JPH11122247A - Cell disassembly / assembly apparatus and ATM communication system - Google Patents

Abstract

(57) [PROBLEMS] To provide a CLAD device and an ATM communication system to simultaneously enable a point-to-point SVC connection of a service interface accommodated in each of the multi-stage connected CLAD devices. SOLUTION: An SVC connection establishing means 6 performs a point-to-point UNI between an ATM exchange 1 and an own apparatus 2.
Perform signaling to establish SVC connection. With the establishment of the SVC connection, the storage means 9 stores the SVC connection channel identifier assigned by the ATM exchange 1 in the correspondence table 5 in association with the PVC connection channel identifier already assigned to the user terminal 4. . A
When receiving the cell including the SVC connection channel identifier from the TM exchange 1, the first transfer means 7
And converts it to a PVC connection channel identifier, and transmits it to another CLAD device 3. Also, the second transfer means 8
The reverse conversion process is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell disassembly / assembly apparatus and an ATM (Asyncronous Transfer Mode) communication system. The present invention relates to a CLAD device to which a cell assembly and disassembly device is connected, and an ATM communication system in which an ATM network accommodates a plurality of CLAD devices connected in tandem or in parallel by an ATM interface.

A CLAD device converts data from a service interface into cells according to an AAL (ATM Adaptation Layer) and sends the cells to an ATM interface.
This is an ATM network terminating device which decelerates cells from the interface according to the AAL and sends it to the service interface. The CLAD device is connected to an ATM exchange via an ATM interface and has a plurality of CLs under its control.
AD devices are connected in tandem or in parallel via an ATM interface (cell relay interface). A user terminal is connected to each CLAD device via a corresponding service interface. The present invention provides a point-to-point UNI (User-Network Interface) of a CLAD device.
rface) signaling function, ATM switch and CL
SVC (Switc) between the user terminal connected to the AD device
hed Virtual Circuit).

[0003]

2. Description of the Related Art FIG. 7 is a diagram illustrating a conventional ATM communication system in which a plurality of CLAD devices are connected in multiple stages. In FIG. 7, an ATM switch 101 is provided in the ATM network, and the ATM switch 101 has a CLAD device (# 1) 1
02 is connected via an ATM interface. CL
Under the AD device (# 1) 102, CLAD devices (# 21) 103 are connected in cascade via a cell relay interface, and CLAD devices (# 22) 104 are connected in cascade via a cell relay interface. .
Further, the CLAD device (# 31) 105 is connected to the CLAD device (# 22) 104 via the cell relay interface.
Are connected in tandem. CLAD device (# 1) 102, C
LAD device (# 21) 103, CLAD device (# 22)
104, CLAD device (# 31) 105,
Various user terminals are connected via various service interfaces. As the user terminal, for example, a private branch exchange (PBX), a TDM device (TDM), a video device (VI
DEO). The service interface is a communication protocol used in digital lines such as a line speed of 1.5 Mbps, 2 Mbps, and 6 Mbps, and is a protocol used in a PBX trunk line, a TDM trunk line, or an ISDN.
Refers to the primary group interface.

FIG. 8 is a diagram exemplifying an internal configuration of the CLAD device (# 1) 102. CLAD device (# 21) 1
03, the CLAD device (# 22) 104, and the CLAD device (# 31) 105 have almost the same configuration.

In FIG. 8, a CLAD device (# 1) 10
2 is a main controller 110 and an ATM interface controller 1
11, service a interface control unit 112, service b interface control unit 113, service c interface control unit 114, cell relay interface # 121
It comprises a control unit 115, a cell relay interface # 122 control unit 116, and the like. The ATM interface control unit 111 includes a service a interface control unit 112, a service b interface control unit 113, a service c interface control unit 114, and a cell relay interface # 1.
21 and a cell relay interface # 122.
The cell transmitted to the M interface (line) and the cell transmitted from the ATM interface (line) are disassembled, and the service a interface control unit 112, the service b interface control unit 113, the service c interface control unit 114, the cell relay interface # 121 control unit 11
5, has a function of transmitting to the cell relay interface # 122 control unit 116, respectively.

