JP3012584B2 - Detour control method and method for STM exchange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detour control system and method for an STM (synchronous transfer mode) switch, and more particularly to a detour control system for an STM switch that performs detour control of an ATM (asynchronous transfer mode) network and its method. About the method.

[0002]

2. Description of the Related Art A conventional example related to this kind of technology will be described with reference to the drawings.

FIG. 3 shows an AT connected to a conventional STM exchange.
It is a block diagram showing an example of M communications system.

In FIG. 3, STM exchanges 1 and 2 process requests from maintenance units 3 and 4 and a circuit mounted inside the exchange. The maintenance terminals 3 and 4 are STM exchanges 1 and
2 is set and controlled. The maintenance terminal 5 sets and controls data of all ATM communication devices of the ATM network.
The line circuits 6 and 7 receive a request from the connected STM terminal. The ATM communication circuits 8 and 9 add header information set by the maintenance terminals 3 and 4 to the data including the control information and convert the data into cells and decells to enable ATM communication. The ATM communication devices 10, 11, 12, and 13 monitor connection control and detours. ATM communication circuits 8, 9 are AT
M communication devices 10 and 11 are connected. The communication paths of the ATM network for connecting the STM exchanges 1 and 2 are the ATM communication devices 10 and 11, respectively, and use high-priority detours.

Next, the operation will be described. STM exchange 1
Receives a connection request from the STM terminal of the line circuit 6 to the STM terminal connected to the line circuit 7 of the STM exchange 2, and connects to the ATM communication circuit 8 which is a communication path. AT
The M communication circuit 8 converts the data including the header information and the control information into cells and transmits the cells to the ATM communication device 10. The ATM communication device 10 transmits the received cell header information to the ATM communication device 11 that is the destination. ATM communication device 1
1 is the destination AT based on the header information of the received cell.
It transmits to the M communication circuit 9. The ATM communication circuit 9 confirms the header information of the received cell, demultiplexes the data, and accepts the requested content according to the control information. STM exchange 2
Is a line circuit 7 in response to a request from the ATM communication circuit 9.
Connected to the STM terminal. The ATM communication device 10 monitors the connection state of the detour by transmitting monitoring cells to the ATM communication devices 12 and 13 which are detours and receiving monitoring cells from the ATM communication device 11. If a failure occurs in the communication path between the ATM communication devices 10 to 11, the communication is performed via the ATM communication device 12, which is a high-priority detour from among the detours that can be connected according to the monitoring result.

FIG. 4 is a block diagram showing an example of an ATM communication system with a bypass function.

[0007] In FIG. 4, this ATM communication system with a detour function is disclosed in Japanese Patent Application Laid-Open No. 7-202894, and is a LAN which transmits and receives information via an ATM communication network.
Terminals 101 and 102, an ATM communication device 103 that converts transmission information a into an ATM cell signal b and an STM cell signal c, and vice versa, and transmits transmission information e ′
An ATM communication device 107 that converts the signal into an M cell signal d 'and an STM cell signal c', and vice versa;
The cellized signal b is transferred to the ATM communication device 107, and the ATM cellized signal b "of the detour signal is taken into its own device, and the ATM cell signal d 'from the ATM communication device 107 is converted to A.
An ATM communication device 105 for transferring the ATM cell signal d ″ of the detour signal to the TM communication device 103 and taking the bypass signal into its own device. The ATM communication lines 104 and 106 serving as a normal information transmission path and an ATM communication line 104 ST to be the detour route
M communication line 108, and when an ATM communication network fails, A
The path is changed from the TM communication lines 104 and 106 to the STM communication line 108 which is a detour line to connect the communication.

[0008]

In this conventional example, when a failure occurs in a communication path, an AT which is a detour having a higher priority among the detours which can be connected based on the monitoring result is selected.
Although communication is performed via the M communication device,
If the ATM communication device connected to the STM exchange does not have a bypass function, there is a problem that the bypass may not be possible.

Further, in the example shown in FIG. 4, when an ATM communication device having a detour function is connected in a detour, a monitoring cell is transmitted to the ATM communication device in a detour, and an AT of a detour destination is transmitted.
Since the connection state of the detour must be monitored by receiving the monitoring cell from the M communication device, there is a problem that a load is applied to the ATM communication device connected to the STM exchange.

