JPH1168774A - Duplex system for mutual stm/atm converting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent omission or overlapping of data or converted data contained in the payload of a converted ATM cell at the time of active system switching by synchronizing the timing to start making the ATM cells into STM data and making STM data into ATM cells between both systems. SOLUTION: In the active system (system 0) at a duplexed STM/ATM mutual converting device, a conversion start signal CSYNC-S at the time of converting the payload of ATM cells to the STM data is supplied from an ATM-STM conversion synchronizing processing part 101 to a reserve system (system 1). At a processing part 202 for data conversion from ATM to STM in the system 1, the phase of a conversion start signal CSYNC-S' generated by the present system is compared with that of CSYNC-S received from the system 0. When there is a phase difference, the start of conversion from ATM cells to STM data is delayed for the unit of a frame on the STM until the phases are coincident, and the processing of conversion from ATM cells to STM data is synchronized between both systems.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a duplex system in an STM (synchronous transfer mode) -ATM (asynchronous transfer mode) mutual conversion apparatus.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. 7-221767 discloses a cell processing device for a duplicated ATM switch.
There has been proposed a configuration of a cell processing device of a duplexed ATM switch in which cell synchronization is performed on the receiving side to maintain synchronization at the time of system switching and that cells are not received from the standby system.

[0003]

By the way, a duplex ST having an operation (working) system and a standby (standby) system is provided.
In the M-ATM interconversion device, the STM of the ATM cell
If the start of data conversion and the timing of conversion of STM data to ATM cells are not synchronized between the two systems, omission or duplication of data contained in the payload of the ATM cell, and ST
Omission or duplication of M data occurs.

[0004] The reason is that, when the operation system is switched in a state where both systems are not synchronized, the timing of the conversion of the ATM cell into STM data and the conversion of the STM data into the ATM cell are shifted between the two systems. When the phase of the standby system is advanced, the operating system is switched while the untransmitted data remains, and when the phase of the standby system is behind the operating system, the operating system is switched. This is because a phenomenon occurs in which data that has already been transmitted is transmitted redundantly later. The STM-ATM mutual conversion control is described in, for example, JP-A-5-22403 and JP-A-5-22.
Reference is made to the description in Japanese Patent Application Publication No. 404 or the like.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide an STM-ATM interconversion apparatus having an operation system and a standby system, and By synchronizing the start of data conversion and the start of conversion of STM data to ATM cells between the two systems, data loss or duplication included in the payload of the STM-ATM converted ATM cell at the time of operation system switching, and ATM. -Duplicated ST that can eliminate omission and duplication of STM converted STM data
An object of the present invention is to provide an M-ATM interconversion device.

[0006]

In order to achieve the above object, a duplex system in an STM-ATM interconversion apparatus according to the present invention comprises an operation system and a standby system for converting an ATM cell payload into STM data. In the duplexer, the conversion start signal for each channel when converting the ATM cell received in the operation system into the STM data, that is, the payload start position indication signal of the ATM cell is supplied to the standby system.
In the operating system, the phase of the conversion start signal received from the standby system and the phase of the conversion start signal of the own system are compared, and if the phases match, the data of the payload of the ATM cell is converted to STM data. In the meantime, when there is a phase difference, the start of conversion to ATM cells or STM data is postponed for each frame on the STM to synchronize the two systems.

Further, in the duplex system in the STM-ATM interconversion device of the present invention, the STM data is converted into a payload of an ATM cell, and is received by the active system in a duplex system having an active system and a standby system. A start signal for each channel when the STM data is converted into a payload of the ATM cell is supplied to the standby system. The standby system converts the STM data into an ATM signal in accordance with the conversion start signal for each channel supplied from the operation system. The conversion operation of the data into the cell payload is started, whereby the standby STM-ATM conversion operation is always synchronized with the operation system.

[Principle of the Invention] An ATM between two systems is eliminated so as to eliminate omission or duplication of data included in the payload of an STM-ATM converted ATM cell and omission or duplication of ATM-STM converted STM data. Cell STM
Means for synchronizing the start of data conversion and the start of ATM cell conversion of STM data between the two systems are required. According to the present invention, in a duplexed STM-ATM interconversion apparatus having an operation system and a standby system, synchronization of the start of the conversion of the ATM cell payload into the STM data and the start of the conversion of the STM data into the ATM cell is performed between the two systems. By taking
Loss or duplication of data contained in the payload of the ATM cell at the time of system switchover, and ST converted to STM-ATM.
Omission and duplication of M data can be prevented.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the STM- of the present invention.
1 is a diagram illustrating an example of a system and a network configuration to which an ATM interconversion device is applied. STM network, STM equipment, STM exchange on left side and ATM on right side
There are exchanges, ATM devices and ATM networks.
STM-ATM of the present invention between the M exchange and the ATM exchange
An interconversion device is provided.

