JPH05252190A - Atm communication equipment and cell band control method - Google Patents

Abstract

PURPOSE:To prevent a user cell from being omitted by performing severe control over the area occupied by a user cell, the occupied area by a supervisory and controlling cell which is closed and used in an ATM(Asynchronous Transfer Mode) communication equipment and the occupied area by the supervisory and controlling cell for network control respectively. CONSTITUTION:The ATM communication equipment which transfers cells in an asynchronous transfer mode and is connected to an ATM transmission line has a supervisory and controlling cell inserting circuit which inserts supervisory and controlling information as the cells, and the supervisory and controlling cell inserting circuit has a 1st supervisory and controlling cell output means 11 which generates and outputs a 1st supervisory and controlling cell for the transfer of network control information between plural ATM communication equipment, a 2nd supervisory and controlling cell output means 13 which generates and outputs the 2nd supervisory and controlling cell utilized by the ATM communication equipment, and output control means 10 and 12 which indicates and controls the output operation of the 1st supervisory and controlling cell output means 11 and 2nd supervisory and controlling cell output means 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching system and a transmission system that form a communication network in an asynchronous transfer mode (ATM: Asynchronous Tranfer Mode), and more particularly to a method of using a cell used in the system and a method of using the cell. The present invention relates to a bandwidth management method.

[0002]

2. Description of the Related Art A supervisory control cell handled by an ATM communication device is a first supervisory control cell (hereinafter referred to as "network OAM (Operation and Maintenance) cell") for transmitting and receiving network management information between a plurality of communication devices. 2), and a second supervisory control cell (hereinafter referred to as "intra-apparatus supervisory control cell") for closing and using the ATM communication device. In ATM, CCITT Recommendation I. As described in 610 in the basic principle, maintenance management information is transferred using OAM cells when performing network management in units of virtual paths. For example, OAM cells can be used to indicate virtual path trace information, transmission path quality, fault notification, and the like. As a known document regarding the latter ATM communication device using the in-device supervisory control cell, "Tanabe,
Others: "ATM switch configuration system", IEICE Technical Report, SSE89-53,
pp.37-42 (flat 1). There is. According to the conventional method, the supervisory control information can perform communication information between the communication path and the control mechanism by in-channel communication. Examples of the in-apparatus monitoring control information include self-diagnosis information in the apparatus and internal control information.

Further, as a known document regarding the handling of empty cells inside an ATM communication device, "Nagano,
Others: “Practical application of high-speed CMOS LSIs for ATM switches”, IEICE Tech., SSE90-36, pp.31-36 (flat 2). There is. The cell conversion circuit that realizes the cell synchronization function and the timing transfer function described in the above-mentioned document is
In order to temporarily store cell information, a FIFO (First In
First Out) has a buffer memory typified by a memory and is realized by controlling the timing of writing and reading of the buffer memory. The serial bit stream signal becomes an empty cell when there is no information because cells are continuously transmitted. At this time, the empty cells received from the ATM transmission line in the front stage of the buffer memory (hereinafter referred to as "transmission line mounted empty cells") are discarded, and the new stage becomes empty when the buffer memory becomes empty in the rear stage of the buffer memory. A cell (hereinafter, referred to as "in-device generated empty cell") is added. Therefore, in the subsequent stage of the circuit, it is not possible to distinguish between the transmission line-equipped empty cells included in the cell flow on the ATM transmission line and the in-device generated cells generated in the process of transferring the timing signal, and as a single type of empty cell. I have no choice but to handle it. In other words, since the transmission line-equipped empty cells are discarded, the position where the in-device generated cell is arranged is not always the same as the position where the transmission line-equipped empty cell was located, and the throughput of cells on the ATM transmission line and the device internal Since the cell throughput is different, the number of cells generated in the device and the number of empty cells installed in the transmission path are not the same.

As described above, it is impossible to distinguish between a transmission line-equipped empty cell and a device-generated cell, and they are treated as a single type of empty cell.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The above-mentioned publicly known document "Tanabe et al .:" ATM switch configuration system ", IEICE Technical Report, SSE89-
53, pp.37-42 (flat 1). In ", when outputting the supervisory control cell, the band occupied by the supervisory control cell is not managed. If the occupied band of the supervisory control cell inserted inside the ATM communication device cannot be managed properly and exceeds the predetermined band, cell overflow occurs in the buffer memory of the ATM switch or the cell configuration conversion circuit, and the user cell is May be discarded. In other words, the above-mentioned network OAM and in-device supervisory control cell inserted inside the ATM communication device are preferentially inserted over other user cells when necessary, and therefore may exceed the predetermined band of the ATM cell. Therefore, when the supervisory control cell is inserted, it is essential to manage the occupied bandwidth of the supervisory control cell, and it is desirable that the bandwidth management method be simple.

An object of the present invention is to facilitate the management of the occupied band of the supervisory control cell and prevent the loss of the user cell.

[0007]

In order to solve the above problems, the present invention proposes an asynchronous transfer mode (ATM).
In an ATM communication device that transfers cells in a nous transfer mode) and connects to an ATM transmission line, it has a supervisory control cell insertion circuit that inserts supervisory control information as cells, and the supervisory control cell insertion circuit is a plurality of ATM communication devices. A first supervisory control cell output means for producing and outputting a first supervisory control cell for transmitting and receiving network management information between devices; and a second supervisory control cell for use in the ATM communication device. It has a second supervisory control cell output means for outputting, and an output management means for instructing and managing the output to the first supervisory control cell output means and the second supervisory control cell output means.

The output management means detects a transmission line-installed empty cell included in the cell flow on the ATM transmission line, and
Of the supervisory control cell output means for detecting the transmission path-equipped empty cell, and an empty cell generated in the apparatus generated inside the ATM communication apparatus are detected, and the second supervisory control cell output means is detected. And an in-apparatus generated empty cell detecting means for instructing the output by the device.