(Purpose) An object of the present invention is to realize detour irrespective of the presence or absence of a detour function of an ATM network,
It is an object of the present invention to provide a detour control system and method for an STM exchange that can reduce the load on the exchange and the ATM network.

[0011]

According to the present invention, there is provided a detour control method for an STM exchange, wherein the STM exchange is connected to a first ATM communication device in an ATM network formed by connecting a plurality of ATM communication devices to each other. In the STM
The exchange switches to a second ATM via the ATM network.
When forming a communication path connecting to a communication destination STM exchange connected to a communication apparatus, a shortest path in the ATM network from the first ATM communication apparatus to the second ATM communication apparatus and all of the shortest paths. The detour information is stored in advance, and the monitoring information of the communication path via the shortest path and all the detours is transmitted to the communication destination STM exchange every predetermined period by the first ATM. Transmitted through a communication device, and determines the failure of all communication paths from the result of the monitoring information returned by the return path, and switches to another communication path when a failure is detected in the communication path in use. First A
Control information transmitting means for transmitting switching control information to the TM communication device, wherein the control information transmitting means, when a failure is detected in the used communication path, a predetermined priority stored in advance. The switching control information is transmitted to the first ATM communication device to switch the communication path based on the detour information of the order.

[0012] A detour control method for an STM exchange according to the present invention is an STM exchange connected to a first ATM communication device in an ATM network configured by connecting a plurality of ATM communication devices to each other. An ATM communication circuit for connecting to the first ATM communication device, wherein the STM exchange forms a communication path for connecting to an STM exchange of a communication destination connected to the second ATM communication device via the ATM network. , The ATM communication circuit unit transmits the second A
Storage means for storing information on the shortest route in the ATM network to the TM communication device and all the prioritized detours; and the shortest route and the all via the first ATM communication device. The monitoring information of the communication path is periodically transmitted to the second ATM communication device through the detour, and the monitoring information returned by the return path is confirmed to check the shortest path and all the detours. Monitoring means for monitoring the status; and, if a fault is detected in the communication path in use as a result of the monitoring means, to switch from a connectable detour to a detour having a higher priority based on the priority. A detour switching control means for transmitting switching control information to the first ATM communication apparatus; and inputting information on the shortest path and all detours which have been prioritized in advance to the storage means. STM And a connected maintenance terminal to 換機.

A detour control method for an STM exchange according to the present invention is a STM exchange connected to a first ATM communication device in an ATM network configured by connecting a plurality of ATM communication devices to each other. An ATM communication circuit unit for connecting to the first ATM communication device, wherein the STM exchange forms a communication path for connecting to a communication destination STM exchange connected to the second ATM communication device via the ATM network. An ATM communication circuit unit for transmitting and receiving an entire control signal of the ATM communication circuit unit from the central processing unit of the STM exchange; and an I / O control unit between central processing units; The shortest route in the ATM network to the ATM communication device and circuit information of all the prioritized detours A storage unit that, the first ATM
A monitoring cell for monitoring a communication path is periodically transmitted to the second ATM communication apparatus via the shortest path and all the detours via a communication apparatus, and the monitoring is returned by the return path. A detour monitoring unit that checks a cell to monitor the state of the shortest path and all the detours and stores the result in the storage unit, and detects a failure of a communication path from the result information of the detour monitoring unit. Detour switching means for reading out the state of all the detours from the storage unit and switching the current communication path from the connectable detours to the detour having the higher priority, and transmitting and receiving from the line circuit of the STM exchange ST
M data is stored in the ST circuit for the line circuit.
An STM data input / output control unit for performing input / output control of M data, and storing the ATM data including the monitoring cells transmitted / received from / to the first ATM communication device and storing the ATM data with respect to the first ATM communication device. An ATM data input / output control unit for performing data input / output control, and a control information processing unit for analyzing a plurality of control information from the STM data input / output control unit and the header information control unit and storing an analysis result in the storage unit And a header information control unit for controlling each unit and each unit based on header information in the ATM data received according to an instruction from each unit and each unit in the ATM communication circuit unit.