FIG. 2 shows an STM according to an embodiment of the present invention.
FIG. 3 is a block diagram showing a basic configuration of the ATM interconversion device, and FIG. 3 is a timing chart for explaining its operation. Referring to FIG. 2, the operation system (system 0) 100 and the standby system (system 1) 200 have the same configuration, and include an ATM-STM conversion synchronization processing unit 101 (201) and an ATM-to-STM data conversion processing unit 102 ( 202), an STM-ATM conversion synchronization processing unit 103 (203), and an STM to ATM data conversion processing unit 104 (204), and the ATM to STM data conversion processing unit 102 (202) is an ATM.
The cell input ATMDATIN is converted to STM and output as STM output data STMDATOUT, and the STM to ATM data conversion processing unit 104 (204)
The cell input STMDATIN is converted to STM to generate and output an ATM cell output ATMDATOUT.

Referring to FIG. 2 and FIG.
Operating system (system 0) of the STM-ATM interconversion device
The ATM cell payloads P0 to P47 are
Conversion start signal CSYNC for conversion to data S (Pay
ATM-STM conversion synchronization processing
From the processing unit 101 to the standby system (system 1).

An ATM-to-STM data conversion processing unit 202 of the system 1 performs a conversion start signal CSYN generated by its own system.
C S ′ (output of the ATM-STM conversion synchronization processing unit 201) and the CSYNC received from the system 0 The phase of S is compared, and if there is a phase difference, the start of conversion from ATM cells to STM data is delayed for each frame on STM until the phases match, and the conversion of ATM cells between both systems to STM data is started. Synchronize the conversion process.

Referring to FIGS. 2 and 4, ST
Regarding the conversion from M data to the ATM cell payload, a start signal CSYNC for converting the STM data received by the system 0 into the ATM cell payload is used. A, ST
The M-ATM conversion synchronization processing unit 103 supplies the data to the system 1 (see FIG. 4). The data conversion processing unit 204 of the system 1 from the STM to the ATM converts the CSYNC supplied from the system 0. In accordance with A, the STM data is converted into the ATM cell payload. As a result, the conversion process from the STM data of the standby system (system 1) to the ATM cell is synchronized with the operation system (system 0).

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 5 is a diagram showing the overall configuration of one embodiment of the present invention. 5, the same elements as those in FIG. 2 are denoted by the same reference numerals. ATM cell input ATMDA
The TIN is input to the ATM cell multiplex input processing unit 105 (205), supplied from the ATM cell multiplex input processing unit 105 to the ATM-to-STM data conversion processing unit 102 (202), and converted from the STM to ATM data.
The output of (204) is the ATM cell multiplex output processing unit 106
ATM cell output supplied to (206) ATMDATOU
Output as T.

In this embodiment, 32.
768 MHz, frame pulse FP, clock CLK
And a virtual channel of 4096 channels is set on the STM line by using the one synchronized with 125 μs. In addition,
It is assumed that the virtual channel number n (0 ≦ n ≦ 4095) has a one-to-one correspondence with the VPI / VCI value of the ATM cell, and that the association data is stored in the apparatus in advance.

The conversion from ATM cells to STM data is as follows:
The payload of the ATM cell received by the operation system (system 0) is
ST uniquely determined from the VPI / VCI value of the received cell
This is performed by inserting one byte at a time into the M virtual channels.

The system 0 is provided with a conversion start signal CSYNC. S
(N) is transmitted to the standby system (system 1) (see FIGS. 5 and 6). However, the actual conversion operation is based on the AT received from the system 1.
Start signal CSYNC for M cell STM data conversion S '
It starts only when the phase is the same as (n). If the phases are different, the start of the ATM cell STM data conversion operation is postponed to the next frame on the STM. Then, when postponed, invalid data is inserted into the virtual channel n on the STM. Thus, ST from the payload of the ATM cell
The conversion to M data is synchronized for each channel in both systems.

