JP3035802B2 - ATM exchange and system using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ATM (Asynchronous
More particularly, the present invention relates to an ATM switch and a system using the same, which can reduce a load at the time of setting up a call.

[0002]

2. Description of the Related Art In a conventional exchange, every time a call occurs,
By properly connecting the switches of the subscriber exchange and the relay exchange, a channel is set in the network, and each time a call is terminated, the switch of each of the above exchanges is released to release the channel. . Regarding this, refer to the Nikkei Communication separate volume "Guide to ISDN Usage" (Nikkei BP
Company, issued December 1, 1988) pp.168-177 is helpful.

[0003]

In the above-mentioned prior art, each time a call is generated, it is necessary to determine a channel route, secure a capacity, connect a switch, and the like in each exchange.
There has been a problem that the load on the exchange when setting up a call is large. Further, in general, the number of communication parties is considerably limited. However, in the above-described conventional technique, it is necessary to perform exactly the same procedure every time a call occurs. The present invention has been made in view of the above circumstances, and an object thereof is to solve the above-described problems in the related art, to maintain a channel once connected, and to set a time when setting up a call. An object of the present invention is to provide an ATM switch which can reduce a load and a system using the same.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide an image processing apparatus comprising:
An ATM exchange for setting and releasing an arbitrary virtual channel between an incoming transmission line and an outgoing transmission line in a TM communication network, means for maintaining the intra-network route / capacity of the virtual channel in the network even after the end of communication; When communication is performed again using the same virtual channel, means for causing the network path / 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 exchange, a system for maintaining an intra-network route / capacity of the virtual channel after the end of the communication is provided in the centralized center. Achieved by

[0005]

The connection of the switch in the ATM exchange is performed by associating the virtual channel identification number of each cell as an information transfer unit with the outgoing line number, and transmitting each cell to an appropriate outgoing line according to this correspondence. It was done. In such a switch, the capacity of the virtual channel can be changed independently of the connection state of the switch. In the ATM switching system and the system using the same according to the present invention, by utilizing the above-mentioned properties, at the end of the call, the path and capacity of the virtual channel are held in the network, and the call between the same terminals occurs again. In such a case, the load of the channel routing and the switch connection in this case is reduced by using the already held virtual channel. Here, the means for maintaining the path and capacity of the virtual channel described above 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 be described below in detail with reference to the drawings. First, a first embodiment of the present invention will be described.
The present embodiment has a function of requesting call connection data to the ATM transit exchange. When a call setup request is generated, each transit exchange can refer to the connection data of its own exchange to connect a call. It is configured to judge whether or not. FIG. 1 is a configuration diagram of an ATM switching system 100 according to a first embodiment of the present invention. In the figure, 101,
Reference numeral 102 denotes a transmission line on the calling terminal side and transmission line on the called terminal side, 103 and 104 denote virtual channels,
Reference numerals 5 and 106 denote transmission line termination units; 107 denotes a switch capable of connecting an arbitrary virtual channel in the calling terminal side transmission line 101 to an arbitrary virtual channel in the called terminal transmission line 102; Is a processor that performs call processing, 109 is a control signal input line through which a control signal is input from an adjacent exchange, 110 is a control signal output line that outputs a control signal to an adjacent exchange, 111 is a control signal receiving unit that receives a control signal, 112 Is a control signal transmitting unit that transmits a control signal,
Reference numeral 113 denotes call setup route data for associating the number of the called terminal to which the call is to be connected with the route for setting up the call
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.
It is associated with the number of the transmission path connected to the adjacent exchange on the call setting path and on the called terminal side. FIG. 3 shows information contents included in the call connection data 114.
The connection relationship of the switch 107 between the virtual channel belonging to the transmission line 101 on the calling terminal side and the virtual channel belonging to the transmission line 102 on the called terminal side, the free space included in the transmission line on the called terminal side, and the connection of the switch 107 The data includes the capacity, the use state ('used', 'unused') and the last use time of the configured virtual channel. FIG. 4 shows information contents included in the control signals transmitted through the control signal lines 109 and 110. (a) to (c) show information contents included in the call setting request signals 1 to 3, respectively. is there. FIG. 5 shows the control signal lines 109, 1
The information contents included in the control signal transmitted through 10 are shown, and (a) and (b) show the information contents included in the release request signals 1 and 2, respectively. As will be described later, the release request signal 1 holds the path, but requests that the capacity be 0, and the release request signal 2 indicates a request to release both the path and the capacity. FIG. 6 shows information contents included in the control signals transmitted through the control signal lines 109 and 110. (a), (b) and (c) show the call setting rejection signal and the call setting confirmation signal, respectively. , And information contents included in the call end signal.

The operation of the ATM switch 100 will be described below. 1. When both the path and capacity of the virtual channel are already secured: When the call setting request signal 1 is received from the adjacent exchange via the control signal receiving unit 111, the call processor 108 performs the following operation. 1.1 Operation for Changing Use State to “Use”: The transmission line number (L1) and the virtual channel number (VCI1) included in the call setup request signal 1 shown in FIG. 4A are read. The read L1 and VCI1 are searched for from the calling terminal side transmission line number and the virtual channel number of the call connection data shown in FIG. 3, and the called terminal side transmission line number corresponding to these numbers ( L2), the free space (E2) of the called terminal transmission line L2, and the called terminal virtual channel number (VCI2). The virtual channel use / unused identifier (see FIG. 3) of the virtual channel whose virtual channel number is VCI2 is defined as “use”.

1.2 Operation for creating a new control signal and transmitting it to an 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 through the control signal transmission unit 112 to the exchange to which the transmission line L2 is connected. 2. When only the virtual channel path is reserved 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), virtual channel number (VCI3) and call capacity (C3) included in the call setting request signal 2 shown in FIG. 4B are read. The read L3 and VCI3 are searched for from the calling terminal side transmission line number and the virtual channel number of the call connection data shown in FIG. 3, and the called terminal side transmission line number (L4 ), The free space (E4) of the transmission line L4 on the called terminal side and the virtual channel number on the called terminal side
(VCI4) is read.