[0014] The detour control method for an STM exchange according to the present invention is directed to a first STM exchange connected to a first ATM communication device in an ATM network configured by connecting a plurality of ATM communication devices to each other. A first STM switch for connecting to a first ATM communication device with a first AT
M communication circuit unit, wherein the first STM exchange
In forming a communication path connected to a second STM exchange of a communication destination connected to the second ATM communication device via the TM network, the first detour monitoring means of the ATM communication circuit includes a first storage unit. The ATM stored in advance in
The information and state of the communication path and the detour of the network are read, and the contents of the monitoring and connection control of the detour are requested to the first header information control unit, and the first header information control unit transmits the header information and The contents of the connection control are received from the first detour processing means, and a request is made to the first ATM data input / output control unit to output a monitoring cell to the ATM communication device of the detour, and as a result, the first ATM The data input / output control unit outputs the monitoring cell to the first ATM communication device, and the first ATM communication device transmits the received monitoring cell to the first ATM communication device.
Output to each route in the TM network, and
The TM communication device connects the received monitoring cell to the ATM.
Output to the communication device, and the second ATM communication device of the communication destination outputs the monitoring cell received from each route to the second ATM communication circuit of the second STM exchange of the communication destination, and The second ATM communication circuit of the second STM exchange decellulates in the second ATM data input / output control section and outputs header information and control information to the second header information control section,
The second header information control unit reads out the information of the communication path and the detour of the ATM network stored in the second storage unit in advance, and returns the monitoring cell to the detour so as to return the monitoring cell. , The second ATM data input / output control unit returns the monitoring cell to the second ATM communication device, and the second ATM data input / output control unit
The TM communication device outputs the received monitoring cell to each route of the ATM network in the same manner as the first ATM communication device, and returns the same to the first ATM communication device. The ATM communication device returns to the ATM communication device in the same manner as the second ATM communication device, and the first A
The TM communication device outputs the monitoring cell returned from each of the routes to the first ATM communication circuit of the first STM exchange, and the first ATM communication circuit outputs the first AT communication signal to the first ATM communication circuit.
The M data input / output control unit de-cellulates the monitoring cell, outputs header information and control information to the first header information control unit, and the first header information control unit performs a detour from the returned header information. If it is a road, it is determined that connection is possible even by a detour, and it is stored in the first storage unit. If the monitoring cell does not return, the first header information control unit does not return. It is determined that a communication path failure has occurred, and the first
And the state of the communication path and the detour route stored in the first storage unit are read out by the first detour switching unit, and are connectable and have a predetermined high-priority detour. The first header information control unit is requested to use the header information of the path as the communication path.

[0015]

Next, the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment A to which an embodiment of the present invention is applied.
FIG. 2 is a block diagram showing a TM communication system, and FIG. 2 is a block diagram showing an ATM communication circuit in the STM exchange in the present embodiment shown in FIG.

Referring to FIG. 1, an ATM communication system to which an embodiment of the present invention is applied includes exchanges 1 and 2 that perform STM (synchronous transfer mode) communication control, and sets and controls information of STM exchanges 1 and 2. Maintenance terminals 3 and 4 and A
All ATM communication devices 10, 1 of the TM network 100
A maintenance terminal 5 capable of setting / controlling 1, 12, 13;
Line circuits 6 and 7 provided in each of the M exchanges 1 and 2 and capable of accepting requests from connected STM terminals A and B, and STM data including control information and maintenance terminals 3 and 4 are set. ATM communication circuits 8 and 9 that add the header information and convert the cells into cells and decells to enable ATM communication, and ATM communication devices 10, 11, 12 and 13 that enable connection control and detour monitoring of ATM data. , And the STM communication circuit 8 is connected to the ATM communication device 10 and the STM communication circuit 9 is connected to the ATM communication device 9.