The transmission path mounted empty cell detecting means and the device generated empty cell detecting means can detect the corresponding empty cell based on predetermined identification information of the transmission path mounted empty cell and the device generated empty cell. ..

The first supervisory control cell output means generates and outputs the first supervisory control cell in the area of the transmission path mounted empty cell, and the second supervisory control cell output means generates in-apparatus. A second supervisory control cell is generated and output in the empty cell area.

The first supervisory control cell further comprises a first supervisory control cell terminating circuit for detecting and terminating the supervisory control cell, wherein the first supervisory control cell terminating circuit is the first supervisory control cell. And a first supervisory control cell terminating means for detecting and terminating the transmission line, and a vacancy for transmission line included in the cell flow on the ATM transmission line when the first supervisory control cell is detected by the first supervisory control cell terminating means. And a transmission line-equipped empty cell generating means for adding information indicating that the cell is a cell and outputting an empty cell.

A second supervisory control cell terminating circuit for detecting and terminating the second supervisory control cell, and further comprising a second supervisory control cell terminating circuit for detecting and terminating the second supervisory control cell.
If the second supervisory control cell terminating means and the second supervisory control cell terminating means detect the second supervisory control cell,
It is also possible to have in-device generated empty cell generation means for adding information indicating that it is an in-device generated empty cell generated inside the M communication device to the cell and outputting the empty cell.

It further comprises an ATM switch for exchanging cells, said ATM switch comprising a first supervisory control cell and a second supervisory control cell.
Identifying means for identifying the first supervisory control cell, a first cell buffer for accumulating the first supervisory control cell, and the second
Second cell buffer for accumulating the supervisory control cells, and the first cell buffer and the second cell so that the first supervisory control cells and the second supervisory control cells are output at a predetermined ratio. And a switch output management means for instructing the buffer.

[0014]

In the supervisory control cell insertion circuit, the transmission path-equipped empty cell detection means of the output management means detects the transmission path-equipped empty cells included in the cell stream on the ATM transmission path.
The monitor control cell output means is instructed to output. First
When instructed, the supervisory control cell output means of (1) generates and outputs a first supervisory control cell for transmitting and receiving network management information over a plurality of ATM communication devices in the area of the transmission path mounted empty cell.

Further, the in-device generated empty cell detecting means of the output management means detects an in-device generated empty cell generated in the ATM communication device, and instructs the second supervisory control cell output means to output. To do. When instructed, the second supervisory control cell output means writes the A
A second supervisory control cell used in the TM communication device is generated and output.

On the termination side, the first supervisory control cell termination means of the first supervisory control cell termination circuit detects the first supervisory control cell. The transmission line mounted empty cell generation means is
When the first supervisory control cell terminating means detects the first supervisory control cell, information indicating that the cell is a transmission channel-equipped empty cell included in the cell flow on the ATM transmission channel is added to the cell to set the empty cell. Output.

The second supervisory control cell terminating means of the second supervisory control cell terminating circuit detects the second supervisory control cell. The in-device generated empty cell generating means generates information indicating that the in-device generated empty cell is generated inside the ATM communication device when the second supervisory control cell terminating means detects the second supervisory control cell. Adds to a cell and outputs an empty cell.

Furthermore, in the ATM switch, the identifying means identifies the first supervisory control cell and the second supervisory control cell, the first cell buffer stores the first supervisory control cell, and the second supervisory control cell stores the second supervisory control cell. Cell buffer stores the second supervisory control cell. The switch output management means instructs the first cell buffer and the second cell buffer to output the first monitor control cell and the second monitor control cell at a predetermined ratio.

This makes it possible to replace the first supervisory control cell with the empty cell equipped with the transmission line and replace the second supervisory control cell with the empty cell generated in the apparatus. Therefore, due to the increase in the number of supervisory control cells in the device, the event that the user cell is lost does not occur.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When cells included in a cell flow inside an ATM communication device are classified, they can basically be roughly classified into the following four types of cells.

Valid cells (user cells and networks)
Includes OAM cells. ) Transmission line mounted empty cell Device generated empty cell Device monitoring control cell Among the above, the valid cell and the transmission line mounted empty cell are A
Although included in the cell flow in the TM transmission path, the in-device generated empty cell and the in-device monitor control cell are unique to the cell flow in the ATM communication device.

Next, using FIG. 7 to FIG.
The communication device will be described. FIG. 7 shows a model of the basic configuration of the speech path portion of the ATM communication device. In FIG. 7, a speech path portion of the illustrated ATM communication device includes a receiving side interface section 40 that receives a signal from the receiving side transmission path 3, a switch function, and an OAM (Operationa).
nd Maintenace) common part 50 including a processing function, and a transmitting side interface part 60 for transmitting a signal to the transmitting side transmission line 4.
Have and.

Further, the receiving side interface section 40 is
SDH (Synchronous Digital Hierachy) terminal 41,
The cell synchronization unit 42 and the cell configuration conversion unit 43 are included. Further, the transmitting side interface unit 60
Is a cell configuration conversion unit 61, HEC addition unit 62 and SD
It is composed of three elements of the H terminal portion 63.

FIG. 8 shows the structure of the common section 50 shown in FIG. 7 in detail. The common unit shown in FIG. 8 has an ATM switch 90, receiving side supervisory control cell processing units 70-1 and 70-2 are connected in front of the ATM switch 90, and transmitting side supervisory control cells in the latter stage. Processing units 80-1 and 80-2
Are connected. The receiving side supervisory control cell processing unit 70-1 has a receiving side network OAM cell processing circuit 71-1 and an in-device supervisory control cell inserting circuit 72-1. In addition, the transmission-side supervisory control cell processing unit 80-1 is an internal supervisory control cell termination circuit.
81-1 and a transmission side network OAM cell processing circuit 81-1. Although not shown in FIG. 8, the inside of the receiving side network OAM cell processing circuit 71-1 and the transmitting side network OAM cell processing circuit 81-1 are as follows.
Further, each has a network OAM cell termination circuit and a network OAM cell insertion circuit. The receiving side supervisory control cell processing unit 70-2 and the transmitting side supervisory control cell processing unit 80-2 have the same configuration as the first circuit.

