JPH0653987A - Atm switchboard and system used for the atm switchboard - Google Patents

Abstract

PURPOSE:To reduce the loads of connecting a switch and deciding the passage of a channel by holding the passage and the capacity, etc., of a virtual channel inside a network at the time of completing a call and responding to the call for a second time by using them. CONSTITUTION:At the time of completing a call, at an ATM switchboard 100, call setting passage data 113 such as the passage and the capacity, etc., of the virtual channel are held through a processor 108 inside the network and also corresponding call connection data for the connection of a switch 107 are held. Then, When communication is performed again using the same virtual channel through a control signal reception part 111, the call is originated using the data 113 and 114 through the processor 108 and the decision of the channel and the connection of the switch are performed under the reduced loads. Also, it is the same even when the data 113 or the like are concentrated to the plural switchboards to be held without making the respective switchboards hold them.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an ATM (Asynchronous
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mode switch and a system using the same, and particularly to an ATM switch and a system using the same that can reduce the load at the time of call setup.

[0002]

2. Description of the Related Art In a conventional exchange, every time a call occurs,
A channel was set up in the network by properly connecting the switches of the subscriber exchanges and transit exchanges, and each time the call was terminated, the switch of each exchange was disconnected to release the channel. . Regarding this, Nikkei Communication separate volume “Guide to using ISDN” (Nikkei BP
Company, issued December 1, 1988) The description in pp.168-177 is helpful.

[0003]

In the above-mentioned prior art, it is necessary to determine a channel route, secure a capacity, connect a switch, etc. in each exchange every time a call occurs.
There is a problem that the load of the exchange is large at the time of call setup. Further, generally speaking, the number of parties to be called is quite limited, but in the above-mentioned conventional technique, it is necessary to perform a completely similar procedure every time a call occurs. The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above-described problems in the related art, to hold a channel once connected, and to set a call when setting a call. An object of the present invention is to provide an ATM exchange capable of reducing the load and a system using the same.

[0004]

The above object of the present invention is to
In an ATM switch for setting and releasing an arbitrary virtual channel between an incoming transmission line and an outgoing transmission line in a TM communication network, a means for holding the intra-network route / capacity of the virtual channel in the network even after the end of communication. In the case where communication is performed again using the same virtual channel, a means for causing the intra-network route / capacity of the virtual channel held by the holding means to be used for the communication is provided. ATM switch and the AT
In a system having a centralized center connected to an M switching system, a system using an ATM switching system is provided with means for holding an intra-network route / capacity of a virtual channel after the end of the communication in the centralized center. Achieved by

[0005]

In the connection of the switch in the ATM switch, the virtual channel identification number and the outgoing line number of each cell, which is an information transfer unit, are associated with each other, and according to this correspondence, each cell is sent to an appropriate outgoing line. It was done. In such a switch, it is possible to change the capacity of the virtual channel independently of the connection state of the switch. In the ATM switch and the system using the same according to the present invention, by utilizing the above-mentioned property, the path and capacity of the virtual channel are held in the network at the end of the call, and the call between the same terminals occurs again. In this case, the load of the channel routing and the switch connection in this case is reduced by using the above-mentioned already held virtual channel. Here, the means for holding the above-mentioned route and capacity of the virtual channel may be provided in each ATM exchange or may be provided in a centralized center connected to a plurality of ATM exchanges.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, a first embodiment of the present invention will be described.
This embodiment has a function of requesting call connection data to the ATM transit exchange, and when a call setup request occurs, each transit exchange can refer to the connection data of its own exchange to establish a call connection. It is configured to judge whether or not. FIG. 1 is a block diagram of an ATM relay exchange 100 according to a first embodiment of the present invention. In the figure, 101,
102 is a transmission line on the calling terminal side and the transmission line is on the called terminal side, and 103 and 104 are virtual channels.
5, 106 is a transmission line terminating unit, 107 is a switch capable of connecting an arbitrary virtual channel in the calling terminal side transmission line 101 and an arbitrary virtual channel in the called terminal side transmission line 102, 108 Is a processor for performing call processing, 109 is a control signal input line for inputting a control signal from an adjacent exchange, 110 is a control signal output line for outputting a control signal to the adjacent exchange, 111 is a control signal receiving unit for receiving the control signal, 112 Is a control signal transmitter that transmits a control signal,
Reference numeral 113 is call setting route data for associating the number of the called terminal to which the call is connected with the route for setting the call, 114
Indicates call connection data storing the connection state of the switch 107.

FIG. 2 shows the information contents included in the call setting route data 113, in which the called terminal number is
It is associated with the number of the transmission path connected to the adjacent exchange on the call setup path and on the called terminal side. Further, FIG. 3 shows the information content included in the call connection data 114.
Depending on the connection relationship of the switch 107 between the virtual channel belonging to the calling terminal side transmission line 101 and the virtual channel belonging to the called terminal side transmission line 102, the free capacity included in the called terminal side transmission line, and the connection of each of the switches 107 It contains the capacity of the configured virtual channel, usage status ('used', 'unused') and last used time as data. FIG. 4 shows the information contents included in the control signals transmitted through the control signal lines 109 and 110, and (a) to (c) are the information contents included in the call setting request signals 1 to 3, respectively. is there. FIG. 5 shows control signal lines 109 and 1
10 shows the information content contained in the control signal transmitted through 10, and (a) and (b) are the information content contained in the release request signals 1 and 2, respectively. As will be described later, the release request signal 1 indicates a request for keeping the path but the capacity is 0, and the release request signal 2 indicates a request for releasing both the path and the capacity. FIG. 6 shows the information contents included in the control signal transmitted through the control signal lines 109 and 110. (a), (b), and (c) are call setup rejection signal and call setup confirmation signal, respectively. , Shows the information content included in the call termination signal.

The operation of the ATM transit exchange 100 will be described below. 1. When both the route and capacity of the virtual channel are already secured: When the call setting request signal 1 is received from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. 1.1 Operation in which the usage state is “used”: The transmission line number (L1) and the virtual channel number (VCI1) included in the call setting request signal 1 shown in FIG. 4A are read. The read L1 and VCI1 are searched from the calling terminal side transmission path number and virtual channel number of the call connection data shown in FIG. 3, and the called terminal side transmission path number ( L2), the free capacity (E2) of the called terminal side transmission line L2, and the called terminal side virtual channel number (VCI2) are read. The virtual channel used / unused identifier (see FIG. 3) of the virtual channel whose virtual channel number is VCI2 is defined as'used '.

1.2 Operation for creating a new control signal and transmitting it to the adjacent exchange: A new call setup request signal 1 having L2 as a transmission line number and VCI2 as a virtual channel number is created, and the called terminal side The signal is transmitted via the control signal transmission unit 112 to the exchange to which the transmission line L2 is connected. 2. When only the route of the virtual channel is secured and the capacity is 0: When the call setting request signal 2 is received from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. The transmission line number (L3), the virtual channel number (VCI3) and the call capacity (C3) included in the call setup request signal 2 shown in FIG. 4B are read. The read L3 and VCI3 are searched from the calling terminal side transmission line number and virtual channel number of the call connection data shown in FIG. 3, and the called terminal side transmission line number (L4) corresponding to these numbers is searched. ), The available capacity (E4) of the called terminal side transmission line L4 and the called terminal side virtual channel number
Read (VCI4).

2.1 When the capacity of the transmission line has a margin:
If C3 ≦ E4, the following operation is performed. 2.1.1 Capacity securing operation: In the call connection data 114 shown in FIG. 3, the free capacity E4 of the transmission line number L4 is changed to E4.
-Rewrite to C3. Also, the virtual channel capacity of the virtual channel number of which the virtual channel number is VCI4 is rewritten to C3. 2.1.2 Operation for changing usage state to “use”: In the call connection data 114, the virtual channel used / unused identifier of the virtual channel having the virtual channel number of the called terminal on the side of VCI4 is rewritten to “use”. 2.1.3 Operation of creating and transmitting a new control signal: L4 as the transmission line number and V as the virtual channel number
A new call setup request signal 2 having CI4 is created and transmitted to the exchange to which the destination terminal side transmission line L4 is connected through the control signal transmission unit 112.

