JPH0653982A - System switching system for atm speech path - Google Patents

Abstract

PURPOSE:To switch systems without the loss and the duplication of cells in duplexed ATM speech paths. CONSTITUTION:A system constitution control part 10 controls duplex system constitution. System state tag addition parts 20 and 21 add tags for indicating the active/standby state of the current system based on signals from the system constitution control part 10 to the cells from an input line to be outputted to speech path parts 30 and 31. The system state tags added to the output cells from the ATM speech path parts 30 and 31 of the both systems are monitored at a system state tag monitoring part 40 and at the time of the active/standby, cell output at the active side and cell abandonment at the standby side are instructed to a cell output control part 50. When the both systems are active, the cell output of the old active system and the primary storage of the cells of the new active system are instructed to the cell output control part 50 and the systems are switched.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an ATM (Asynchr)
The present invention relates to a system switching method for a channel of an empty transfer mode, and particularly to a system switching method for an ATM channel that switches a system without loss or duplication of cells accumulated in the channel.

[0002]

2. Description of the Related Art Conventionally, in system switching of ATM speech paths,
Without giving the system status tag to the cell itself, when the system switching instruction was given, the output side of the duplexed ATM speech path was switched.

FIG. 3 is a diagram for explaining the system switching operation of the ATM speech path in the conventional example. Input line 1 to ATM speech path units 30 and 31 operating in system 0 act state
It is assumed that cells A, B, and C are input from 00 (Fig. 3
(A)). As shown in FIG. 3B, the cell A is output from the selector 60, the cells B and C are in the 0-system ATM speech path unit 30, and the cell C is in the 1-system ATM speech path unit 31 in the buffer. If the system is switched while the data is stored in the new ACT system, cell C is output from the new ACT system (1 system), and cell B is lost (Fig. 3).
(C)).

[0004]

In the ATM speech path section,
Generally, it has a buffer for temporary storage to perform various processing in cell units and to perform cell speed conversion.Both systems do not operate in perfect synchronization. There is a gap in Therefore, the conventional ATM described above
In the system for switching the communication path, since the output side is switched while the flow of cells is deviated, there is a problem that cells are lost or duplicated after switching.

[0005]

The ATM switching system switching system according to the present invention is an ATM communication system in which fixed length cells composed of a header section containing destination and control information and a payload section containing user information are used for communication. A system configuration control unit for controlling the system configuration of a duplexed ATM speech path unit in a duplexed speech path system device, and a system configuration signal from the system configuration control unit for an input cell from an input line. From the ATM call path section of both systems, a system status tag adding section that adds a tag indicating whether the own system is in an act state or a standby state and outputs it to the ATM call path section of the own system based on To the output cell of the system status tag adding section for monitoring the system status tag added by the system status tag adding section; Output to line, discard, And a cell output control unit that performs any of the following accumulations. When the ATM communication path unit is switched, the system configuration information of the old act system is added from the time when the system configuration signal from the system configuration control unit is switched. The unit adds a tag indicating the standby state to the input cell, and the system configuration information adding unit of the old standby system adds the tag indicating the act state to the input cell and passes the tag to the ATM call path unit. The system status tag monitoring unit instructs the cell output control unit to output the cell on the act side and discard the cell on the standby side when one of the cells received from both systems is the act and the other is the stand-by. Is in the act state, the cell output control unit is instructed to output the cells of the old act system and the primary accumulation of the cells of the new act system, and when the cell received from the old act system becomes standby, And performing the system switching by instructing the cell output of the system to the cell output control unit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an ATM speech path system switching system of the present invention will be described with reference to the drawings. FIG. 1 shows A of the present invention.
FIG. 2 is a block diagram showing an embodiment of the system switching system for the TM communication path, and FIG. 2 is a diagram for explaining the system switching operation in this embodiment.

