JPH03270342A - Atm communication network - Google Patents

Abstract

PURPOSE:To prevent sophisticated communication service able to be served substantially by an ATM exchange network (broad area multimedium information exchange or the like) from being hindered by constituting the network with a traffic control layer, an ATM exchange layer and a communication layer in existing between the layers and making transmission and reception of traffic control information. CONSTITUTION:An ATM communication network at first is roughly classified into an ATM exchange layer 10 and a traffic control layer 20 to be brought into a form easily implemented by cell traffic control. The traffic control layer 20 manages each ATM exchange layer 11 of the ATM exchange layer 10 in the lump, monitors integrally a traffic of all cells in the ATM exchange layer 10 and gives a proper traffic control command to all ATM exchanges 11 based on the result of monitor. Thus, the network copes with a specific cell traffic in the ATM. Thus, the merit in high speed lots of multi-medium service expected in the ATM exchange is enjoyed without deteriorating the communication service quality.

Description

[Detailed Description of the Invention] [Summary] Regarding an ATM communication network j′: in which information of each subscriber terminal is divided into cells and exchanged between each subscriber terminal, transmission and reception is carried out between subscriber terminals in communication. The purpose of this system is to maintain high quality communication services by controlling traffic for cells that are accessed, and it is comprised of multiple ATM exchanges that accommodate multiple subscriber terminals and are capable of interoperating with each other. ATM
A switching layer, a traffic control layer that monitors and controls cell traffic exchanged in the ATM switching layer and transmitted and received between subscriber terminals;
It consists of a communication layer that sends and receives traffic control information to and from the TM switching layer, and a traffic monitoring means that collects cell traffic information is provided in each ATM switch, and traffic monitoring means that collects cell traffic information is provided in each ATM switch. An analysis means for analyzing the cell traffic situation in the ATM switching layer based on the information is provided in the traffic control layer, and an optimal traffic control command based on the analysis result of the analysis means is sent to each ATM switch via the communication layer. :
A command means for giving this information is provided in the traffic control layer, and a command execution means for executing cell traffic control in accordance with the optimum traffic control command given from the command means is provided in each ATV exchange. Further, the command execution means is configured to include subscriber instruction means for transmitting an instruction signal for controlling the amount of cells sent out at the corresponding subscriber terminal.

[Industrial application field]

The present invention is an ATM (^5yn) system in which information of each subscriber terminal is divided into cells and exchanged between each subscriber terminal.
(chronous transfer mode) communication network.

The ATM switching network expected to be one of the next generation communication systems is B (Broadband)-15DN.
(It is built based on D core technology, and this ATM
In a switched network, information sent and received between subscriber terminals is divided into cells and then transferred within the network. To put such transfer into practical use, traditional call (call)
In addition to control at the cell level, it is essential to establish traffic control on a cell-by-cell basis.

The present invention is directed to an ATM whose main subject is the above-mentioned traffic control.
Let's talk about communication networks.

[Conventional technology]

In communication networks, switching systems are used as key points, and relay networks are structured in a hierarchical manner to reduce costs by sharing switching and line equipment necessary for relaying. For this reason, if more calls (traffic) occur than planned in the design, congestion will occur and communication services will inevitably deteriorate.

Conventional communication networks (telephone networks) are circuit-switched, so the traffic suppression function is effective after the occurrence of a congestion edge; and controls to mark new calls that occur, such as ■ Outgoing call restriction, ■ Incoming call restriction, ■ Priority control, ■Mainly involved in detour control, etc. Since the line is maintained for calls in progress, service continuity is guaranteed and traffic control is not performed.

In other words, forced disconnection of the call in progress is not executed.

[Problem to be solved by the invention]

However, in an ATM switching network, traffic control is performed on a cell basis as described above, which is completely different in concept from traffic control in conventional communication networks. Therefore, there is a problem that existing traffic control technology cannot be directly incorporated. If it were possible to incorporate it, it would be limited to call-level traffic control. This is because, regarding call-level traffic control, it is expected that the ATM switching network will also follow the signaling system adopted in the conventional telephone network. For example, N (Narrow-ban
d) - ISDN signaling system, subscriber line signaling system (
O3SL) and common line signaling system (CC5Ncc7).