The conversion from STM data to ATM cells is as follows:
The conversion is performed by converting the STM data received by the system 0 into a payload of an ATM cell having a VPI / VCI value corresponding to a virtual channel, and further, a conversion start signal CSYNC. A
(N) is transmitted to the system 1, and the system 1 receives the CS received from the system 0.
YNC ATM of received STM data according to A (n)
The conversion operation to the cell is started (see FIG. 6).

When the operation system is switched, CSY
NC Cancel the synchronous operation for A (n). The operation switches to the synchronous operation for A '(n). As a result, the conversion of STM data to ATM cells is in a synchronized state for each channel in both systems.

[0020]

As described above, according to the present invention,
According to the multiplexed STM-ATM interconversion device, the omission or duplication of the data included in the payload of the ATM cell at the time of switching the operation system, and the ATM-STM converted S
There is an effect that omission and duplication of TM data can be eliminated. For this reason, according to the present invention, complete duplication is possible, and the reliability of a system and a network using the present apparatus can be improved.

The reason is that, in the present invention, the operation system,
This is because the start of the conversion of the ATM cell payload into the STM data and the start of the conversion of the STM data into the ATM cell are synchronized between the two standby systems.

[Brief description of the drawings]

FIG. 1 is a diagram showing a system configuration to which a duplexed STM-ATM interconversion device according to the present invention is applied.

FIG. 2 is a diagram showing a basic configuration of an embodiment of a duplex STM-ATM mutual conversion apparatus according to the present invention.

FIG. 3 is a diagram showing a basic timing chart for explaining the operation of the embodiment of the duplexed STM-ATM interconversion device according to the present invention.

FIG. 4 is a diagram showing a basic time chart for explaining the operation of the embodiment of the duplexed STM-ATM mutual conversion apparatus according to the present invention.

FIG. 5 is a diagram showing a configuration of an embodiment of a duplexed STM-ATM mutual conversion device according to the present invention.

FIG. 6 is a diagram showing a time chart for explaining the operation of one embodiment of the duplexed STM-ATM interconversion device according to the present invention.

FIG. 7 is a diagram showing a time chart for explaining the operation of one embodiment of the duplexed STM-ATM mutual conversion apparatus according to the present invention.

[Explanation of symbols]

 Reference Signs List 100 operation system (system 0) 101 ATM-STM conversion synchronization processing unit 102 ATM-to-STM data conversion processing unit 103 STM-ATM conversion synchronization processing unit 104 STM-to-ATM data conversion processing unit 105 ATM cell multiplex input processing unit 106 ATM cell multiplex output processing section 200 Operation system (system 1) 201 ATM-STM conversion synchronization processing section 202 Data conversion processing section from ATM to STM 203 STM-ATM conversion synchronization processing section 204 Data conversion processing section from STM to ATM 205 ATM cell multiplex input processing unit 206 ATM cell multiplex output processing unit

Claims (3)

[Claims] 1. A duplexer having an operation system and a standby system for converting a payload of an ATM cell into STM data and converting the STM data into a payload of an ATM cell, comprising: The data conversion operation is synchronized by mutually notifying the start of the conversion of the ATM cell to the STM data and the start of the conversion of the STM data to the ATM cell, so as to prevent omission or duplication of data when the system is switched. A duplex system in an STM-ATM interconversion apparatus, characterized in that: 2. A conversion apparatus for converting a payload of an ATM cell into STM data, comprising a working system and a standby system, and starting conversion of each channel when converting an ATM cell received by the working system into STM data. A signal, that is, an ATM cell payload head position indication signal, is supplied to the standby system. Further, in the operating system, the phase of the conversion start signal received from the standby system and the phase of the conversion start signal of the own system are compared. If they match, the operation of converting the ATM cell payload data to STM data is started. On the other hand, if there is a phase difference, the start of conversion from ATM cells to STM data is started on the STM frame. A duplex system in an STM-ATM interconversion device, characterized in that it is postponed to a unit, thereby achieving synchronization in both systems. 3. A duplexer having an operation system and a standby system for converting STM data into an ATM cell payload, wherein each STM data received in the operation system is converted into an ATM cell payload in each channel. A start signal is supplied to the standby system, and the standby system converts the STM data into AT data in accordance with the conversion start signal for each channel supplied from the operation system.
A conversion operation of data into an M cell payload is started, whereby the standby STM-ATM conversion operation is synchronized with the operation system.
A duplex system in the ATM interconversion device.