[0006] The service a interface control unit 112,
The service b interface control unit 113 and the service c interface control unit 114 respectively convert the digital data sent from the corresponding service interface (line) into
The cell is formed together with the channel identifier designated by the main control unit 110 and the ATM interface control unit 111
And has a function of de-celling cells having the channel identifiers specified by the main control unit 110 among the cells passed from the ATM interface control unit 111 and transmitting the cells to the corresponding service interface (line). The channel identifier is stored in the header of the cell.
This is a label for identifying the channel, and is a VPI (Virtu
al Path Identifier) and VCI (Virtual Channel Identifier)
ifier).

Cell relay interface # 121 control unit 1
15. The cell relay interface # 122 control unit 116 passes the cells having the channel identifiers respectively designated from the main control unit 110 to the ATM interface control unit 111 among the cells transmitted from the corresponding cell relay interface (line). In addition, among the cells passed from the ATM interface control unit 111, the main control unit 110 has a function of transmitting cells having the channel identifiers respectively designated to the corresponding cell relay interface.

[0008] The main control unit 110 decomposes / receives cells having channel identifiers for point-to-point signaling transmitted and received by the ATM interface control unit 111.
In addition to controlling the assembling process, performing signaling control based on control information extracted from the cell,
It has a function of controlling transmission and reception of AM (Operataion and Maintenance) cells, and a function of controlling the entire apparatus.

The main control unit 110 includes an ATM interface control unit 111, a service a interface control unit 112, a service b interface control unit 113, a service c interface control unit 114, a cell relay interface # 121 control unit 115, a cell relay interface Instruct one of the # 122 control units 116 (ACTIVATE / DEA
By sending (CTIVATE), the start / stop of the processing operation of the apparatus can be controlled.

Here, the SVC connection of the CLAD device will be described. Service a to CLAD device (# 1) 102
The SVC connection between the PBX and the ATM switch 101 connected via the interface will be described as an example.

In order to make the SVC connection, it is necessary to perform UNI signaling for the SVC connection between the ATM switch 101 and the CLAD device (# 1) 102. First, the normal ATM exchange 1
01, a channel identifier for SVC connection (for example, SVC # 1a) is dynamically allocated.
When the channel identifier of the cell to be transferred is determined, the ATM exchange 101 can transmit and receive the cell having the determined channel identifier SVC # 1a on the ATM interface with the CLAD device (# 1) 102. The settings are made. The CLAD device (# 1) 102 also transmits and receives a cell having the determined channel identifier SVC # 1a on the ATM interface with the ATM exchange 101 by a predetermined operation (usually software control by the main control unit 110). The settings are made to be possible. That is, the main control unit 110 activates (ACTIVATE) the ATM interface control unit 111, and furthermore, the service a interface control unit 11 transmits and receives the cell via the service a interface control unit 112.
2 is activated (ACTIVATE) by a predetermined operation (normally, software control by the main control unit 110).

The above description shows the principle of the SVC connection process. Usually, the CLAD device (# 1)
In the ATM interface control unit 111 of 102, UN
In order to enable transmission and reception of cells having information other than user data, such as cells carrying I signaling information and OAM cells, transmission and reception of cells having channel identifiers related to such cells are enabled in advance. Then, after the channel identifier of the transfer cell is determined by the UNI signaling, transmission / reception of only the cell having this channel identifier is performed by the service a interface control unit 112.
The service a interface control unit 112 is activated (ACTIVATE) by a predetermined operation.

[0013]

However, next, CLA
When the SVC connection is attempted between the PBX connected to the D device (# 21) 103 via the service a interface and the ATM switch 101, the following problem occurs.