In addition, since cell-based traffic control for calls in progress is possible in the ATM switching network, if sufficient measures are not taken for traffic control, the quality of communication services will deteriorate. There is a problem in that the advanced communication services (such as broadband multimedia information exchange) that could originally be enjoyed are obstructed.

In view of the above problems, it is an object of the present invention to propose an ATM communication network based on an ATM switching network, which is equipped with a feasible traffic control system and can ensure the provision of advanced communication services. be.

[Means to solve the problem]

FIG. 1 is a principle block diagram of an ATM communication network according to the present invention.

The ATM communication network according to the present invention basically consists of three independent layers. That is, (1) an ATM switching layer 10 that accommodates a plurality of subscriber terminals 12 and has a plurality of ATM switches 11 that can cooperate with each other; a traffic control layer 20 that monitors and controls cell traffic transmitted and received between subscriber terminals 12; (iii)
The communication layer 30 is configured to send and receive traffic control information between the traffic control layer 20 and the ATM switching layer 10.

More specifically, the traffic monitoring means 15 for collecting cell traffic information TI is connected to the ATM switching layer 10.
is provided in each ATM switch 11. The traffic control layer 20 is provided with an analysis means 21 for analyzing the cell traffic situation in the ATM switching layer 10 based on the traffic information TI obtained through the communication layer 30. The optimum traffic control command CM based on the analysis result of the analysis means 21 is transmitted to each AT of the ATM switching layer 10 via the communication layer 30.
A command means 22 for giving commands to the M exchange 11 is provided in the traffic control layer 20. A command execution means 16 for executing cell traffic control according to the optimum traffic control command CM given from the command means 22 is provided in each ATM switch 11 of the ATM switching layer 10. The command execution means 16 further includes subscriber instruction means 17 for transmitting an instruction signal Is for controlling the amount of cells sent out in the corresponding subscriber terminal 12.

[For production]

First, an ATM communication network is broadly divided into an ATM switching layer 10 and a traffic control layer 20, so that cell traffic can be easily controlled.

The traffic control layer 20 controls each ATM in the ATM switching layer 10.
The exchanges are collectively managed, the traffic of all cells in the ATM switching layer 10 is monitored in an integrated manner, and appropriate traffic control instructions are given to all ATM exchanges 11 based on the monitoring results.

Thus, unique cell traffic in ATM can be accommodated.

〔Example〕

FIG. 2 is a diagram showing a concrete image of the ATM communication network of the present invention. Note that similar components are designated with the same reference numbers or symbols throughout the drawings.

In FIG. 2, it can be seen that the traffic control layer 20 is arranged above the ATM switching layer l. AT on the lower side
The M switching layer 10 accommodates a large number of subscriber terminals 12 and has a plurality of ATMs that perform exchange between these subscriber terminals.
It has a built-in exchange 11. What actually constitutes the ATM switch 11 is the central office C○.
) and line concentrator RE (Remote Blectron)
ics).

Each ATM switch 11 (CO, R) of the ATM switch layer 10
is equipped with the traffic monitoring means 15 shown in FIG. 1, and the traffic information T collected by the means 15 is
I is connected to the upper traffic control layer 2 via the communication layer 30.
It gets sucked up to 0. Note that the communication layer 30 may be wired or wireless.

The traffic control layer 20 actually includes at least one traffic control center (TCC).
The center 23 includes at least the above-mentioned analysis means 21 for analyzing the traffic information TI sucked up from each ATM switch 11 and a command means 22. Center(
TCf'l:) When there are two or more centers 23, communication regarding traffic information TI is also carried out between these centers 23.

If we were to draw a concrete image of a conventional telephone network (circuit switching or packet switching network) as shown in Figure 2, we would have three
It does not become a dimensional structure, but remains a two-dimensional structure. That is,
There is no traffic control layer 20 and communication layer 30, and the functional parts corresponding to these layers 20.30 are completely embedded in each central office (corresponding to CO in Figure 2) that forms the core of the telephone network. It is.