2.1 When there is room in the capacity of the transmission line:
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 space E4 of the transmission line number L4 is changed to E4.
Rewrite to -C3. Further, the virtual channel number of the virtual channel number of VCI4 is rewritten to C3. 2.1.2 Operation to change the use state to “use”: In the call connection data 114, the virtual channel used / unused identifier of the virtual channel of the called terminal virtual channel number VCI4 is rewritten to “use”. 2.1.3 Operation for creating and transmitting new control signal: L4 as transmission line number and V as virtual channel number
A new call setup request signal 2 having a CI4 is created and transmitted to the exchange to which the destination terminal side transmission line L4 is connected via 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 use state is “unused” and a virtual channel having a virtual channel capacity of C3 or more exists in the called terminal transmission line L4, the following operation is performed. 2.2.1 Set capacity of other virtual channels (≧ C3) to 0
In the call connection data 114, among the virtual channels whose virtual channel use / unused identifier is “unused” and whose virtual channel capacity is C3 or more, for example, the use end time of the virtual channel is the shortest. The old virtual channel is selected, and its called terminal side virtual channel number (VCI5) and virtual channel capacity (C5) are read. The virtual channel number of the called terminal selected above is V
The capacity C5 of the virtual channel of CI5 is rewritten to 0, and the virtual channel use / unused identifier is rewritten to “unused”. Further, the free space of the transmission line L4 is rewritten to E4 + C5.

[0012] From the called terminal transmission line number and the called terminal virtual channel number in the above-mentioned call connection data 114, the called terminal transmission line number L4 and the called terminal virtual channel number VCI5 are searched. The calling terminal side transmission channel 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. 5A) having L4 as a transmission line number and VCI5 as a virtual channel number is created, and a control signal transmitting unit is transmitted to the exchange to which the transmission line number L4 is connected. Transmit via 112. Further, a 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 transmission line L6 on the calling terminal side is connected. 2.2.2 Operation for securing capacity of own channel: In call connection data 114, empty capacity E4 + C5 of transmission line L4 is set to E
4 + C5-C3. Further, the virtual channel capacity of the virtual channel whose virtual channel number is VCI4 is rewritten to C3.

2.2.3 Operation to change use state to “use”: In the call connection data 114, the virtual channel number of the virtual channel whose virtual channel number is VCI4 is rewritten to “use”. 2.2.4 Control signal transmission operation to adjacent exchange: L4 as transmission line number, VCI4 as virtual channel number
Is generated and transmitted via the control signal transmission unit 112 to the exchange to which the called terminal transmission line L4 is connected. (b) If the use state is “unused” and a virtual channel having a 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
A call setting rejection signal having VCI3 as a virtual channel number is generated and transmitted to the exchange to which the calling terminal side transmission line L3 is connected via the control signal transmission unit 112.

3. Operation when neither the route nor the capacity of the 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 path 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 stored in the call setting route data 1
13 and retrieves the corresponding called terminal side transmission path number (L8). The called terminal side transmission line number L8 is searched from the called terminal side transmission line number in the call connection data 114, and the transmission line free capacity (E8) of the called terminal side 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 When C7 ≦ E8: 3.1.1 Operation for Connecting Own Channel: Among the virtual channel numbers of the called terminal belonging to the called terminal transmission line L8, the switch 107 selects the calling terminal side. The called terminal's virtual channel not connected to the virtual channel
(VCI8) and connects it to the virtual channel VCI7 belonging to the called terminal transmission line L7. 3.1.2 Operation for securing 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 called terminal side virtual channel VCI8 is rewritten to C7. 3.1.3 Operation of setting use state to “use”: In call connection data 114, called terminal side virtual channel VC
Rewrite the virtual channel use / unused identifier of I8 to “use”.

3.1.4 Control signal transmission operation to adjacent exchange: New release request signal 3, L as transmission path number
8, a virtual channel number VCI8, a call capacity C7, and a called terminal number N7 are created and transmitted to the exchange to which the called terminal transmission line L8 is connected through the control signal transmitting unit 112. I do. 3.2 Case of C7> E8: (a) If the use state is “unused” in the called terminal transmission line L8 and a virtual channel having a virtual channel capacity of C7 or more exists, The following operation is performed. 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
Of the virtual channels belonging to the called terminal, the virtual channel use / unused identifier is “unused” and the virtual channel capacity is C7 or more. The old virtual channel is selected, and the called terminal side virtual channel number (VCI9) and virtual channel capacity (C9) are read.

The virtual channel capacity C9 of the virtual channel VCI9 is rewritten to 0. In addition, the transmission path L
8 is rewritten to E8 + C9. From the transmission line number on the called terminal side and the virtual channel number in the call connection data 114, the transmission line number L on the called terminal side
8. Search for the called terminal virtual channel number VCI9, the calling terminal transmission line number (L10) and the calling terminal virtual channel number corresponding to L8 and VCI9.
(VCI10) is read. L8 as transmission path number, virtual channel number VC
A release request signal 1 having I9 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. Also, L1 is used as the transmission line number.
0, a release request signal 1 having a virtual channel number VCI 10 is transmitted through the control signal transmission unit 112 to the exchange to which the calling terminal side transmission line L10 is connected.

3.2.2 Operation for Connecting Own Channel: Among the virtual channel numbers belonging to the called terminal transmission line L8, the virtual channel (VCI8) not connected to the calling terminal virtual channel by the switch 107.
Is connected to the virtual channel VCI7 belonging to the calling terminal side transmission line L7. 3.2.3 Operation to secure capacity of own channel: In call connection data 114, free space E8 + C9 of transmission line number L8 on the called terminal side is rewritten to E8 + C9-C7. Further, the virtual channel capacity of the called terminal side virtual channel VCI8 is rewritten to C7. 3.2.4 Operation to change the use state to “use”: In the call connection data 114, the called terminal side virtual channel VC
Rewrite the virtual channel use / unused identifier of I8 to “use”.

3.2.5 Transmission operation of control signal to adjacent exchange: L8 as transmission line number, VCI8 as virtual channel number, C7 as call capacity, and called terminal number as new call setup request signal 3 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. (b) If the use state is “unused” in the called terminal transmission line L8 and there is no virtual channel whose virtual channel capacity is C7 or more, the following operation is performed. 3.2.6 Call rejection operation: L as transmission line number
7 is generated via the control signal transmitting unit 112 to the exchange to which the calling terminal side transmission line L7 is connected, having a call setting rejection signal having VCI7 as the virtual channel number. If there is no 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 path number L8, the following operation is performed.

3.3 When there is a channel that can be released: (a) When C7 ≦ E8: 3.3.1 Operation to release the route of the oldest other channel: In the call connection data 114, the called terminal side Transmission line L8
Of the called terminal virtual channel whose virtual channel use / unused identifier is “unused” among the virtual channels belonging to
1. Read the capacity C11 of the virtual channel. The virtual channel capacity C11 of the called terminal side virtual channel VCI11 is rewritten to 0. Further, the free space of the transmission line L8 is rewritten to E8 + C11. From the called terminal side transmission line number and the virtual channel number of the call connection data 114, the called terminal side transmission line number L
8. Search for the called terminal virtual channel number VCI11 and read the calling terminal transmission line number (L12) and calling terminal virtual channel number (VCI12) corresponding to L8 and VCI11.

