JPH0646085A - Traffic parameter control system in atm exchange - Google Patents

Abstract

PURPOSE:To attain proper traffic control independently of traffic modification due to a shaping function or the like in an ATM multiplexer. CONSTITUTION:A monitor CPU 5014 in a traffic monitor circuit 501 provided to a terminal interface in an ATM exchange generates a traffic parameter for each call channel based on a transmission cell count from a cell counter 5011 for each time interval given from a timer 5013 and the parameter is stored in a RAM 5015 as an application traffic parameter from a terminal equipment and informed to a CPU 53 via an I/O circuit 5012. The CPU 53 controls a policing circuit based on the noticed traffic parameter to avoid abort of a required number of cells or undesired traffic security even against traffic modification due to a shaping function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM used in a wide band ISDN which realizes exchange of a transmission rate of several 100 Mbps.
The present invention relates to improvement of traffic parameter control method in exchanges.

[0002]

2. Description of the Related Art FIG. 5 shows an example of an ATM network.
A configuration as shown in is known. As is clear from the figure, this ATM network is
An ATM multiplexer 3 which realizes a function of multiplexing cells from the terminal 1 or a function of distributing the multiplexed cells to the terminal 1 and an ATM switch 5 which realizes a function of exchanging cells in units of cells are configured. .

Among them, the ATM multiplexer 3 has a configuration as shown in FIG. 6, and multiplex-transmits cells input from the terminal interface 31a to the multiplex interface 32 and VPI receives cells received by the multiplex interface 32. /
It has a function of disassembling and communicating with a specific terminal interface 31b according to the VCI value. Corresponding to this function, as for the structure of the transmission side (terminal interface → multiplex interface) of the multiplex interface 32, as shown in FIG. 7, from the cell extracting unit 321a for extracting cells from the ATM multiplex bus 33, It has a structure in which cells are transmitted to the multiplex line 4 through the cell sending unit 323a via the shaping circuit 322 that realizes the shaping function described below.

As shown in the conceptual diagram of FIG. 8, this shaping function allows the cell transmission interval for each terminal 1 or each multiplex line 4 by passing the fluctuating cell traffic from the terminal 1 through the shaping circuit 322. This is a function to equalize the values so that they are constant. From this, the AT having the above configuration
In the M network, it can be said that the traffic characteristic from the terminal 1 is deformed at the time of passing through the ATM multiplexer 3.

By the way, in the ATM switch 5, the trunk line 6
It is necessary to grasp the cell flow rate from the terminal 1 in order to allocate the bandwidth value of 1 or to avoid congestion. This cell flow rate is called a traffic value, and its attribute parameters include those shown in a to d below. It should be noted that these traffic parameters can be more easily understood by capturing them in the conceptual diagram shown in FIG.

A. Average speed = total number of cells (X) / total communication time (T) b. Peak speed = maximum number of communicable cells (X0) / minimum cell time interval (T0) c. Burst rate = number of burst cells (X1) / minimum burst time interval (T1) d. Maximum number of continuous cells (X2) The cells described so far are CCITT / I. 36
1 is specified, and an example of a specific format thereof is shown in FIG. The address, which is the exchange unit of this cell, is called VPI / VCI, and in the following description, that unit is called a channel.

ATM according to the format shown in FIG.
The cell transmitted from the multiplexer 3 is input to the ATM exchange 5 and exchanged according to the VPI / VCI in the cell. FIG. 11 is a block diagram showing a general configuration of the ATM exchange 5 which performs the exchange processing.

In this type of ATM switch 5, there are cases where the terminal 1 is directly received and where the ATM multiplexer 3 is accommodated. In either case, the call signal is sent to the CP of the exchange on the accommodated line.
A call signal channel 54 for transmitting to U53 and a data channel 55 for transmitting user data to the trunk line 6 are allocated. That is, the call message is notified to the CPU 53 through the call signal channel 54 of the lines 2 and 4, and after setting the switch for the data channel, it is relayed to the corresponding relay line 6 according to the corresponding called number. Regarding the call message, for example, CCITT / Q. 9
As defined in No. 31, the call setup message is particularly focused here.

By the way, in the conventional ATM switch 5 which is responsible for such control, the switch terminal interface 51 has a circuit structure as shown in FIG. As shown in the figure, the conventional exchange terminal interface 51 has a policing circuit (UPC) 512 interposed between a cell extraction unit 511a and a cell transmission unit 513a, for example, on a cell transfer path from the terminal to the exchange. It has a different configuration.

