is mentioned whether each technique can solve the above-mentioned problem.

Japanese Patent Application Laid-Open No. 7-202929 (hereinafter referred to as Prior Art 1) discloses "A which can communicate between small networks and realize a large network as a whole.
V network system "is disclosed. That is, in the AV network system disclosed in the prior art 1, the AV network control device controls the coupling device to divide the small network into a plurality of groups. When transmitting and receiving video and audio between communication terminal devices beyond the group, the AV network control device grasps the use status of the frequency within each group via the data network and communicates with each of the communication terminals. A frequency usable in the group is determined, and a frequency transmitted by the communication terminal device in one group of the plurality of groups is converted by the coupling device into a frequency usable in the other group, and is converted into the frequency usable in the other group. Received by the communication terminal device.

Japanese Patent Application Laid-Open No. Hei 6-2610075 (hereinafter referred to as Prior Art 2) discloses a distributed switching system suitable for high-speed broadband communication, which has excellent expandability from a small scale to a large scale. An economical, high throughput distributed "switching system" is disclosed. That is, in the prior art 2, a plurality of independently operating switching units each having a call processing unit including a call processing processor for performing a call process corresponding to information from a subscriber line or a trunk line are provided. The switching system is connected to a communication network having a transmission unit for transmitting a fixed-length packet in which a header including a destination of information is added to information from a trunk line. With this configuration, each switching unit is an independent distributed switching unit that performs call processing in its own call processor, and the communication network is a mere transmission unit that carries fixed-length packets to each switching unit. Processing capacity does not become a bottleneck in the communication network,
A high processing capacity can be obtained as the whole switching system, and a switching system having a flexible configuration that can be easily expanded and expanded can be realized by changing the number of switching means connected to the communication network.

Further, Japanese Patent Application Laid-Open No. 5-26865 (hereinafter referred to as Prior Art 3) discloses that a small-scale host having a small resource at a packet link level can simultaneously communicate with many terminals in a packet network accommodating many terminals. The "packet link setting method" described above is disclosed. That is, in the prior art 3, the virtual FEP function is provided in the packet switch accommodating the host. The packet link from the host is temporarily terminated by the virtual FEP function. After the termination, the virtual FEP function exchanges information for each terminal with the host according to the upper layer protocol. Then, virtual FEP is
Set up a packet link to each terminal. By repeating this operation for the number of terminals, a plurality of packet links for the terminal can be multiplexed on one of the packet links with the host.

Furthermore, Japanese Patent Application Laid-Open No. Hei 2-244937 (hereinafter referred to as Prior Art 4) discloses an economically superior "ISDN packet switching system" in which the processing capacity of a packet switch is set to an appropriate value. ing. According to the prior art 4, in a packet switch installed after a circuit switch, a class is divided according to a throughput of a packet call set on a B channel, and a plurality of types of packets having packet processing capabilities corresponding to the class are classified. An exchange device is provided.
The circuit exchange receiving the call from the subscriber terminal connects to the IS
The throughput for each DN subscriber line is read from a subscriber data database registered in advance, and a packet switching device of a class suitable for the throughput is selected and connected.

However, the above-mentioned prior arts 1 to 4
Does not disclose any technology relating to the ATM network system, and does not disclose any technical concept of accommodating a network in consideration of the characteristics of a subscriber.

That is, the prior art 1 grasps the usage status of the frequency in each group, determines the frequency that can be used in each group, and changes the transmission frequency of one group to the frequency that can be used in the other group. It only discloses an AV network system for conversion. Prior art 2 only discloses a distributed switching system in which each peripheral switching module can independently process a call. Further, Prior Art 3 only discloses a packet link setting method that enables a small-scale host with little resource at the packet link level to communicate with a large number of terminals at the same time. Further, Prior Art 4 only discloses an ISDN packet switching system having a plurality of types of packet switching devices that are classified according to the throughput of packet calls set on the B channel.

Therefore, the present invention provides a function equivalent to a data exchange service provided by a large-scale ATM switch by accommodating a network in consideration of the characteristics of a subscriber.
It is intended to be realized by a plurality of small-scale ATM exchanges.