FIG. 9 shows the positional relationship between the generation points and termination points of various cells handled inside the ATM communication device, corresponding to the functional blocks shown in FIGS. 7 and 8. In FIG. 9, white circles represent generation points of new cells, and black circles represent end points (points at which ATM cells are erased). Also, the solid line with an arrow in the figure indicates a section in which an ATM cell of the corresponding type is transmitted. The cell types handled in FIG. 9 are the four types described above. In the figure, for valid cells, in order to clarify the positional relationship between the generation point and the termination point, a user cell that transmits user information and a network that carries network supervisory control information. It is displayed separately from the OAM cell.

In the description, first, the meaning of the in-device generated empty cell will be described. Generally, the throughput of the cell accommodating area on the internal highway of the ATM communication device is set relatively higher than the throughput of the cell accommodating area on the ATM transmission line. As a result, the dummy cells generated in the device will be damaged when adjusting the bearer speed.
Has the meaning of. Therefore, the intra-device generated empty cell is generated by the reception side cell configuration conversion unit 43 shown in FIG. 7 in which the cell output becomes high, and finally terminated by the transmission side cell configuration conversion unit 61 in which the output becomes low. Will be done. This is because, in FIG. 9, the first generation point of the intra-device generation empty cell is located in the reception-side cell configuration conversion unit 43, and the last termination point of the intra-device generation empty cell is located in the transmission-side cell configuration conversion unit 61. Correspond to that.

The circuit for realizing the reception side cell configuration conversion unit has the following configuration. An ATM transmission line for transferring cells of a fixed length block in the asynchronous transfer mode is connected, and a cell configuration conversion unit for transferring the timing on the transmission line to the timing in the own device stores the cells from the ATM transmission line. A cell buffer, a write address control circuit for instructing a write address of the cell buffer at a timing on the transmission path, a read address control circuit for instructing a read address of the cell buffer at a timing in the own device, and a write address and a read address. An address comparison circuit for comparison, an empty cell instruction circuit that outputs an instruction of an empty cell based on the comparison result from the address comparison circuit, an empty cell generated by an instruction from the empty cell instruction circuit, and other cells And an additional circuit for adding information for distinguishing between the cell and the read address system. Circuit can stop reading of the cell in response to an instruction from the air-out cell indicating circuit.

In consideration of the above points, the band allocation situation will be described with reference to FIG. First, as shown in the following Expression 1, the total band Ti of the internal highway after the output of the receiving side cell configuration conversion unit 43 is determined by the occupied band Ur of the effective cell on the receiving side and the empty cell installed on the transmission line on the receiving side. Occupied bandwidth Vlr,
It is the sum of the occupied band Ser of the monitoring control cell in the device on the receiving side and the occupied band Ver of the empty cell generated in the device on the receiving side. Here, Ur + Vlr in the first parenthesis in Formula 1 corresponds to the entire band Tl in the ATM transmission line.

[0029]

[Equation 1]

Next, as shown in equation (2), the total band Ti of the internal highway before input to the transmission side cell configuration conversion unit 41 is the occupied band Us of the effective cell on the transmission side, and the transmission path mounted on the transmission side. It is the sum of the occupied band Vls of the empty cell, the occupied band Ses of the in-device supervisory control cell on the transmitting side, and the occupied band Ves of the in-device generated empty cell on the transmitting side.

[0031]

[Equation 2]

In the present invention, since the area of the intra-apparatus generated empty cell is used for inserting the intra-apparatus supervisory control cell, the following expression 3 is established. Even when terminating the in-apparatus supervisory control cell, the supervisory control cell is replaced with an in-apparatus generated empty cell, and therefore, the same expression 3 holds.

Further, as shown in FIG.
When the TM switch 90 is provided, the entire band of the switch is divided into two fixed bands, and in the first band, the effective cell and the empty cell equipped with the transmission path are accommodated, and the second band. In the band, by accommodating the intra-apparatus supervisory control cell and the intra-apparatus generated empty cell, the expression 3 is satisfied even in the subsequent stage of the switch.

[0034]

[Equation 3]

That is, the constant value shown in Expression 3 is a surplus cell due to the difference in throughput between the transmission line and the device,
The device supervisory control cell is inserted within this range.

Therefore, Us + Vls in the first parenthesis of the equation 2
Matches the entire bandwidth Tl on the ATM transmission line, and can always secure the occupied bandwidth Us of the effective cell on the transmission side including the user cell. Therefore, as a conclusion, due to the increase of the occupied band Ses of the in-device supervisory control cell, the event that the user cell is lost does not occur.

A specific embodiment for managing the occupied bandwidth of the supervisory control cell will be described below with reference to the drawings.

The first embodiment will be described with reference to the block diagram of the supervisory control cell insertion circuit shown in FIG. The supervisory control cell insertion circuit of the first embodiment is the empty cell detection circuit 1 equipped with a transmission line.
0, network OAM cell generation circuit 11, in-device generated empty cell detection circuit 12, in-device monitoring control cell generation circuit 1
It has 3 and 3-1 selectors 14. The in-device input highway 1 and the in-device output highway 2 are connected to the supervisory control cell insertion circuit. Here, the transmission line mounted empty cell detection circuit 10 and the network OAM cell generation circuit 11 form a pair, and the in-device generated empty cell detection circuit 12 and the in-device monitoring control cell generation circuit 13 form a pair. .. These two pairs of circuit groups are connected in parallel to the 3-1 selector 14.