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. A release request signal 2 having L8 as the transmission path number and VCI 11 as the virtual channel number is created, and transmitted to the exchange to which the called terminal transmission path L8 is connected via the control signal transmission unit 112. Further, a release request signal 2 having L12 as the transmission line number and VCI 12 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 of connecting own channel: switch 107
Thus, of the virtual channel numbers belonging to the transmission line L8, the called terminal side virtual channel VC selected above
I11 is connected to the virtual channel VCI7 belonging to the calling terminal side transmission line L7.

3.3.3 Operation for Securing Own Channel Capacity: In call connection data 114, free space E8 + C11 of called terminal side transmission line number L8 is rewritten to E8 + C11-C7. Further, the virtual channel capacity of the virtual channel whose virtual channel number is VCI11 on the called terminal side is rewritten to C7. 3.3.4 Operation to Change Use State to “Use”: In the call connection data 114, the virtual channel used / unused identifier of the virtual channel of the VCI 11 is rewritten to “use” in the called terminal side virtual channel number. 3.3.5 Operation for transmitting control signal to adjacent exchange: L8 as a transmission path number as new call setup request signal 3,
A VCI 11 is created as a virtual channel number, C7 is created as a call capacity, and N7 is created as a called terminal number, and transmitted to the exchange to which the called terminal transmission line L8 is connected through the control signal transmitting unit 112. I do.

(B) When C7> E8: A virtual channel used / unused identifier is "unused" and a virtual channel having a virtual channel capacity of C7 or more exists in the called terminal transmission line L8. In the case, the following operation is performed. 3.4.1 Operation for releasing capacity / route of other virtual channel: In the call connection data, among the virtual channels belonging to the called terminal side transmission line L8, the virtual channel use / unused identifier is “unused”. And the virtual channel having the oldest 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 zero. Further, the free space of the transmission line L8 is rewritten to E8 + C13.

From the called terminal side transmission line number and the virtual channel number in the call connection data 114, the called terminal side transmission line number L8, 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
And deletes the data corresponding to the called terminal side virtual channel VCI 13 belonging to. A release request signal 2 having L8 as the transmission path number and VCI 13 as the virtual channel number is created and transmitted to the exchange to which the called terminal transmission path L8 is connected via the control signal transmission unit 112. Further, a release request signal 2 having L14 as the transmission line number and VCI 14 as the virtual channel number is transmitted to the exchange to which the calling terminal side transmission line L14 is connected via the control signal transmission unit 112.

3.4.2 Operation of Connecting Own Channel: The switch 107 causes 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 to be connected. Connect. 3.4.3 Operation to secure capacity of own channel: In call connection data 114, free capacity E8 + C13 of called terminal side transmission line number L8 is rewritten to E8 + C13-C7.
The virtual channel number of the called terminal is VCI13.
The virtual channel capacity of the virtual channel C7
Rewrite to 3.4.4 Operation to Change Use State to “Use”: In the call connection data 114, the called terminal side virtual channel number rewrites the virtual channel use / unused identifier of the virtual channel of the VCI 13 to “use”.

3.4.5 Control signal transmission operation to adjacent exchange: L8 as transmission line number, VCI 13 as virtual channel number as new call setup request signal 3,
C7 as the call capacity, N7 as the destination, and N7 as the called terminal number
Is created and transmitted through the control signal transmitting unit 112 to the exchange to which the called terminal side transmission line L8 is connected. 3.5 When there is no channel that can be released: If the use state is “unused” and a virtual channel having a virtual channel capacity of C7 or more does not exist in the called terminal transmission line L8, the following is performed. The operation is performed. 3.5.1 Call setting rejection operation: L as transmission line number
7 is generated via the control signal transmitting unit 112 to the exchange to which the calling terminal side transmission line L7 is connected, having a call setting rejection signal having VCI7 as the virtual channel number.

4. Operation when release request signal 1 is received: When the call processor 108 receives the release request signal 1 from the adjacent exchange via 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 read virtual channel VCI15 belonging to the 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), virtual channel capacity ( Read C16). The free space E16 of the called terminal transmission line L16 is changed to E16 +
Rewrite to C16. The virtual channel capacity C16 of the called terminal side virtual channel VCI16 is rewritten to 0. A release request signal 1 having L16 as the transmission path number and VCI 16 as the virtual channel number is created, and transmitted to the exchange to which the transmission path L16 is connected via the control signal transmission unit 112.

4.2 When the release request signal 1 is received from the transmission line on the called terminal side: The transmission line number (L17) and the virtual channel number (VCI17) included in the release request signal 1 are read. The read free space of the called terminal side transmission line L17 (E1
7) is read from the call connection data 114. Further, the virtual channel VCI 17 belonging to the read called terminal transmission line number L17 is searched from the call connection data 114, and the virtual channel capacity (C17), the corresponding calling terminal transmission line number (L18), The call terminal side virtual channel number (VCI 18) is read. The free space E17 of the called terminal transmission line L17 is changed to E17 +
Rewrite to C17. The virtual channel capacity C17 of the called terminal side virtual channel VCI17 is rewritten to 0. A release request signal 1 having L18 as the transmission path number and VCI 18 as the virtual channel number is created and transmitted to the exchange to which the transmission path L18 is connected via the control signal transmission unit 112.

5. Operation when release request signal 2 is received: When the release request signal 2 is received from the adjacent exchange via 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 read virtual channel VCI23 belonging to the 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 free capacity E24 of the called terminal transmission line L24 is changed to E24 +
Rewrite to C24. In the call connection data 114, the virtual channel V
The data corresponding to the CI 24 is deleted. A release request signal 2 having L24 as the transmission line number and VCI 24 as the virtual channel number is created, and transmitted to the exchange to which the called terminal side transmission line L24 is connected via the control signal transmission unit 112.

5.2 When the release request signal 2 is received from the called terminal transmission line: The transmission line number (L25) and the virtual channel number (VCI25) included in the release request signal 2 are read. The read free space (E2
5) is read from the call connection data 114. Further, the virtual channel VCI 25 belonging to the read called terminal transmission line number L25 is searched from the call connection data 114, and the virtual channel capacity (C25), the corresponding calling terminal transmission line number (L26), The call terminal side virtual channel number (VCI 26) is read. The free space E25 of the transmission line L25 on the called terminal side is changed to E25 +
Rewrite to C25. In the call connection data 114, the data corresponding to the virtual channel number VCI25 is deleted. A release request signal 2 having L26 as the transmission line number and VCI 26 as the virtual channel number is created, and transmitted to the exchange to which the calling terminal side transmission line L26 is connected via the control signal transmission unit 112.