That is, the ATM switch 101 and the CLAD
If a signaling path has previously been established with the device (# 1) 102, the signaling path for implementing UNI signaling is originally terminated one-to-one between the user and the network (point-to-point).・ Point / signaling form), the CL of the CLAD device (# 21) 103 etc.
A signaling path cannot be established between the CLAD device under the control of the AD device (# 1) 102 and the ATM switch 101.

In other words, the CLAD device (# 1) 10
In order to implement an SVC connection between the CLAD device (# 21) 103 under two
It is necessary to configure the CLAD device (# 21) 103 to terminate the signaling path without terminating the signaling path in the D device (# 1) 102. Specifically, in the CLAD device (# 1) 102, a cell having a channel identifier for point-to-point signaling (for example, VPI = 0, VCI = 5) is assigned to the main control unit 1.
The transfer is performed to the cell relay interface # 121 control unit 115 without performing the signaling control by the C.10. That is, the CLAD device (# 1) 102 and the CL
At the cell relay interface # 121 with the AD device (# 21) 103, transmission and reception of cells having a signaling channel identifier by PVC connection are performed. Thereby, the ATM switch 101 and the CLAD device (# 2
1) A signaling path is established between the CLAD device (# 21) 103 and the service a interface accommodated in the CLAD device (# 1) 102. SVC connection of the accommodated service a interface can be realized.

As is apparent from the above description, the conventional C
In an ATM communication system at the time of multi-stage connection of LAD devices,
When the point-to-point SVC connection of the service interface accommodated in the multi-stage connection destination CLAD device is realized, it becomes impossible to simultaneously implement the SVC connection of the service interface accommodated in another CLAD device.

The present invention has been made in view of such a point, and a point-to-point S of a service interface accommodated in each multi-stage CLAD device.
Cell disassembly / assembly apparatus and AT enabling simultaneous VC connection
It is an object to provide an M communication system.

[0018]

According to the present invention, in order to achieve the above object, as shown in FIG. 1, a correspondence table 5 showing a correspondence relationship between an SVC connection channel identifier and a PVC connection channel identifier, A specific user terminal 4 accommodated in another cell disassembly / assembly device 3 connected directly or indirectly to the own device 2 by executing point-to-point UNI signaling between the exchange 1 and the own device 2 SVC connection establishing means 6 for establishing an SVC connection between the ATM switch 1 and an SVC connection channel identifier included in a cell transmitted from the ATM switch 1 by referring to the correspondence table 5 for the corresponding PVC connection. A first transfer unit 7 for converting the cell into a channel identifier and transmitting the converted cell to another cell disassembly / assembly apparatus 3 directly connected to the own apparatus 2; Has been another the PVC connection channel identifier included in the cell transmitted from the cell disassembling and assembling apparatus 3, converts by referring to the correspondence table 5 to the corresponding SVC connection channel identifier, the converted cell ATM switch 1
And a second transfer means 8 for transmitting the data to the cell disassembly / assembly apparatus.

Further, the SV connection establishment means 6
The storage means 9 stores the SVC connection channel identifier assigned by the ATM switch 1 when the C connection is established in the correspondence table 5 in association with the PVC connection channel identifier already assigned to the user terminal 4. Have more.

In the above configuration, if it is necessary to establish an SVC connection between a specific user terminal 4 and the ATM switch 1, the SVC connection establishing means 6 connects the ATM switch 1 and the own device 2 with each other. Point-to-point U between
Perform NI signaling to establish SVC connection.
With the establishment of the SVC connection, the ATM switch 1 sends the SVC
The connection channel identifier is assigned,
Stores the assigned SVC connection channel identifier in the correspondence table 5 in association with the PVC connection channel identifier already assigned to the user terminal 4.

Next, in the own cell disassembling / assembling apparatus 2, the AT
When a cell is received from the M exchange 1, the first transfer means 7
Converts the SVC connection channel identifier included in the cell into a corresponding PVC connection channel identifier with reference to the correspondence table 5, and transmits the converted cell to another cell disassembly / assembly apparatus 3. When a cell is received from another cell disassembly / assembly device 3, the second transfer means 8 converts the PVC connection channel identifier included in the cell to the corresponding SVC connection channel identifier with reference to the correspondence table 5. The cell is converted, and the converted cell is transmitted to the ATM switch 1.