The exchange terminal interface 51 having such a configuration
In the above, the policing circuit 512 in the
Under the control management of No. 3, the declared traffic parameter values (a to d) corresponding to the above a to d sent from the terminal placed in the transfer capability area in the "call setup message" having the format as shown in FIG. (See) and is set, and traffic that exceeds this set value flows in, this is discarded as a violating cell. This polishing circuit 51
The function of discarding the violating cell based on the set traffic parameter value according to 2 is called a policing function, and its schematic diagram is shown in FIG. With this policing function, the ATM switch 5 can avoid a congestion state due to the inflow of more cells than declared in the switching network.

However, in the conventional ATM switch 5 of this kind as described above, even if the cell is transmitted from the terminal 1 in accordance with the declared parameters, if the ATM multiplexer 3 intervenes between the cells, the shaping function is used. Since the traffic is transformed, the policing circuit 5 uses the policing control parameter values as declared above in the ATM switch 5.
Even if 12 is controlled, the traffic to be controlled has not already changed as declared, so the policing circuit 5
In 12, the cells are discarded more than necessary, or extra traffic is secured, resulting in a significant decrease in the line usage efficiency.

[0012]

As described above, in the conventional ATM network described above, the cell is transmitted from the terminal to the ATM exchange in accordance with the traffic parameter declared in the call setup message, and the ATM exchange always uses the declared value. Since the illegal cell is discarded, when the ATM multiplexer is interposed between the terminal and the ATM switch and the traffic is deformed due to the shaping function, the declared value and the actual traffic are significantly increased. As a result of the difference, cells are unnecessarily discarded in the policing circuit, and extra traffic is secured, so that there is a problem that the reduction of the line use efficiency cannot be avoided.

According to the present invention, this problem is eliminated, and even if traffic deformation occurs in an ATM multiplexing device interposed in the middle,
It is an object of the present invention to provide a traffic parameter control system in an ATM switch which can realize a proper amount of cell discard and traffic securing corresponding to the traffic after the modification and thus contribute to improvement of line usage efficiency.

[0014]

The first invention of the present application is to provide an ATM multiplexer having a shaping function for uniformizing the cells which are fluctuated and transmitted from a terminal so that the cell transmission intervals are constant. When exchanging the cell, which is a fixed-length packet, according to the address information added in the cell by accommodating via the terminal interface, the violating cell that exceeds the declared value based on the declared traffic parameter value from the terminal In an ATM switch having a discarding policing function, the traffic information for each call is calculated at the terminal interface in the switch based on the number of cells transmitted at a certain time interval, and the result is stored as a call-declared traffic parameter value. A monitoring means is provided, and the control section of the ATM switch concerned controls the policing function. As data values, characterized by using the traffic information stored in the traffic monitor means.

The second invention of this application provides an ATM multiplexer having a shaping function for uniformizing cells fluctuatingly sent out from a terminal so that the cell sending intervals are constant, via a terminal interface in the exchange. To accommodate
An ATM having a policing function for discarding a violating cell which exceeds the declared value based on the declared traffic parameter value from the terminal when the cell which is a fixed length packet is exchanged according to the address information added in the cell.
The exchange has a registration means for predicting the traffic information after being uniformized by the shaping function, and pre-registering the traffic information as a call-declared traffic parameter value in the ATM exchange. The controller of the ATM exchange has the policing function. The traffic information registered by the registration means is used as the control parameter value of the function.

[0016]

In the first invention of this application, a cell which is a fixed length packet is identified by address information (VPI / X) indicated in the cell.
In an ATM network switching according to CI),
In the case where the ATM multiplexer is interposed between the terminal and the ATM switch, the traffic information of the terminal is expressed based on the number of transmission cells for each certain time interval measured by the terminal interface in the ATM switch in the direction from the terminal to the ATM switch. , It is set to the ATM switch terminal interface by replacing it with the call-declared traffic parameter value, and the control section of the ATM switch uses the traffic parameter set as the policing control parameter value while the traffic by the ATM switch or ATM multiplexer is used. Address the control of discarding traffic violation cells after transformation.

Further, in the second invention of this application, the traffic parameter value predicted in advance in consideration of the traffic deformation due to the shaping function is registered by replacing it with the call declaration traffic parameter from the command input device or the like connected to the ATM switch. While using this registered traffic parameter as a policing control parameter value, the AT
It deals with the discard control of traffic violation cells after traffic modification by the M switch or ATM multiplexer.