FIG. 3 is a conceptual diagram of an ATM switch, which is basically not much different from a general electronic switch. That is, it consists of a communication path system 13 that exchanges cells and sets paths, and a control system 14 that controls the path settings.

4A, 4B, and 4C are diagrams showing implementation examples of communication path systems, and show a first example (FIG. 4A), a second example (FIG. 4B), and a third example (FIG. 4C).

There may be other implementation examples, but they are not directly related to the essence of the present invention, so the above three examples will be used.

The first example is called the self-routing type,
Each cell selects its own cell routing module SRM and is transferred towards the path to the other subscriber's terminal.

The second example is called a memory switch type, in which each cell is once stored in a buffer memory and then sent out to a path specified by a route determining section.

The third example is called a broadcast path type, in which a large number of nodes are connected to a plurality of paths, and each cell is sucked in at a required node and sent out from each node onto the path.

FIG. 5 is a diagram showing an example of traffic monitoring means.

However, for ease of understanding, traffic monitoring means 15
The surrounding area is also drawn, and the entire drawing is AT.
It represents the M exchange 11.

The ATM switch 11 is connected to the communication path system 13 shown in FIG.
and a control system 14, into which a traffic monitoring means 15 is inserted. Control system 14
is composed of a central control unit CC, and the communication path system 13 is represented in a diagrammatic image.From the left of the figure, the receivers are large cells (diagrammatically ○
CL (represented by mark) is distributed to the distribution unit 18 under the control of the CC.
and temporarily stores it in the queue buffer 19 for a predetermined route (path).

Each cell CL stored here is then sequentially sent out to the right side of the figure.

Traffic monitoring means 15 cooperating with this communication path system 13
includes, for example, a passing cell counter 151, a discarded cell counter 152, a buffer usage rate counter 153, etc., and count data from these counters is collected via a transfer circuit 154 to the central control unit CC.

How many cells CL have been taken into the channel system 13 (passing cell counter 151), and how many cells CL have been written out by subsequent cells CL in the queue buffer 19 due to an increase in cell traffic? (discarded cell counter 152), and what percentage of the maximum capacity of each queue buffer is the amount of cells CL constantly stored in the queue buffer 19 on average?
3>, etc. are basic data representing the traffic situation of the cell, and this becomes the traffic information TI described above. Note that, in principle, the CC does not directly control traffic by itself using the information TI, but immediately transmits the information to the traffic control layer 20. For this transmission, the communication layer 30 mentioned above is present.

FIG. 6 is a diagram showing the upstream side of the communication layer in more detail.

However, the surrounding area of the communication layer 30 is also depicted, and the diagram as a whole only partially represents the ATM communication network.

Cell traffic information TI obtained from the communication path system 13 shown in FIG. 5 by the traffic monitoring means 15 shown in the same figure.
The information is collected by the central WCC and then enters the communication layer 30. First, the information transmitter 31 is entered, and the uplink 32
The information reaches the information receiving device 33 at the end of the communication layer 30. This information receiving device 33 is connected to the traffic control layer 20
The traffic control center (T
CC) Central processing unit (CPt]) which forms the center of 23
The received traffic information TI is input to 24. This input information TI is sent to the analysis means 2 in the CPU 24.
1. Note that the analysis means 21 similarly receives traffic information TI from other ATM switches 11 in the ATM switching layer 10 through the corresponding uplinks 32 and information receiving devices 33.

In addition, 131 in the figure indicates the communication line system 13 and the central control unit (
This is the original path control line for path setting that connects with CCH4.

Figure 7 is a diagram showing the downstream side of the communication layer in a somewhat more concrete manner.
The optimum traffic control information based on the analysis result by the analysis means 21 in FIG.
A system is shown in which the command CM is transmitted to the ATM switching layer 10 side as the above-mentioned command CM. First, the signal enters the command transmitting device 35, passes through the downlink 36, and reaches the command receiving device 37 at the end of the communication layer 30.