2.2 When there is no margin in the capacity of the transmission line:
If C3> E4, the following operation is performed. (a) When the usage state is “unused” and the virtual channel having the virtual channel capacity of C3 or more exists in the called terminal side transmission line L4, the following operation is performed. 2.2.1 Set the capacity (≧ C3) of other virtual channels to 0
Operation: In the call connection data 114, the virtual channel use / unused identifier is “unused” and the virtual channel capacity is C3 or more, for example, the use end time of the virtual channel is the highest. The old virtual channel is selected, and the virtual channel number (VCI5) and virtual channel capacity (C5) of the called terminal are read. The virtual channel number on the called terminal side selected above is V
The capacity C5 of the virtual channel of CI5 is rewritten to 0, and the virtual channel used / unused identifier is rewritten to "unused". Further, the free capacity of the transmission line L4 is rewritten to E4 + C5.

From the above-mentioned called terminal side transmission path number and called terminal side virtual channel number of the call connection data 114, the called terminal side transmission path number L4 and called terminal side virtual channel number VCI5 are searched, The calling terminal side transmission line number (L6) and the calling terminal side virtual channel number (VCI6) corresponding to L4 and VCI5 are read. A release request signal 1 (see FIG. 5 (a)) having L4 as the transmission line number and VCI5 as the virtual channel number is created, and a control signal transmission unit is sent to the exchange to which the called terminal side transmission line number L4 is connected. Send through 112. Also, the release request signal 1 having L6 as the transmission line number and VCI6 as the virtual channel number is transmitted through the control signal transmission unit 112 to the exchange to which the calling terminal side transmission line L6 is connected. 2.2.2 Operation for securing capacity of own channel: In the call connection data 114, the free capacity E4 + C5 of the transmission line L4 is set to E
Rewrite as 4 + C5-C3. Also, the virtual channel capacity of the virtual channel having the virtual channel number VCI4 is rewritten to C3.

2.2.3 Operation for changing usage status to "used": In the call connection data 114, the virtual channel used / unused identifier of the virtual channel having the virtual channel number VCI4 is rewritten to "used". 2.2.4 Control signal transmission operation to adjacent exchange: L4 as transmission line number, VCI4 as virtual channel number
A new release request signal 2 having the following is created and transmitted to the exchange to which the called terminal side transmission line L4 is connected via the control signal transmission unit 112. (b) When the usage state is “unused” and the virtual channel having the virtual channel capacity of C3 or more does not exist in the called terminal side transmission line L4, the following operation is performed. 2.3.1 Operation to reject call setup: L as transmission line number
3, a call setup rejection signal having VCI3 as a virtual channel number is created and transmitted to the exchange to which the calling terminal side transmission line L3 is connected through the control signal transmission unit 112.

3. Operation when neither path nor capacity of virtual channel is secured: When the call setting request signal 3 is received from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. The transmission line number (L7), virtual channel number (VCI7), call capacity (C7) and called terminal number (N7) included in the call setting request signal 3 are read. The read called terminal number N7 is used as the call setting route data 1
It searches from 13 called terminal numbers and reads the corresponding called terminal side transmission line number (L8). The read called terminal side transmission line number L8 is searched from the called terminal side transmission line number of the call connection data 114, and the transmission line free capacity (E8) of the called terminal transmission line number L8 is read. If there is a virtual channel that is not connected to the calling terminal side virtual channel by the switch 107 among the virtual channel numbers belonging to the called terminal side transmission line number L8, the following operation is performed.

3.1 In the case of C7 ≦ E8: 3.1.1 Operation for connecting the own channel: Among the virtual channel numbers of the called terminal on the called terminal side transmission line L8, the calling terminal side is switched by the switch 107. Called terminal side virtual channel not connected to virtual channel
(VCI8) is selected and connected to the virtual channel VCI7 belonging to the called terminal side transmission line L7. 3.1.2 Operation to secure capacity of own channel: In call connection data 114, free capacity E8 of transmission line number L8 is rewritten to E8-C7. Further, the virtual channel capacity of the virtual channel VCI8 on the called terminal side is rewritten to C7. 3.1.3 Operation for changing usage status to “use”: In the call connection data 114, the virtual channel VC on the called terminal side
The virtual channel used / unused identifier of I8 is rewritten to'used '.

3.1.4 Control signal transmission operation to adjacent exchange: As a new release request signal 3, L as transmission line number
8, VCI8 as a virtual channel number, C7 as a call capacity, and N7 as a called terminal number are created and transmitted to the exchange to which the called terminal side transmission line L8 is connected through the control signal transmitting unit 112. To do. 3.2 In the case of C7> E8: (a) If the usage state is “unused” in the called terminal side transmission line L8 and there is a virtual channel with a virtual channel capacity of C7 or more, Perform the following operations. 3.2.1 Capacity of other oldest virtual channels (≧ C
Operation of setting 7) to 0: In the call connection data 114, the called terminal side transmission line L8
Out of the virtual channels belonging to the callee terminal side virtual channel whose virtual channel used / unused identifier is'unused 'and whose virtual channel capacity is C7 or more, for example, the use end time of the virtual channel is the most The old virtual channel is selected, and the virtual channel number (VCI9) and virtual channel capacity (C9) on the called terminal side are read.

The virtual channel capacity C9 of the virtual channel VCI9 is rewritten to 0. In addition, the transmission line L
The free space of 8 is rewritten to E8 + C9. From the transmission line number and the virtual channel number on the called terminal side of the call connection data 114, the transmission line number L on the called terminal side
8. Called terminal side virtual channel number VCI9 is searched, and calling terminal side transmission line number (L10) and calling terminal side virtual channel number corresponding to L8 and VCI9
Read (VCI10). L8 as transmission line number, virtual channel number VC
The release request signal 1 having I9 is created and transmitted to the exchange to which the called terminal side transmission line L8 is connected through the control signal transmission unit 112. Also, as the transmission line number,
The release request signal 1 having 0 and VCI10 as the virtual channel number is transmitted via the control signal transmitting unit 112 to the exchange to which the calling terminal side transmission line L10 is connected.

3.2.2 Operation of connecting own channel: Of the virtual channel numbers belonging to the called terminal side transmission line L8, the virtual channel not connected to the calling terminal side virtual channel by the switch 107 (VCI8)
Is selected, and this is connected to the virtual channel VCI7 belonging to the transmission line L7 on the calling terminal side. 3.2.3 Operation for securing capacity of own channel: In the call connection data 114, the free capacity E8 + C9 of the called terminal side transmission path number L8 is rewritten to E8 + C9-C7. Further, the virtual channel capacity of the virtual channel VCI8 on the called terminal side is rewritten to C7. 3.2.4 Operation to change usage status to “use”: In the call connection data 114, the virtual channel VC on the called terminal side
The virtual channel used / unused identifier of I8 is rewritten to'used '.

3.2.5 Control signal transmission operation to the adjacent exchange: As a new call setting request signal 3, L8 is used as the transmission line number, VCI8 is used as the virtual channel number, C7 is used as the call capacity, and the called terminal number is used. Is generated, and is transmitted through the control signal transmitting unit 112 to the exchange to which the called terminal side transmission line L8 is connected. (b) If the used state is “unused” in the called terminal side transmission line L8 and there is no virtual channel with a virtual channel capacity of C7 or more, the following operation is performed. 3.2.6 Operation to reject call setup: L as transmission line number
7, a call setup refusal signal having VCI7 as a virtual channel number is created, and is transmitted to the exchange to which the calling terminal side transmission line L7 is connected through the control signal transmission unit 112. If there is no virtual channel connected to the calling terminal side virtual channel by the switch 107 among the virtual channel numbers belonging to the called terminal side transmission line number L8, the following operation is performed.

3.3 When there is a channel that can be released: (a) When C7 ≦ E8: 33.1 Operation for releasing the route of the oldest other channel: In the call connection data 114, the called terminal side Transmission line L8
Of the virtual channels belonging to the virtual channel used / unused identifier is “unused”, the virtual channel having the oldest use end time of the virtual channel on the called terminal side is selected, and the virtual channel number VCI1 is selected.
1, Read the capacity C11 of the virtual channel. The virtual channel capacity C11 of the virtual channel VCI11 on the called terminal side is rewritten to 0. Also, the free capacity of the transmission line L8 is rewritten to E8 + C11. The called terminal side transmission line number L is selected from the called terminal side transmission line number and the virtual channel number of the call connection data 114.
8. The callee terminal side virtual channel number VCI11 is searched, and the caller terminal side transmission line number (L12) and the caller terminal side virtual channel number (VCI12) corresponding to L8 and VCI11 are read.