6. Operation when a call setting rejection signal is received: When a call setting rejection signal is received from the adjacent exchange via the control signal receiving unit 111, the call processor 108 performs the following operation. The transmission path number (L27), virtual channel number (VCI27), and channel capacity (C2
Read 7). The read virtual channel VCI 27 belonging to the called terminal transmission line L27 is searched from the called terminal number in the call connection data 114, and the corresponding calling terminal transmission line number (L28), calling terminal virtual Channel number (VC
Read I28). 6.1 Operation of setting use state to "unused": in call connection data 114, virtual channel use / unused identifier of called terminal virtual channel VCI 27 belonging to called terminal transmission line L27 is set to "unused". rewrite. 6.2 Operation of sending call setup rejection signal to adjacent exchange:
A call setting rejection signal having L28 as the transmission line number and VCI28 as the virtual channel number is created, and transmitted to the exchange to which the transmission line L28 on the calling terminal side is connected via the control signal transmission unit 112.

7. Operation when a call setting confirmation signal is received: When the call processor 108 receives a call setting confirmation signal from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. The transmission path number (L29), virtual channel number (VCI29), and channel capacity (C2
Read 9). The read virtual channel VCI29 belonging to the called terminal 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 VCI29 are searched. Read. After confirming that C29 = C29 ′, L30 is used as the transmission line number and VCI30 is used as the virtual channel number.
Is created and transmitted to the exchange to which the transmission line L30 is connected via the control signal transmission unit 112.

8. Operation when a call termination signal is received: When the call processor 108 receives a call termination signal from the adjacent exchange through the control signal receiving unit 111, the call processor 108 performs the following operation. First, the transmission line number (L31) and the virtual channel number (VCI31) included in the call end signal are read. The read virtual channel VCI31 belonging to the calling terminal side transmission path 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 path number (L32), and the called terminal side virtual channel number (VCI32). In the call connection data 114, the called terminal transmission line L3
The virtual channel use / unused identifier corresponding to the called terminal side virtual channel VCI 32 belonging to No. 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 destination terminal side transmission line L32 is connected through the control signal transmission unit 112.

Next, the configuration of the ATM subscriber exchange 600 according to one embodiment of the present invention will be described with reference to FIG. The ATM subscriber exchange 600 according to the present embodiment is different from the transit exchange shown in FIG. 1 in that a subscriber line accommodating unit 601, connection data 602, and a subscriber side transmission line 603 are provided. FIG. 8 shows the connection data 602 described above.
, The connection relationship 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 free space of the transmission line included in the called terminal-side transmission line, the virtual Channel capacity,
The usage status ('used', 'unused') and the last use time are included as data. The operation of the ATM subscriber exchange according to the present embodiment is the same as that of the above-described transit exchange. However, in the case of a transit exchange, the control signal transmission unit 112 transmitted to an adjacent exchange, whereas in the case of a subscriber exchange, transmission to the subscriber termination unit of the own exchange is performed. And different.

The operation of the above-described subscriber line accommodation unit 601 will be described below. Upon detecting a call, the subscriber line accommodation unit 601 performs the following operation. 1. When Originating Call is Detected: When the subscriber line accommodation unit 601 detects an outgoing call, it reads the subscriber-side transmission line number (L22) and the subscriber-side virtual channel number (VCI 33) that made the call. From the call signal, the destination terminal number (N33) and the call capacity (C
Read 33). In the connection data 602, the transmission line L read above
A search is made for a called terminal number corresponding to the virtual channel VCI 33 belonging to the V.33. 1.1 When there is a channel: the above called terminal number is N
Virtual channel (VC
I34), in the connection data 602,
The transmission line number L34, the capacity C34, and the free space E34 of the transmission line on the calling terminal side corresponding to the virtual channel number VCI34 on the calling terminal side are read. Connection terminal number is N
If 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 and route are secured: C34
In the case of = C33, a call setup request signal 1 having L33 as the transmission path number and VCI 33 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 the transmission path number and VCI34 as the virtual channel number is created and transmitted to the call processor 108. 1.1.2 In the case of E34 <C33: When there is a virtual channel connected to the terminal having the called terminal number N33 on a transmission line other than the transmission line L34 on the calling terminal side: Section 1.1 (when the channel is (If any). Otherwise: The call is regarded as a call loss, and the call setting procedure is terminated.

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

2. When the end of the call is detected: When the subscriber line accommodating unit 601 detects the end of the call, the subscriber-side transmission line number (L37) and the subscriber-side virtual channel number (VCI 37) at which the call is ended are read. . Also, the time at which the call was terminated (T
Read 37). In the connection data 602, the transmission line L read above
37. The called terminal-side transmission line number (L38), the called terminal-side transmission line free space (E38), and the called terminal-side virtual channel number (V
CI38) is read. Using the virtual channel of the virtual channel VCI 38 belonging to the read called terminal side transmission path number L38
Rewrite unused identifiers to 'unused'. Further, the virtual channel use end time is rewritten to T37. A call termination signal having L38 as the transmission path number and VCI38 as the virtual channel number is created and transmitted to the call processor 108.

3. When the call setting request signal 1 is received: When the call setting request signal 1 is received from the call processing processor 108, the subscriber line accommodating unit sets the transmission line number (L39) and the virtual channel number included in the call setting request signal 1. (V
CI39) is read. In the connection data 602, the calling terminal side transmission path L39
, The subscriber-side transmission line number (L40), the subscriber-side virtual channel number (VCI40), and the terminating terminal number (N40) corresponding to the virtual channel VCI39 belonging to.
Further, the virtual channel use / unused identifier of the virtual channel VCI 39 belonging to the calling terminal side transmission line L39 is rewritten to “use”. A call setup confirmation signal having L40 as the transmission path number and VCI40 as the virtual channel number is created and transmitted to the call processing processor 108. The called 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 sets the transmission line number (L41) and the virtual channel number included in the call setup request signal 2. (V
CI41) is read. In the connection data 602, the calling terminal side transmission line L41
The subscriber-side transmission line number (L42), the subscriber-side virtual channel number (VCI42), and the terminating terminal number (N42) corresponding to the virtual channel VCI41 belonging to.
Further, the virtual channel use / unused identifier of the virtual channel VCI41 belonging to the calling terminal side transmission line L41 is rewritten to “use”. A call setting confirmation signal having L41 as the transmission path number and VCI41 as the virtual channel number is created and transmitted to the call processor 108. The called terminal N42 is connected to the virtual channel number VCI42 belonging to the subscriber side transmission line L42.