This command receiving device 37 is located in the ATM switching layer 10, and is located in the ATM switching layer 10.
The optimum traffic control command CM is given to the central control unit (CCH 4) in the M exchange 11. This command CM is supplied to the command execution means 16, and traffic control based on the command CM is performed on the communication path system 13. The means 16 drives the instruction means 17 as required and sends the instruction signal IS to the corresponding subscriber terminal 12.

FIG. 8 is a diagram showing the traffic control center in a somewhat more concrete manner, and also depicts the surrounding area. Note that the peripheral parts of the device 33 in FIG. 6 and the device 35 in FIG. 7 are actually configured as one unit, so in FIG. show. The analysis means 21 and the command means 22 are also shown integrated within the CP[I 24.

Central processing unit (CP[J) 24 is the main memo! j (
MM) 25 and file memory (FM) 26.

Main memo! J (MM) 25 contains traffic information (TI
) data and processed data after analysis are stored. Of course, general programs governing various other operations are also stored in the MM 25.

On the other hand, file memo! J(FM) 26 is the analysis means 21
It holds reference data necessary for issuing commands from the command means 22 in response to the analysis results.

FIG. 9A is a diagram schematically representing the operation of the analysis means within the central processing unit, and FIG. 9B is a diagram schematically representing the operation of the command means within the central processing unit. The processing in FIG. 9B is executed by the central processing unit (CPU) 24 shown in FIG. 9A subsequent to the analysis processing shown in FIG. 9A.

In FIG. 9A, the traffic information transfer process (step a) for sucking up traffic information TI from the transmitting/receiving device 38 corresponding to each ATM switch shown in FIG. 8 is constantly repeated.

The traffic information (so-called raw data) sucked up in step a is stored at a predetermined address in the main memory (MM) 25 as data (2), data (2), . . . data@.

The data sucked up in step a and stored in the MM 25 is processed in step b. This step b is a process for analyzing the above accumulated data, and various processes are applied to each data.

The processed data is stored in other areas within the same MM25, with data “a”, “b”, etc. corresponding to each data ■, ■...@
・It is accumulated like “X”. Note that "processing" of data here refers to, for example, calculating the cumulative number of passages of the cell CL within a certain period of time, or calculating the usage rate of the queue buffer (19 in Figure 5) within a certain period of time ( (Calculated from the maximum and minimum number of cells accommodated in the queue buffer)
It means to do something.

When the above-described traffic analysis processing is completed, steps (:+a, e, f, and g) in FIG. 9B start. These steps are processing for issuing the above-described optimal traffic control command CM. Specifically, this command CM can be executed in the form of issuing "activation" and "cancellation", for example, and "activation" instructs the corresponding ATM switch 11 to suppress the cell flow rate. "Release" means to order the flow rate suppression to be returned to the normal flow rate level.The determination of activation and release of these is made in steps d and f of FIG. 9B, respectively. These issuances are performed in step e and step g, respectively.

In order to determine whether to activate or cancel the activation, it is necessary to compare predetermined reference value data with the processed data. −
For example, regarding kiss buffer 19, if you preset 70% as the maximum standard value and 30% as the minimum standard value, it will be "activated" when it is determined that the queue buffer usage rate exceeds 70%. Yes, and it is "released" when it falls below 30%. Provides so-called hysteresis to ensure stability in cell flow rate control. The above file memo IJ (
FM) 26 holds the above-mentioned reference value data, which is read out in step C and used to determine activation or cancellation.

FIG. 10 is a diagram showing an ATM switch that operates in response to an optimal traffic control command, and is almost the same as the ATM switch 11 shown in FIGS. 6 and 7, but is linked to the subscriber instruction means 17. SGtJ (Signal Gen
Also shown is erating [Inlt) 171. The SG[I 171 controlled by the means 17 sends a signal to the corresponding subscriber terminal 12 transmitting the cells, instructing it to lengthen the cell transmission interval.1. (when activated), or instruct it to return to its original state (cancellation, etc.).

This is done via the so-called 15DN D channel.

