JPH1023027A - Atm communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow the communication equipment to discriminate in which processing in the unit of cells or processing in the unit other than the cell unit, a fault of an internal circuit has taken place. SOLUTION: A 2nd monitor cell-generating circuit 16 and a 2nd monitor cell collation circuit 17 are arranged, respectively between a receiving end and a transmission end in the equipment, to detect a fault of monitored circuits 20-1 to 20-M, conducting processing of a cell level. Moreover, 1st monitor cell- generating circuits 14-1 to 14-N and 1st monitor cell collation circuits 15-1 to 15-N are arranged at both ends of each of monitored circuits 13-1 to 13-N, and a fault for each of the monitored circuits 13-1 to 13-N is detected by using a 1st monitor cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an asynchronous transfer mode.
The present invention relates to an ATM communication device that processes and transfers fixed-length cells in (ATM: Asynchronous Transfer Mode) and autonomously monitors the normal operation of internal circuits.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 5-244187 discloses a technique for enabling an ATM communication apparatus to autonomously monitor the normality of the operation of an internal circuit using a monitoring cell. And a technique described in Japanese Unexamined Patent Publication No. Hei 5-327757, "Monitoring Cell Insertion Control System". In both technologies, the operation of generating a monitor cell in the device, transferring the monitor cell to the monitored circuit, and collating the contents of the monitor cell after the transfer is the same. However, in these technologies, the internal circuit is divided into blocks,
Since the monitoring of each block is not considered, it is difficult to specify an abnormal portion.

[0003] As a technique enabling monitoring for each block, an "ATM cross connect technique" (NTT R & D, 42, No. 3,
pp. 357-366 (1993)). FIG. 8 is a diagram showing a configuration example of an ATM communication device using this technique. In the apparatus shown in the figure, the internal circuit to be monitored is divided into three blocks (monitored circuits 102-i), and the monitored cell generating means 103-i is provided on the input side and the output side of each monitored circuit 102-i, respectively. The monitoring cell matching means 104-i is arranged. After the main signal 101-1 input to the device is inserted by the first monitoring cell generating means 103-1 into the first monitoring cell in which the monitoring pattern is set,
It is input to the monitored circuit A 102-1. The output signal of the monitored circuit A 102-1 is inserted into the second monitoring cell by the second monitoring cell generation means and is input to the first monitoring cell collation means 104-1. The first monitoring cell matching means 104-1 detects and separates the first monitoring cell from the input signal, and compares and matches the monitoring pattern set in the monitoring cell with an internally generated expected value. And outputs the collation result 105-1. The monitoring result (normal or abnormal) of the monitored circuit A 102-1 is notified by the comparison result 105-1. Similarly, the second monitoring cell inserted by the second monitoring cell generation means passes through the monitored circuit B 102-2 and the third monitoring cell generation means 103-3, and thereafter, the second monitoring cell collation means. The signal received at 104-2 is used for detecting an abnormality of the monitored circuit B102-2. Similarly, the third
Monitoring cell generating means 103-3 and third monitoring cell collating means 1
By 04-3, an abnormality of the monitored circuit C102-3 is detected.
The above technique can be said to be an effective technique for specifying an abnormal part of the device because the monitored circuit to be monitored can be divided into blocks and an abnormality can be monitored for each block.

[0004]

The processing in the ATM communication apparatus is classified into two processes, a cell level (cell unit) process and a bit level (unit other than the cell unit) process. Cell-level processing includes processing such as cell multiplexing / demultiplexing, cell switching, and cell transfer, and bit-level processing includes processing such as serial-parallel / parallel-serial conversion of signals. Further, bit-level processing and cell-level processing are further divided into blocks, and an LSI is provided for each block.
Or a circuit on one substrate. In particular, cell-level processing is almost always realized by LSI. For this reason, for example, if it can be specified that the abnormality has occurred in the cell-level processing, the abnormality can be identified by an LSI that performs the cell-level processing.
Can be presumed to be the cause.

SUMMARY OF THE INVENTION It is an object of the present invention to specify whether an abnormality in an internal circuit has occurred in processing in units of cells or processing in units other than units of cells.