5. When the call setting request signal 3 is received: When the call setting request signal 3 is received from the call processor 108, the subscriber line accommodating unit sets the transmission line number (L43) and the virtual channel number included in the call setting request signal 3. (V
CI43) is read. In the connection data 602, the calling terminal side transmission line L43
, The subscriber-side transmission line number (L44), the subscriber-side virtual channel number (VCI44), and the terminating terminal number (N44) corresponding to the virtual channel VCI43 belonging to.
Further, the virtual channel use / unused identifier of the virtual channel VCI 43 belonging to the calling terminal side transmission line L43 is rewritten to “use”. A call setting confirmation signal having L43 as the transmission path number and VCI 43 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 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 accommodating unit transmits 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
Is rewritten to zero. 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 accommodating unit transmits 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 a call setting rejection signal is received: The transmission path number (L4
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 setting confirmation signal is received: The transmission path number (L4
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 to As described above in detail, according to the above-described embodiment, when communicating with the same communication partner, if there is room for both the capacity of the transmission path and the virtual channel number, the ATM repeater exchanges the page 4-5. 1. Since only the operation of the item needs to be performed, the number of processes can be reduced, and in a communication network in which communication between the same terminals is large, the load on the exchange can be significantly reduced.

Next, another embodiment of the present invention will be described. This embodiment is different from the first embodiment in that a plurality of exchanges are connected to a centralized center, and in a system configured to be controlled from the centralized center, the centralized center has call connection data. The transit exchange does not need to make any call connection determination regarding call setting. FIG. 9 illustrates a centralized center (hereinafter, referred to as a centralized center)
FIG. 1 shows a configuration diagram of a “control center”. The control center 800 according to the present 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 denotes a control signal receiving unit that receives a control signal, 804 denotes a control signal transmitting unit that transmits a control signal, 805 denotes a processor that performs call processing, and 806 denotes a method between the calling terminal and the called terminal by any method. Call setup route data corresponding to a predetermined call route, 807 is call connection data storing a connection state of a virtual channel set in an exchange in the network, and 808 is an exchange number to which the transmission path is connected. 809, transmission line corresponding data in which
Indicates connection data holding a call connection state of the subscriber line accommodating unit 1201 described later.

FIG. 10 shows the above-described call setting route data 806.
The transmission path accommodating the virtual channel set between the calling terminal and the called terminal is associated with the order in which the call passes. FIG.
Indicates the information content included in the call connection data 807. In all the exchanges in the network, the calling terminal side transmission line number, the calling terminal side virtual channel number, the called terminal side transmission line number, the called terminal Call terminal side transmission line free space capacity, route number, called terminal side virtual channel number, virtual channel capacity, virtual channel use state ('use',
'Unused') and last use time are included as data. 12 and 13 show the connection data 80 described above.
9 indicates a calling terminal number, a called terminal number, a path number, and a called terminal virtual number corresponding to a virtual channel belonging to a called terminal transmission line in the subscriber line accommodating unit 1201. Channel number, virtual channel capacity, virtual channel usage status
('Use', 'Unused') and last use time are included as data. FIG. 14 shows information contents included in the transmission line correspondence data 808, which includes a transmission line number for connecting each exchange as data.

FIG. 15 is a block diagram of the ATM switching system 1100 according to this embodiment.
Are the components 10 in the first embodiment described above.
These correspond to items 1 to 112. Reference numeral 1114 denotes call connection data storing 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 the subscriber system exchange 1200, 110 in the figure.
Numerals 1 to 1112 denote the same components as those of the ATM switch 1100 shown in FIG.
Reference numeral 1201 denotes a subscriber line accommodating unit; 1202, connection data; 1203, a subscriber-side transmission path. FIG.
15 shows information contents included in the call connection data 1114 of the ATM switching system 1100 shown in FIG. 15, and includes a virtual channel belonging to the calling terminal side transmission line 1101 and a 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 included in the call connection data 1114 of the ATM subscriber exchange 1200 shown in FIG. 16, and shows the virtual channel belonging to the subscriber side transmission line 1203 and the called terminal side. Transmission line 1102
The connection relation with the virtual channel belonging to the group is included as data. FIG. 19 shows control signal lines 1201 and 120
2 shows the information content included in the control signal transmitted through the control signal 2. FIGS. 19 (a), (b) and (c) respectively show
It shows information included in the call connection signal, the call disconnection signal, and the route release signal. FIG. 20 shows control signal lines 1201 and 1
2 shows the information content included in the control signal transmitted through 202. FIGS. 20 (a), (b), and (c) show information included in the call setup request signal, the call loss signal, and the call end signal, respectively. Hereinafter, the operation of the present embodiment will be described. First, the operation of the subscriber line accommodating unit 1201 in the ATM subscriber exchange 1200 will be described.

1. When a call is detected: When the subscriber line accommodating unit 1201 detects a call, the subscriber's transmission line number (L50) and the subscriber's virtual channel number (VCI50) from which the call was made are read. From the call signal, calling terminal number (N50), called terminal number
(N51), the call capacity (C50) is read. N50 as the calling terminal number and N5 as the called terminal number
1. A call setup request signal having C50 as the call capacity is created, and the control signal transmission unit 111
Send through 2. 2. When the end of the call is detected: subscriber line accommodation unit 1201
Performs the following operation when detects the end of the call. When the termination of the call is detected, the transmission line number (L52) and the virtual channel number (VCI52) of the subscriber transmission line where the termination of the call has occurred are read.

A call termination signal having L52 and a virtual channel number VCI52 as a transmission path number is created and transmitted to the control center 800 through a control signal transmission unit 1112. 3. When a call connection signal is received: When the subscriber line accommodation unit 1201 receives a call connection signal from the control center 800, the subscriber line accommodation unit 1201 performs the following operation. The calling terminal side transmission path number (L5
3), the calling terminal side virtual channel number (VCI5
3) The called terminal side transmission path number (L54) and the called terminal side virtual channel number (VCI54) are read. In the call connection data 1114, the read virtual channel VC belonging to the calling terminal side transmission path L53 is read.
The data is rewritten so that I53 and the virtual channel VCI 54 belonging to the called terminal transmission line L54 are connected. Connect the call and end the call setup procedure.

4. When a call loss signal is received: When receiving a call loss signal from the control center 800, the subscriber line accommodation unit 1201 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 regarded as a call loss, and the call setting procedure ends. 5. When a route release signal is received: When receiving a route release signal from the control center 800, the subscriber line accommodation unit 1201 performs the following operation. Calling terminal side transmission path number (L5
7), calling terminal side virtual channel number (VCI5
7) The called terminal side transmission path number (L58) and the called terminal side virtual channel number (VCI 58) are read. In the connection data 1202, the calling terminal side transmission line L5
The data of the subscriber-side transmission path and the subscriber-side virtual channel corresponding to the virtual channel VCI 57 belonging to 7 are deleted.