Referring to FIG. 2, the STM of the present embodiment
The ATM communication circuit 8 of the exchange 1 includes an inter-central processing unit input / output control unit 81, a storage unit 82, and a means 8 for monitoring a detour.
3; means 84 for switching to a detour in the event of a failure;
M data input / output control 85, control information processing unit 86, header information control unit 87, ATM data input / output control unit 88
And

The input / output control unit 81 between the central processing units is an STM.
The ATM communication circuit 8 is controlled according to an instruction from the central processing unit of the exchange 1. The storage unit 82 stores information for controlling the ATM communication circuit 8. The detour monitoring unit 83 reads the detour information from the storage unit 82 and stores the status of the detour in the storage unit 82. When detecting a failure in the communication path of the ATM network, the detour switching means 84 reads the state of the detour from the storage unit 82 and switches a detour having a higher priority from among the connectable detours. The STM data input / output control unit 85 accumulates STM data and controls input / output. The control information processing unit 86 analyzes the control information and stores it in the storage unit 82. The header information control section 87 controls the header information according to an instruction from each section. ATM data input / output control unit 8
Reference numeral 8 stores and controls ATM data.

ATM in STM exchange 2 of the present embodiment
The communication circuit 9 has the same configuration as the ATM communication circuit 8.

Next, the operation of the ATM communication system to which the present embodiment is applied will be described in detail with reference to FIGS.

Referring to FIG. 1, STM exchange 1 and STM
A procedure until each of the STM terminals A and B of the exchange 2 is connected will be described. The STM terminal A connected to the line circuit 6 of the STM exchange 1 requests the line circuit 6 to connect to the STM terminal B connected to the STM exchange 2. The line circuit 6 requests the connection request to the central processing unit (not shown) of the STM exchange 1. The central processing unit of the STM exchange 1 receives the connection request from the line circuit 6,
It requests the ATM communication circuit 8 to connect a communication path to the exchange 2. The ATM communication circuit 8 converts the data including the header information and the control information into cells and transmits the cells to the ATM communication device 10.
The ATM communication device 10 transmits the received cell header information to the ATM communication device 11 that is the destination. The ATM communication device 11 transmits the received cell header information to the ATM communication circuit 9 as the destination. ATM communication circuit 9
Decellulates the received cell, confirms the header information and the control information, and issues a connection request to the central processing unit (not shown) of the STM exchange 2. The central processing unit of the STM exchange 2 receives the connection request from the ATM communication circuit 9 and requests the STM terminal B of the line circuit 7 to connect. The STM terminal B connected to the line circuit 4 receives a connection request from the line circuit 7 and notifies the line circuit 7 of connection permission. The line circuit 7 receives the connection permission from the STM terminal B, and notifies the central processing unit of the STM exchange 2 of the connection permission. The central processing unit of the STM exchange 2 notifies the ATM communication circuit 9 of the connection permission, and connects the line circuit 7 and the ATM communication circuit 9. The ATM communication circuit 8 receives the connection permission notification from the ATM communication circuit 9 and notifies the central processing unit of the STM exchange 1 of the connection permission. The central processing unit of the STM exchange 1 notifies the line circuit 6 of the connection permission, and connects the line circuit 6 and the ATM communication circuit 8. The line circuit 6 notifies the connected STM terminal of connection permission and connects.

Referring to FIG. 2, ATM communication circuit 8 (9)
The detour setting will be described based on the operation of the embodiment. When data including header information and control information is transmitted from the ATM communication circuit 8, a connection request from the central processing unit of the STM exchange 1 is transmitted to the input / output control unit 81 between the central processing units.
And the control information is stored in the storage unit 82. Storage unit 8
The control information stored in 2 is read by the control information processing unit 86, and outputs a control information transmission request to the header information control unit 87. The header information control unit 87 reads the state of the communication path stored in the storage unit 82 and outputs the header information to be used to the ATM data input / output control unit 88. The ATM data input / output control unit 88 is the ATM communication device 1
The header information and the control information are sent to 0. STM exchange 2
On the side, when processing the header information and control information received from the ATM communication circuit 9, the received ATM data input / output control unit 88 decelerates and outputs the header information and control information to the header information control unit 87. Header information control unit 87
Reads the header information and status of the communication path and the detour stored in the storage unit 82, determines whether the header information is one for which connection is permitted, and outputs it to the connection information control unit 86. The connection information control unit 86 reads out the control information and stores the connection request contents in the storage unit 82. The connection request stored in the storage unit 82 is read from the inter-central processing unit input / output control unit 81. The inter-central processing unit input / output control unit 81 requests connection to the central processing unit of the STM exchange 2. Thereafter, when the connection is permitted from the STM terminal B of the line circuit 7, the input / output of data from the STM terminal B of the line circuit 7 is controlled by the STM data input / output control unit 85. Next, detour setting control will be described with reference to FIGS.