As described above, according to the present invention, the AT traffic parameter value actually sent from the terminal is not the AT traffic value.
Since the policing function operation is controlled according to the traffic value measured at the input end of the M switch or the traffic parameter value generated based on the traffic value predicted in advance on the premise of receiving the shaping function, the AT
Even if an ATM multiplexer is interposed between the M switch and the terminal and the cell traffic is deformed due to its shaping function, appropriate cell discard processing corresponding to the traffic value after the deformation is always carried out. Therefore, it is possible to prevent the required cells from being discarded or extra traffic is secured based on the value actually reported from the terminal.

[0019]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. First, a first embodiment of the present invention will be described with reference to FIGS. However, since the present invention is the same as the conventional one except for the structure of the ATM switch, the drawings used in the section of the conventional art will be used together in the description.

The ATM switch 5 according to the first embodiment of the present invention, after setting the policing control parameter value using the traffic value measured at the input end, that is, the switch terminal interface accommodating the ATM multiplexer 3. The CPU of the exchange controls the operation of the policing function based on the set value.

In response to this control, the ATM exchange 5 according to the first embodiment has a traffic monitor means (a cell is defined by a traffic parameter) in the exchange terminal interface for accommodating the terminal 1 or the ATM multiplexer 3. The function of counting at each time interval), and the CPU of the ATM exchange 5 measures the value measured by the traffic monitoring means in units of the calling number of the terminal 1 accommodated via the ATM multiplexer 3. It has a table that stores the traffic parameter values generated from.

FIG. 1 is a block diagram showing a specific example of the exchange terminal interface 50 according to the first embodiment, in which a traffic monitor circuit 501 is provided between a cell extraction unit 511a and a policing circuit 512 and a cell transmission unit 513a. It is implemented.

On the other hand, a concrete example of the main CPU 53 of the ATM exchange 5 according to the first embodiment is shown in FIG. 3, and an I / O for connecting to the exchange terminal interface 50.
A circuit 531, a CPU 532 for performing exchange control including a policing function operation, and an RA as a storage destination of the above table
It comprises an M533 and a call channel termination I / O circuit 534.

Here, the traffic monitor function in the exchange terminal interface 50 will be described first. As shown in FIG. 1, the exchange terminal interface 50 of the present invention includes a cell extraction unit 511a and a policing circuit 512.
This is different from the conventional one (see FIG. 12) in that a traffic monitor circuit 501 is mounted between them.

The details of the traffic monitor circuit 501 are, as shown in FIG. 2, a cell counter 5011, an I / O circuit 5012, a timer 5013, a monitor CPU 5014,
It is configured by including a RAM 5015. In the traffic monitor circuit 501, the timer 5013 gives the timing of the maximum communicable cell to the monitor CPU 5014 and the cell counter 5011, while notifying the monitor CPU 5014 of this at each increment of this timing. The monitor CPU 5014 calculates the information shown in A to D below based on the cell count value in the cell counter 5011 at this time, and the calculation result is R in the mode shown in FIG.
Stored in AM5015. However, each piece of information as the calculation result is valid for each call, and the measurement unit is the channel (i) unit secured by the call.
The main CPU 53 previously stores only the relationship between the calling number and the channel.

A. (X, T): Average call speed parameter X: Total counter value T: Total number of timings of maximum communicable cells B. (X0, T0): Peak speed parameter of one call X0: Maximum number of communicable cells (fixed value) T0: Minimum timing number for counter up C.I. (X1, T1): Burst rate parameter of one call X1: Number of cells with continuous peaks T1: Minimum number of timings between bursts with continuous peaks D. X2: The maximum number of consecutive cells for a call X2: If the counter is continuously incremented at the timing of the maximum communicable cell, the consecutive number.

After that, the traffic monitor circuit 501
The traffic information stored in the RAM 5015 as described above is transferred from the I / O circuit 5012 to the CPU bus 5 when the call is released.
02 to the main CPU 53.

As described above, the main CPU 53 is shown in FIG.
The CPU 532 has the configuration as shown in FIG. 1 and takes in the traffic information notified from the traffic monitor circuit 501 through the I / O circuit 531. Organize as
Store in M533.

A ′. (X, T): Average speed parameter of terminal X: Cumulative value of counter value in call unit T: Cumulative value of timing number of maximum communicable cell in call unit B '. (X0, T0): Peak speed parameter of terminal X0: Maximum number of communicable cells (fixed value) T0: Minimum value of minimum timing number for incrementing one counter per call C '. (X1, T1): burst rate parameter of terminal X1: number of cells with continuous peaks of B'T1: minimum number of timing between bursts with continuous peaks of B'D '. X2: Maximum number of consecutive cells of the terminal X2: Maximum value of the consecutive number when the counter continuously increases at the timing of the maximum communicable cell of each call.