6. When a call disconnection signal is received: When receiving a call disconnection signal from the control center 800, the subscriber line accommodating unit 1201 performs the following operation. 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 the call connection signal is received from the control center 800: The transmission line number (L6
1), calling terminal side virtual channel number (VCI6
1) The called terminal side transmission path number (L62) and the called terminal side virtual channel number (VCI62) are read. In the call connection data 1114, the calling terminal side transmission path L
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 path release signal from the control center 800, the call processor 1108 performs the following operation. Calling terminal side transmission path number (L6
7), the calling terminal side virtual channel number (VCI6
7) The called terminal side transmission path number (L68) and the 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 7 is deleted. Hereinafter, the operation of the control center 800 will be described. 1. When a call setting request signal is received: control signal receiving unit 8
Upon receiving the call setting request signal from the subscriber line accommodating unit 1201 through the call 03, the call processor 805 performs the following operation. The calling terminal number (N69) and the called terminal number (N70) included in the call setting request signal are read in the call capacity (C70). Also, the subscriber line accommodating unit number (S
69), the exchange number (SW69) is read.

The connection data 809 is searched to determine whether or not a virtual channel connecting the calling terminal N69 and the called terminal N70 exists in the subscriber line accommodation unit S69. 1.1 If there is a route setting and the capacity is secured:
In the connection data 809, if a 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 connecting the calling terminal N69 and the called terminal N70 is searched for from among the virtual channels belonging to the subscriber line accommodating unit S69, and the calling terminal side transmission line number (L70), calling Call terminal side virtual channel number (VCI70), called terminal side transmission line number
(L71), the called terminal's virtual channel number (VCI
Read 71).

In the connection data 809, the virtual channel used / unused identifier of the called terminal virtual channel VCI 71 in the called terminal transmission line L71 belonging to the subscriber line accommodation unit S69 is rewritten to “use”. The call connection data 807 is searched for the calling terminal side virtual channel VCI71 in the calling terminal side transmission line L71 belonging to the exchange SW69, and the corresponding called terminal side transmission line is searched.
(L72), called terminal side virtual channel (VCI71)
Read. The called terminal side virtual channel VCI7 in the called terminal side transmission line L72 belonging to the exchange SW69 read above.
Rewrite the virtual channel use / unused identifier corresponding to No. 2 to “use”. In the transmission path correspondence data 808, the exchange number (SW73) to which the called terminal transmission path L72 belonging to the exchange SW69 is connected is read.

Next, in the call connection data 807, the called terminal side transmission line (L73) corresponding to the calling terminal side virtual channel VCI71 in the calling terminal side transmission line L72 belonging to the exchange SW73 and the called terminal side virtual Read the channel (VCI 73). The called terminal side virtual channel VCI7 in the called terminal side transmission line L73 belonging to the exchange SW73 read above.
Rewrite the virtual channel use / unused identifier corresponding to No. 3 to “use”. The above procedure is repeated until the virtual channel use / 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 use / unused identifier to “use” 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 unit S69 through the control signal transmission unit 804.

1.2 When there is a route setting and the capacity is 0: In the connection data 809, a virtual channel for connecting the calling terminal N69 and the called terminal N70 is set, and when the capacity is 0, The operation is performed. In the connection data 809, a virtual channel connecting the calling terminal N69 and the called terminal N70 is searched for from among the virtual channels belonging to the subscriber line accommodating unit S69, and the calling terminal side transmission line number (L70), calling Call terminal side virtual channel number (VCI70), called terminal side transmission line number
(L71) and the virtual channel number (V
CI71) is read. In the connection data 809, the transmission line free capacity (E7) of the called terminal transmission line L71 belonging to the subscriber line accommodation unit S69.
Read 1). 1.2.1 When E71 ≧ C70: Transmission line free space capacity E7
When 1 is equal to or larger than the call capacity C70, the following operation is performed.

In the connection data 809, the virtual channel capacity of the called terminal side virtual channel VCI72 in the called terminal side transmission line L71 belonging to the subscriber line accommodation unit S69 is set to C70, and the virtual channel use / unused identifier is set to Rewrite to 'use'. Next, in the call connection data 807, the calling terminal side virtual channel V71 in the calling terminal side transmission line L71 belonging to the exchange SW69 connected to the subscriber line accommodation unit S69.
CI 71 is searched, and the corresponding transmission line number (L
72), the called terminal side virtual channel number (VCI7
Read 2). In the call connection data 807, the transmission line free space (E72) of the called terminal transmission line L72 belonging to the exchange SW69 is read. A comparison is made between the transmission line free capacity E72 and the call capacity C70,
If E72 ≧ C70, the operation (a) is performed. If E72 <C70, the following operation is performed.

1.2.2 In the case of E71 <C70: When the available transmission path capacity E71 is smaller than the call capacity C70, the connection data 807 indicates that the transmission path free capacity E71 is in the called terminal transmission path L71 belonging to the subscriber line accommodation unit S69. A search is made for a virtual channel in which the virtual channel use / unused identifier is “unused” and a virtual channel capacity of C70 or more is secured. (a) Called terminal side transmission line L belonging to subscriber line accommodation unit S69
If the virtual channel use / unused identifier is “unused” in 71 and there is a virtual channel securing a virtual channel capacity of C70 or more, the following operation is performed. The called terminal transmission line L7 belonging to the subscriber line accommodation unit S69.
In step 1, among the virtual channels whose virtual channel use / unused identifier is “unused” and which secures the virtual channel capacity of C70 or more, the virtual channel with the oldest use end time is selected and the call is received. The terminal-side virtual channel number (VCI 74) and virtual channel capacity (C74) are read.

The following virtual channel capacity releasing operation is performed for the called terminal side virtual channel VCI 74 belonging to the called terminal transmission line L71. In the transmission path correspondence data 808, the exchange number (SW73) to which the called terminal transmission path L72 belonging to the exchange SW69 is connected is read. In the call connection data 807, the transmission line free capacity (E72) of the calling terminal side virtual channel VCI72 in the calling terminal side transmission line L72 belonging to the exchange SW73 is read. The same operation as described in the above item 1.1 or 1.2 is performed by comparing the read transmission line empty capacity E72 with the call capacity C70.