A description will be given of the setting control of the detour route starting from the STM exchange 1. The detour monitoring means 83 of the ATM communication circuit 8 of the STM exchange 1 reads out the information and status of the communication path and the detour of the ATM network 100 stored in the storage unit 82 in advance, and monitors the detour and the connection control. The contents are requested to the header information control unit 87.

The header information control section 87 receives the header information and the contents of the connection control from the detour monitoring section 83 and outputs the ATM cell input / output control section 88 so as to output the monitored cells of the ATM communication devices 12 and 13 which are the detours. Request to. As a result, the ATM data input / output control unit 88 sets the monitoring cell to AT
Output to the M communication device 10.

The ATM communication device 10 outputs the received monitoring cell to each route (ATM communication devices 11, 12, 13). The ATM communication devices 12 and 13 transmit the received monitoring cells to A
The monitoring cell is output to the TM communication device 11, and the ATM communication device 11 outputs the monitoring cell received from each route (ATM communication 10, 12, 13) to the ATM communication circuit 9 of the STM exchange 2.

The ATM communication circuit 9 of the STM exchange 2
The M data input / output control unit 88 decelerates and outputs header information and control information to the header information control unit 87. The header information control unit 87 has an AT stored in the storage unit 82 in advance.
The information of the communication path and the detour of the M network 100 is read, and the ATM data input / output control unit 88 is requested to return a monitoring cell to the detour. The ATM data input / output control unit 88 returns a monitoring cell to the ATM communication device 11.

The ATM communication device 11 is an ATM communication device 1
As in the case of 0, the received monitoring cell is output to each route (ATM communication devices 12 and 13) and returned to the ATM communication device 10. Similarly, the ATM communication devices 12 and 13 return to the ATM communication device 10 in the same manner as the ATM communication device 11.

The ATM communication device 10 outputs the monitoring cell returned from each route to the ATM communication circuit 8 of the STM exchange 1. The ATM communication circuit 8 includes an ATM data input / output control unit 8
At 8, the monitoring cell is decellulated and the header information and the control information are output to the header information control unit 87.

The header information control section 87 determines from the returned header information that the connection is possible even if the detour is a detour, and stores it in the storage section 82. If, for example, AT
If the monitoring cell from the M communication device 11 does not return,
The header information control unit 87 determines that a failure in the communication path has occurred and stores it in the storage unit 82. The detour switching unit 84 reads out the states of the communication path and the detour path stored in the storage unit 82 and allows connection. Requests the header information control unit 87 to use the header information of the detour with the higher priority determined in advance as a communication path.

The monitoring of the detour shown above is periodically performed by the AT.
This is performed by the M communication circuit 8.

As described above, the ST of this embodiment
Each of the storage units 82 of the ATM communication circuits 8 and 9 incorporated in each of the M exchanges 1 and 2 stores information on the communication path set by the maintenance terminals 3 and 4 and the detour with priority. The detour monitoring means 83 that monitors the state of the detour is
The monitoring cells are periodically transmitted from the TM communication circuits 8 and 9 to the respective routes, and the return of the monitoring cells due to the return route is confirmed. The detour switching means 89 for switching to a detour reads header information of a detour having a higher priority from among the detours that can be connected when a failure in the communication path is detected from the storage unit 82 and switches the detour.

[0033]

As described above, according to the present invention, a plurality of A
In an STM exchange connected to a first ATM communication device in an ATM network configured by interconnecting TM communication devices, the STM exchange communicates with a communication destination connected to a second ATM communication device via the ATM network. S
When forming a communication path connected to a TM exchange, an ATM from a first ATM communication device to a second ATM communication device is formed.
Information on the shortest path and all the detours in the network is stored in advance, and the monitoring information of the communication path via the shortest path and all the detours to the communication destination STM exchange at predetermined intervals. Is transmitted via the first ATM communication device, and failures in all communication paths are determined based on the result of the monitoring information returned in the return path. If a failure is detected in the communication path being used, another communication path is used. By providing the control information transmitting means for transmitting the switching control information to the first ATM communication device in order to switch to the above, the following effects are obtained.

