JP2003087301A - Synchronous operating system for atm switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shift the operating state of a standby system to a synchronous operating state with the active system even when a conventional circuit switching processing device is employed for SW sections. SOLUTION: The synchronous operating system includes SW sections 1, 2 and an IF section 3 for receiving transmission cell data of the both. When a cell monitor section 34 records and monitors the transmission cell data from the both and detects dissidence, the cell monitor section 34 records and monitors only the transmission cell data from e.g. an active system data transfer management section 311 to update the recordings and instructs e.g. a standby system data transfer management section 312 to stop transmission of only one cell data from the standby system SW section 2. Repeating the procedures above can bring the SW section started later and acting like the standby system into the synchronous operating state with the active system SW section in operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to match cell data in a working system with cell data in a working system of an ATM (asynchronous transfer mode) switch having a duplicated structure. The present invention relates to a synchronous operation method when cell data is received from each of the two switch units and the cell data received from the operating system is output to the outside. Particularly, when a line processing device is used as a basic structure of ATM, the cell is controlled by an external control. The present invention relates to a synchronous operation method capable of synchronizing data.

[0002]

2. Description of the Related Art In a device forming a basic structure, if an operation stop occurs due to a failure of the device, its influence on services is immeasurable. Therefore, it is general that the circuit portion related to the signal processing in the device is configured to be duplicated. In particular, for the main signal common processing unit, the necessity of the duplex configuration is firstly mentioned because of its influence.

In this duplicated circuit part, it is necessary to minimize the service stop period when switching due to a failure and to continue the service when a forcible operating system switching occurs due to maintenance by a maintenance person. Therefore, synchronous operation is required.

On the other hand, ATM (asynchronous transfer mod)
e) Since the circuit switching (switch) processing section provided in the common section of the communication system device has a buffer for storing cell data, control is required to bring it into the synchronous operation state.

Further, recently, many devices controlling the ATM communication system have been developed, but few have been considered for application to a device having a basic structure, and in particular, the circuit switching processing device itself is preliminarily provided with functions. Few.

[0006] Conventionally, in the synchronous operation system of the operating system and the non-operating system, there is an ATM switch system disclosed in, for example, Japanese Patent Application Laid-Open No. 8-139726. According to this system, as shown in FIG.
The input signal branched by 00 is the operation system SW (switch)
The output from the working SW unit is selected and sent to the outside by the selection circuit 130 that is sent to the unit 110 and the non-working system SW unit 120, and the respective outputs are connected. In this circuit, cell switching information is formed in the T cell and supplied from the T cell insertion circuit 140 to the branch circuit 100 for the purpose of realizing non-instantaneous switching to the redundant system.

In each of the working SW unit 110 and the non-working SW unit 120, the T cell detectors 112 and 122 have T
When a cell input is detected, each buffer 11
The difference calculation circuit 124, which detects the number of retained cells in cells 1, 121 by the respective retained cell number detection circuits 113 and 123, and provides the difference in the number of retained cells between the active system and the inactive system on the side of the standby SW unit 120, Ask. The read control circuit 125 uses the buffer 1 according to the difference obtained by the difference calculation circuit 124.
21 controls the cell transmission to increase / decrease the number of retained cells to synchronize the cells transmitted by the respective SW units 110 and 120,
It realizes non-instantaneous switching.

[0008]

The above-mentioned conventional synchronous operation system has a problem that a general-purpose device cannot be used as the circuit switching processing device forming the SW section.

The reason is that it is necessary to provide the SW unit with means for detecting the retention of cell data, calculating the difference, and synchronizing.

An object of the present invention is to solve such problems and to provide a synchronous operation system capable of synchronous operation using a general-purpose circuit switching processing device.

[0011]

In the synchronous operation system according to the present invention, a general-purpose circuit switching device is externally controlled to make the asynchronous operation state of cell data a synchronous operation state.

That is, the synchronous operation system according to the present invention is
The cell data in the working system of the ATM (asynchronous transfer mode) switch having the duplex configuration is matched with the cell data in the non-working system, and the interface unit shown below is provided. This interface section receives cell data from each of the operating and non-operating switch sections, and outputs only the cell data received from the operating switch section to the outside. In case of disagreement, only the cell data of the working system is monitored and updated until they match, and when they match, the transmission of one cell data to the switch unit of the working system is stopped. Is characterized by.