[0021]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to configure an ATM network system at low cost and efficiently as described below.

The ATM network system of the present invention comprises:
A plurality of ATM exchanges for exchanging data from an arbitrary input to an arbitrary output, an ATM for multiplexing data arriving from a plurality of inputs into one output, and further separating data arriving from one input into a plurality of outputs A demultiplexer.

Further, not all subscribers are equal,
According to the usage form of the TM network system, it can be classified into two groups. The first group is a group of subscribers (hereinafter, referred to as servers) that provide services such as information provision and information processing via a network. The second group is a group of subscribers (hereinafter, referred to as clients) that use services provided by the server. Client group and server
The ATM network system is realized by accommodating the groups in the small-scale ATM switch and the demultiplexer, respectively.

The following assumptions are made for the configuration of the present invention and the usage form of the ATM network system.

(1) The number of subscribers belonging to the server group is much smaller than the number of subscribers belonging to the client group.

(2) The traffic between the subscribers belonging to the client group is much smaller than the traffic between the server group and the client group.

Furthermore, among the client groups, for example, certain subscribers belonging to the same region, company, organization, etc. often have a lot of traffic to and from each other. Therefore, the client group can be divided into several smaller sub-client groups. Each sub-client group is housed in a separate ATM switch. server·
The group connects to the ATM switch via an ATM demultiplexer.

The ATM network system of the present invention having such a configuration operates as described below.

Data transmitted and received between clients belonging to the same client group is exchanged via a single ATM exchange. Data transmitted and received between clients belonging to another client group passes through the ATM switch to which the originating client is connected, passes through the connection between the ATM exchange and another destination client, and The message is transmitted via the ATM switch to which the called client is connected.

The data transmitted from the client to the server includes an AT from the client to which the client is connected.
The data is transmitted to the server via the M exchange and the ATM demultiplexer. The data transmitted from the server to the client passes through the ATM demultiplexer from the server, passes through the ATM switch to which the destination client is connected,
Sent to the terminating client. In other words, AT
The M demultiplexer multiplexes the data arriving from the ATM switch and transmits the multiplexed data to the server, and transmits the data arriving from the server to the desired ATM switch according to the destination.

On the other hand, in the related art, since the ATM switch is arranged where the ATM demultiplexer is to be arranged, the cost for disposing the ATM switch is higher than that of the ATM demultiplexer. In the ATM network considered here, a relatively large amount of data is transmitted from the server to the client, and a relatively large amount of data is transmitted and received between the clients connected to the same ATM exchange. The accommodation is taking into account the traffic volume.

By the above method, a large-capacity ATM exchange can be realized by combining a small-scale ATM exchange, and an inexpensive and flexible ATM network can be constructed.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings.

An ATM network system according to the first embodiment of the present invention will be described with reference to FIG.

The illustrated ATM network system comprises a first client group 11, a second client group 12, a first ATM switch 21, and a second
, An ATM switch 22, an ATM multiplexer / demultiplexer 30, and a server 40. Here, the server 40
May be a server group consisting of a plurality of servers.

The first client group 11 includes:
First, second, and third clients 11-1, 11-
2, and 11-3. Similarly, the second client group 12 includes first, second, and third clients 12-1, 12-2, and 12-3.

The clients included in the first client group 11 are connected to the first ATM switch 21, and the clients included in the second client group 12 are connected to the second ATM switch 22. . That is, the first to third clients 11-1 to 11-1
11-3 is connected to the first ATM switch 21 and
The third to 12th clients 12-1 to 12-3 are connected to the second ATM switch 22. In this way, the ATM exchange connected to the client is
It will be referred to as a client-side ATM switch. In the present embodiment, there are only two client-side ATM exchanges, but it goes without saying that there may be three or more.

As shown in FIG. 1, the first ATM switch 2
The first and second ATM exchanges 22 are connected to each other, and furthermore, the first and second ATM exchanges 21 and 22
Are connected to the ATM demultiplexer 30, respectively. A server 40 is connected to the ATM demultiplexer 30.

The first ATM switch 21 receives data transmitted from a client included in the first client group 11 and data transmitted from the second ATM switch 22 and the ATM demultiplexer 30. Have the ability to exchange according to.