In the call connection data 114, the called terminal side virtual channel V belonging to the called terminal side transmission line L8.
The data corresponding to CI11 is deleted. The release request signal 2 having L8 as the transmission line number and VCI11 as the virtual channel number is created and transmitted to the exchange, which is the connection destination of the called terminal side transmission line L8, through the control signal transmitting unit 112. In addition, the release request signal 2 having L12 as the transmission line number and VCI12 as the virtual channel number is transmitted through the control signal transmission unit 112 to the exchange to which the calling terminal side transmission line L12 is connected. 3.3.2 Operation for connecting own channel: Switch 107
Accordingly, among the virtual channel numbers belonging to the transmission line L8, the virtual channel VC on the called terminal side selected above is selected.
I11 and the virtual channel VCI7 belonging to the transmission line L7 on the calling terminal side are connected.

3.3.3 Operation for securing capacity of own channel: In the call connection data 114, the free capacity E8 + C11 of the called terminal side transmission line number L8 is rewritten to E8 + C11-C7. Also, the virtual channel capacity of the virtual channel having the called terminal side virtual channel number VCI11 is rewritten to C7. 3.3.4 Operation for changing usage status to "use": In the call connection data 114, the virtual channel used / unused identifier of the virtual channel of the called terminal side virtual channel number VCI11 is rewritten to "use". 3.3.5 Control signal transmission operation to adjacent exchange: In addition, as a new call setup request signal 3, L8 is set as a transmission line number,
A virtual channel number of VCI11, a call capacity of C7, and a called terminal number of N7 are created and transmitted to the exchange to which the called terminal side transmission line L8 is connected through the control signal transmitting unit 112. To do.

(B) In the case of C7> E8: The virtual channel used / unused identifier is "unused", and the virtual channel having the virtual channel capacity of C7 or more exists in the called terminal side transmission line L8. If so, do the following: 3.4.1 Operation to release capacity / route of other virtual channel: In the call connection data, the virtual channel used / unused identifier is “unused” among the virtual channels belonging to the called terminal side transmission line L8. , And the virtual channel with the earliest use end time of the virtual channel is selected from the virtual channels having the virtual channel capacity of C7 or more, and the virtual channel number VC
I13, the capacity C13 of the virtual channel is read. The virtual channel capacity of the called terminal side virtual channel VCI 13 is rewritten to 0. Also, the free capacity of the transmission line L8 is rewritten to E8 + C13.

From the called terminal side transmission line number and virtual channel number of the call connection data 114, the called terminal side transmission line number L8 and the called terminal side virtual channel number VC
I13 is searched and the calling terminal side transmission line number L14 and the calling terminal side virtual channel number VCI14 corresponding to L8 and VCI13 are read. In the call connection data 114, the called terminal side transmission line L8
Delete the data corresponding to the virtual channel VCI13 on the called terminal side belonging to. A release request signal 2 having L8 as the transmission line number and VCI13 as the virtual channel number is created and transmitted through the control signal transmission unit 112 to the exchange to which the called terminal side transmission line L8 is connected. Further, the release request signal 2 having L14 as the transmission line number and VCI14 as the virtual channel number is transmitted to the exchange, which is the connection destination of the calling terminal side transmission line L14, through the control signal transmission unit 112.

3.4.2 Operation for connecting own channel: By the switch 107, the calling terminal side virtual channel VCI7 belonging to the calling terminal side transmission line L7 and the virtual channel VCI13 belonging to the called terminal side transmission line L8 Connect. 3.4.3 Operation for securing capacity of own channel: In the call connection data 114, the free capacity E8 + C13 of the called terminal side transmission line number L8 is rewritten to E8 + C13-C7.
Also, the virtual channel number on the called terminal side is VCI13.
The virtual channel capacity of the virtual channel of C7
Rewrite 3.4.4 Operation for setting usage state to “use”: In the call connection data 114, the virtual channel used / unused identifier of the virtual channel of the called terminal side virtual channel number VCI13 is rewritten to “use”.

3.4.5 Control signal transmission operation to the adjacent exchange: As a new call setting request signal 3, L8 is used as the transmission line number, VCI13 is used as the virtual channel number,
C7 as the call capacity, N7 as the called terminal number
Is created and transmitted to the exchange to which the called terminal side transmission line L8 is connected through the control signal transmitting unit 112. 3.5 When there is no releasable channel: If the usage status is “unused” and the virtual channel with the virtual channel capacity of C7 or more does not exist in the called terminal side transmission line L8, The operation of. 3.5.1 Operation to reject call setup: L as transmission line number
7, a call setup refusal signal having VCI7 as a virtual channel number is created, and is transmitted to the exchange to which the calling terminal side transmission line L7 is connected through the control signal transmission unit 112.

4. Operation When Releasing Request Signal 1 is Received: When the call processor 108 receives the release request signal 1 from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. 4.1 When the release request signal 1 is received from the transmission line on the calling terminal side: The transmission line number (L15) and the virtual channel number (VCI15) included in the release request signal 1 are read. The virtual channel VCI15 belonging to the read calling terminal side transmission line L15 is searched from the call connection data 114, and the corresponding called terminal side transmission line number (L16), virtual channel number (VCI16), and virtual channel capacity ( Read C16). The available capacity E16 of the called terminal side transmission line L16 is set to E16 +
Rewrite as C16. The virtual channel capacity C16 of the virtual channel VCI16 on the called terminal side is rewritten to 0. A release request signal 1 having L16 as the transmission line number and VCI16 as the virtual channel number is created and transmitted to the exchange to which the transmission line L16 is connected through the control signal transmission unit 112.

4.2 When the release request signal 1 is received from the called terminal side transmission line: The transmission line number (L17) and the virtual channel number (VCI17) included in the release request signal 1 are read. The read free capacity of the called terminal-side transmission line L17 (E1
7) is read from the call connection data 114. Also, the virtual channel VCI 17 belonging to the read call-terminal-side transmission path number L17 is searched from the call connection data 114, and the virtual channel capacity (C17), the corresponding call-terminal-side transmission path number (L18), and the caller The virtual channel number (VCI18) on the call terminal side is read. Free space E17 of the called terminal side transmission line L17 is set to E17 +
Rewrite as C17. The virtual channel capacity C17 of the virtual channel VCI17 on the called terminal side is rewritten to 0. The release request signal 1 having L18 as the transmission line number and VCI18 as the virtual channel number is created and transmitted to the exchange to which the transmission line L18 is connected through the control signal transmitting unit 112.

5. Operation when the release request signal 2 is received: When the release request signal 2 is received from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. 5.1 When the release request signal 2 is received from the transmission line on the calling terminal side: The transmission line number (L23) and the virtual channel number (VCI23) included in the release request signal 2 are read. The virtual channel VCI 23 belonging to the read calling terminal side transmission line L23 is searched from the call connection data 114, and the corresponding called terminal side transmission line number (L24), virtual channel number (VCI24), virtual channel capacity ( Read C24). The empty capacity E24 of the called terminal side transmission line L24 is set to E24 +
Rewrite as C24. In the call connection data 114, the virtual channel V
The data corresponding to CI 24 is deleted. The release request signal 2 having L24 as the transmission line number and VCI24 as the virtual channel number is created and transmitted to the exchange, which is the connection destination of the called terminal side transmission line L24, through the control signal transmission unit 112.

5.2 When Release Request Signal 2 is Received from Called Terminal Side Transmission Line: The transmission line number (L25) and virtual channel number (VCI25) included in the release request signal 2 are read. The read free space of the called terminal-side transmission line L25 (E2
5) is read from the call connection data 114. Also, the virtual channel VCI 25 belonging to the read called terminal side transmission line number L25 is searched from the call connection data 114, and the virtual channel capacity (C25), the corresponding calling terminal side transmission line number (L26), and the calling line data are transmitted. The virtual channel number (VCI26) on the call terminal side is read. E25 + the available capacity E25 of the called terminal side transmission line L25
Rewrite as C25. In the call connection data 114, the data corresponding to the virtual channel number VCI25 is deleted. The release request signal 2 having L26 as the transmission line number and VCI26 as the virtual channel number is created and transmitted to the exchange to which the calling line L26 is connected through the control signal transmitting unit 112.