Thus, when a PVC connection has been established between the cell disassembly / assembly apparatus 2 and the user terminal 4 (the PVC channel in this case does not need to be a channel allocated from the ATM exchange 1), the ATM exchange The cell having the SVC channel identifier sent from
It is possible to transmit the cell having the PVC channel identifier transmitted from the user terminal 4 to the PVC channel on the side of the ATM switch 1 to the SVC channel on the side of the ATM switch 1. Therefore, the SVC connection between the ATM exchange 1 and each user terminal connected to each cell disassembly / assembly apparatus can be simultaneously performed only by the control of the cell disassembly / assembly apparatus 2.

Further, there is provided an ATM communication system having a plurality of cell disassembly and assembly apparatuses connected in tandem or in parallel by an ATM interface and accommodated in an ATM network having an ATM switch.

That is, the first switch connected to the ATM exchange
And a point-to-point UNI signaling between the ATM switch and the first cell disassembly / assembly unit provided in the cell disassembly / assembly unit of FIG. To establish an SVC connection between a specific user terminal accommodated in a second cell disassembly / assembly apparatus directly or indirectly connected to the first cell disassembly apparatus and the ATM exchange.
When the SVC connection is established by the VC connection establishment means and the first cell disassembly / assembly apparatus, and the SVC connection is established by the SVC connection establishment means, the second cell disassembly / assembly apparatus is assigned in advance to a specific user terminal. When a permission signal is transmitted to permit transmission / reception processing of a cell having a PVC connection channel identifier, and establishment of the SVC connection is released by the SVC connection establishment means, the second cell disassembly / assembly apparatus is transmitted to the second cell disassembly apparatus. A permission / non-permission signal transmitting means for transmitting a permission / non-permission signal which prohibits the transmission / reception processing from being performed, and a time when the permission signal is received from the permission / non-permission signal transmission means provided in the second cell disassembly / assembly apparatus. To transmit and receive a cell having a PVC connection channel identifier assigned to a specific user terminal before receiving a non-permission signal. The processing means is provided in the first cell disassembly / assembly apparatus, and is pre-assigned to a specific user terminal to be performed with the subordinate cell disassembly / assembly apparatus only while the SVC connection is established by the SVC connection establishing means. Second transmission / reception permission means for permitting transmission / reception of a cell having a PVC connection channel identifier, and an SVC connection channel identifier provided in the first cell disassembly / assembly apparatus and included in a cell transmitted from the ATM exchange. A first transfer unit that converts the converted cell into a corresponding PVC connection channel identifier with reference to the correspondence table and transmits the converted cell to the subordinate cell disassembly / assembly apparatus, and is provided in the first cell disassembly / assembly apparatus; PV included in a cell transmitted from a subordinate cell disassembly / assembly apparatus
A second transfer means for converting the C connection channel identifier into a corresponding SVC connection channel identifier with reference to the correspondence table and transmitting the converted cell to the ATM exchange.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. First, the principle configuration of the first embodiment will be described with reference to FIG. The first embodiment relates to a cell disassembly / assembly apparatus, which has a correspondence table 5 indicating a correspondence relationship between an SVC connection channel identifier and a PVC connection channel identifier, and a point-to-point connection between the ATM switch 1 and its own apparatus 2. Perform point UNI signaling,
SVC connection establishing means 6 for establishing an SVC connection between a specific user terminal 4 accommodated in another cell disassembly apparatus 3 directly or indirectly connected to the own apparatus 2 and the ATM exchange 1, and an ATM exchange 1. The SVC connection channel identifier included in the cell transmitted from No. 1 is converted to a corresponding PVC connection channel identifier with reference to the correspondence table 5, and the converted cell is connected to another device directly connected to the own device 2. The first transfer means 7 for transmitting to the cell disassembly / assembly apparatus 3 and the PVC connection channel identifier included in the cell transmitted from the other cell disassembly / assembly apparatus 3 directly connected to the own apparatus 2 are stored in the correspondence table 5. And a second transfer means 8 for converting the converted cell identifier into a corresponding SVC connection channel identifier and transmitting the converted cell to the ATM switch 1.