In this state, when a call setup message arrives at the ATM exchange 5 from a certain terminal 1, the CPU 532 uses the traffic parameter value stored in the RAM 533 corresponding to the calling terminal at this time as a policing control parameter value. Set to 512. As a result, the policing circuit 512 performs the discarding process of the violating cell according to the set policing control parameter.

As is apparent from the above-mentioned processing, the policing control parameter at this time is set based on the traffic measurement value after passing through the ATM multiplexer 3. Therefore, in the first embodiment, the ATM
Even if the traffic is deformed by the shaping function of the multiplexer 3, the cell discard processing corresponding to the traffic after the deformation is performed. by this,
A so-called policing circuit 5 in which cells are discarded more than necessary, or extra traffic is secured
It is possible to minimize the effect of 12 on the line usage efficiency.

Next, a second embodiment of the present invention will be described with reference to FIG. ATM switch 5 according to the second embodiment
Registers policing control parameters predicted in advance in consideration of traffic deformation associated with the shaping function in the ATM exchange 5, and controls the policing function operation while setting these parameters as the traffic parameters declared by the terminal 1. Is. Corresponding to this control,
The ATM switch 5 according to the second embodiment of the present invention has its CP
A configuration is provided in which a table is stored in U for storing traffic parameter values in units of calling numbers of terminals 1 accommodated via the ATM multiplexer 3, and a command input device for previously inputting the traffic parameter values is attached as an auxiliary device. I am taking it.

FIG. 4 is a block diagram showing a concrete example of the main CPU 53A of the ATM switch 5 according to the second embodiment, which is an I / O circuit 531, a CPU 532, and a RAM 53.
3, call channel termination I / O circuit 534, I / O circuit 53
5, a command input device 536 is provided. This main CPU 53A is different from the configuration of the main CPU 53 shown in FIG. 3 in that a command input device 536 is connected via an I / O circuit 535.

In the first embodiment, the traffic value after passing through the ATM multiplexer 3 is measured, and the policing control parameter is set based on the measured value. However, in the second embodiment, the traffic control value is set. A mode shown in the same figure from the command input device 536 connected to the main CPU 53A with the calling number of the terminal 1 accommodated in advance via the ATM multiplexing device 3 and its expected traffic value in the RAM 533 without performing this type of measurement. When the call setting message is notified from the terminal 1, the traffic value set in the RAM 533 corresponding to the calling terminal is set in the policing circuit 512 as a policing control parameter. Here, as described above, the traffic value set in the RAM 533 needs to be predicted in consideration of the traffic deformation caused by passing through the ATM multiplexer 3.

Thus, in the second embodiment of the present invention,
In consideration of the parameters of the shaping circuit 322 of the ATM multiplexer 3 and the like, the traffic value after notifying the ATM multiplexer 3 is predicted and defined in advance.
Even if traffic deformation is caused by the shaping function of the TM multiplexer 3, the cell can be exactly discarded and the traffic can be secured by using the policing control parameter that is predicted and set to suit the traffic after the deformation. It is possible to obtain the same effect as that of the first embodiment.

According to each of the above-described embodiments of the present invention, even when traffic deformation occurs with respect to the declared value from the terminal 1, it is possible to discard cells without excess or deficiency and secure the traffic corresponding to the modified traffic. A that has a shaping function etc. as a factor that causes this kind of traffic deformation
This means that the communication quality can be guaranteed even when the TM multiplexer 3 is installed between the ATM multiplexer 5 and the ATM switch 5. From this, the present invention is extremely useful when applied to a communication system between image terminals in a wideband ISDN that needs to maintain high communication quality.

By the way, in the present invention, the traffic measurement value after passing through the ATM multiplexer 3 or the predicted value thereof is used as the policing control parameter instead of the declared traffic parameter from the terminal 1. Therefore, as far as the traffic control is concerned, It is not necessary to notify the declared traffic parameters by the call setup message (see FIG. 14).

However, considering the actual state of billing in this type of ATM switch, it is preferable to bill the declared traffic rather than bill the modified traffic. In consideration of this point, according to the present invention, in any of the above-described embodiments, the call setting message from the terminal 1 (see FIG. 14) is added with the declared traffic parameter value as is conventionally transmitted, and the ATM receiving this is sent. Switch 5
Then, the declared traffic parameter value is extracted from the call setup message, and charging is performed based on this declared value. As described above, in the present invention, by using the reporting parameter value from the terminal 1 as the charging index in any of the above embodiments, the charging value can be always matched with the reporting value of the terminal 1. .