6 Operation When Receiving Call Setup Rejection Signal: When the call setup rejection signal is received from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. Channel number (L27), virtual channel number (VCI27), channel capacity (C2) included in the call setup rejection signal
Read 7). The virtual channel VCI 27 belonging to the read called terminal side transmission line L27 is searched from the called terminal numbers in the call connection data 114, and the corresponding calling terminal side transmission line number (L28) and calling terminal side virtual Channel number (VC
Read I28). 6.1 Operation for Setting Usage State to'Unused ': In the call connection data 114, the virtual channel used / unused identifier of the virtual channel VCI 27 of the called terminal on the called terminal side transmission line L27 is set to'Unused' rewrite. 6.2 Operation to send call setup rejection signal to adjacent exchange:
A call setup refusal signal having L28 as the transmission line number and VCI28 as the virtual channel number is created and transmitted through the control signal transmission unit 112 to the exchange to which the transmission line L28 of the calling terminal side is connected.

7. Operation when a call setting confirmation signal is received: When the call processing confirmation signal is received by the call processing processor 108 from the adjacent exchange through the control signal receiving unit 111, the call processing processor 108 performs the following operation. Transmission line number (L29), virtual channel number (VCI29), channel capacity (C2) included in the call setting confirmation signal
Read 9). The virtual channel VCI 29 belonging to the read called terminal side transmission line L29 is searched from the call connection data 114, and the transmission number (L30), virtual channel number (VCI30), and virtual channel capacity (C29 ') corresponding to the VCI 29 are searched. To read. After confirming that C29 = C29 ′, L30 is set as the transmission line number and VCI30 is set as the virtual channel number.
A call setup confirmation signal having the following is created and transmitted to the exchange to which the transmission line L30 is connected through the control signal transmission unit 112.

8. Operation When Receiving Call End Signal: When the call processor 108 receives the call end signal from the adjacent exchange through the control signal receiver 111, the call processor 108 performs the following operation. First, the transmission line number (L31) and virtual channel number (VCI31) included in the call termination signal are read. The virtual channel VCI31 belonging to the read calling terminal side transmission line L31 is searched from the call connection data 114, and the virtual channel capacity corresponding to the VCI31 is searched.
(C32), the called terminal side transmission line number (L32), and the called terminal side virtual channel number (VCI32) are read. In the call connection data 114, the called terminal side transmission line L3
The virtual channel used / unused identifier corresponding to the called terminal side virtual channel VCI 32 belonging to 2 is rewritten to'unused '. A call termination signal having L32 as the transmission line number and VCI32 as the virtual channel is created and transmitted to the exchange to which the called terminal side transmission line L32 is connected through the control signal transmitting unit 112.

Next, the structure of the ATM subscriber exchange 600 according to the embodiment of the present invention will be described with reference to FIG. The ATM subscriber exchange 600 according to this embodiment is different from the repeater exchange shown in FIG. 1 in that it includes a subscriber line accommodation unit 601, connection data 602, and a subscriber side transmission line 603. FIG. 8 shows the connection data 602 described above.
Which is the information content contained in the connection channel between the virtual channel belonging to the subscriber side transmission line 603 and the virtual channel belonging to the called terminal side transmission line, the transmission line free space included in the called terminal side transmission line, and the virtual channel. Channel capacity,
It contains the usage status ('used', 'unused') and the last use time as data. The operation of the ATM subscriber exchange according to this embodiment is the same as that of the above-mentioned relay exchange. However, in the case of the repeater exchange, the control signal transmitting unit 112 transmits to the adjacent exchange, whereas in the case of the subscriber exchange, it is transmitted to the subscriber terminal unit of the own exchange. Different from

The operation of the subscriber line accommodation unit 601 will be described below. When the subscriber line accommodation unit 601 detects a call, the subscriber line accommodation unit 601 performs the following operation. 1. When a call is detected: When the subscriber line accommodation unit 601 detects a call, the subscriber-side transmission line number (L22) and the subscriber-side virtual channel number (VCI33) that have made the call are read. From the call signal, the destination terminal number (N33), the call capacity (C
Read 33). In the connection data 602, the transmission line L read above
The called terminal number corresponding to the virtual channel VCI 33 belonging to 33 is searched. 1.1 If there is a channel: The called terminal number is N
The virtual channel (VC
I34), in the connection data 602,
The calling terminal side transmission line number L34, the capacity C34, and the calling terminal side transmission line free capacity E34 corresponding to the calling terminal side virtual channel number VCI34 are read. Connected terminal number is N
When there are a plurality of virtual channels connected to the terminal 33, one of them is selected.

1.1.1 When E34 ≧ C33: When there is a channel whose capacity / route is secured: C34
= C33, the call setup request signal 1 having L33 as the transmission line number and VCI33 as the virtual channel number is created and transmitted to the call processor 108. When only the route is secured: When C34 = 0,
A call setup request signal 1 having L34 as a transmission line number and VCI34 as a virtual channel number is created and transmitted to the call processor 108. 1.1.2 When E34 <C33: When there is a virtual channel connected to the terminal whose called terminal number is N33 on a transmission line other than the transmission line L34 on the calling terminal side: Section 1.1 (where the channel is (If yes). Otherwise: The call is lost and the call setup procedure is terminated.

1.2 When there is no channel: When there is no virtual channel connected to the terminal whose called terminal number is N33, the connection data 602 is searched for a transmission path having a free transmission path capacity of C33 or more. To do. 1.2.1 When there is a transmission line with a free transmission line capacity of C33 or more: Select one of the transmission lines with a free transmission line capacity of C33 or more. In the connection data 602, the selected transmission line number (L35) and free transmission line capacity (E35) are read. L35 as a transmission line number and a number VCI not used in the transmission line L35 as a virtual channel number
A call setup request signal 3 having 36 is created and transmitted to the call processor 108. 1.2.2 Free space of transmission line is C3
If there is no transmission path of 3 or more: The call is lost and the call setup procedure is terminated.

2. When the call end is detected: When the subscriber line accommodation unit 601 detects the call end, the subscriber side transmission line number (L37) and the subscriber side virtual channel number (VCI37) at which the call is ended are read. . In addition, from the clock of the exchange, the time (T
Read 37). In the connection data 602, the transmission line L read above
37. Called terminal side transmission path number (L38) corresponding to the virtual channel VCI 37 belonging to 37, called terminal side transmission path free capacity (E38), called terminal side virtual channel number (V
Read CI 38). Use of the read virtual channel of the virtual channel VCI 38 belonging to the called terminal side transmission line number L38
Rewrite unused identifiers to'unused '. Also, the virtual channel use end time is rewritten to T37. A call end signal having L38 as the transmission line number and VCI38 as the virtual channel number is created and transmitted to the call processor 108.

3. When the call setup request signal 1 is received: When the call setup request signal 1 is received from the call processor 108, the subscriber line accommodating unit determines the transmission line number (L39) and the virtual channel number included in the call setup request signal 1. (V
Read CI 39). In the connection data 602, the calling terminal side transmission line L39
The transmission line number (L40) on the subscriber side, the virtual channel number (VCI40) on the subscriber side, and the receiving terminal number (N40) corresponding to the virtual channel VCI39 belonging to the above are read.
Also, the virtual channel used / unused identifier of the virtual channel VCI 39 belonging to the calling terminal side transmission line L39 is rewritten to “used”. A call setup confirmation signal having L40 as the transmission line number and VCI40 as the virtual channel number is created and transmitted to the call processing processor 108. The call-in terminal N39 is connected to the virtual channel number VCI40 belonging to the subscriber-side transmission line L40.

4. When the call setup request signal 2 is received: When the call setup request signal 2 is received from the call processor 108, the subscriber line accommodating unit determines the transmission line number (L41) and the virtual channel number included in the call setup request signal 2. (V
Read CI 41). In the connection data 602, the calling terminal side transmission line L41
The transmission line number (L42) on the subscriber side, the virtual channel number (VCI42) on the subscriber side, and the receiving terminal number (N42) corresponding to the virtual channel VCI41 belonging to the group are read.
Further, the virtual channel used / unused identifier of the virtual channel VCI 41 belonging to the calling terminal side transmission line L41 is rewritten to “used”. A call setup confirmation signal having L41 as the transmission line number and VCI41 as the virtual channel number is created and transmitted to the call processor 108. The call-in terminal N42 is connected to the virtual channel number VCI42 belonging to the subscriber-side transmission line L42.

5. When the call setup request signal 3 is received: When the call setup request signal 3 is received from the call processor 108, the subscriber line accommodating unit receives the transmission line number (L43) and the virtual channel number included in the call setup request signal 3. (V
Read CI 43). In the connection data 602, the calling terminal side transmission line L43
The transmission line number (L44) on the subscriber side, the virtual channel number (VCI44) on the subscriber side, and the receiving terminal number (N44) corresponding to the virtual channel VCI43 that belongs to
Also, the virtual channel used / unused identifier of the virtual channel VCI 43 belonging to the calling terminal side transmission line L43 is rewritten to “used”. A call setting confirmation signal having L43 as the transmission line number and VCI43 as the virtual channel number is created and transmitted to the call processing processor 108. The called terminal N44 is connected to the virtual channel number VCI44 belonging to the subscriber side transmission line L44.