[0006]

In order to achieve the above object, an ATM communication apparatus according to the present invention performs at least one cell level circuit unit which performs processing in units of cells, and performs processing in units other than units of cells. An ATM communication device comprising: an internal circuit including one or more non-cell level circuit units; and a monitoring unit that detects an abnormality of the internal circuit using a monitoring cell, wherein the monitoring unit is configured to store predetermined data. A plurality of monitoring cell generating means for generating the set monitoring cell and inserting the generated monitoring cell into a signal input to the cell level circuit unit or the non-cell level circuit unit; Detecting the monitoring cell inserted by the monitoring cell generation means associated with the pair 1 from the signal output from the cell level circuit unit or the non-cell level circuit unit;
A plurality of monitoring cell matching means for generating an expected value of predetermined data set in the detected monitoring cell, and notifying an abnormality of the circuit unit when the predetermined data does not match the expected value. At the input terminal and the output terminal of the non-cell level circuit unit, the associated monitoring cell generation unit and monitoring cell matching unit are arranged, respectively, and also at the input terminal and the output terminal of the internal circuit, The monitoring cell generating means and the monitoring cell collating means associated with each other are arranged. This ATM communication device detects an abnormality of each non-cell level circuit unit, enables identification of the non-cell level circuit unit where the abnormality has occurred, and also detects an abnormality of the cell level circuit unit.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is a block diagram of an ATM communication apparatus according to an embodiment of the present invention. In the illustrated ATM communication device,
The internal circuit to be monitored is divided into a monitored circuit that performs processing in units of cells and a monitored circuit that performs processing in units of bits. The monitored circuit that performs bit-level processing
Furthermore, it is divided into N monitored circuits 13-1 to 13-N for each functional block (unit such as a serial-parallel / parallel-serial conversion circuit). Input terminals and output terminals of the monitored circuits 13-1 to 13-N are respectively connected to first monitored cell generating circuits 14-1 to 14-N and first monitored cell matching circuits 15-1 to 15-N. N is arranged. That is, in the monitored circuit 13-i (1 ≦ i ≦ N), the first terminal is connected to the input terminal.
Of the monitoring cell generator 14-i, and a first monitoring cell matching circuit 15-i at the output end. The first monitoring cell generation circuit 14-i and the first monitoring cell matching circuit 15-i are for detecting an abnormality of the monitored circuit 13-i, and transmit and receive the first monitoring cell. On the other hand, a second monitor cell generating circuit 16 and a second monitor cell matching circuit 17 are arranged at the input terminal and the output terminal of the entire internal circuit to be monitored. The second monitored cell generation circuit 16 and the second monitored cell collation circuit 17 include monitored circuits 20-1 to 20 that perform cell-level processing.
This is for detecting an abnormality of -M, and transmits and receives the second monitoring cell. The first and second monitoring cell generation circuits have the same configuration, and the first and second monitoring cell comparison circuits have the same configuration. The monitored circuits 20-1 to 20-M that perform cell-level processing are the same as the first monitored cell generation circuit 14-i and the first monitored cell generation circuit 14-i.
An arbitrary number can be arranged at an arbitrary position between the second monitor cell generating circuit 16 and the second monitor cell comparing circuit 17 except between the monitor cell matching circuits 15-i.

FIG. 2 is a diagram showing a configuration example of the above monitoring cell. An ATM cell has a header part of 5 bytes and an information part of 48 bytes, for a total of 53 bytes, on the transmission line. However, in the apparatus, the header part is 6 bytes, and the information part is a total of 54 bytes for easy processing. It is common to use bytes. In the ATM communication device, information for determining an output route, information indicating a monitor cell, and identification of the first monitor cell and the second monitor cell are provided in a part of a 6-byte header portion. Set information that enables In the second monitoring cell, an arbitrary value set from the outside is mounted as information for determining an output route so as to be transferred in a desired direction. As a result, the second monitoring cell becomes the second monitoring cell.
Is transferred to the monitoring cell matching circuit 17 of FIG. In the information part of each monitoring cell, a monitoring pattern used for detecting an abnormality of the monitored circuit is set. In this ATM communication device, the information for determining the output route of the first monitoring cell used for monitoring the processing circuit irrespective of the cell switching or the like is set to a fixed value, thereby reducing the hardware scale. Is being planned.