In the method of using the cell of this embodiment, a plurality of A
Insert the network OAM cell for transmitting and receiving the network management information between the TM communication devices,
This is performed using the area of the transmission path-equipped empty cell included in the cell stream received by the M communication apparatus from the ATM transmission path. Also, the A
Insertion of the closed intra-apparatus supervisory control cell into the TM communication apparatus is performed using the intra-apparatus generated empty cell area generated in the process of changing the timing inside the corresponding ATM communication apparatus.

Next, the operation of the first embodiment will be described. The transmission line mounted empty cell detection circuit 10 and the in-device generated empty cell detection circuit 12 monitor the cell flow received from the in-device input highway 1. The transmission path mounted empty cell detection circuit 10 detects the presence or absence of a transmission path mounted empty cell, and the in-device generated empty cell detection circuit 12 detects the presence or absence of an empty cell generated in the device. The distinction between an empty cell installed in the transmission line and an empty cell generated in the device is made by adding a predetermined identification code to each cell when the empty cell generated in the device is generated in the cell configuration conversion unit in the previous stage. , By distinguishing by detecting the identification code. Alternatively, when the information indicating the distinction between the empty cell installed in the transmission line and the empty cell generated in the device is output from the cell configuration conversion unit in the previous stage via a control line different from the transmission line, the information is output from the control line. The cells are received and the cells are distinguished by predetermined information. The network OAM cell generation circuit 11 generates and stores network OAM cells. OAM cells include cells indicating virtual path trace information, transmission path quality, fault notification, and the like. Also, predetermined identification information indicating that the cell is an OAM cell is added to the header portion of the cell. When the transmission path mounted empty cell detection circuit 10 detects a transmission path mounted empty cell, the network OAM cell generation circuit 11 outputs the network OAM cell. Further, the in-device monitoring control cell generation circuit 13 generates and stores in-device monitoring control cells. Examples of the in-apparatus monitoring control information include self-diagnosis information in the apparatus and internal control information.
Further, predetermined identification information indicating that the cell is an in-apparatus monitoring control cell is added to the header part of the cell. When the in-device generated empty cell detection circuit 12 detects an in-device generated empty cell, the in-device monitoring control cell generating circuit 13 outputs the in-device monitoring control cell. When the corresponding transmission path-equipped empty cell is detected in the transmission path-equipped empty cell detection circuit 10 and the network OAM cell generation circuit 11 outputs the network OAM cell, the 3-1 selector 14 outputs the network OAM cell. You are instructed to select. In other words, the transmission path mounted empty cell detection circuit 10 and the network OAM cell generation circuit 11 output a selection control signal to the 3-1 selector 14 to instruct to select the network OAM cell. In addition, the device-generated empty cell detection circuit 12
When a corresponding in-device generated empty cell is detected in and the in-device monitor control cell generation circuit 13 outputs the in-device monitor control cell, the 3-1 selector 14
Selection is instructed to output the in-device supervisory control cell.
That is, the in-device generated empty cell detection circuit 12 and the in-device monitor control cell generation circuit 13 output a selection control signal to the 3-1 selector 14 to instruct to select the in-device monitor control cell. In the 3-1 selector 14,
Normally, the signal from the in-device input highway 1 is selected, and if there is a selection control signal from the circuit, the corresponding signal is selected and output to the in-device output highway 2. In this way, the 3-1 selector 14 outputs the signal of the in-device input highway 1, the output signal of the network OAM cell generation circuit 11 and the output signal of the in-device monitoring control cell generation circuit 13 according to the content of the selection control signal. One of them is output to the in-device output highway 2.

By the above operation, the supervisory control cell corresponding to the type of the empty cell is inserted. In this way, the in-device monitoring control cell used in the device is assigned only to the in-device generated cell that has become an empty cell in the device, and is also connected to another ATM switching device or the like via the transmission line. The network OAM cells that are also used are assigned only to the transmission line-equipped empty cells. Since each control cell is output instead of the corresponding empty cell, the user cell is not lost.
As a result, the occupied band Us of the effective cell on the transmission side including the user cell can be always secured. Therefore, due to the increase of the occupied bandwidth Ses of the in-device supervisory control cell, the event that the user cell is lost does not occur.

The second embodiment will be described with reference to the block diagram of the supervisory control cell insertion circuit shown in FIG. The supervisory control cell insertion circuit of the second embodiment is the empty cell detection circuit 1 equipped with a transmission line.
0, network OAM cell generation circuit 11, in-device generated empty cell detection circuit 12, in-device monitoring control cell generation circuit 1
3, a first 2-1 selector 15-1 and a second 2-1 selector 15-2. Further, the supervisory control cell insertion circuit includes an in-device input highway 1 and an in-device output highway 2
Connect. Here, the transmission line mounted empty cell detection circuit 10
And network OAM cell generation circuit 11 and first 2-1
The selector 15-1 forms a pair, and the in-device generated empty cell detection circuit 12, the in-device monitor control cell generation circuit 13, and the second 2-1 selector 15-2 form a pair. These two
The pair of circuit groups are connected in series with each other.

The operation of the second embodiment is basically the same as that of the first embodiment. However,
Since the two circuit groups for inserting the supervisory control cells are connected in series, the control of the first 2-1 selector 15-1 and the control of the second 2-1 selector 15-2 are independent. The only difference is that each selector operates as follows. When the corresponding transmission path-equipped empty cell is detected by the transmission path-equipped empty cell detection circuit 10 and the network OAM cell generation circuit 11 outputs the network OAM cell, the first 2-1 selector 15-1 Network OA
Selection is instructed to output M cells. That is, the transmission line mounted empty cell detection circuit 10 and the network OAM
The cell generation circuit 11 outputs a selection control signal to the 2-1 selector 15-1 to instruct to select the network OAM cell. In addition, when the in-device generated empty cell detection circuit 12 detects a corresponding in-device generated empty cell and the in-device monitoring control cell generating circuit 13 outputs the in-device monitoring control cell, the second 2-1 The selector 15-2 is instructed to select to output the in-device supervisory control cell. That is, the device-generated empty cell detection circuit 12
And the in-apparatus supervisory control cell generation circuit 13 has a second 2-
By outputting a selection control signal to the 1-selector 15-2, it is instructed to select the in-device supervisory control cell. First two
The -1 selector 15-1 normally selects the signal from the in-device input highway 1 and also selects and outputs the corresponding signal when there is a selection control signal from the above circuit. Second 2-1
The selector 15-2 normally selects the signal from the first 2-1 selector 15-1 and also selects and outputs the corresponding signal when there is a selection control signal from the above circuit.