6. When the release request signal 1 is received: When the release request signal 1 is received from the call processor 108, the subscriber line accommodation unit determines the transmission line number (L45) and the virtual channel number (VCI) included in the release request signal 1.
Read 45). In the connection data 602, the calling terminal side transmission line L45
The capacity of the virtual channel VCI 45 belonging to the above is rewritten to 0. 7. When the release request signal 2 is received: When the release request signal 2 is received from the call processor 108, the subscriber line accommodation unit determines the transmission line number (L46) and the virtual channel number (VCI) included in the release request signal 2.
Read 46). In the connection data 602, the calling terminal side transmission line L46
Delete the data of the virtual channel VCI 46 belonging to.

8. When the call setup rejection signal is received: The transmission line number (L4 included in the received call setup rejection signal
8) Read the virtual channel number (VCI48). In the connection data 602, the calling terminal side transmission line L48
Delete the data of the virtual channel VCI 48 belonging to. 9. When a call setup confirmation signal is received: The transmission line number (L4 included in the received call setup confirmation signal
9), virtual channel number (VCI49), call capacity
Read (C49). In the connection data 602, the calling terminal side transmission line L49
The capacity of the virtual channel VCI49 belonging to
Rewrite As described above in detail, according to the above embodiment, when communicating with the same communication partner, when the capacity of the transmission path and the virtual channel number have a margin, the ATM repeater exchange has the pages 4-5. 1. Since only the operation of the item is required to be performed, a small amount of processing is required, and it is possible to obtain an effect that the load of the exchange can be extremely reduced in a communication network in which communication between the same terminals is large.

Next, another embodiment of the present invention will be described. This embodiment differs from the first embodiment in that in a system configured to connect a plurality of exchanges to a centralized center and control from the centralized center, the centralized center has call connection data, The repeater exchange does not need to make a call connection availability determination regarding call setup. FIG. 9 shows a centralized center (hereinafter,
"Control center") is shown. The control center 800 according to this embodiment has a function of transmitting and receiving control information to and from each exchange. In FIG. 9, 80
1 is a control signal input line to which a control signal is input from the exchange,
802 is a control signal output line for inputting a control signal to the exchange,
Reference numeral 803 is a control signal receiving unit for receiving a control signal, 804 is a control signal transmitting unit for transmitting a control signal, 805 is a processor for performing call processing, and 806 is a method between a calling terminal and a called terminal. Call setup route data associated with a predetermined call route, 807 is call connection data that stores the connection state of the virtual channel set in the exchanges in the network, and 808 is the exchange number that is the connection destination of the transmission line. , Which is saved as data
Indicates connection data holding a call connection state of a subscriber line accommodation unit 1201 described later.

FIG. 10 shows the call setup route data 806 described above.
Shows the information content included in, and the transmission paths accommodating the virtual channels set between the calling terminal and the called terminal are associated in the order in which the call passes. Figure 11
Represents the information content included in the call connection data 807, and is the transmission line number of the calling terminal side, the virtual channel number of the calling terminal side, the transmission line number of the called terminal, and the called line of all the exchanges in the network. Call terminal side transmission line free capacity, route number, called terminal side virtual channel number, virtual channel capacity, virtual channel usage status ('used',
'Unused') and last used time are included as data. Also, FIGS. 12 and 13 show the connection data 80 described above.
9 shows the content of information contained in 9, and the calling terminal number, the called terminal number, the route number, and the called terminal side virtual corresponding to the virtual channel belonging to the called terminal side transmission line in the subscriber line accommodation unit 1201. Channel number, virtual channel capacity, virtual channel usage
It contains ('used', 'unused') and last used time as data. FIG. 14 shows the information content included in the transmission path correspondence data 808, and includes, as data, the transmission path number for connecting the respective exchanges.

FIG. 15 is a block diagram of an ATM repeater exchange 1100 according to this embodiment, in which 1101 to 1112 are shown.
Are respectively the constituent elements 10 in the first embodiment shown above.
It corresponds to 1-112. Also, 1114 is call connection data that stores the connection state of the switch 1107. FIG. 16 shows an ATM according to the second embodiment of the present invention.
It is a block diagram of a subscriber exchange 1200, in the figure, 110
Reference numerals 1 to 1112 denote the same constituent elements as those of the ATM transit exchange 1100 shown in FIG.
Also, 1201 is a subscriber line accommodation unit, 1202 is connection data, and 1203 is a subscriber side transmission line. FIG. 17
15 shows the information content included in the call connection data 1114 of the ATM repeater exchange 1100 shown in FIG. 15, and the virtual channel belonging to the calling terminal side transmission line 1101 and the virtual channel belonging to the called terminal side transmission line 1102. The connection relation of the switch 1107 with the channel is included as data.

FIG. 18 shows the contents of information contained in the call connection data 1114 of the ATM subscriber exchange 1200 shown in FIG. 16. The virtual channels belonging to the subscriber side transmission line 1203 and the called terminal side. Transmission line 1102
The data includes the connection relationship with the virtual channel belonging to. FIG. 19 shows control signal lines 1201 and 120.
2 shows the content of information contained in the control signal transmitted through the control unit 2. 19 (a), (b), and (c) respectively show
It shows the information contained in the call connection signal, the call disconnection signal, and the route release signal. FIG. 20 shows control signal lines 1201 and 1
The information content included in the control signal transmitted through 202 is shown. 20 (a), (b), and (c) show information included in the call setup request signal, the call loss signal, and the call end signal, respectively. The operation of this embodiment will be described below. First, the operation of the subscriber line accommodation unit 1201 in the ATM subscriber exchange 1200 will be described.

1. When a call is detected: When the subscriber line accommodation unit 1201 detects a call, the transmission line number (L50) on the subscriber side and the virtual channel number (VCI50) on the subscriber side that have made the call are read. From call signal, calling terminal number (N50), called terminal number
(N51), read the call capacity (C50). N50 as the calling terminal number and N5 as the called terminal number
1. A call setup request signal having C50 as a call capacity is created, and the control signal transmission unit 111 is sent to the control center 800.
Send through 2. 2. When end of call is detected: subscriber line accommodation unit 1201
Detects the end of the call, it performs the following actions. When the end of the call is detected, the transmission line number (L52) and the virtual channel number (VCI52) of the subscriber transmission line where the end of the call has occurred are read.

A call end signal having L52 as the transmission line number and the virtual channel number VCI52 is created and transmitted to the control center 800 through the control signal transmission section 1112. 3. When a call connection signal is received: When the subscriber line accommodation unit 1201 receives the call connection signal from the control center 800, the subscriber line accommodation unit 1201 performs the following operation. Calling terminal side transmission line number (L5
3), Calling terminal side virtual channel number (VCI5
3) Read the called terminal side transmission line number (L54) and the called terminal side virtual channel number (VCI54). In the call connection data 1114, the virtual channel VC belonging to the above-mentioned read calling terminal side transmission line L53
The data is rewritten so as to connect the I53 and the virtual channel VCI54 belonging to the called terminal side transmission line L54. Connect the call and complete the call setup procedure.

4. When a call loss signal is received: When the subscriber line accommodation unit 1201 receives the call loss signal from the control center 800, it performs the following operation. The calling terminal number (N55) and the called terminal number (N56) included in the call loss signal are read. The call from the calling terminal N55 to the called terminal N56 is lost and the call setting procedure is completed. 5. When the route release signal is received: Further, when the subscriber line accommodation unit 1201 receives the route release signal from the control center 800, it performs the following operation. Calling terminal side transmission line number (L5
7), Calling terminal side virtual channel number (VCI5
7), Called terminal side transmission line number (L58), Called terminal side virtual channel number (VCI58) are read. In the connection data 1202, the calling terminal side transmission line L5
The data on the subscriber side transmission line and the subscriber side virtual channel corresponding to the virtual channel VCI 57 belonging to No. 7 are deleted.