The SVC connection establishing means 6 sets the SV
The storage means 9 stores the SVC connection channel identifier assigned by the ATM switch 1 when the C connection is established in the correspondence table 5 in association with the PVC connection channel identifier already assigned to the user terminal 4. Have more.

In the above configuration, when it is necessary to establish an SVC connection between a specific user terminal 4 and the ATM exchange 1, the SVC connection establishment means 6 establishes a connection between the ATM exchange 1 and the own device 2. Point-to-point U between
Perform NI signaling to establish SVC connection.
With the establishment of the SVC connection, the ATM switch 1 sends the SVC
The connection channel identifier is assigned,
Stores the assigned SVC connection channel identifier in the correspondence table 5 in association with the PVC connection channel identifier already assigned to the user terminal 4.

Next, in the own cell disassembling / assembling apparatus 2, the AT
When a cell is received from the M exchange 1, the first transfer means 7
Converts the SVC connection channel identifier included in the cell into a corresponding PVC connection channel identifier with reference to the correspondence table 5, and transmits the converted cell to another cell disassembly / assembly apparatus 3. When a cell is received from another cell disassembly / assembly device 3, the second transfer means 8 converts the PVC connection channel identifier included in the cell to the corresponding SVC connection channel identifier with reference to the correspondence table 5. The cell is converted, and the converted cell is transmitted to the ATM switch 1.

Thus, when a PVC connection is established between the cell disassembly / assembly apparatus 2 and the user terminal 4 (the PVC channel in this case does not need to be a channel allocated from the ATM exchange 1), the ATM exchange The cell having the SVC channel identifier sent from
It is possible to transmit the cell having the PVC channel identifier transmitted from the user terminal 4 to the PVC channel on the side of the ATM switch 1 to the SVC channel on the side of the ATM switch 1. Therefore, the SVC connection between the ATM exchange 1 and each user terminal connected to each cell disassembly / assembly apparatus can be simultaneously performed only by the control of the cell disassembly / assembly apparatus 2.

Next, the first embodiment will be described in detail. FIG. 2 is a diagram showing a configuration and an operation sequence of the ATM communication system according to the first embodiment. That is, the CLAD device (# 1) 1
2 are connected via an ATM interface and CLAD
A CLAD device (# 2) 13 is connected to the device (# 1) 12 via a cell relay interface (ATM interface). A user terminal 14 is connected to the CLAD device (# 2) 13 via a service a interface. CLAD devices are originally connected in cascade or in multiple stages as shown in FIG. 7, but only two are shown here. Although a plurality of user terminals are originally connected to the CLAD device, only one is shown here.

As the ATM interface, DS3, SONET, SDH, etc. are used as physical interfaces, and the line speed is 45 Mbps, 156 Mbps, 6
This is a communication protocol applied to a line using 22 Mbps or the like. The cell relay interface is the same as the ATM interface. Examples of the user terminal include a private branch exchange (PBX), a TDM device (TDM), a video device (VIDEO), and the like. The service interface has a line speed of 1.5 Mbps, 2 Mbps, 6 Mbps
A communication protocol used in digital lines such as s, and refers to a protocol used in a PBX trunk line or a TDM trunk line, or an ISDN primary group interface.

The CLAD device (# 1) 12 is a main controller 1
6, an ATM interface control unit 17, a cell relay interface control unit 18, and the like. Although there may be more cell relay interface controllers, they are not shown. A service interface control unit may be present, but is not shown. Similarly, the CLAD device (# 2) 13
Are the main controller 19, the ATM interface controller 20,
It comprises a service a interface control unit 21 and the like. More service interface control units may be present but are not shown. A cell relay interface control unit may be present, but is not shown.