By the above-mentioned operation, as in the first embodiment, the supervisory control cell corresponding to the type of empty cell is inserted.

Next, a third embodiment will be described with reference to the block diagram of the supervisory control cell termination circuit shown in FIG. The supervisory control cell terminating circuit of the third embodiment includes a network OAM cell terminating circuit 16, a transmission line mounting empty cell generating circuit 17, an in-apparatus supervisory control cell terminating circuit 18, an in-apparatus producing empty cell generating circuit 19 and 3-1. It has a selector 14. The in-device input highway 1 and the in-device output highway 2 are connected to the supervisory control cell termination circuit. Here, the network OAM cell terminating circuit 16 and the transmission line mounting empty cell generating circuit 17 form a pair, and the in-device supervisory control cell terminating circuit 18 and the in-device generating empty cell generating circuit 19 form one pair.
These two pairs of circuit groups form a pair, and the 3-1 selector 14
Connected in parallel to.

In the supervisory control cell terminating circuit, the network OA is terminated when the network OAM cell is terminated.
When the M cell is replaced with the empty cell equipped with the transmission path and the intra-apparatus supervisory control cell is terminated, the intra-apparatus supervisory control cell is replaced with the intra-apparatus generated empty cell.

Next, the operation of the third embodiment will be described. The network OAM cell termination circuit 16 and the in-device supervisory control cell termination circuit 18 monitor the cell flow received from the in-device input highway 1. Network OAM
The cell terminating circuit 16 detects the presence / absence of a network OAM cell, and the in-device supervisory control cell terminating circuit 18 detects the presence / absence of an in-device supervisory control cell. The network OAM cell and the in-device supervisory control cell are identified by the predetermined identification information included in the header of the cell. In the transmission line mounted empty cell generation circuit 17, in the network OAM cell termination circuit 16, the network OA
When an M cell is detected, the empty cell equipped with the transmission path is output. In addition, the in-device generated empty cell generation circuit 19 outputs the in-device generated empty cell when the in-device monitor control cell terminating circuit 18 detects the in-device monitor control cell. In each generation circuit, a predetermined identification code indicating that it is an empty cell mounted on a transmission line and an empty cell generated in the apparatus is added to the cell and the empty cell is output. The supervisory control cell is terminated by outputting an empty cell instead of the supervisory control cell in each generation circuit. When the corresponding network OAM cell is detected in the network OAM cell terminating circuit 16 and the network OAM cell needs to be terminated, the 3-1 selector 14 is instructed to select to output the transmission path mounted empty cell. .. Further, when the corresponding in-device monitoring control cell is detected in the in-device monitoring control cell terminating circuit 18 and it is necessary to terminate the in-device generated empty cell, the 3-1 selector 14
Are instructed to output the generated empty cells in the device. The network OAM cell termination circuit 16 and the in-device supervisory control cell termination circuit 18 perform the above-mentioned termination processing,
A selection control signal is sent to the 3-1 selector 14 between the in-device input highway 1 and the in-device output highway 2. Three
In the -1 selector 14, according to the content of the selection control signal,
One of the signal from the in-device input highway 1, the output signal from the transmission path mounted empty cell generation circuit 17, and the output signal from the in-device generated empty cell generation circuit 19 is selected and output to the in-device output highway 2.

As described above, the empty cell installed in the transmission line is inserted at the end of the network OAM cell, and the empty cell generated in the apparatus is inserted at the end of the in-apparatus supervisory control cell.

Further, the network OAM cell termination circuit 1
It is also possible to have only one terminating circuit out of 6 and the in-device supervisory control cell terminating circuit 18. In this case, when the network OAM cell terminating circuit 16 is provided, the corresponding transmission line mounted empty cell generating circuit 17 is provided. Further, when the in-device supervisory control cell terminating circuit 18 is provided, the corresponding in-device produced empty cell producing circuit 19 is provided. For example, when the network OAM cell is not terminated and is output as it is on the transmission line, the network OAM cell is output without termination by having the in-device supervisory control cell termination circuit 18 and the in-device generated empty cell generation circuit 19. You can also do it.

With the above operation, the network O
When terminating the AM cell and the in-device supervisory control cell,
An empty cell corresponding to the supervisory control cell is inserted. In this way, the in-device supervisory control cell used in the device is
In-device generated cells are assigned and network OA
An empty cell equipped with a transmission path is assigned to the M cell. Since each control cell is output as a corresponding empty cell, the user cell is not lost. That is, even when the network OAM cell and the in-device supervisory control cell are terminated, the occupied band Us of the effective cell on the transmission side including the user cell can be always secured. Therefore, due to the increase of the occupied bandwidth Ses of the in-device supervisory control cell,
The event that the user cell is missing does not occur.

A fourth embodiment will be described with reference to the block diagram of the supervisory control cell termination circuit shown in FIG. The supervisory control cell termination circuit of the fourth embodiment is the network OAM cell termination circuit 1
6, transmission line mounted empty cell generation circuit 17, in-device supervisory control cell termination circuit 18, in-device generated empty cell generation circuit 19,
First 2-1 selector 15-1 and second 2-1 selector
Have 15-2. Also, in the supervisory control cell termination circuit,
The in-device input highway 1 and the in-device output highway 2 are connected. Here, the network OAM cell termination circuit 16
And the transmission path mounted empty cell generation circuit 17 and the first 2-1 selector 15-1 form a pair, and the in-device supervisory control cell termination circuit 18, the in-device generated empty cell generation circuit 19 and the second The 2-1 selector 15-2 makes a pair. These two pairs of circuit groups are connected in series with each other.