Further, one embodied interface section includes a data transfer management section, a line selection section, and a cell monitor section, and has the following features. The data transfer management unit receives cell data from each of the two switch units having the duplex configuration, one of which is the active system and the other of which is the non-active system. The line selection unit receives the cell data from each of the data transfer management units, selects the cell data to be the operating system, and outputs the cell data to the outside. Also, the cell monitor unit inputs and compares the cell data sent from each of the two data transfer management units to the line selection unit, and when the cell data do not match, the cell data of the working system until they match. Only the data is monitored and updated, and when they match, the data transfer management units of both the active system and the non-active system are instructed to perform the phase adjustment, and when the phase adjustment is completed, the initial state is restored. Further, the non-operating system data transfer management unit that has received the phase adjustment instruction responds to the corresponding switch unit that cell data transmission has stopped.

With the above arrangement, in the case of one phase difference, synchronization can be obtained by one phase adjustment. In addition, a plurality of phase differences require a plurality of phase adjustments, but a synchronized state can be reliably obtained. In this way, since the synchronous operation between the active system and the non-active system is executed by the interface section provided outside the switch, the general-purpose circuit switching processing device can be used as it is.

Further, the cell monitor unit is informed of either the operating system or the non-operating system of the data transfer management unit, and starts the phase adjustment to both of the operating system and the non-operating data transfer management unit. Then, when the completion notification of the phase adjustment is received from the data transfer management unit of the active system, the data transfer management unit of the non-operation system is instructed to stop the phase adjustment and the phase adjustment is ended. Characterize.

The data transfer management unit is informed of either the active system or the non-active system, and the active data transfer management unit responds when receiving a phase adjustment start instruction from the cell monitoring unit. When the cell data is received in response to the transmission confirmation of the cell data received from the connection destination switch unit, the cell monitor unit is notified of the completion of the phase adjustment, and the non-operation data transfer management unit When a phase adjustment start instruction is received from the cell monitor unit, a transmission stop response is responded to the cell data transmission confirmation from the corresponding connection destination switch unit, and a phase adjustment stop instruction is received from the cell monitor unit. The feature is that this phase adjustment is canceled.

Further, it is preferable that the cell monitor section includes a counter for counting the number of times of data mismatch, and when the mismatch continues up to a predetermined count value, the count value of the counter is cleared to return to the initial state. . The reason for this is
This is because it is possible to deal with the situation where the cell data of the non-operating system does not appear in the operating system.

Furthermore, the interface section starts a normal operation after instructing the switch section set to the non-operation system to reset and discarding the cell stored in the buffer section of the switch. It is desirable to start monitoring two accept cell data.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. In the drawings, only the portion related to the present invention is shown due to space limitations. Therefore, some components are omitted even if they are necessary for normal related functional operations. Also, the operation procedure shown is normal operation,
The operation procedure due to a failure is omitted.

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

The synchronous operation system shown in FIG. 1 comprises SW (switch) units 1 and 2 and an IF (interface) unit 3. Each of the SW units 1 and 2 is composed of a general-purpose circuit switching processing device, shares an operating system and a non-operating system, and receives the same input signal and operates synchronously.
The IF unit 3 receives the cell data from each of the SW units 1 and 2, selects only the cell data received from the working SW unit, and sends it as an output signal.

The SW section 1 includes buffer sections 111, 112, ... Included in the SW processing section 11 and data transfer management sections 121, 122 ,.
The SW unit 2 is a buffer unit 21 included in the SW processing unit 21.
, And data transfer management units 221, 222, ... Connected to the IF unit 3. The IF unit 3 also includes data transfer management units 311 and 312, a line selection unit 33, and a cell monitor unit 34.

SW units 1 and 2 which are circuit switching processing devices
The transition to the synchronous operation state of can be realized as follows.
First, the IF unit 3 is provided with a cell monitor unit 34 for monitoring the cell data of the active system and the cell data of the non-operation system to detect the asynchronous state. When in the asynchronous state, the data transfer management units 311 and 312 set the cell data phase of the non-operation system to 1
Delay the cell data phase. A transition to the synchronous operation state can be realized by repeating the detection of the asynchronous state and the phase adjustment processing.