FIG. 3 is a block diagram showing a configuration of the monitoring cell generation circuit. In the figure, the monitoring cell generation circuit includes a monitoring cell insertion timing detection unit 33, a monitoring cell generation unit 35, and a monitoring cell insertion unit 34. The monitoring cell insertion timing detection unit 33 detects an empty cell in the received main signal 31, and sends a cell insertion timing signal 36 to the monitoring cell generation unit 35 upon detection. The monitoring cell generator 35 receives the monitoring cell insertion timing signal 36 and generates a monitoring cell (FIG. 2). The monitoring cell insertion unit 34 inserts the monitoring cell generated by the monitoring cell generation unit 35 into the position of the empty cell detected by the monitoring cell insertion timing detection unit 33, and transmits the main signal 32.

FIG. 4 is a block diagram showing the configuration of the monitoring cell matching circuit. In the figure, the monitoring cell matching circuit includes a monitoring cell detection unit 43, a monitoring cell separation unit 44, a monitoring pattern expected value generation unit 45, and a monitoring cell matching unit 46. The monitoring cell detection unit 43 detects a monitoring cell in the received main signal 41 and sends a monitoring cell detection timing signal 48 to the monitoring pattern expected value generation unit 45. The monitoring pattern expected value generation unit 45 receives the monitoring cell detection timing signal 48 and generates an expected value of the monitoring pattern of the detected monitoring cell. The monitor cell separation unit 44 separates the monitor cell detected by the monitor cell detection unit 43 from the main signal, sends the main signal to the monitor cell matching unit 46, and inserts an empty cell into the main signal for transmission. Monitoring cell collation unit 46
Compares and compares the monitoring pattern of the monitoring cell sent from the monitoring cell separating unit 44 with the expected value of the monitoring pattern generated by the expected monitoring pattern generation unit 45, and compares the result with the matching result 47.
Output as The matching result 47 indicates that a monitored cell is detected within a certain period of time, and that the monitored pattern of the monitored cell matches the expected value, the normal operation of the monitored circuit is notified. (If the monitoring cell is not detected or the monitoring pattern does not match the expected value), the abnormality of the monitored circuit is notified.

FIG. 5 is a circuit diagram showing a configuration example of the monitor cell generator 35 of the monitor cell generator. In the figure, the monitoring cell generation unit 35 includes a 54-base counter / decoder 51, a monitoring cell cell header generation circuit 52, a shift register 53, and a selector 54.
It consists of. The 54-base counter / decoder 51 starts counting in response to the cell insertion timing signal 36,
The count value of ~ 53 is output. When the count value is 0 to 5, the cell header generation circuit 52 generates the header part (6 bytes) of the monitoring cell in units of 1 byte, and outputs it to the selector.
54 selects and outputs. When the count value is 6 to 53, the shift register 53 generates a monitoring pattern (48 bytes) in 1-byte units, and the selector 54 outputs this.
That is, when the count value is 6, the shift register 53 takes in the initial pattern “10000000” or “01111111” from the initial value input terminal and outputs it to the selector 54. Then, every time the count value changes thereafter, the fetched initial pattern is shifted one bit at a time, and the result is output. The expected monitoring pattern generation unit 45 of the monitoring cell matching circuit also includes the same counter and shift register as described above, and generates the same monitoring pattern (expected value) as the monitoring cell generation unit 35.

FIG. 6 shows the configuration of a monitoring pattern generated by the above circuit. The monitoring pattern includes (a) in FIG.
And a negative polarity pattern shown in FIG. 6B. The monitoring cell generation unit 35 generates a positive pattern, which is an array of unit matrices, by selecting an initial pattern of “10000000”, and selects a bit of the positive pattern by selecting an initial pattern of “01111111”. A negative polarity pattern, which is an inverted pattern, is generated. Further, the monitoring cell generation unit 35 generates a positive polarity pattern and a negative polarity pattern alternately and sets them in the information section of the monitoring cell to be transmitted.

As described above, by using both the positive polarity pattern and the negative polarity pattern as the monitoring patterns, the present ATM communication device can also detect a 0/1 stuck-at fault and obtain sufficient detection accuracy. Further, since a fixed pattern is used as the monitoring pattern, the hardware scale of a circuit for generating the monitoring pattern and its expected value is reduced as compared with a conventional device using a pseudo random pattern (for example, a PN sequence).