The first effect is that the detour can be performed even if the ATM communication device does not have the detour function.

The reason is that the detouring process is performed by the STM exchange, so that the ATM communication device only needs to control the connection.

The second effect is that the load on the ATM communication device connected to the STM exchange can be reduced.

The reason is that the detour process is performed by the STM exchange, so that the ATM communication device only needs to control the connection.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an ATM communication system to which an embodiment of the present invention is applied.

FIG. 2 is a block diagram showing an ATM communication circuit of the STM exchange in the embodiment shown in FIG.

FIG. 3 is a block diagram showing an example of an ATM communication system connected to a conventional STM exchange.

FIG. 4 is a block diagram showing an example of an ATM communication system with a detour function.

[Explanation of symbols]

 1, 2 STM exchange 3, 4, 5 Maintenance terminal 6, 7 Line circuit 8, 9 ATM communication circuit 10, 11, 12, 13 ATM communication device 81 Input / output control unit between central processing units 82 Storage unit 83 Detour monitoring means 84 detour switching means 85 STM data input / output control unit 86 control information processing unit 87 header information control unit 88 ATM data input / output control unit 100 ATM network A, B STM terminal

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-125661 (JP, A) JP-A-8-242240 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/28 H04L 29/14 H04M 3/22 H04L 12/56

Claims (6)