Each of the CLAD device (# 1) 12 and the CLAD device (# 2) 13 is constituted by a processor comprising a CPU, a ROM, a RAM and the like.
It corresponds to the function realized by these processors. AM main control units 16 and 19, ATM interface control units 17 and 20, cell relay interface control unit 1
8. Since the contents of each function of the service a interface control unit 21 are basically the same as those of the components having the same names described with reference to FIG. 8, their description is omitted.

Main control unit 16 of CLAD device (# 1) 12
A channel identifier conversion table 16a is provided therein. Further, the main control unit 16 of the CLAD device (# 1) 12
Control is performed so that the ATM interface control unit 17 can take in and transmit a cell having the C signaling channel identifier. Further, the main control unit 16 realizes the UNI signaling by using the acquired payload information of the cell. User information at the time of performing UNI signaling is registered in the main control unit 16 of the CLAD device (# 1) 12. The user information is a CLAD in the present embodiment.
This is identification information of the user terminal 14 connected to the device (# 2) 13 via the service a interface. Also, C
The ATM interface controllers 17 and 20 of the LAD device (# 1) 12 and the CLAD device (# 2) 13 are configured so that cells having an arbitrary channel identifier can be always transmitted and received.

Next, the procedure for SVC connection and connection release is as follows.
This will be described with reference to the sequence shown in FIG. Hereinafter, FIG.
Are described along with the sequence number (S) shown in FIG. [S1] First, before the SVC connection, the cell relay interface control unit 18 of the CLAD device (# 1) 12
Then, the service a interface control unit 21 of the CLAD device (# 2) 13 is activated (ACTIVATE) with, for example, the channel identifier PVC # 2a. That is, it is set so that only cells having the channel identifier PVC # 2a are transmitted and received. The channel identifier used here need not be the one assigned by the ATM switch 11. That is, the CLAD device (# 1) 12 and the CLAD device (#
2) Locally determined with 13 may be used.

On the ATM exchange 11 side, the channel identifier P
The reception of the cell of VC # 2a is set to deactivate (DEACTIVATE). Thereby, the data from the user terminal 14 is included in the cell payload, and the channel identifier PVC # 2
Even if the cell having "a" is transmitted in the direction of the ATM exchange 11, this cell is discarded on the ATM exchange 11 side. A
With such a setting on the TM exchange 11 side, the cell of the channel identifier PVC # 2a is transmitted from the ATM exchange 11 to the CL.
It is not transmitted to the AD device (# 1) 12.

[S2] Here, the ATM switch 11 and C
It is assumed that an SVC call connection with the user terminal 14 connected to the LAD device (# 2) 13 has been requested. In that case, C
By the connection control from the LAD device (# 1) 12 or the ATM exchange 11, the establishment of the SVC call connection between the ATM exchange 11 and the user terminal 14 is established by the CLAD device (# 1) 1.
2 and the ATM switch 11. This allows
For example, an SVC connection channel SVC # 2a is allocated from the ATM exchange 11 to the user terminal 14.

With this allocation, the CLAD device (#
1) The 12 main control units 16 perform the channel identifier conversion table 1
6a, an SVC connection channel identifier SVC # 2a,
A PVC connection channel identifier PVC # 2a assigned to the same user terminal 14 is registered in association with the same.