FIG. 7 is a processing flow of the monitoring cell matching section 46 of the monitoring cell matching circuit. When the monitoring cell detection unit 43 detects a monitoring cell to be processed, the monitoring cell matching unit 46 (S
1), it is determined whether the monitoring pattern set for the monitoring cell separated by the monitoring cell separation unit 44 has a positive polarity,
In the case of the positive polarity, the monitoring pattern is compared with the expected value of the positive polarity generated by the expected monitoring pattern generation unit 45 (S2). If they match, it is determined to be normal and the next monitoring cell (a negative polarity monitoring pattern is set) is detected (S6). In the process S2, if it is determined that the polarity is not positive, the separated monitoring pattern is compared with the expected value of the negative polarity pattern generated by the expected value generator 45 (S3). And the next monitoring cell (a monitoring pattern of positive polarity is set) is detected (S10). If they do not match, it is determined that there is an abnormality, and a collation result 47 for notifying the abnormality is output (S
4). Further, in the process S1, even when the monitoring cell to be processed is not detected for a certain period of time or more, the matching result 47 for notifying the abnormality is output. When it is determined in step S2 or S3 that the pattern is normal, in steps S6 to S8 and S10 to S12, the alternately generated negative pattern and positive pattern are compared with the separated monitoring pattern, and a mismatch or a fixed number is determined. If there is no detection within the time, it is determined that there is an abnormality, and a comparison result 47 indicating the abnormality is output (S9).

However, in the ATM communication device, when an abnormality occurs in the bit-level processing, the abnormality is also detected in the second monitoring cell matching circuit 17 that monitors the cell-level processing in principle. Therefore, when the comparison results 18-1 to 18-N notify the abnormality of the circuit that performs the bit-level processing, the second monitoring cell collation circuit 17 suppresses the notification of the abnormality based on the collation result 19. As described above, the monitoring cell matching circuit alternately detects a positive polarity monitoring pattern and a negative polarity monitoring pattern and compares it with the expected value of the same polarity pattern. If the two do not match, or if no monitoring cell is detected within a certain period of time, an error in the monitored circuit is notified.

Next, the operation of the ATM communication device will be described.

In FIG. 1, a main signal 11 input to the ATM communication device is input to a second monitor cell generating circuit 16, and an appropriate empty cell is replaced with a second monitor cell.
The main signal into which the second monitoring cell is inserted is transferred through the monitored circuit 20-1 which performs cell-level processing, and then is input to the first monitoring cell generation circuit 14-1, and an appropriate An empty cell is replaced with the first monitoring cell. First and second
The main signal into which the monitored cell is inserted is transferred to the monitored circuit 13-1, and then input to the first monitored cell matching circuit 15-1. In the first monitoring cell matching circuit 15-1, the first monitoring cell is detected and separated from the input main signal, and the monitoring pattern of the separated first monitoring cell, the expected value generated internally, and the Is compared and the comparison result is 18-1
Is output as If there is an abnormality in the monitored circuit 13-1, the first monitoring cell matching circuit 15-1 may not be able to detect the monitoring cell within a predetermined time or the monitoring pattern may not match the expected value. This allows the monitored circuit 13-1
A matching result 47 for notifying the abnormality is output.

A first monitoring cell generating circuit 14-2 to 14-N;
The same processing is performed in the first monitoring cell matching circuits 15-2 to 15-N, and abnormalities in the monitored circuits 13-2 to 13-N are detected. Then, the main signal including only the second monitoring cell as the monitoring cell is output to the monitored circuit 20 that performs the cell level processing.
-M is transferred to the second terminal located at the output end of the device.
Is input to the monitoring cell matching means 17. The second monitoring cell matching means 17 detects and separates the second monitoring cell from the input main signal, and compares and matches the monitoring pattern of the separated monitoring cell with an internally generated expected value. I,
The collation result 19 is output. The collation result 19 notifies an abnormality only when all bit-level processing is performed normally and there is an abnormality in the cell-level processing.

As described above, the present ATM device can individually detect and notify the abnormality of the circuit performing the bit level processing and the abnormality of the circuit performing the cell level processing. In addition, by alternately using a fixed pattern in which a unit matrix is arranged as a monitoring pattern and a fixed pattern in which each bit of the fixed pattern is inverted, the hardware scale can be reduced while maintaining sufficient monitoring accuracy. We are trying to reduce it.

[0021]

According to the present invention, it is possible to specify whether an abnormality in an internal circuit has occurred in processing in units of cells or processing in units other than units of cells.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a configuration example of a monitoring cell transferred inside the device.

FIG. 3 is a block diagram of a monitoring cell generation circuit.

FIG. 4 is a block diagram of a monitoring cell matching circuit.

FIG. 5 is a circuit diagram of a monitoring cell generator.