The operation of the fourth embodiment is basically the same as that of the third embodiment. However,
Since the two circuit groups for terminating the supervisory control cells are connected in series, the control of the first 2-1 selector 15-1 and the control of the second 2-1 selector 15-2 are independent. Only the points differ.

The fifth embodiment will be described with reference to the block diagram of the ATM switch shown in FIG. When an ATM switch is provided inside the ATM communication device, the entire band of the switch is divided into two fixed bands, and in the first band, a user cell and a network extending between a plurality of communication devices. A network OAM cell for transmitting and receiving management information and an empty cell equipped with a transmission line to be sent to an ATM transmission line are accommodated, and in the second band, an in-device monitoring control cell closed in the communication device, and It accommodates in-device generated empty cells that disappear inside the communication device.

The ATM switch of the fifth embodiment shows a case where the present invention is applied to an output buffer type switch having a matrix size of 2 × 2. The ATM switch of the fifth embodiment has a multiplexer circuit 37 for multiplexing signals of the switch input highways 30-1 and 30-2 and a switch output highway 33-1.
And 33-2 respectively corresponding to the highway corresponding switch circuits 20-1 and 20-2 for performing the switching process, and the timing signal generating circuit 38 for generating the timing signal for controlling the switch operation.

Further, the highway compatible switch circuit 20-1
Is an effective cell cell buffer 22-1, a first marker addition circuit 23-1, an effective cell buffer control circuit 24-1, a supervisory control cell buffer 25-1, and a second marker addition circuit. 26-1, Cell buffer control circuit 27-1 for supervisory control cell, Address filter
21-1 and the multiplex circuit 28-1. Of these, the effective cell cell buffer 22-1, the first marker addition circuit 23-1, and the effective cell buffer control circuit 24-1 form a group of functional blocks. The functional block diagram performs switching processing of valid cells (user cells and network OAM cells) and generation processing of transmission path mounted empty cells. On the other hand, the cell buffer for supervisory control
25-1, the second marker adding circuit 26-1, and the supervisory control cell cell buffer control circuit 27-1 also form a group of functional blocks. The functional block performs switching processing of the in-device monitoring control cell and generation processing of the in-device generated empty cell. The address filter 21-1 has a function of distributing the cell received from the multiplexing circuit 37 to the above-mentioned two functional blocks according to the cell type.

The configuration of the highway-compatible switch circuit 20-1 has been described above.
The 20-2 also has exactly the same configuration.

Next, the operation of the fifth embodiment will be described. Since the highway-compatible switch circuits 20-1 and 20-2 shown in FIG. 5 operate on the same operating principle, the operation of the highway-compatible switch circuit 20-1 will be described below, and the operation of the switch circuit 20-2 will be described. Is also the same.

First, two switch input highways 30-1
The signals of 30 and 30-2 are multiplexed on a cell-by-cell basis by the multiplexing circuit 37, and the highway-compatible switch circuits 20-1 and 20-2.
-2 are sent respectively. Highway compatible switch circuit
In 20-1, the multiplexed cell signal from the multiplexing circuit 37 is received by the address filter 21-1. Address filter 21-1
ATM switching is performed according to the routing information. The address filter 21-1 determines the cell type as a valid cell or a supervisory control cell by analyzing the header portion of the cell, analyzes the address indicating the routing information for the user cell and the network OAM cell, and determines whether the cell is valid. / Judge as invalid. According to the determination result of the address filter 21-1, the valid cells (user cells and network OAM cells) corresponding to the switch output highway 33-1 are written in the valid cell cell buffer 22-1, and the switch output highway 33-1 is also written. The corresponding in-device supervisory control cell is written in the supervisory control cell cell buffer 25-1. The cells not corresponding to the switch output highway 33-1, the empty cells equipped with the transmission path, and the empty cells generated in the apparatus are discarded without being written in the cell buffer.

Next, the operation on the read side of the effective cell cell buffer 22-1 and the supervisory control cell cell buffer 25-1 shown in FIG. 5 will be described in detail with reference to FIG.

The timing signal generating circuit 38 receives the switch operation timing signal 34 from the outside and generates a band control signal 35 and a multiplexing control signal 36. The band control signal 35 is a signal for designating a cell buffer for reading a cell. When the signal is at H level, reading from the monitor control cell cell buffer 25-1 is permitted, and at L level, the valid cell cell buffer 22 is permitted. -Reading from -1 is permitted. In the operation explanatory diagram shown in FIG. 6, four cells are set as one cycle and three cells are provided for the effective cell cell buffer 22-1, and one cell is provided for the supervisory control cell cell buffer 25-1.
Allocating cells. The read control from the cell buffer is executed exclusively for the valid cell cell buffer 22-1 and the supervisory control cell cell buffer 25-1.

Effective cell buffer output signal 31-1 shown in FIG.
Shows the output of the first marker adding circuit 23-1, and when the reading of the valid cell cell buffer 22-1 is stopped once every four cells, the dummy cells D-2 and It is shown that D-6 is inserted. Also, cells U-1 to U-5 are
It is a valid cell composed of a user cell and a network OAM cell output from the valid cell cell buffer 22-1. Cells VL-1 and VL-2 are cell buffers 22 for valid cells.
-1 is a cell inserted because it is empty, and corresponds to an empty cell equipped with a transmission path generated by the highway-compatible switch circuit 20-1. In order to identify the empty cell equipped with this transmission line, the first
In the marker adding circuit 23-1, the identification information of the empty cell equipped with the transmission path is written in the cell.