1.2.3 Release operation of virtual channel capacity: (A) In connection data 809, subscriber line accommodation unit S69
Is rewritten to E71 + C74 in the called terminal side transmission line L71 belonging to. (I) In the call connection data 807, the subscriber line accommodation unit S6
9 on the calling terminal side transmission line L71 belonging to the connected switch SW69 connected to the calling terminal side.
The transmission line number (L74) and the virtual channel number (VCI 74) of the called terminal corresponding to 74 are read. (C) In the transmission line correspondence data 808, the exchange number (SW75) to which the called terminal transmission line L74 belonging to the exchange SW69 connected to the subscriber line accommodation unit S69 is connected.
Read. (E) In the call connection data 807, the called terminal transmission line number corresponding to the calling terminal virtual channel VCI74 in the calling terminal transmission line L74 belonging to the exchange SW75.
(L75), called terminal side virtual channel number (VCI
Read 75).

Next, in the transmission path correspondence data 808, the called terminal transmission path number L7 belonging to the exchange SW75
The exchange number (SW76) to which the connection No. 5 is connected is read. If the same operation is performed and a subscriber line accommodating unit that terminates the virtual channel whose capacity is to be released is searched, the virtual channel of the virtual channel whose capacity is to be released is rewritten to 0 in the connection data 809. (b) Called terminal side transmission line L belonging to subscriber line accommodation unit S69
If the virtual channel use / unused identifier is “unused” in 71 and there is no virtual channel securing the virtual channel capacity of C70 or more, the following operation is performed. The called terminal transmission line L7 belonging to the subscriber line accommodation unit S69.
If the virtual channel use / unused identifier is "unused" in 1 and there is no virtual channel securing 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. A call loss signal is generated and transmitted to the subscriber line accommodating unit 1201 through the control signal transmitting unit 804.

1.3 When no route is set and no capacity is set: If there is no setting of a virtual channel connecting the calling terminal N69 and the called terminal N70 in the connection data 809, the following operation is performed. In the call setup route data 806, one of the routes set between the calling terminal N69 and the called terminal N70 is selected, and the route number (R79), the number of the exchange in the order of passing, and the number of the The number of the called terminal transmission line to be accommodated is read. In the connection data 809, the subscriber line accommodation unit (S69)
Transmission line free capacity of the called terminal transmission line (L80) belonging to
Read (E80). Further, it searches for an unused virtual channel number in the called terminal transmission line L80 belonging to the subscriber line accommodation unit S69.

1.3.1 When E80 ≧ C70 and there is an empty virtual channel number: (a) Release operation of virtual channel capacity: (a) In connection data 809, subscriber line accommodation unit S69
The unused virtual channel number (VCI80) on the called terminal side in the called terminal transmission line L80 belonging to. (I) In the connection data 809, the subscriber line accommodation unit S69
The unused virtual channel on the called terminal side in the called terminal transmission line L80 belonging to
Route number R79, calling terminal side virtual channel number in calling terminal side transmission line (L70) belonging to subscriber line accommodation unit S69 to which calling terminal N70 and calling terminal N69 are connected.
(VCI 70), the calling terminal number N69, the virtual channel capacity to C70, and the virtual channel use / unused identifier to "use". Also, call connection data 807
In the transmission line (L81) belonging to the exchange (SW69) to which the subscriber line accommodation unit S69 is connected,
A search is performed for an unused virtual channel number, and a corresponding operation is performed based on the search result.

Next, in the call connection data 807,
In the exchange (SW82) located next on the route of the virtual channel to be set, search is made as to whether there is an unused virtual channel number in the called terminal 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, a call connection signal having N70 as the calling terminal number is sent. A control signal transmitting unit 8 is provided to all the subscriber line accommodating units and exchanges which have been read as the created and set routes.
04 for transmission.

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

Regarding the called terminal side virtual channel VCI 83 belonging to the called terminal side transmission line L80, 1.2.3
In accordance with the operation of releasing the virtual channel capacity described in the paragraph (pages 33 to 34), the virtual channel capacity of the subscriber line accommodating unit that terminates the virtual channel whose capacity is released is set to 0.
Rewrite to Further, in the call connection data 807, the exchange (SW6) to which the subscriber line accommodating unit S69 is connected.
A search is made for an unused virtual channel number in the calling terminal side transmission path (L81) belonging to 9), and a corresponding operation is performed based on the result. Next, in the call connection data 807, the switch (SW84) located next on the route of the virtual channel to be set
In step (2), it is searched whether there is an unused virtual channel number in the called terminal transmission line (L84) belonging to the exchange SW84 read as the route, and the corresponding operation is performed based on the result. When the above operation is repeated and the data change of the connection data 809 of the subscriber line accommodating section (S85) accommodating the called terminal N70 is completed, the call having the calling terminal number N69 and the called terminal number N70. A connection signal is created and transmitted through the control signal transmission unit 804 to all the subscriber line accommodating units and exchanges read as a path to be set.

(B) When there is no virtual channel whose virtual channel use / unused identifier is “unused”:
If there is no virtual channel whose virtual channel use / 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 accommodating unit is created. In response to S69, transmission is performed through the control signal transmission unit 804. 1.3.3 When E80 <C70: Transmission Line Free Space E8
If 0 is less than the call capacity C70, the connection data 80
9, the called terminal whose virtual channel use / unused identifier is "unused" and whose virtual channel capacity is equal to or greater than the call capacity C70 in the called terminal transmission line L80 belonging to the subscriber line accommodating unit S69. Search for the presence or absence of the side virtual channel. (a) The virtual channel use / unused identifier is "unused" and the virtual channel capacity is the call capacity C7.
If there is a virtual channel that is 0 or more:

When there is a virtual channel whose virtual channel use / unused identifier is “unused” and whose virtual channel capacity is equal to or greater than the call capacity C70,
The following operation is performed. In the connection data 809, the transmission line free capacity (E) in the called terminal transmission line L80 belonging to the subscriber line accommodation unit S69.
Read 80). The virtual channel used / unused identifier in the called terminal transmission line L80 belonging to the subscriber line accommodating unit S69 is "unused" and the virtual channel capacity is equal to or larger than the call capacity C70. , The virtual channel having the oldest use end time is selected, and the virtual channel number (VCI
86), the virtual channel capacity (C86) is read. The following virtual channel release operation is performed for the called terminal virtual channel VCI 86 belonging to the called terminal transmission line L80. When the release operation is completed, in the connection data 807, the data corresponding to the virtual channel VCI 86 on the called terminal side, the transmission line number of the called terminal side is L80, the free space of the transmission line is E80-C70,
The called terminal side virtual channel number 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 to

(A) Release operation of virtual channel: (A) In connection data 809, subscriber line accommodation unit S69
The transmission line free capacity of the called terminal transmission line L80 belonging to
Rewrite to 80 + C70. In addition, the subscriber line accommodation unit S6
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. (I) In the call connection data 807, the subscriber line accommodation unit S6
9 on the calling terminal side transmission line L80 belonging to the connected switch SW69 connected to the calling terminal side.
The virtual channel number (V
CI87), and reads the transmission line number (L87) of the called terminal.