In the circuit switching apparatus composed of the circuit switching processing device, the cell data input from each signal input section is once input to the SW sections 1 and 2 as an input signal. S
Each of the W units 1 and 2 has a SW processing unit 11 or 21 and performs a circuit switching process. The basic operation of this circuit switching process is to determine the output port number for each input cell data and store the cell data in the buffer unit 111, 112, ... In the buffer unit corresponding to this port, for example, the SW unit 1. Is. After that, the SW unit 1 reads the cell data from the corresponding buffer units 111, 112, ... With the data transfer management units 121, 122, ... Prepared for each output port, and outputs the read cell data. To do. SW section 2
The same is true for.

For example, when the data transfer management unit 121 decides to send cell data, the corresponding buffer unit 11
1 is instructed by the control signal to output the cell data to the data path, and further the cell data is output to the data path 41 to the IF unit 3.

The SW section 1 has a SW processing section 11 which is a basic switching structure. The SW processing unit 11 distributes and stores the cells received as the input signal to, for example, a plurality of buffer units 111, 112, ... For each destination. The buffer unit 111 connects the output to the data transfer management unit 121, and sequentially outputs the cells stored in the buffer based on the control signal from the data transfer management unit 121. Buffer unit 11
Other than 1, for example, the buffer unit 112 is the data transfer management unit 1
22 and has the same function as the buffer unit 111. The data transfer management unit 121 transfers a cell to the IF unit 3 through the data path 41 on the output side, and has a signal path r for confirming transmission at the time of cell transfer and a signal path a for permission response. . Other than the data transfer management unit 121, for example, the data transfer management unit 122 is connected to another IF unit and performs the same function.

The SW unit 2 also has the same configuration and performs the same function as the SW unit 1 in which the number "2" at the beginning of the assigned number code is replaced with the number "1", and therefore the description thereof will be given. Omit it. However, the data transfer management unit 221
The cell is transferred to the IF unit 3 via the data path 42.

That is, in the device having the basic structure, the SW
The unit 1 and the SW unit 2 have the same constituent parts, and have the same operating state by making the input signals the same, and have a redundant configuration in case of an emergency such as a failure. Therefore, the signal output to one IF unit 3 exists on the data path 41 from the SW unit 1 and exists on the data path 42 from the SW unit 2. Since the cell data transferred through the two data paths 41 and 42 are the same, in the IF section 3, one of the data paths 41 and 42 is used in the line selection section 33 via the data transfer management sections 311 and 312. Can be selected and output as an output signal.

The outputs of the data transfer management units 311 and 312 are connected to both the line selection unit 33 and the cell monitoring unit 34 via the data paths 321 and 322, respectively.

The data transfer management unit 311 includes a data transfer management unit 121 of the SW unit 1, a data path 41, and signal paths r and a.
Connected by. In addition, the data transfer management unit 311
The data transfer management unit 1 of the connection destination SW unit 1 is connected to the cell monitor unit 34 and is functioning in a non-operation system, and while receiving a phase adjustment instruction from the cell monitor unit 34.
In response to the transmission confirmation received from 21 through the signal path r, the transmission stop is responded through the signal path a.

On the other hand, the data transfer management unit 312 also has the same function as the data transfer management unit 311 and therefore its explanation is omitted.

The data transfer management unit 311 and the data transfer management unit 312 are connected to each other, and the cell transfer received from the SW units 1 and 2 via the data paths 41 and 42, that is, the cell position is synchronized by a known technique. You are driving.

The line selection unit 33 sets one of the SW units 1 and 2 as an active system and the other as a non-operation system according to the control of the entire system (not shown), and the SW of the active system is set.
Selects a cell to be received from the data transfer management unit connected to the unit and outputs it to the outside.

The cell monitor unit 34 includes a data transfer management unit 3
The cell data output by both 11 and 312 are captured and stored in the memory for comparison. If the comparison results are inconsistent, the cell monitoring unit 34 monitors only the cell data of the operating system and updates the record until they match, and then when they match, the data transfer management unit 31 adjusts the phase of the cell data.
Instruct both 1 and 312.

Now, consider a case where the line selection unit 33 selects the data path 321 connected to the data transfer management unit 311 as an output signal. In this case, as described above, S
The cell data of the data path 41 output from the W unit 1 is selected as the output signal. This is S
This means that the W unit 1 is selected for device operation. That is, it means that the SW unit 1 is the active system and the SW unit 2 is the non-active system.