Similarly, the second ATM switch 22 is connected to the second
Has the ability to exchange data transmitted from clients included in the client group 12 with data transmitted from the first ATM switch 21 and the ATM demultiplexer 30 according to the destination.

The ATM multiplexer / demultiplexer 30 comprises first and second ATM demultiplexers.
Multiplexes the data transmitted from the ATM exchanges 21 and 22 and transmits the multiplexed data to the server 40. The data transmitted from the server 40 is transmitted to the first ATM exchange 21 or the second ATM exchange 22 in accordance with the destination. It has the ability to sort out and send.

On the other hand, the ATM multiplexer / demultiplexer 30 has a capability of outputting data input from a plurality of interfaces to a single interface and outputting an input from the interface to a plurality of interfaces. Therefore, since the relation between the data input and output can be considered as an ATM switch fixedly determined, the ATM multiplexer / demultiplexer 30 can be constituted by an ATM switch.

The first to third clients 11-1 to 11-3 belonging to the first client group 11 and the first to third clients 12-1 to 12-12 belonging to the second client group 12 -3 are connected to the first and second ATM exchanges 21 and 22, respectively, and the connection destination ATM exchange is determined as follows. That is, when it is considered that the amount of data to be transmitted and received mutually is relatively large, the data is accommodated in the same ATM exchange.

Next, the operation of the ATM network system shown in FIG. 1 will be described.

Data transmitted from first to third clients 11-1 to 11-3 belonging to the first client group (hereinafter, referred to as first group data)
Is transmitted to the first ATM exchange 21.

Here, it is assumed that the first group data is data addressed to a client belonging to the first client group 11 connected to the first ATM exchange 21. In this case, the first ATM switch 21
Transmits the first group data to the destination client.

On the other hand, the first group data is the second group data.
Second client connected to the ATM switch 22
First to third clients 12 belonging to group 12
It is assumed that the data is addressed to -1 to 12-3. In this case, the first ATM switch 21 transfers the first group data to the second ATM switch 22, and the second ATM switch 22 transfers the first group data to the destination client. Forward.

Assume that the first group data is data addressed to the server 40. In this case, the first ATM switch 21 stores the first group data in A
The ATM multiplexer / demultiplexer 30 transmits the first group data to the server 4 and transmits the first group data to the server 4.
Send to

Similarly, first to third clients 12-1 to 12-3 belonging to the second client group
(Hereinafter, referred to as second group data) is transmitted to the second ATM switch 22.
This will also be described by dividing the cases in the same manner as described above.

First, when the second group data is the second A
It is assumed that the data is addressed to a client belonging to the second client group 12 connected to the TM exchange 22. In this case, the second ATM switch 22 transmits the second group data to the destination client.

On the other hand, the second group data is the first group data.
The first client connected to the ATM switch 21
First to third clients 11 belonging to group 11
Assume that the data is addressed to -1 to 11-3. In this case, the second ATM exchange 22 transfers the second group data to the first ATM exchange 21, and the first ATM exchange 21 transmits the second group data to the destination client. Forward.

Assume that the second group data is data addressed to the server 40. In this case, the second ATM switch 22 transmits the second group data to A
The ATM demultiplexer 30 transmits the second group data to the server 4 and transmits the second group data to the server 4.
Send to

Next, data transmitted from the server 40 to the ATM demultiplexer 30 (hereinafter, referred to as server data) will be described. Here, the destinations of this server data are all the first client group 1
1st to 3rd clients 11-1 to 11 belonging to 1
It is assumed that the data is data addressed to any one of the first to third clients 12-1 to 12-3 belonging to the third client group 12 and the second client group 12.

In such a situation, the ATM demultiplexer 30 transmits the server data to the ATM switch to which the destination client is connected. That is, when the server data is data addressed to the first to third clients 11-1 to 11-3 belonging to the first client group 11, the ATM demultiplexer 30 transmits the first A
The server data is transmitted to the TM exchange 21. If the server data is data addressed to the first to third clients 12-1 to 12-3 belonging to the second client group 12, the ATM data is sent to the ATM switch 21. The demultiplexing device 30 includes a second
The server data is transmitted to the ATM switch 22.