(C) In the transmission line correspondence data 808, the exchange number (SW88) which is the connection destination of the called terminal transmission line L87 belonging to the exchange SW69 connected to the subscriber line accommodation unit S69 is read. (E) Next, in the call connection data 807, the exchange SW8
8 and the called terminal transmission line number (L88) in the calling terminal transmission line 87 and the called terminal virtual channel number.
(VCI88) is read. (E) In the transmission path correspondence data 808, the exchange SW 88
Exchange number (SW) to which the transmission line L88 belonging to
Read 89). (A) The same operation is performed, and the data is deleted up to the subscriber line accommodating unit that terminates the virtual channel to be released.

The call connection data 807 is searched for an unused virtual channel number in the calling terminal side transmission line (L80) belonging to the exchange (SW69) to which the subscriber line accommodating unit S69 is connected. The corresponding operation is performed based on the result. In the call connection data 807, on the route of the virtual channel to be set, in the next switch (SW90), the unused virtual channel number in the called terminal transmission line (L90) belonging to the switch SW90 read as the route is read. A search is performed to determine whether or not there is, and a corresponding operation is performed 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, a 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 the subscriber line accommodation units and exchanges read as the route to be set.

(B) When the virtual channel use / unused identifier is “unused” and there is no virtual channel whose virtual channel capacity is equal to or greater than the call capacity C70: the virtual channel use / unused identifier is “unused”. 'And the virtual channel capacity is the call capacity C7.
If there is no virtual which is 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 accommodation unit S69 through the control signal transmission unit 804. 2. When a call end signal is received: control signal receiving section 803
Upon receiving the call end signal from the subscriber line accommodating unit 1201, 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, a search is made for a virtual channel connecting the calling terminal N92 and the called terminal N93 read above, and the number of the subscriber line accommodating unit or exchange to be passed and the route to be passed. Read all the numbers of the transmission lines on the called terminal side accommodated in the subscriber's orchid accommodation section or the exchange. In the connection data 809, the virtual channel for the called terminal N93 and the virtual channel for the called terminal N93 are set in the called terminal transmission line (L94) belonging to the subscriber line accommodation unit (S94) accommodating the calling terminal N92 read above. Channel use
Search for the called terminal virtual channel whose unused identifier is 'used', and call the called terminal virtual channel number.
(VCI94) is read.

In the connection data 809, the called terminal transmission line L belonging to the subscriber line accommodation unit S94 read above
The virtual channel use / unused identifier corresponding to the called terminal side virtual channel VCI 94 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
Of 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 connected exchange (SW94). In the transmission path corresponding data 808, the exchange number (SW96) which is the connection destination of the called terminal transmission path L95 belonging to the exchange SW94 is read. Next, in the call connection data 807, the exchange SW 96
The virtual channel number (VCI96) of the called terminal corresponding to the virtual channel VCI95 of the calling terminal in the calling line L95 belonging to
Read (L96).

The called terminal side virtual channel VCI 96 in the called terminal side transmission line L96 belonging to the exchange SW96.
Is rewritten to "unused" and the use end time is rewritten to the time at which the signal was received. By repeating the above procedure and completing the change of the connection data of the subscriber line accommodation unit (S97) accommodating the called terminal N93, the call having the calling terminal number N92 and the called terminal number N93. A disconnection signal is created and transmitted to the subscriber line accommodating unit that sent the call termination 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 transit exchange, the processing at the transit exchange becomes unnecessary when the capacity is changed. And the load on the exchange can be reduced. Also, it is possible to reduce the physical quantity as compared with a case where each relay exchange has connection data individually.

FIG. 21 is a flowchart showing the outline of the operation of the present invention. FIGS. 22 to 24 show the details of the parts (a) to (c) in FIG. Please refer to it. Further, each of the embodiments described above is an example of the present invention, and it is needless to say that the present invention should not be limited thereto.

[0077]

As described above in detail, according to the present invention, an ATM switch and a ATM switch which can reduce the load at the time of setting up a call by retaining the channel once connected. This has a remarkable effect of realizing a system using.

[0078]

[Brief description of the 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 information contents of call setting route data 113 according to the embodiment.

FIG. 3 is a diagram showing information contents 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 illustrating information contents of release request signals 1 and 2 according to the embodiment.

FIG. 6 is a diagram illustrating information contents of a call setting rejection signal, a call setting 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 contents of connection data 602 according to the embodiment.

FIG. 9 shows a control center 800 according to a second embodiment of the present invention.
FIG.

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 contents of call connection data 807 according to the embodiment.

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

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

FIG. 14 is a diagram illustrating information contents of transmission line correspondence data 808 according to the embodiment.

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

FIG. 16 is an ATM subscriber system exchange 120 according to the embodiment.
FIG.

FIG. 17 is a diagram showing information contents of call connection data 1114 of the ATM switching system 1100 according to the embodiment.

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

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

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

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

FIG. 22 is a detailed view of part (a) in the flowchart shown in FIG. 20;

FIG. 23 is a detailed view of a part (b) in the flowchart shown in FIG. 20;

FIG. 24 is a detailed view of a part (c) in the flowchart shown in FIG. 20;

[Explanation of symbols]

100: ATM transit exchange, 101, 102: transmission line,
103, 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 accommodating 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 path corresponding data, 80
9: connection data, 1100: ATM transit exchange, 110
1, 1102: transmission path, 1103, 1104: virtual channel, 1107: switch, 1108: call processor, 1109: control signal input line, 1110: control signal output line, 1111: control signal receiving section, 1112: control signal transmission Section, 1114: call connection data, 1201: subscriber line accommodation section, 1202: connection data, 1203: subscriber side transmission line.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H04L 12/56 H04L 12/28

Claims (4)

(57) [Claims] 1. An ATM exchange for setting and releasing an arbitrary virtual channel between an incoming transmission line and an outgoing transmission line in an ATM communication network. Means for holding, and means for causing the network path / 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. ATM switch. 2. In addition to the means, the capacity of the virtual channel, whose path and capacity have been held in the network by the holding means, is redirected to a request for setting a new virtual channel for another communication. 2. The ATM exchange according to claim 1, further comprising means for setting a virtual channel. 3. In addition to the above-mentioned means, when performing communication again using the above-mentioned virtual channel whose path and capacity have been held by the holding means, another virtual channel not used for communication is used. 3. The ATM switch according to claim 1, further comprising means for setting the communication virtual channel by reducing the capacity of the ATM switch. 4. The ATM according to claim 1, wherein:
In a system having a centralized center connected to an exchange, a system for using an ATM exchange, wherein the centralized center is provided with means for maintaining a network route / capacity of a virtual channel after the end of the communication.