[0039]

As described above, according to the present invention,
AT regardless of the traffic parameter value declared from the terminal
Since the policing circuit controls the discard processing of the violating cell based on the traffic parameter value calculated from the cell measurement value after passing through the M-multiplexing device, the traffic after passing through the ATM multiplexing device is controlled. Even for deformation, it is possible to discard cells without excess or deficiency and secure traffic according to appropriate policing control parameters corresponding to the deformation, which can contribute to a great improvement in line usage efficiency.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a terminal interface in an ATM exchange according to the present invention.

FIG. 2 is a block diagram showing the configuration of a traffic monitor circuit in the ATM exchange terminal interface of the present invention.

FIG. 3 is a block diagram showing an embodiment of a CPU in the ATM exchange of the present invention.

FIG. 4 is a block diagram showing another embodiment of the CPU in the ATM exchange of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of an ATM switching network.

FIG. 6 is a block configuration diagram of an ATM multiplexer in an ATM switching network.

FIG. 7 is a block configuration diagram of a multiple interface in the ATM multiplexer.

FIG. 8 is an explanatory diagram of a shaping function in a multiple interface.

FIG. 9 is a diagram showing an example of traffic parameters related to an ATM switching system.

FIG. 10 is a diagram showing an example of a cell format used in the ATM switching system.

FIG. 11 is a block diagram of an ATM exchange in an ATM exchange network.

FIG. 12 is a block diagram of a terminal interface in a conventional ATM exchange.

FIG. 13 is an explanatory diagram of a policing function in the ATM switching system.

FIG. 14 is a configuration diagram of a call setup message for notifying a declared traffic value from a terminal.

FIG. 15 is a diagram showing an example of a call setup sequence in an ATM switching network.

[Explanation of symbols]

 1 Terminal 2 Subscriber Line 3 ATM Multiplexer 31a, 31b Terminal Interface 32 Multiplex Interface 321a, 321b Cell Extractor 322 Shaping Circuit 323a, 323b Cell Sender 33 ATM Multiplex Bus 4 Multiplexed Line 5 ATM Switch 50, 51 Switch Terminal Interface 501 Traffic monitor circuit 5011 Cell counter 5012 I / O circuit 5013 Timer 5014 Monitor CPU 5015 RAM 502,514 CPU bus 511a Cell extraction unit 512 Polishing circuit 513a Cell transmission unit 52 ATM switch 53, 53A CPU 531,535 I / O circuit 532 CPU 533 RAM 534 Call channel terminating I / O circuit 536 Command input device 54 Call signal channel 55 Data channel 56 Relay bus 6 Relay line

Claims (4)

[Claims] 1. An ATM multiplexer having a shaping function for uniformizing cells sent out by fluctuation from a terminal so that the cell sending intervals are constant, is accommodated via a terminal interface in a switch, and is a fixed length packet. An ATM switch having a policing function for discarding a violating cell exceeding a declared value based on a declared traffic parameter value from the terminal when the cell is exchanged according to address information added to the cell, The terminal interface is provided with traffic monitoring means for calculating traffic information for each call based on the number of transmission cells for each certain time interval, and storing the result as a call-declared traffic parameter value. As the control parameter value of the policing function, the traffic monitor means Traffic Parameter Control in ATM switching system, which comprises using the stored traffic information. 2. An ATM multiplexer having a shaping function for uniformizing the cells sent out by fluctuation from a terminal so that the cell sending intervals are constant, is accommodated via a terminal interface in the exchange, and is a fixed length packet. In the ATM exchange having a policing function for discarding a violating cell exceeding the declared value based on the declared traffic parameter value from the terminal when exchanging the cell according to the address information added in the cell, the shaping function Has a registration means for predicting the traffic information after being equalized by the above, and pre-registering this in the ATM exchange as a call-declared traffic parameter value,
The traffic parameter control method in the ATM switch, wherein the control section of the ATM switch uses the traffic information registered by the registration means as the control parameter value of the policing function. 3. The traffic parameter control method in an ATM switch according to claim 1, wherein at least a cell average speed, a cell peak speed, a cell burst speed, and a maximum number of continuous cells are used as the traffic parameter value. 4. The traffic in the ATM switch according to claim 1, wherein the control unit of the ATM switch charges based on the original traffic parameter value declared by the terminal. Parameter control method.