FIG. 6 is a diagram illustrating a configuration example of a monitoring pattern in a monitoring cell.

FIG. 7 is a processing flow of a monitoring cell matching unit.

FIG. 8 is a block diagram of an ATM communication device according to the related art.

[Explanation of symbols]

11, 12: Main signal transmission path, 13-1 to 13-N: Monitored circuit that performs bit-level processing, 14-1 to 14-N: First monitor cell generating means, 15-1 to 15-N ... first monitoring cell matching means, 16 ... second
Monitoring cell generating means, 17 ... second monitoring cell collating means, 18
-1 to 18-N, 19: Output of verification result, 20-1 to 20-M: Monitored circuit that performs cell-level processing, 31, 32: Main signal transmission path, 33 ...
Monitoring cell insertion timing detector, 34 ... monitoring cell insertion unit,
35 ... monitoring cell generator, 36 ... monitoring cell insertion timing detection signal, 41,42 ... main signal transmission line, 43 ... monitoring cell detector, 44
... Monitoring cell separation unit, 45 ... Monitoring pattern expected value generation unit, 46
... monitoring cell collation unit, 47 ... collation result output, 48 ... monitoring cell detection timing signal, 51 ... 54 base counter + decoder, 52
... Monitor cell header generation unit, 53 ... Shift register, 54 ... Selector, 101-1 to 101-2 ... Main signal transmission line, 102-1 to 102-3 ...
Monitored circuit, 103-1 ... first monitoring cell generating means, 103-2 ...
Second monitoring cell generation means, 103-3 ... third monitoring cell generation means, 104-1 ... first monitoring cell collation means, 104-2 ... second monitoring cell collation means, 104-3 ... third Monitoring cell collation means, 1
05-1 to 105-3: Output of collation results.

Claims (5)

[Claims] 1. An internal circuit comprising one or more cell level circuit units for performing processing in a cell unit, one or more non-cell level circuit units for performing processing in a unit other than a cell unit, and An ATM communication device comprising: a monitoring unit that detects an abnormality using a monitoring cell, wherein the monitoring unit generates the monitoring cell in which predetermined data is set, and the cell level circuit unit or the non-cell level circuit A plurality of monitoring cell generating means for inserting the generated monitoring cell into a signal inputted to the unit; and the plurality of monitoring cell generating means being associated with the monitoring cell generating means in a one-to-one manner, and inserted by the associated monitoring cell generating means. A monitor cell is detected from a signal output from the cell level circuit unit or the non-cell level circuit unit, an expected value of predetermined data set in the detected monitor cell is generated, and the predetermined data is compared with the period. A plurality of monitoring cell matching means for notifying an abnormality of the circuit unit when the values do not match, and an input terminal and an output terminal of the non-cell level circuit unit, each of which corresponds to the monitoring cell ATM communication, wherein a generating means and a monitoring cell collating means are arranged, and the associated monitoring cell generating means and monitoring cell collating means are also arranged at an input terminal and an output terminal of the internal circuit, respectively. apparatus. 2. The ATM communication device according to claim 1, wherein said monitoring cell generating means includes information indicating a monitoring cell in a header of said generated monitoring cell, and a non-cell level circuit. Information indicating which abnormality of the cell level circuit unit is to be used for detection is set, and the monitoring cell matching unit detects the monitoring cell to be processed by checking the information set in the header unit. An ATM communication device characterized by the above-mentioned. 3. The ATM communication device according to claim 1, wherein said monitoring cell collating means disposed at an output terminal of said non-cell level circuit unit reports an abnormality, and is disposed at an output terminal of said processing circuit unit. An ATM communication apparatus characterized in that the monitored cell collation means does not notify an abnormality. 4. The ATM communication device according to claim 1, wherein the monitoring cell generation means sets a monitoring pattern to be set to the monitoring cell to be generated to a value of 1 in a predetermined cycle and to set all other values to a value of 0. The first fixed pattern and the second fixed pattern obtained by inverting the 1 value and the 0 value of the first pattern are alternately generated, and the monitoring cell matching unit also sets the first value as the expected value. An ATM communication device characterized by alternately generating a fixed pattern and the second fixed pattern. 5. The ATM communication device according to claim 1, wherein said cell generation means performs generation and insertion of said monitoring cell at least one time for each period divided into a predetermined time length.
The ATM communication device according to claim 1, wherein the cell matching unit notifies the abnormality even when the monitoring cell cannot be detected within the predetermined time length.