The supervisory control cell buffer output signal 32-1 represents the output of the second marker addition circuit 26-1, and is 4
Since the reading of the cell buffer 25-1 for supervisory control cells from the cell is stopped three times, the dummy cells D-1, D-3 to D-5, D-7 to
It has been shown that D-9 is inserted. Also, cell S-1
Is the in-device supervisory control cell output from the supervisory control cell cell buffer 25-1. Cell VE-1 is a cell in which the cell buffer 25-1 for supervisory control cells is inserted because it is empty,
This corresponds to an in-device generated empty cell generated by the highway compatible switch circuit 20-1. In order to identify this in-device generated empty cell, the second marker addition circuit 26-1 writes the in-device generated empty cell identification information into the cell.

The valid cell buffer output signal 31-1 described above
And the supervisory control cell buffer output signal 32-1 is input to the multiplexing circuit 28-1 at the subsequent stage, and the timing signal generating circuit 3
After being multiplexed by the multiplexing control signal 36 received from the switch 8, the switch output highway 33-1 outputs. At this time, when the multiplexing control signal 36 is at the H level, the supervisory control cell buffer output signal 32-1 is selected, and when it is at the L level, the valid cell buffer output signal 31-1 is selected. .. As a result, the dummy cells D-1 to D-9 are all removed, and the effective cells U-1 to U-5, the in-device supervisory control cell S-1, and the transmission line mounted empty cells VL-1 to VL-2 are removed. , And only the intra-device generated empty cell VE-1 is output to the switch output highway 33-1.

In the ATM switch of this embodiment, the relative value of the sum of the bands of the in-device supervisory control cell and the in-device generated empty cell is always 0.25 (1 /
4). The area allocated to the in-device supervisory control cell and the in-device generated empty cell is shown as a supervisory control cell allocation area in FIG. On the other hand, the relative value of the sum of the bands of the effective cell and the transmission path mounted empty cell is always 0.75 (3/4). The area to which the effective cell and the empty cell equipped with the transmission path are allocated is shown as an effective cell allocation area in FIG.

As described above, according to the ATM switch of this embodiment, even on the output side of the ATM switch,
The sum of the occupied band Ses of the in-device supervisory control cell and the occupied band Ves of the in-device generated empty cell becomes constant. Therefore, the occupied band of the user cell, the occupied band of the supervisory control cell closed and used in the ATM communication device, and the occupied band of the supervisory control cell for network management can be strictly managed even in the subsequent stage of the ATM switch. ..

[0066]

According to the cell utilization method and the bandwidth management method of the present invention, the occupied bandwidth of the user cell, the occupied bandwidth of the supervisory control cell closed and used in the ATM communication apparatus, and the occupation of the supervisory control cell for network management. It is possible to strictly manage each of the bands, and it is possible to prevent the user cell from being lost due to an abnormal increase in occupied band of these two types of supervisory control cells.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a supervisory control cell insertion circuit showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a supervisory control cell insertion circuit showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a supervisory control cell termination circuit showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a supervisory control cell termination circuit showing a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of an ATM switch showing a fifth embodiment of the present invention.

FIG. 6 is an operation explanatory diagram of the fifth embodiment of the present invention.

FIG. 7 is a basic configuration diagram of a communication path portion of an ATM communication device for explaining the operation of the present invention.

FIG. 8 is a configuration diagram of a common unit including an ATM switch for explaining the operation of the present invention.

FIG. 9 is a positional relationship diagram of generation points and termination points of various cells for explaining the operation of the present invention.

FIG. 10 is a band allocation diagram when the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... In-device input highway, 2 ... In-device output highway, 10 ... Transmission path mounted empty cell detection circuit, 11 ... Network OAM cell generation circuit, 12 ... In-device generated empty cell detection circuit, 13 ... In-device monitoring control cell generation Circuit, 14 ...
3-1 selector, 15-1, 15-2 ... 2-1 selector, 16 ... Network OAM cell terminating circuit, 17 ... Transmission path mounted empty cell generating circuit, 18 ... In-apparatus supervisory control cell terminating circuit, 19 ... In-apparatus Generation empty cell generation circuit, 20-
1.20-2 ... Highway compatible switch circuit, 21-1
21-2 ... Address filter, 22-1, 22-2 ...
Cell buffer for valid cells, 23-1, 23-2 ... First marker addition circuit, 24-1, 24-2 ... Buffer control circuit for valid cell, 25-1, 25-2 ... For supervisory control cell Cell buffer, 26-1, 26-2 ... Second marker addition circuit, 27-1, 27-2 ... Monitor control cell buffer control circuit, 28-1, 28-2 ... Multiplex circuit, 30-1・ 30
-2 ... Switch input highway, 31-1, 31-2 ...
Effective cell buffer output signal, 32-1, 32-2 ... Monitor control cell buffer output signal, 33-1, 33-2 ... Switch output highway, 34 ... Switch operation timing signal, 35 ... Band control signal, 36 ... Multiplexing Control signal, 37
... Multiplexing circuit, 38 ... Timing signal generating circuit, 3 ... Receiving side transmission line, 4 ... Sending side transmission line, 40 ... Receiving side interface section, 41 ... Receiving side SDH terminating section, 42 ... Cell synchronizing section, 43 ... Receiving side cell configuration conversion unit, 50 ... Common unit, 60
... transmission side interface section, 61 ... transmission side cell configuration conversion section, 62 ... HEC addition section, 63 ... transmission side SDH termination section,
70-1, 70-2 ... Reception side supervisory control cell processing unit, 71
-1-71-2 ... Receiving side network OAM cell processing circuit, 72-1, 72-2 ... In-apparatus supervisory control cell inserting circuit, 80-1, 80-2 ... Transmitting side supervisory control cell processing unit,
81-1, 81-2 ... Transmitting side network OAM cell processing circuit, 82-1. 82-2 ... In-apparatus supervisory control cell terminating circuit, 90 ... ATM switch.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Nobu Nishimura, 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture, Ltd. Information & Communication Division, Hitachi, Ltd. No. Japan Telegraph and Telephone Corp. (72) Inventor Takashi Nakajima 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (12)