The SW section 1 and the SW section 2 each have a buffer section for storing cell data. SW
When the unit 1 and the SW unit 2 start operating at the same time, the same cell data are sequentially input to the corresponding predetermined buffers, so the cell data are in the synchronized state. However, since the non-operational SW unit is normally started with a delay with respect to the SW unit in operation, the difference in the operation start timing causes a difference in the cell storage state in the buffer. That is, an asynchronous state occurs in which the operating states do not match.

In the present invention, the IF unit shifts such an asynchronous state to a synchronous operating state in preparation for switching to the non-operating system without trouble when the operating system fails.

Next, the asynchronous state between the active system and the non-active system will be described with reference to FIGS. In the two upper and lower positions shown in the figure, the upper part is the working system and the lower part is the non-working system. In addition, in each output port buffer section of the SW section, the buffer is often divided into a plurality of pieces due to the provision of a Qos (Quality of Service) function or the like, and in FIG. An example with two buffers is shown in.

FIG. 2 is a diagram showing an example of an asynchronous situation.

In the figure, the cell data A1 and A2 are stored in the active system buffer before the non-operating system SW unit is activated, and the cell data B1 arrives after the non-operating system SW unit is activated. Since the cells are sequentially read from the buffer, when monitoring this, the first cell data A of both
1, B1 do not match. The cell data B1 monitored in the non-operating system will be monitored two points after the simultaneous point in the operating system.

FIG. 3 is a diagram showing an example of an asynchronous state in the Qos-compatible buffer structure.

The figure shows a state in which the cell data A1 to A3 are stored in the active system buffer before the non-operation system SW unit is activated, and the cell data B1 and B2 arrive after the non-operation system SW unit is activated. There is. Cell data is sequentially read from the two buffers by a predetermined method. It is certain that the cell data B1 in the non-operation system will be monitored after the simultaneous point in the operation system, but the cell data A1, A2, B1, A in the operation system depends on the read method.
The order may be 3, B2. Therefore, the first cell data B1 is two later, while the following cell data B2 is four later. That is, the delay causes a difference between the cell data B1 and the next cell data B2.

FIG. 4 is a diagram showing an example of an asynchronous state and showing contents to be noted in other than the example described above.

That is, in the figure, the buffer amount is the same in the active SW unit and the non-active SW unit, but since the input cell data exceeds the accumulated amount in this buffer, the cell data B1 is stored in the buffer. It shows the case where it is discarded without being processed.

In consideration of the fact that the standby SW unit is normally activated later, each buffer in the active system has a large amount of accumulated cell data with respect to each corresponding buffer in the non-active system. This means that when cell data arrives, there are only three states for the working and protection buffers: store in both, discard both, or store in protection buffer only. To do. Further, it means that the storage capacity of the cell data cannot be larger than that of the working buffer even after that. In addition, there is a case where the cell data monitored by the non-operating system cannot be monitored by the above-mentioned discarding process, although the cell data should be monitored after the simultaneous point by the operating system.

Next, returning to FIG. 1, the transition process for realizing the synchronous operation of the present invention in the IF section 3 will be described.

The cell monitor unit 34 stores and monitors the cell data from the SW unit 1 on the data path 321 and the cell data from the SW unit 2 on the data path 322 for comparison. When the phase shift that the cell data does not match is detected, the phase adjustment mode is entered and the data transfer management units 311 and 312 are instructed to start the phase adjustment via the control signal path. Data transfer management unit (for example) 31 belonging to the operating system
1 determines the timing of completion of the phase adjustment, and notifies the cell monitor 34 of the completion of the phase adjustment via the control signal path. In response to this, the cell monitor unit 34 issues a phase adjustment stop instruction to the data transfer management unit 312 belonging to the non-operation system via the control signal path. Data transfer management unit 312 belonging to non-operation system
Controls transmission stop so that cell data is not transmitted from the connected SW unit 2 between the phase adjustment start instruction and the phase adjustment stop instruction.

Next, the control for stopping the transmission will be described with reference to FIG.

In the ATM communication method, UTOPIA (Universal Test & Op
erations PHY Interface for ATM) is specified and widely applied. This can be adopted as it is between the SW parts 1 and 2 and the IF part 3 which compose the apparatus. Even if different interfaces are used, the data transfer method is often the same.