6. When the call disconnection signal is received: Further, when the subscriber line accommodation unit 1201 receives the call disconnection signal from the control center 800, the following operation is performed. The calling terminal number (N59) and the called terminal number (N60) included in the call disconnection signal are read. In the connection data 1202, the call from the calling terminal N59 to the called terminal N60 is disconnected. Next, the operation of the call processor 1108 of the ATM subscriber exchange 1200 will be described. 1. When a call connection signal is received from the control center 800: Calling terminal side transmission line number (L6 included in the call connection signal
1), Calling terminal side virtual channel number (VCI6
1) Read the called terminal side transmission line number (L62) and the called terminal side virtual channel number (VCI62). In the call connection data 1114, the transmission line L on the calling terminal side
The data of the called terminal side virtual channel VCI 62 belonging to the called terminal side transmission line L62 is rewritten so as to correspond to the virtual channel VCI 61 belonging to 61.

2. When a route release signal is received:
Upon receiving the route release signal from the control center 800, the call processor 1108 performs the following operation. Calling terminal side transmission line number (L6
7), Calling terminal side virtual channel number (VCI6
7), Called terminal side transmission line number (L68), Called terminal side virtual channel number (VCI68) are read. In the connection data 1202, the calling terminal side transmission line L6
The connection state data of the called terminal side bar channel VCI 68 belonging to the calling terminal side transmission line L68 corresponding to the virtual channel VCI 67 belonging to No. 7 is deleted. The operation of the control center 800 will be described below. 1. When a call setup request signal is received: control signal receiving unit 8
Upon receiving a call setup request signal from the subscriber line accommodation unit 1201 through 03, the call processor 805 performs the following operation. The calling terminal number (N69), the called terminal number (N70) and the call capacity (C70) included in the call setting request signal are read. Also, the subscriber line accommodation unit number (S
69) and the exchange number (SW69) are read.

The connection data 809 is searched for whether or not the virtual channel connecting the above-mentioned calling terminal N69 and the called terminal N70 is in the subscriber line accommodation section S69. 1.1 If there is route setting and capacity is secured:
In the connection data 809, when the virtual channel for connecting the calling terminal N69 and the called terminal N70 is set and the capacity is secured, the following operation is performed. In the connection data 809, a virtual channel that connects the calling terminal N69 and the called terminal N70 is searched for from among the virtual channels that belong to the subscriber line accommodation unit S69, and the calling terminal side transmission line number (L70) Calling terminal side virtual channel number (VCI 70), Called terminal side transmission line number
(L71), Called terminal side virtual channel number (VCI
71) Read.

In the connection data 809, the virtual channel used / unused identifier of the callee terminal side virtual channel VCI 71 in the callee terminal side transmission line L71 belonging to the subscriber line accommodation section S69 is rewritten to "use". In the call connection data 807, the calling terminal side virtual channel VCI71 in the calling terminal side transmission path L71 belonging to the exchange SW69 is searched for, and the corresponding called terminal side transmission path is searched.
(L72), Called terminal side virtual channel (VCI71)
To read. Called terminal side virtual channel VCI7 in the called terminal side transmission line L72 belonging to the exchange SW69 read above
The virtual channel used / unused identifier corresponding to 2 is rewritten to'used '. In the transmission line corresponding data 808, the exchange number (SW73) which is the connection destination of the called terminal side transmission line L72 belonging to the exchange SW69 is read.

Next, in the call connection data 807, the called terminal side transmission line (L73) and the called terminal side virtual line corresponding to the calling terminal side virtual channel VCI71 in the calling terminal side transmission line L72 belonging to the exchange SW73. Read the channel (VCI73). Called terminal side virtual channel VCI7 in the called terminal side transmission line L73 belonging to the exchange SW73 read above
The virtual channel used / unused identifier corresponding to 3 is rewritten to'used '. The above procedure is repeated until the virtual channel used / unused identifier of the connection data 809 of the subscriber line accommodation unit (S70) accommodating the called terminal N70 is rewritten to "use". When the operation of rewriting the virtual channel used / unused identifier to “used” is completed, N6 is set as the calling terminal number.
9. A call connection signal having N70 as the called terminal number is created and transmitted to the subscriber line accommodation section S69 through the control signal transmission section 804.

1.2 When there is a route setting and the capacity is 0: In the connection data 809, there is the setting of the virtual channel connecting the calling terminal N69 and the called terminal N70, and when the capacity is 0, The operation of. In the connection data 809, a virtual channel that connects the calling terminal N69 and the called terminal N70 is searched for from among the virtual channels that belong to the subscriber line accommodation unit S69, and the calling terminal side transmission line number (L70) Calling terminal side virtual channel number (VCI 70), Called terminal side transmission line number
(L71) and the virtual channel number (V
Read CI 71). In the connection data 809, the free space of the transmission line of the called terminal side transmission line L71 belonging to the subscriber line accommodation unit S69 (E7
Read 1). 1.2.1 When E71 ≧ C70: Transmission line free space E7
When 1 is the call capacity C70 or more, the following operation is performed.

In the connection data 809, the virtual channel capacity of the called terminal side virtual channel VCI 72 in the called terminal side transmission line L71 belonging to the subscriber line accommodation section S69 is set to C70, and the virtual channel used / unused identifier is set. Rewrite as'use '. Next, in the call connection data 807, the calling terminal side virtual channel V in the calling terminal side transmission line L71 belonging to the exchange SW69 connected to the subscriber line accommodation unit S69.
The CI 71 is searched, and the transmission line number (L
72), the virtual channel number of the called terminal (VCI7
2) Read. In the call connection data 807, the free capacity (E72) of the transmission path of the called terminal side transmission path L72 belonging to the exchange SW69 is read. The transmission line free capacity E72 is compared with the call capacity C70,
If E72 ≧ C70, the above operation (a) is performed. If E72 <C70, the following operation is performed.

1.2.2 When E71 <C70: When the free capacity E71 of the transmission line is less than the capacity C70 of the call, the connection data 807 indicates that the transmission line L71 belonging to the subscriber line accommodation unit S69 is included in the transmission line L71. A virtual channel whose virtual channel used / unused identifier is'unused 'and which secures a virtual channel capacity of C70 or more is searched for. (a) Called terminal side transmission line L belonging to subscriber line accommodation section S69
If there is a virtual channel in 71 where the virtual channel used / unused identifier is'unused 'and the virtual channel capacity of C70 or more is secured, the following operation is performed. Called terminal side transmission line L7 belonging to subscriber line accommodation section S69
In 1, the virtual channel whose unused / unused identifier is'unused 'and the virtual channel capacity of which is C70 or more is secured, and the virtual channel with the oldest use end time is selected, and the incoming call is received. The terminal side virtual channel number (VCI74) and the virtual channel capacity (C74) are read.

For the virtual channel VCI 74 on the called terminal side belonging to the called terminal side transmission line L71, the following virtual channel capacity releasing operation is performed. In the transmission line corresponding data 808, the exchange number (SW73) which is the connection destination of the called terminal side transmission line L72 belonging to the exchange SW69 is read. In the call connection data 807, the transmission line free capacity (E72) of the calling terminal side virtual channel VCI 72 in the calling terminal side transmission line L72 belonging to the exchange SW73 is read. The read transmission line free capacity E72 is compared with the call capacity C70, and the same operation as described in the item 1.1 or 1.2 is performed.

1.2.3 Virtual channel capacity release operation: (A) In connection data 809, subscriber line accommodation unit S69
The free space of the transmission line in the transmission line L71 on the called terminal side belonging to is rewritten to E71 + C74. (Ii) In the call connection data 807, the subscriber line accommodation unit S6
Virtual channel VCI on the calling terminal side in the calling terminal side transmission line L71 belonging to the exchange SW69
The called terminal side transmission line number (L74) and the called terminal side virtual channel number (VCI74) corresponding to No. 74 are read. (C) In the transmission line corresponding data 808, the exchange number (SW75) which is the connection destination of the called terminal side transmission line L74 belonging to the exchange SW69 connected to the subscriber line accommodation unit S69.
To read. (E) In the call connection data 807, the called terminal side transmission line number corresponding to the calling terminal side virtual channel VCI74 in the calling terminal side transmission line L74 belonging to the exchange SW75
(L75), virtual channel number of the called terminal (VCI
Read 75).