(57) [Claims] 1. An STM exchange connected to a first ATM communication device in an ATM network in which a plurality of ATM communication devices are connected to each other, wherein the STM exchange is connected to a second ATM via the ATM network. When forming a communication path for connecting to a communication destination STM exchange connected to a communication device, the first ATM
The AT from the communication device to the second ATM communication device
The information on the shortest route and all the detours in the M network is stored in advance, and the ST of the communication destination is stored at predetermined intervals.
The monitoring information of the communication path is transmitted to the M exchange via the shortest path and all the detours via the first ATM communication device, and the entire monitoring information is returned from the result of the monitoring information returned on the return path. Control information transmitting means for judging a failure in a communication path and transmitting switching control information to the first ATM communication device to switch to another communication path when a failure is detected in a communication path being used. A detour control method for an STM exchange characterized by the following. 2. The control information transmitting means, when a failure is detected in the communication path in use, switches the communication path based on previously stored detour information of a predetermined priority. 2. The STM according to claim 1, wherein the switching control information is transmitted to the first ATM communication device for the purpose.
Switch detour control method. 3. An STM exchange connected to a first ATM communication device in an ATM network in which a plurality of ATM communication devices are connected to each other, wherein the STM exchange is connected to the first ATM communication device. An ATM communication circuit unit, wherein the STM exchange
In forming a communication path connecting to a communication destination STM exchange connected to a second ATM communication device via a TM network, the ATM communication circuit unit is configured to switch from the first ATM communication device to the second ATM communication device. Storage means for storing information on the shortest path in the ATM network leading to the ATM network and all the detours assigned in advance, and the shortest path and all the detours via the first ATM communication device Monitoring information of the communication path is periodically transmitted to the second ATM communication device via the communication line, and the monitoring information returned by the return path is checked to monitor the state of the shortest path and all the detours Monitoring means for switching, and when a fault is detected in the communication path in use as a result of the monitoring means, switching from a connectable detour to a detour having a higher priority based on the priority. Detour switching control means for transmitting switching control information to the first ATM communication apparatus. 4. The method according to claim 1, further comprising the step of inputting information on the shortest route and all the detours which have been prioritized in advance into the storage means.
4. The detour control method for an STM exchange according to claim 3, further comprising a maintenance terminal connected to the TM exchange. 5. An STM exchange connected to a first ATM communication device in an ATM network configured by connecting a plurality of ATM communication devices to each other, wherein the STM exchange is connected to the first ATM communication device. An ATM communication circuit unit, wherein the STM exchange
In forming a communication path connecting to a communication destination STM exchange connected to a second ATM communication device via a TM network, the ATM communication circuit unit is configured to transmit the ATM communication circuit unit from a central processing unit of the STM exchange. An inter-central processing unit input / output controller for transmitting and receiving the entire control signal;
A from the M communication device to the second ATM communication device
A storage unit for storing circuit information of the shortest path in the TM network and all the detours which have been prioritized in advance, and a memory for storing the shortest path and all the detours via the first ATM communication device. A monitoring cell for monitoring the communication path is periodically transmitted to the second ATM communication apparatus, and the monitoring cell returned by the return path is checked to check the state of the shortest path and all the detours. Detour monitoring means for monitoring the result and storing the result in the storage part, and from the result information of the detour monitoring means, upon detecting a failure in the communication path, reading out the states of all the detours from the storage part and connecting them. A detour switching means for switching the current communication path from the detour to the higher priority detour, storing STM data transmitted and received from a line circuit of the STM exchange, and storing the STM data for the line circuit. STM data and output control unit, the first to accumulate ATM data from the first ATM communication apparatus including the monitor cell to transmit and receive to perform output control of the
An ATM data input / output control unit that controls input / output of the ATM data to / from the ATM communication device, and a plurality of control information from the STM data input / output control unit and the header information control unit are analyzed, and an analysis result is obtained. A control information processing unit stored in the storage unit, and the header information control for controlling the units and units based on header information in the ATM data received in accordance with instructions from the units and units in the ATM communication circuit unit And a detour control method for an STM exchange. 6. A first STM exchange connected to a first ATM communication device in an ATM network configured by connecting a plurality of ATM communication devices to each other, wherein the first STM exchange is the first STM exchange. A first ATM communication circuit unit connected to an ATM communication device;
A TM exchange switches to the second A via the ATM network.
In forming a communication path connected to a second STM exchange of a communication destination connected to the TM communication device, a first detour monitoring unit of the ATM communication circuit includes the ATM stored in a first storage unit in advance. The information and state of the communication path and the detour of the network are read, and the contents of the monitoring and connection control of the detour are requested to the first header information control unit, and the first header information control unit transmits the header information and The contents of the connection control are received from the first detour processing means, and a request is made to the first ATM data input / output control unit to output a monitoring cell to the ATM communication device of the detour, and as a result, the first ATM The data input / output control unit outputs the monitoring cell to the first ATM communication device, and the first ATM communication device outputs the received monitoring cell to each route in the ATM network. Road A The TM communication device outputs the received monitoring cell to the connected ATM communication device, and the second ATM communication device of the communication destination transmits the monitoring cell received from each route to the second STM of the communication destination.
Output to the second ATM communication circuit of the exchange,
The second ATM communication circuit of the TM exchange decelerates in the second ATM data input / output control section and outputs header information and control information to the second header information control section. A stored in the second storage unit in advance
Read the information of the communication path and detour of the TM network,
To return the monitoring cell to this detour,
Of the second AT.
The M data input / output control unit returns the monitoring cell to the second ATM communication device, and the second ATM communication device transmits the monitoring cell received in the same manner as the first ATM communication device to the ATM network. Output to each route of the first
To the ATM communication device, and similarly, the ATM of each said route
The communication device replies to the connected ATM communication device in the same manner as the second ATM communication device, and the first ATM communication device transmits the monitoring cell returned from each of the routes to the first ST.
Output to the first ATM communication circuit of the M exchange, and the first ATM communication circuit de-cellulates the monitoring cell in the first ATM data input / output control unit and outputs header information and control information to the first ATM communication circuit. 1 header information control unit, and the first header information control unit determines from the returned header information that the connection can be established even in a detour if it is a detour, and stores the data in the first storage unit. If the monitoring cell does not return, the first header information control unit determines that a failure has occurred in the communication channel that does not return, stores the failure in the first storage unit, and stores the failure in the first storage unit. The communication path and the state of the detour stored in the first storage unit are read by one detour switching unit,
A detour control method for an STM exchange, characterized by requesting the first header information control unit to use header information of a detour that is connectable and has a predetermined high priority as a communication path.