Also in this embodiment, the SW unit 1 and the IF unit 3
This kind of data transfer method shall be used to transfer data to and from. In this case, the data transfer management unit 121 inquires of the data transfer management unit 311 whether transmission is possible, using the control signal path a, and the data transfer management unit 311 considers the processing capacity of the IF unit 3 and the like, Transfer management unit 1
21 is responded to the permission of transmission through the control signal path r. Further, the data transfer management unit 121 transmits the cell data via the data path 41 when deciding the data transmission.

That is, the data transfer management unit 312 belonging to the non-operation system controls to stop the transmission of cell data from the corresponding SW unit 2 by responding to the transmission permission via the control signal path r. If not, it means good. Therefore, in this phase adjustment, the response of the transmission permission is considered only in consideration of the normal IF unit processing capacity and the like, and is stopped only during the phase adjustment of the cell data in the non-operation system.

Next, with reference to FIG. 5 together with FIGS. 1 to 4, the main operation procedure in the cell monitor unit 34 of the IF unit 3 will be described.

As described above, the cell monitor unit 34 stores and compares the cell data output from the data transfer management units 311 and 312, respectively, and confirms that they are in the synchronous operation state by detecting a match. Further, the cell monitor unit 34 is provided with a counter (MCTR) for measuring the update of the monitor because the coincidence confirmation by the cell data discarded in the operation system as described with reference to FIG. 4 is impossible. MCTR is "0 value" at initial or reset.
The “X value” is set in advance as a limit value for a situation in which matching confirmation is impossible. Here, "X = 2" will be described according to the memory capacity of the buffer in FIG.

When the cell monitor unit 34 is activated, the MC monitor unit 34
TR is reset and set to "0 value" (step S1), and the cell data of the operating system and the non-operating system are simultaneously recorded and monitored in the memory, and if there is previously recorded data, it is updated ( In steps S2 and S3), the contents of the recorded cell data are compared (step S4).

When this step S4 is "YES" and both cell data contents are the same and MCTR is "0" (YES in step S5), the cell monitor unit 34 indicates that "the system is in the synchronous operation state. It is determined that "there is" in step S2 and S3 to detect the next synchronization. That is, both the active system and the non-active system repeat the procedure from the procedure of simultaneously monitoring the cell data appearing on the data paths 41 and 42 and updating the previously recorded data.

If the contents of the cell data recorded as "NO" in step S4 do not match, that is, "the system is in the asynchronous operation state", the process goes to the cell data matching confirmation process. Therefore, as shown in FIG. 2 or 3, in order to confirm that the same cell data is transferred on the non-operation side with a delay from the operation side, the cell monitoring unit 34
Indicates that MCTR has not reached "X = 2" (step S10).
No.), the MCTR count value is incremented by “+1” (step S11) to “MCTR = 1”, and only the active system records and monitors the next cell data.
Update the previously recorded cell data (Tejuu S12),
The procedure returns to step S4 for comparing the contents with the non-operation system memory.

As a result, the cell data stored in each of SW1 and SW2 are sequentially transferred by both the data transfer management units of both the active system and the non-active system. However, in the cell monitor 34, the record is updated only in the active system, and not updated in the non-active system.

This state will be described with reference to the example of FIG.
That is, in the IF unit 3, the next cell data A2 is transmitted and recorded by the SW unit 1 on the operating side, but the cell data transmitted from the SW unit 2 on the non-operating side is not recorded. Means that is left. Therefore, in the present procedure S4, both of the cell data A2 and B1 are compared. As a result, steps S4 and S10 are "NO".
Therefore, “MCTR = 2” is set in step S11, and the cell data B1 is compared in step S4. As a result, the step S4 becomes "YES", and it is confirmed that the cell data match.

In this case, since "MCTR = 2" and the next step S5 is "NO", the cell monitor unit 34 causes the data transfer management units 311 and 3 of both the active system and the non-active system.
A phase adjustment start instruction is sent to 12 (step S13).