(E) Next, in the transmission line correspondence data 808, the transmission line number L7 of the called terminal belonging to the exchange SW75.
The exchange number (SW76), which is the connection destination of No. 5, is read. (Or) If a similar operation is performed and a subscriber line accommodation unit terminating the virtual channel for releasing the capacity is searched for, the virtual channel of the virtual channel for releasing the capacity is rewritten to 0 in the connection data 809. (b) Called terminal side transmission line L belonging to subscriber line accommodation section S69
If the virtual channel used / unused identifier is “unused” in 71 and there is no virtual channel that secures the virtual channel capacity of C70 or more, the following operation is performed. Called terminal side transmission line L7 belonging to subscriber line accommodation section S69
When the virtual channel used / unused identifier is “unused” in 1 and there is no virtual channel that secures the virtual channel capacity of C70 or more, N69 is set as the calling terminal number and N70 is set as the called terminal number. The generated call loss signal is generated and transmitted to the subscriber line accommodation unit 1201 through the control signal transmission unit 804.

1.3 When no path is set and no capacity is set: When the virtual channel for connecting the calling terminal N69 and the called terminal N70 is not set in the connection data 809, the following operation is performed. In the call setting route data 806, one is selected from the routes set between the calling terminal N69 and the called terminal N70, and the route number (R79), the number of the exchanges in the order in which they are passed, and the exchanges to be passed are selected. Read the number of the transmission path on the called terminal side that is accommodated. In the connection data 809, the subscriber line accommodation unit (S69)
Line free capacity of the called terminal side transmission line (L80) belonging to
Read (E80). Also, the presence / absence of an unused virtual channel number in the called terminal side transmission line L80 belonging to the subscriber line accommodation unit S69 is searched.

1.3.1 When E80 ≧ C70 and there is a vacant virtual channel number: (a) Virtual channel capacity release operation: (a) In connection data 809, subscriber line accommodation unit S69
The unused virtual channel number (VCI80) of the called terminal on the called terminal side transmission line L80 belonging to is selected. (Ii) In the connection data 809, the subscriber line accommodation unit S69
So that an unused virtual channel on the called terminal side in the called terminal side transmission line L80 belonging to
Calling terminal side virtual channel number in the calling terminal side transmission line (L70) belonging to the subscriber line accommodation section S69 to which the route number R79, the receiving terminal N70, and the calling terminal N69 are connected
(VCI70), calling terminal number N69, virtual channel capacity C70, and virtual channel used / unused identifier rewritten to "used". Also, call connection data 807
In the calling terminal side transmission line (L81) belonging to the exchange (SW69) to which the subscriber line accommodation unit S69 is connected,
The presence / absence of an unused virtual channel number is searched, and the corresponding operation is performed based on the result.

(U) Next, in the call connection data 807,
In the exchange (SW82) located next on the route of the virtual channel to be set, search whether there is an unused virtual channel number in the called terminal side transmission line (L82) belonging to the exchange SW82 read as the route. Then, the corresponding operation is performed based on the result. (E) In the above (U), when the data change of the connection data 809 of the subscriber line accommodation unit (S83) accommodating the called terminal N70 is completed, the call connection signal having N70 as the calling terminal number is transmitted. A control signal transmission unit 8 is provided for all subscriber line accommodation units and exchanges that are created and read as routes to be set.
Send through 04.

1.3.2 E80 ≧ C70 and when there is no vacant virtual channel number: Connection data 809
In, the presence / absence of a virtual channel whose virtual channel used / unused identifier is “unused” is searched for in the called terminal side transmission line L80 belonging to the subscriber line accommodation unit S69. (a) When there is a virtual channel that is a birch with a virtual channel used / unused identifier being'unused ': If there is a virtual channel with a virtual channel used / unused identifier is'unused', the following operation is performed. I do. In the connection data 809, the virtual channel whose use end time is the oldest among the virtual channels whose virtual channel used / unused identifier in the called terminal side transmission line L80 belonging to the subscriber line accommodation unit S69 is “unused” is selected. Select the virtual channel number (VC
I83) and the virtual channel capacity (C83) are read.

Regarding the called terminal side virtual channel VCI 83 belonging to the called terminal side transmission line L80, 1.2.3
According to the operation of releasing the virtual channel capacity described in the section (pages 33 to 34), the virtual channel capacity of the subscriber line accommodation unit terminating the virtual channel for which the capacity is released is set to 0.
Rewrite Further, in the call connection data 807, the exchange (SW6) to which the subscriber line accommodation unit S69 is connected is connected.
In the calling terminal side transmission line (L81) belonging to 9), the presence or absence of an unused virtual channel number is searched, and the corresponding operation is performed based on the result. Next, in the call connection data 807, the exchange (SW84) located next on the route of the virtual channel to be set.
In step 2, it is searched whether or not there is an unused virtual channel number in the called terminal side transmission line (L84) belonging to the exchange SW84 which is read as the route, and the corresponding operation is performed based on the result. When the data change of the connection data 809 of the subscriber line accommodation section (S85) accommodating the called terminal N70 is completed by repeating the above operation, a call having N69 as the calling terminal number and N70 as the called terminal number is performed. A connection signal is generated and transmitted through the control signal transmission unit 804 to all of the subscriber line accommodating unit and the exchange that have been read as a route to be set.

(B) When there is no virtual channel whose virtual channel used / unused identifier is'unused ':
When there is no virtual channel whose virtual channel used / unused identifier is'unused ', a call loss signal having N69 as the calling terminal number and N70 as the called terminal number is created, and the subscriber line accommodation unit It transmits to S69 through the control signal transmission part 804. 1.3.3 When E80 <C70: Transmission line free space E8
If 0 is less than the call capacity C70, connection data 80
In 9, the called terminal having a virtual channel used / unused identifier in the called terminal side transmission line L80 belonging to the subscriber line accommodation unit S69 is “unused” and the virtual channel capacity is equal to or more than the call capacity C70. Search for the existence of a side virtual channel. (a) Virtual channel used / unused identifier is'unused ', and virtual channel capacity is call capacity C7
If you have a virtual channel that is greater than or equal to 0:

When the virtual channel used / unused identifier is “unused” and the virtual channel capacity is equal to or greater than the call capacity C70,
Perform the following operations. In the connection data 809, the free capacity of the transmission line in the transmission line L80 of the called terminal belonging to the subscriber line accommodation unit S69 (E
Read 80). Further, among the virtual channels whose virtual channel use / unused identifier in the called terminal side transmission line L80 belonging to the subscriber line accommodation unit S69 is'unused 'and the virtual channel capacity is equal to or more than the call capacity C70 , The virtual channel with the oldest end time is selected, and the virtual channel number (VCI
86) and read the virtual channel capacity (C86). The virtual channel VCI 86 of the called terminal side belonging to the called terminal side transmission line L80 is subjected to the following virtual channel release operation. When the release operation is completed, in the connection data 807, the data corresponding to the callee terminal side virtual channel VCI 86 is set to the callee terminal side transmission line number L80, the transmission line free space E80-C70,
The virtual channel number on the called terminal side is VCI86, the called terminal number is N70, the calling terminal number is N69, the virtual channel capacity is C70, and the used / unused identifier is "used".
Rewrite

(A) Virtual channel release operation: (A) In connection data 809, subscriber line accommodation unit S69
The free space of the transmission line of the called terminal side transmission line L80 belonging to
Rewrite as 80 + C70. Also, the subscriber line accommodation unit S6
The data corresponding to the called terminal side virtual channel VCI 86 in the called terminal side transmission line L80 belonging to No. 9 is deleted from the connection data 809. (Ii) In the call connection data 807, the subscriber line accommodation unit S6
9 is a virtual channel VCI of the calling terminal side in the calling terminal side transmission line L80 belonging to the switch SW69 to which 9 is connected.
Called terminal side virtual channel number (V
CI87) and the called terminal side transmission line number (L87) are read.

(C) In the transmission line correspondence data 808, the exchange number (SW88) which is the connection destination of the called terminal side transmission line L87 belonging to the exchange SW69 connected to the subscriber line accommodation section S69 is read. (E) Next, in the call connection data 807, the exchange SW8
Called terminal side transmission path number (L88) in the calling terminal side transmission path 87 belonging to No. 8 and called terminal side virtual channel number
Read (VCI88). (O) Switch SW88 in the transmission path correspondence data 808
Switch number (SW) that is the connection destination of the transmission line L88 belonging to
Read 89). (Or) The same operation is performed, and data is deleted up to the subscriber line accommodation unit that terminates the virtual channel to be released.