Next, an ATM network system according to a second embodiment of the present invention will be described with reference to FIG. The ATM network system shown is the same as that shown in FIG. 1 except that a third ATM switch 50 is added and a server group 40A and a fourth ATM switch 60 are used instead of the server 40. It has the same configuration as the above. Therefore, components having the same functions as those shown in FIG. 1 are denoted by the same reference numerals, and only the differences will be mainly described below in order to simplify the description.

In the first embodiment described above, the first A
Although the TM exchange 21 and the second ATM exchange 22 are directly connected to each other, in the second embodiment, the first ATM
The exchange 21 and the second ATM exchange 22 are composed of first and second ATM switches.
Are connected via a third ATM exchange 50 different from the ATM exchanges 21 and 22 of the first embodiment. Thus, the third ATM switch 50 is connected to the client-side ATM switch 21.
And 22 are also called relay ATM switches.

In the first embodiment, the ATM multiplexer / demultiplexer 30 is directly connected to the server 40. In the second embodiment, the ATM multiplexer / demultiplexer 30 is connected to the fourth server. Is connected to the server group 40A via the ATM switch 60 of the first embodiment. The server group 40A includes first to third servers 40-1 and 40-
2, and 40-3. As described above, since the fourth ATM exchange 60 is connected to the server, the server A
Also called a TM exchange.

As can be understood from the above, the second
In the second embodiment, different from the first embodiment, a plurality of servers 40-1 to 40-3, that is, server groups, are connected to the ATM network.

Although two client-side ATM exchanges for directly accommodating clients are not shown in the figure, there are actually many client-side ATM exchanges. As described above, when there are a large number of client-side ATM exchanges, the relay ATM exchange 50 is used for exchanging data to be transmitted and received between the client-side ATM exchanges. In the present embodiment, this A
A plurality of servers 40-1 to 40-3 in the TM network
Can be connected.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0061]

As described above, according to the present invention, a plurality of client-side ATM exchanges each directly accommodating a plurality of clients, data transmitted from the plurality of client-side ATM exchanges are multiplexed and output. An ATM multiplexer / demultiplexer that separates input data and outputs the data to a plurality of client-side ATM exchanges has the following effects.

The first effect is that the ATM network system can be configured with a minimum amount of hardware, so that it can be realized at low cost. The reason is that by grouping the client and the server according to the amount of data transmitted / received to / from each other, redundant hardware is not required.

The second effect is that the configuration and the scale of the ATM network system can be flexibly changed and expanded. The reason is that the ATM network system can be realized by connecting small-scale ATM exchanges to each other, so that even if the configuration is changed, the influence on the user can be minimized.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of an ATM network system according to a second embodiment of the present invention.

[Explanation of symbols]

11 First Client Group 12 Second Client Group 11-1 First Client 11-2 Second Client 11-3 Third Client 12-1 First Client 12-2 Second Client 12 -3 third client 21 first ATM switch 22 second ATM switch 30 ATM demultiplexer 40 server 40A server group 40-1 first server 40-2 second server 40-3 third server 50 Third ATM Switch (Relay ATM Switch) 60 Fourth ATM Switch (Server-side ATM Switch)

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 16, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction contents]

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

Claims (6)

[Claims] 1. A plurality of client-side ATM exchanges each directly accommodating a plurality of clients, and data transmitted from the plurality of client-side ATM exchanges are multiplexed and output, and input data are separated and separated. An ATM demultiplexer for outputting to a plurality of client-side ATM exchanges.
TM network system. 2. The ATM network system according to claim 1, wherein users of said ATM network system are classified into clients and servers and connected. 3. The ATM network system according to claim 1, wherein a server is directly connected to said ATM demultiplexer. 4. A server-side ATM accommodating a plurality of servers.
Further comprising an exchange, wherein the server-side ATM exchange comprises the AT
2. A according to claim 1 connected to an M demultiplexer.
TM network system. 5. The ATM network system according to claim 1, wherein said plurality of client-side ATM exchanges are directly connected to each other. 6. The ATM network system according to claim 1, further comprising a relay ATM exchange for connecting said plurality of client-side ATM exchanges.