As a result, in the active system, the next cell data is transmitted from the SW unit 1 as will be described later in detail with reference to FIG. 7, and the active data transfer management unit 311 accepts this cell data. Then, the notification of the completion of the phase adjustment is sent to the cell monitor 34. The cell monitor unit 34 receives a phase adjustment completion notification from the data transfer management unit 311 of the active system.
(Procedure S14), so the non-operation data transfer management unit 3
Send a phase adjustment stop instruction to 12 (step S15)
TR is reset to "0" (step S16), and the above step S
2. Returning to S3, the procedure is repeated from the beginning.

On the other hand, in the non-operation system, as will be described later in detail with reference to FIG. 8, the transmission of cell data is stopped to the transmitting side in response to the instruction in step S13, so that the next cell is stored in the buffer. But the transfer is stopped. Therefore, the next cell data is transferred only to the active system, and not to the non-active system.

As described with reference to FIG. 4, when there is cell data discarded in the operating system, the above step S4 is performed.
Since there is no match between the two cell data in "MCT
The “R” limit is preset.

When the above step S10 is "YES", "MCTR
= X ”, the procedure jumps to step S16 and M
The CTR is reset to "0" and the procedure returns to the steps S2 and S3, and the procedure is repeated from the beginning.

Next, referring to FIGS. 6 and 7 together with FIGS. 1 and 5, the data transfer management units 311 and 31 of the IF unit 3 will be described.
The phase adjustment operation in 2 will be described. In the data transfer management units 311 and 312, for example, one data transfer management unit 311 is an active system and the other data transfer management unit 312 is a non-operation system, like the line selection unit 33 from the control unit of the system (not shown). It is assumed that they are notified.

FIG. 6 is a flow chart showing one form of the phase adjustment procedure in the active data transfer management unit 311. Here, steps S22 to S24 shown in the figure are regular steps when receiving cell data transmission from the SW unit, regardless of whether it is an active system or a non-active system.

After the "phase adjustment start instruction" is accepted in step S13 (YES in step S21), the "transmission confirmation" is accepted from the SW section 1 through the signal path r (step S21).
22), the data transfer management unit 311
After confirming that the other conditions of the transmission permission are satisfied, returns a "transmission permission response" to the SW unit 1 via the signal path a (YES in step S23). As a result, since the next cell data is received from the SW unit 1 (YES in step S24), the data transfer management unit 311 sends a "phase adjustment completion notification" to the cell monitor unit 34 (step S25) and ends the procedure. .
That is, the "phase adjustment completion notification" is transmitted when the cell data transfer is received only when the "phase adjustment start" instruction is received in the start procedure S21.

FIG. 7 is a flow chart showing one form of the phase adjustment procedure in the non-operation data transfer management unit 312.

The data transfer management unit 312 uses the above step S1.
After receiving the "phase adjustment start instruction" (YES in step S31) in step 3 and before receiving the "phase adjustment stop instruction" (NO in step S32), a "transmission confirmation" is issued from the SW unit 2 via the signal path r. When accepted (YES in step S33), a "transmission stop response" is returned to the SW unit 2 (step S34).
To do. In steps S33 and S34, if step S32 is "YE
The operation is continued until the "phase adjustment stop instruction" that is "S" is received.

Therefore, when the cell monitor unit decides to implement the phase adjustment, it instructs the data transfer management units of the active system and the non-operation system to start the phase adjustment, and then notifies the phase adjustment completion from the active system data transfer management unit. Accordingly, the non-operation system data transfer management unit is instructed to stop the phase adjustment, and the process returns to the main flow for detecting and processing the asynchronous state again.

That is, the operational data transfer management unit determines the phase adjustment completion time when the phase adjustment start instruction is received from the cell monitoring unit.
In addition to the process of sending a transmission permission response to the transmission confirmation from the W unit, it is confirmed that one cell data is actually transmitted in response to this transmission permission response, and the phase adjustment is made to the cell monitoring unit with this cell data transmission confirmation. Sending a completion notification.
Further, the non-operation system data transfer management unit continues to return a transmission stop response to the transmission confirmation from the SW unit from the phase adjustment start instruction received from the cell monitor unit to the phase adjustment stop instruction.

The procedure for obtaining this synchronized state will be described with reference to the simple example of FIG. 8 together with FIGS. 1 and 5 to 7.

In FIG. 8, the non-operating system lags behind the active system by two cell data C1 and C2, and six cell data D1-
6 is an explanatory diagram of phase adjustment showing a simple example in which 6 is stored in each of the buffer units 111 and 211 of the SW units 1 and 2. FIG.