In FIG. 1, the system configuration control unit 10 controls the system configuration of the duplicated ATM speech path units 30 and 31, and the 0 system / 1 system act / standby (hereinafter referred to as ACT / S).
BY) Output information. System status tag addition unit (0 system) 20
And the system status tag addition unit (1 system) 21 is the input line 100.
ACT from the system configuration control unit 10 for input cells from
/ Whether the system is in the ACT state based on the SBY information SBY
A tag indicating whether it is in a state is added and output to the ATM speech path units 30 and 31 of the own system. The ATM speech path unit (0 system) 30 and the ATM speech path unit (1 system) 31 have primary storage buffers for performing processing in cell units. The 0 system output 200 and the 1 system output 201 are Synchronization is not achieved because the processing timing, etc. is shifted. That is, 0 system output 3
The 00 and 1-system output 301 may output different cells when observed at a certain time. System status tag monitoring unit 4
0 monitors the system status tag added to the output cell from the 0 system output 300 and the system status tag added to the output cell from the 1 system output 301, and the cell output control unit 50
To cell selection, discard, and primary storage. When one of the cells received from both systems is ACT and the other is SBY, the cell output controller 50 is instructed to output the cell on the ACT side and discard the cell on the SBY side. When both systems are in the ACT state, the cell output control unit 50 is instructed to output the cells of the old ACT system and the primary accumulation of the cells of the new ACT system, and when the cells received from the old ACT system become SBY, the new ACT The cell output of the system is instructed to the cell output control unit 50. As a result, ACT / SB
It is possible to prevent a cell order inversion that may occur at the time of Y switching.

Next, the system switching operation according to this embodiment will be described with reference to FIG.

It is assumed that cells A, B and C are input in the 0 system ACT state as in FIG. 3A (FIG. 2A). If the system switching is performed at the time when the input cells A and B are output from the system state tag addition units 20 and 21 of both systems, FIG.
As shown in (b), tags of 0-system ACT and 1-system SBY are provided for cells A and B, and 1-system ACT and 0 system S are provided for cell C.
The BY tag is added and input to the ATM speech path units 30 and 31. After that, the cells processed by the ATM speech path units 30 and 31 are input to the cell output control unit 50. Figure 2 (c)
As shown in FIG. 3, in the 0 system, the cell A having the ACT tag is output from the cell output control unit 50, and the cells B and C are ATM.
It is stored in a buffer in the communication path unit 30. Further, in the 1-system, all cells are output from the ATM speech path unit 31, but since the cells A and B are SBY tags, they are discarded in the cell output control unit 50, and the cell C is in the ACT state of both systems. It is temporarily stored in the cell output control unit 50. When cells B and C are output from the 0-system ATM call path unit 30, the cell output control unit 50 outputs the cell B having the ACT tag.
For the cell, the cell C from the 0 system having the SBY tag is discarded, and the cell C from the 1 system that has been temporarily stored is output.

[0010]

As described above, the system switching system for the ATM speech path according to the present invention can prevent the loss or duplication of cells, which has occurred at the system switching in the conventional system. It is possible to carry out a system switching without any effect, and there is an effect that the quality of the communication path is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a system switching system for an ATM speech path according to the present invention.

FIG. 2 is a diagram for explaining a system switching operation in the present embodiment.

FIG. 3 is a diagram for explaining a system switching operation of an ATM speech path in a conventional example.

[Explanation of symbols]

 10 system configuration control unit 20 system status tag addition unit (0 system) 21 system status tag addition unit (1 system) 30 ATM speech path unit (0 system) 31 ATM speech path unit (1 system) 40 system status tag monitoring unit 50 Cell output control unit 60 Selector 100 Input line 300 0 system output 310 1 system output

Claims (1)

[Claims] 1. A duplex ATM call in an ATM duplex channel apparatus for performing communication by a fixed length cell consisting of a header section containing destination and control information and a payload section containing user information. The system configuration control unit that controls the system configuration of the road unit, and the own system is in the act state or the standby state for the input cell from the input line based on the system configuration signal from the system configuration control unit. A system status tag adding section for adding a tag indicating whether or not to output to the ATM call path section of the own system, and the system status tag adding section for output cells from the ATM call path section of both systems A system status tag monitoring unit that monitors the system status tag, and a cell output that outputs, discards, or temporarily stores a cell to the line from the ATM communication path unit of both systems according to an instruction from the system status tag monitoring unit. It consists of a control unit and At the time of switching the system of the ATM call path unit, from the time when the system configuration signal from the system configuration control unit is switched, the system configuration information adding unit of the old act system sends the tag indicating the standby state to the old cell to the old system. The system configuration information adding unit of the standby system attaches a tag indicating the act state to the input cell and passes it to the ATM speech path unit. In the system state tag monitoring unit, one of the cells received from both systems is received. Act, when the other is standby, the cell output control unit is instructed to output the cell on the act side and discard the cell on the standby side. When both systems are in the act state, the output of the cell of the old act system and the new act By instructing the cell output control unit to perform the primary storage of cells of the system, and by instructing the cell output control unit to output the cell of the new act system when the receiving cell from the old act system becomes the standby system ATM speech path system switching method which is characterized in that the Toggles.