In the call connection data 807, the presence or absence of an unused virtual channel number is searched for in the calling terminal side transmission line (L80) belonging to the exchange (SW69) to which the subscriber line accommodating section S69 is connected. Perform the corresponding action based on the result. In the call connection data 807, an unused virtual channel number in the called terminal side transmission line (L90) belonging to the exchange SW90 read as a route in the exchange (SW90) located next on the route of the virtual channel to be set. Search whether or not there is, and perform the corresponding operation based on the result. In the above, when the data change of the connection data 809 of the subscriber line accommodation unit (S91) accommodating the called terminal N70 is completed, the call connection signal having N69 as the calling terminal number and N70 as the called terminal number Is transmitted through the control signal transmission unit 804 to all of the subscriber line accommodation unit and the exchange that have been read as the route to be created and set.

(B) When the virtual channel used / unused identifier is'unused 'and there is no virtual channel whose virtual channel capacity is greater than or equal to the call capacity C70: Virtual channel used / unused identifier is'unused''And the virtual channel capacity is the call capacity C7
If there is no virtual value of 0 or more, a call loss signal having N69 as the calling terminal number and N70 as the called terminal number is created and transmitted to the subscriber line accommodating section S69 through the control signal transmitting section 804. 2. When a call end signal is received: control signal receiving unit 803
When the call end signal is received from the subscriber line accommodation unit 1201 through the call processing unit 808, the call processor 808 performs the following operation. The calling terminal number (N92) and the called terminal number (N93) included in the call end signal are read.

In the call setting route data 806, the virtual channel connecting the calling terminal N92 and the called terminal N93 read above is searched for, and the number of the subscriber line accommodation unit or exchange to be passed and the route are passed. Read all the numbers of the transmission lines on the called terminal side that are accommodated in the subscriber ordinance accommodation unit or exchange. In the connection data 809, in the called terminal side transmission line (L94) belonging to the subscriber line accommodating unit (S94) accommodating the calling terminal N92 read above, a virtual channel for the called terminal N93 and a virtual channel Channel usage
Search for the virtual channel on the called terminal side whose unused identifier is'used 'and find the virtual channel number on the called terminal side
Read (VCI94).

In the connection data 809, the called terminal side transmission line L belonging to the subscriber line accommodation section S94 read above.
The virtual channel used / unused identifier corresponding to the virtual channel VCI 94 on the called terminal side in 94 is rewritten to “unused”, and the use end time is rewritten to the time when the signal is received. In the call connection data 807, the subscriber line accommodation unit S94
The called terminal side virtual channel number (VCI95) and the called terminal side transmission line number (L95) corresponding to the virtual channel VCI94 in the calling terminal side transmission line L94 belonging to the exchange (SW94) connected to are read. In the transmission line corresponding data 808, the exchange number (SW96) which is the connection destination of the called terminal side transmission line L95 belonging to the exchange SW94 is read. Next, in the call connection data 807, the exchange SW96
Called terminal side virtual channel number (VCI96) corresponding to the called terminal side virtual channel VCI95 in the called terminal side transmission line L95 belonging to
Read (L96).

Called terminal side virtual channel VCI96 in the called terminal side transmission line L96 belonging to the exchange SW96.
The virtual channel used / unused identifier corresponding to is rewritten to “unused”, and the use end time is rewritten to the time when the signal is received. When the change of the connection data of the subscriber line accommodating unit (S97) accommodating the called terminal N93 is completed by repeating the above procedure, a call having N92 as the calling terminal number and N93 as the called terminal number is performed. A disconnection signal is created and transmitted to the subscriber line accommodating unit that has transmitted the call end signal through the control signal transmitting unit. According to the above embodiment, as a system configuration using a control center, when the control center is provided with connection data of each relay exchange, when the capacity is changed, the processing in the relay exchange becomes unnecessary. Therefore, it is possible to reduce the load on the exchange. Further, it is possible to reduce the physical quantity as compared with the case where each relay exchange has connection data individually.

FIG. 21 is a flow chart showing the outline of the operation of the present invention, and FIGS. 22 to 24 show the details of the portions (a) to (c) in FIG. Please refer to it. Further, it goes without saying that the above-described embodiments show examples of the present invention, and the present invention should not be limited thereto.

[0077]

As described above in detail, according to the present invention, the ATM switch and the ATM switch capable of reducing the load at the time of call setting by holding the channel once connected are provided. It has a remarkable effect that a system using is realized.

[0078]

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ATM transit exchange 100 according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the information content of call setup route data 113 according to the embodiment.

FIG. 3 is a diagram showing the information content of call connection data 114 according to the embodiment.

FIG. 4 is a diagram showing information contents of call setting request signals 1 to 3 according to the embodiment.

FIG. 5 is a diagram showing information contents of release request signals 1 and 2 according to the embodiment.

FIG. 6 is a diagram showing information contents of a call setup refusal signal, a call setup confirmation signal, and a call end signal according to the embodiment.

FIG. 7 is a configuration diagram of an ATM subscriber exchange 600 according to the first embodiment of the present invention.

FIG. 8 is a diagram showing information content of connection data 602 according to the embodiment.

FIG. 9 is a control center 800 according to the second embodiment of the present invention.
It is a block diagram of.

FIG. 10 is a diagram showing information contents of call setup route data 806 according to the embodiment.

FIG. 11 is a diagram showing information content of call connection data 807 according to the embodiment.

FIG. 12 is a part of a diagram showing the information content of connection data 809 according to the embodiment.

FIG. 13 is another part of the diagram showing the information content of connection data 809 according to the embodiment.

FIG. 14 is a diagram showing information content of transmission path corresponding data 808 according to the embodiment.

FIG. 15 is a configuration diagram of an ATM repeater exchange 1100 according to the second embodiment of the present invention.

FIG. 16 is an ATM subscriber exchange 120 according to the embodiment.
It is a block diagram of 0.

FIG. 17 is a diagram showing information contents of call connection data 1114 held by the ATM relay exchange 1100 according to the embodiment.

FIG. 18 is an ATM subscriber exchange 1200 according to an embodiment.
It is a figure which shows the information content of the call connection data 1114 which it has.

FIG. 19 is a diagram showing information contents of a call connection signal, a call disconnection signal, and a route release signal according to the embodiment.

FIG. 20 is a diagram showing information contents of a call setup rejection signal, a call loss signal, and a call termination signal according to the embodiment.

FIG. 21 is a flowchart showing an outline of the operation according to the present invention.

22 is a detailed diagram of a portion (a) in the flowchart shown in FIG.

23 is a detailed view of a portion (b) in the flowchart shown in FIG.

24 is a detailed diagram of a portion (c) in the flowchart shown in FIG.

[Explanation of symbols]

100: ATM transit switch, 101, 102: transmission line,
103 and 104: Virtual channel, 107: Switch, 108: Call processor, 109: Control signal input line, 110: Control signal output line, 111: Control signal receiving unit, 112: Control signal transmitting unit, 113: Call setting path Data, 114: call connection data, 600: ATM subscriber exchange, 601: subscriber line accommodation unit, 602: connection data,
603: transmission line on the subscriber side, 800: control center, 80
1: control signal input line, 802: control signal output line, 80
3: Control signal receiving unit, 804: Control signal transmitting unit, 80
5: Call processor, 806: Call setup route data, 8
07: call connection data, 808: transmission line corresponding data, 80
9: connection data, 1100: ATM relay exchange, 110
1, 1102: transmission line, 1103, 1104: virtual channel, 1107: switch, 1108: call processor, 1109: control signal input line, 1110: control signal output line, 1111: control signal receiver, 1112: control signal transmission Part, 1114: Call connection data, 1201: Subscriber line accommodation part, 1202: Connection data, 1203: Subscriber side transmission line.

Claims (4)

[Claims] 1. An ATM switch for setting and releasing an arbitrary virtual channel between an incoming transmission line and an outgoing transmission line in an ATM communication network, wherein the intra-network route / capacity of the virtual channel is maintained even after the end of communication. And a means for causing the intra-network route / capacity of the virtual channel held by the holding means to be used for the communication when performing communication again using the same virtual channel. An ATM exchange characterized by that. 2. In addition to the above-mentioned means, the capacity of the virtual channel whose intra-network route / capacity is held by the holding means is redirected to a request for setting a new virtual channel for other communication, 2. An ATM switching system according to claim 1, further comprising means for setting various virtual channels. 3. In addition to the means, another virtual channel that is not used for communication when communication is performed again using the virtual channel whose network route / capacity is held by the holding means 3. The ATM switch according to claim 1, further comprising means for setting the virtual channel for communication by reducing the capacity of the ATM switch. 4. The ATM according to claim 1.
In a system having a centralized center connected to a switching system, a system using an ATM switching system, characterized in that the centralized center is provided with means for holding a network route / capacity of a virtual channel after completion of the communication.