In the first step S4, the cell data C1,
Both D1 are compared, and since they do not match, MCTR is "1" in step S11. Cell data C2 for the next lap
By comparing D1, MCTR becomes “2”. During this period, in step S12, the cell data of only the active system is recorded in the memory, and the non-active system is not recorded. Therefore, the cell data D2 and D3 of the non-active system are discarded.

In the procedure S4 of the third cycle, the cell data D1 match, so the procedure proceeds to the procedure S5. Here, "MC
Since "TR = 2", the cell monitor unit 34 in the above step S13 instructs the data transfer management units 311 and 312 to start phase adjustment.

By the phase adjustment procedure described above, the transmission of the next cell data D4 is stopped in the non-operation system, although the next cell data D2 is transmitted in the operation system. When one of the cell data D2 is transmitted, the transmission stoppage of the protection system is released and the phase adjustment is completed.

Therefore, the MCTR returns to "0", and the cell data D3 to be stored next in the buffer of the SW section in the active system and the cell data D4 for which the transmission has been stopped are transmitted in the non-operation system. If the same procedure as described above is performed in this state, only the data D5 is discarded in the non-operation system, and the phase synchronization is surely obtained with the cell data D6.

That is, in the case of a simple storage order, the non-operating system discards subsequent cell data by the number of differences in the same cell data position from the first confirmation of matching of cell data. As a result, if there is a difference of one, reliable synchronization can be obtained in the next round of procedures. Normally, switching to the non-active system due to a failure in the active system rarely occurs, and since periodic maintenance also has a predetermined period, immediacy is not required for the phase synchronization processing accompanying the startup of the non-active system. is there. Therefore, even if the order of the data stored in each of the active system and the daily system is complicated, the synchronization can be surely obtained by closing the differences one by one until the phase synchronization is obtained.

In the above description, the data transfer management unit, like the line selection unit, receives the notification of the active system and the non-active system, but the cell monitor unit recognizes the active system and the non-active system. Therefore, instead of the “phase adjustment start instruction”, the “transmission stop instruction” may be sent to the non-operation data transfer management unit.

Further, in the above description, the non-operation system is activated while the operation system is operating, but in the case of simultaneous activation, the normal operation should be the cell data synchronous operation state immediately. However, the operating system may not be able to store the initial input data and may enter the buffer storage state opposite to the above. This case can be solved by resetting up to the buffer section of the SW section package set to the non-operation system and executing the phase synchronization adjustment according to the present invention.

For example, since a normal switch processing device has a threshold value setting for determining whether to store an input cell, discarding or storing can be determined based on the relationship between this threshold value and the cell retention amount. . Therefore, the buffer can be made "empty" by setting the threshold value to "0" and leaving it as it is. If this control is also used, the conditions regarding the activation of the working SW unit and the non-working SW unit can be set as the prerequisites of the present invention.

In the above description, the MCTR is reset when the number of times of monitoring is measured up to the "X value".
A timer may be provided separately and the timer may be reset at a preset time.

In the above description, reference is made to the functional blocks and procedures shown in the drawings, but changes such as distribution by dividing and merging functions or rearrangement of procedures are free as long as the above functions are satisfied. Is not limited.

[0083]

As described above, according to the present invention, it is possible to obtain the effect that a general-purpose circuit switching processing device can be used to bring about a synchronous operation state.

The reason for this is that the interface section is also used outside the circuit switching processing device to control the synchronization processing. In this synchronization processing, the cell data of the active system and that of the non-operation system are monitored, and if they do not match, only the cell data of the active system is monitored and updated until they match. This is because the transmission of one cell data is stopped to the switch unit.

That is, since the circuit switching processing device has a buffer for storing cell data, it cannot be expected to enter the synchronous state naturally. On the other hand, many circuit switching processing devices are not provided with a function for synchronous operation because they are not considered for application in equipment in a backbone structure. On the other hand, in the present invention, these circuit switching processing devices can be applied to the backbone structure device.
In addition, since the circuit switching processing device has many basic processing items and is a centralized processing unit of the circuit, it is difficult to mount additional functions. The synchronization by external control this time also makes it possible to reduce the centralized processing load in the circuit switching processing unit.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an asynchronous situation in two buffers.