Optimal traffic control command CM, especially “activation” command cc
The activation actions performed by the command execution means 16 received via the communication path system 14 include, for example, (i) cell discard instruction (all clearing of cells in the queue buffer 19), and (ii) cell bypass within the communication path system 13. instruction (rewriting the VC table (not shown) in the communication path system 13), (VCI is an identifier included in the cell header) (iii) passing cell priority instruction (rewriting the priority displayed in the cell in advance) (discarded) in descending order of degree flag.

E. Effects of the Invention] As explained above, according to the present invention, it is possible to fully enjoy the benefits of high-speed, large-volume multimedia services expected in ATM exchanges without deteriorating the quality of communication services.

[Brief explanation of drawings]

Fig. 1 is a principle block diagram of an ATM communication network according to the present invention, Fig. 2 is a diagram representing a concrete image of the ATM communication network of the present invention, Fig. 3 is a conceptual diagram of an ATM switch, and Figs. 4A, 4B, and 40. Figure 5 is a diagram showing an example of implementation of a communication path system, Figure 5 is a diagram showing an example of traffic monitoring means, Figure 6 is a diagram showing the upstream side of the communication layer in a slightly more concrete manner, and Figure 7 is the diagram showing the downstream side of the communication layer. Figure 8 is a diagram showing the traffic control center in a slightly more concrete manner, Figure 9A is a diagram schematically representing the operation related to the analysis means within the central processing unit, and Figure 9B is a diagram showing the central processing unit. FIG. 10 is a diagram schematically showing the operation of the command means in the device. FIG. 10 is a diagram showing an ATM exchange operating in response to an optimal traffic control command. In the figure, 10...ATM switching layer, 11...ATV exchange, 12...Subscriber terminal, 13...Communication path system, 14...Control system, 15...Traffic monitoring means , 16... Command execution means, 17... Subscriber instruction means, 20... Traffic control layer, 21... Analysis means, 22... Command means, 2
3...Traffic control center, 24...Central processing unit, 25...Main memory, 26...File memory, 30...Communication layer, 31...Information transmission device, 32...Upstream Line, 33... Information receiving device, 35... Command transmitting device, 36... Downlink, 37... Command receiving device, 38... Transmitting/receiving device, TI... Traffic information, CM... - Optimal traffic control command, Is...instruction signal. Conceptual diagram of ATM exchange $3 Figure An example of traffic monitoring means Figure 5 Figure 4A Example of implementation of communication line system Okazuzu Figure $48 Example of implementation of flash line system Additional diagrams Figure 4C Figure Communication Figure 8I shows a slightly more detailed view of the traffic control center
2]

Claims (1)

[Claims] 1. An ATM (Asynchronous Tran) that accommodates a plurality of subscriber terminals (12) and can cooperate with each other.
monitors cell traffic exchanged between an ATM switching layer (10) comprising a plurality of (sferMode) switches (11) and the subscriber terminal (12) and the ATM switching layer (10); a traffic control layer (20) that controls the traffic control layer (20) and the ATM switching layer (1);
1. An ATM communication network characterized by comprising a communication layer (30) for transmitting and receiving traffic control information between the ATM communication network and the communication layer (30). 2. A traffic monitoring means (15) for collecting traffic information (TI) of the cell is connected to the ATM switching layer (1).
0) in each of the ATM switch (11), and analyzes the traffic situation of the cell in the ATM switch layer (10) based on the traffic information (TI) obtained through the communication layer (30). Analysis means (21)
provided in the traffic control layer (20).
ATM communication network described. 3. The optimum traffic control command (CM) based on the analysis result of the analysis means (21) is transmitted to each ATM switch (1) of the ATM switch layer (10) via the communication layer (30).
3. The ATM communication network according to claim 2, wherein said traffic control layer (20) is provided with command means (22) for giving commands to said traffic control layer (20). 4. A command execution means (16) for executing traffic control of the cell according to the optimal traffic control command (CM) given from the command means (22);
4. The ATM communication network according to claim 3, wherein said ATM communication network is provided in each said ATM switch (11) of an M switching layer (10). 5. The command execution means (16) further includes subscriber instruction means (17) for transmitting an instruction signal (IS) for controlling the amount of cells sent out in the corresponding subscriber terminal (12). 5. The ATM communication network according to claim 4.