[Claims] 1. Asynchronous transfer mode (ATM)
In an ATM communication device that transfers cells in Transfer Mode) and connects to an ATM transmission line, a supervisory control cell insertion circuit that inserts supervisory control information as cells is provided, and the supervisory control cell insertion circuit is a plurality of ATM communication devices. First supervisory control cell output means for generating and outputting a first supervisory control cell for transmitting and receiving network management information over a range, and generating and outputting a second supervisory control cell used in the ATM communication device. And an output management unit for instructing and managing the output to the first monitoring control cell output unit and the second monitoring control cell output unit. Communication device. 2. The transmission according to claim 1, wherein the output management means detects an empty cell on the transmission path included in the cell flow on the ATM transmission path, and instructs the first supervisory control cell output means to output. An on-device generated empty cell detecting means for detecting an on-device generated empty cell generated inside the ATM communication device and for instructing output to the second supervisory control cell output means. A characterized by having
TM communication device. 3. The empty cell detecting means and the in-device generated empty cell detecting means according to claim 2, wherein the empty cells corresponding to the predetermined identification information of the in-device empty cell and the in-device generated empty cell. An ATM communication device characterized by detecting a. 4. The second supervisory control cell output means according to claim 2 or 3, wherein the first supervisory control cell output means generates and outputs the first supervisory control cell in an area of an empty cell equipped with a transmission line, and outputs the second supervisory control cell. The means is an ATM communication device characterized by generating and outputting a second supervisory control cell in an area of an empty cell generated in the device. 5. The first aspect of claim 1, 2, 3 or 4.
Further includes a first supervisory control cell terminating circuit for detecting and terminating the supervisory control cell of the first supervisory control cell, wherein the first supervisory control cell terminating circuit detects and terminates the first supervisory control cell. 1 supervisory control cell termination means,
When the first supervisory control cell terminating means detects the first supervisory control cell, information indicating that the cell is a transmission channel-equipped empty cell included in the cell flow on the ATM transmission channel is added to the cell to set the empty cell. An ATM communication device comprising: a transmission path-equipped empty cell generating means for outputting. 6. The method according to claim 1, 2, 3, 4 or 5.
A second supervisory control cell terminating circuit for detecting and terminating the supervisory control cell, the second supervisory control cell terminating circuit detecting and terminating the second supervisory control cell. Second supervisory control cell terminating means for
When the second supervisory control cell terminating means detects the second supervisory control cell, information indicating that the cell is an intra-apparatus generated empty cell generated inside the ATM communication apparatus is added to the cell and the empty cell is output. And an in-device generated empty cell generating means. 7. The ATM switch according to claim 1, 2, 3, 4, 5 or 6, further comprising: a first supervisory control cell and a second supervisory control cell. Identifying means, a first cell buffer that stores the first supervisory control cells, a second cell buffer that stores the second supervisory control cells, and a first cell buffer that stores the first supervisory control cells.
Of the first and second cell buffers and the second monitor and control cell so as to output the second monitor and control cell at a predetermined ratio.
And an output control means for instructing the cell buffer of the ATM communication device. 8. A first supervisory control cell for transmitting and receiving network management information between a plurality of ATM communication devices in an ATM communication device for transferring cells in an asynchronous transfer mode (ATM) and connecting to an ATM transmission line. First supervisory control cell terminating means for detecting and terminating, second supervisory control cell terminating means for detecting and terminating the second supervisory control cell used in the ATM communication device, and first supervisory control cell When the first supervisory control cell is detected by the terminating means,
In the second supervisory control cell terminating means, there is provided a transmission path-equipped empty cell generating means for adding information indicating that the cell is a transmission path-equipped empty cell included in the cell flow on the ATM transmission path to output an empty cell. When a supervisory control cell of No. 2 is detected, an in-device generated empty cell generating means for outputting an empty cell by adding information indicating that it is an in-device generated empty cell generated in the ATM communication device to the cell. An ATM communication device characterized by having. 9. Asynchronous transfer mode (ATM)
A first supervisory control cell for transmitting and receiving network management information between a plurality of ATM communication devices in an ATM switch that exchanges cells in an ATM communication device that transfers cells in Transfer Mode) Identifying means for identifying a second supervisory control cell, a first cell buffer for accumulating the first supervisory control cell, a second cell buffer for accumulating the second supervisory control cell, and Switch output management means for instructing the first cell buffer and the second cell buffer to output the first supervisory control cell and the second supervisory control cell at a predetermined ratio. Do A
TM switch. 10. A first supervisory control cell for transmitting and receiving network management information between a plurality of ATM communication devices in an ATM communication device that transfers cells in an asynchronous transfer mode (ATM) and is connected to an ATM transmission line. Replace the empty cell with the transmission line included in the cell flow on the ATM transmission line,
A second supervisory control cell and A used in the TM communication device
A cell management method characterized by replacing an in-device generated empty cell generated inside a TM communication device. 11. AT for transferring cells in asynchronous transfer mode
A method of bandwidth management inside an M communication device, comprising:
The occupied bandwidth of the supervisory control cell closed in the TM communication device and the A
A bandwidth management method characterized in that the sum of the occupied bandwidth of a device-generated empty cell generated and lost inside a TM communication device is set to a constant value. 12. AT for transferring cells in asynchronous transfer mode
A band management method in an ATM switch of an M communication device, wherein the entire band of the switch is divided into two fixed bands, and in the first band, a user cell used by a user and a plurality of ATM communication devices are used. A first supervisory control cell for transmitting and receiving network management information over the line and an empty cell equipped with a transmission path included in the cell flow of the ATM transmission path are accommodated.
The band management method is characterized by accommodating a second supervisory control cell used in the ATM communication apparatus and an intra-apparatus generated empty cell generated and lost in the ATM communication apparatus.