FIG. 3 is a diagram showing an example of an asynchronous situation in two sets of buffers.

FIG. 4 is a diagram showing an example in which cells are discarded in an active system in two sets of buffers.

5 is a flowchart showing an example of a main operation procedure in the cell monitor unit of FIG.

FIG. 6 is a flowchart showing one form of a main operation procedure of the present invention of the operational data transfer management section of the IF section shown in FIG. 1.

7 is a flowchart showing one form of a main operation procedure in the present invention of the non-operation system data transfer management section of the IF section shown in FIG. 1. FIG.

FIG. 8 is an explanatory diagram of phase adjustment showing a simple embodiment in which the non-operating system is delayed by two cell data from the operating system and six cell data are stored in each buffer section of the SW section. is there.

FIG. 9 is a functional block diagram showing a conventional example.

[Explanation of symbols]

1, 2 SW (switch) section 3 IF (interface) section 11, 21 SW processing section 33 Line selection section 34 Cell monitor section 41, 42, 321, 322 Data path 111, 112, 211, 212 Buffer section 121, 122, 221 222, 311, 312
Data transfer management unit

Claims (6)

[Claims] 1. In a synchronous operation method in which cell data of a working system of an ATM (asynchronous transfer mode) switch having a duplex configuration is matched with cell data of a working system, from a working system and a non-working system, both switch parts are provided. It receives cell data and outputs only the cell data received from the switch unit that is the active system to the outside.When the two received cell data are monitored and if they do not match, only the cell data of the active system is used until they match. The synchronous operation system is characterized by comprising an interface unit that monitors and updates the cell number, and then stops the transmission of one cell data to the switch unit of the non-operation system when they match. 2. In a synchronous operation method in which cell data in a working system of an ATM (asynchronous transfer mode) switch having a duplex configuration is matched with cell data in a non-working system, a switch unit of each of the working system and the non-working system is used. An interface unit is provided that receives cell data and outputs only the cell data received from the operating switch unit to the outside. The interface unit operates one that receives the cell data from each of the two switch units in the duplex configuration. A data transfer management unit that makes the rest the non-operation system, a line selection unit that receives cell data from each of the data transfer management units and selects the cell data to be the operation system and outputs it to the outside, and the two data Cell data sent from each transfer management unit to the line selection unit is input and compared. When they do not match, only the cell data of the working system is monitored and updated until they match, and then
A cell monitor unit that instructs the data transfer management units of both the active system and the non-operation system to perform phase adjustment when they match, and returns to the initial state upon completion of the phase adjustment. The synchronous operation method, wherein the data transfer management unit of the system responds to the corresponding switch unit with a stop of cell data transmission. 3. The cell monitoring unit according to claim 2, wherein the cell transfer unit is informed of either the operating system or the non-operating system of the data transfer management unit, and both of the operating system and the non-operation system data transfer management unit are notified. When the start of the phase adjustment is instructed and then when the completion notice of the phase adjustment is received from the data transfer management unit of the active system, the data transfer management unit of the non-operation system is instructed to stop the phase adjustment and the phase adjustment is performed. A synchronous operation method characterized by terminating the. 4. The data transfer management unit according to claim 2, wherein either the active system or the non-active system is informed, and the active data transfer management unit instructs the phase adjustment start instruction from the cell monitoring unit. When the cell data is received in response to the transmission permission response to the cell data transmission confirmation received from the corresponding connection destination switch unit, the cell monitor unit is notified of the completion of the phase adjustment, and the non-operation is performed. When receiving a phase adjustment start instruction from the cell monitor unit, the system data transfer management unit responds to the cell data transmission confirmation from the corresponding connection destination switch unit with a transmission stop response, and the cell monitor unit performs the phase adjustment. This synchronous operation method is characterized in that this phase adjustment is released when the stop instruction of is received. 5. The cell monitoring unit according to claim 2, further comprising a counter that counts the number of times of data mismatch, and when the mismatch continues up to a predetermined count value, clears the count value of the counter to the initial state. Synchronous operation method characterized by returning. 6. The interface unit according to claim 1, wherein after the interface unit instructs the switch unit set to a non-operation system to reset, the cell stored in the buffer unit of the switch is discarded, Synchronous operation method characterized by starting the operation and monitoring of two reception cell data.