[S3] In the cell relay interface control unit 18 of the CLAD device (# 1) 12, when a cell is transmitted from the cell relay interface, a PVC connection channel identifier (for example, a cell identifier set in the cell header of the transmitted cell) , PVC # 2a) are registered in the channel identifier conversion table 16a of the main controller 16. If it is registered, the corresponding SVC connection channel identifier (in this case, SVC # 2a) is read, and the PVC is read.
The connection channel identifier PVC # 2a is replaced with the SVC connection channel identifier SVC # 2a. Then, the cell in which the channel identifier has been replaced is transferred to the ATM interface control unit 17. On the other hand, if the ATM interface control unit 17 sends a cell in which the SVC connection channel identifier SVC # 2a is set in the cell header, the channel identifier conversion table 16a of the main control unit 16 is similarly referred to. Then, the channel identifier PVC # 2a for the PVC connection corresponding to the channel identifier SVC # 2a for the SVC connection is read, and the channel identifier SVC # 2a for the SVC connection is read as the PV.
Replace with the C connection channel identifier PVC # 2a. Then, the cell in which the channel identifier is replaced is transmitted to the cell relay interface.

It should be noted that the ATM exchange 11 starts transmitting and receiving cells having the channel identifier SVC # 2a when the SVC call connection is completed. As described above, the ATM switch 11
And user terminal 1 connected to CLAD device (# 2) 13
4 can transmit and receive data.

[S4] Next, the ATM exchange 11 and the CL
It is assumed that a request to release the SVC call connection with the user terminal 14 connected to the AD device (# 2) 13 is made. In that case, the CLAD device (# 1) 12 or the ATM switch 11
, The SVC call connection between the ATM switch 11 and the user terminal 14 is released between the CLAD device (# 1) 12 and the ATM switch 11. At this point, the SVC connection channel SVC # 2a assigned from the ATM switch 11 to the user terminal 14 becomes invalid.

[S5] With the release of the SVC call connection,
The main controller 16 of the CLAD device (# 1) 12 deletes the correspondence data between the SVC connection channel identifier SVC # 2a and the PVC connection channel identifier PVC # 2a registered in the channel identifier conversion table 16a.

Thereafter, when the CLAD device (# 1) 12 receives a cell having the PVC connection channel identifier PVC # 2a from the cell relay interface, the CLA
In the cell relay interface control unit 18 of the D device (# 1) 12, the channel identifier conversion table 16a of the main control unit 16
, The PVC connection channel identifier PVC # 2
Since the channel identifier corresponding to a is not registered,
Leave the cell as it is.

On the other hand, when the SVC call connection release is completed, the ATM exchange 11 stops transmitting / receiving the cell having the channel identifier SVC # 2a. Therefore, the channel identifier S
The cell having the VC # 2a does not reach the CLAD device (# 1) 12.

As described above, the state returns to the state before the SVC call connection. It should be noted that the ATM exchange 1 shown in FIG.
Corresponding to the exchange 11, and similarly, the CLAD device 2
D device (# 1) 12 and other CLAD device 3
In the device (# 2) 13, the user terminal 4 is connected to the user terminal 14
And the correspondence table 5 includes the channel identifier conversion table 16a,
The SVC connection establishing means 6 is connected to the main control unit 16 and the ATM interface control unit 17, and the first transfer means 7 is connected to the main control unit 1
6, the ATM interface control unit 17 and the cell relay interface control unit 18, the second transfer unit 8 is the main control unit 16, the ATM interface control unit 17 and the cell relay interface control unit 18, and the storage unit 9 is the main control unit 16
Corresponding to

Next, a second embodiment will be described. FIG.
FIG. 7 is a diagram showing a configuration and an operation sequence of an ATM communication system according to a second embodiment. The second embodiment has basically the same configuration as the configuration in the first embodiment. Therefore, the same components will be denoted by the same reference characters, and the description thereof will be omitted, and only different portions will be described.

In the second embodiment, the CLAD device (#
1) The ACTIVATE / DEACTIVATE instruction unit 16b is added to the 12 main control units 16. Activate / deactivate instruction section 16b
In the cell transmission / reception performed by the cell relay interface controller 18, the cell transmission / reception of the designated channel is activated / deactivated, and the cell relay interface controller 1 is activated.
8 is a function for permitting or disallowing cell transmission / reception of a designated channel to be performed. Next, a procedure of SVC connection and connection release according to the second embodiment will be described with reference to a sequence shown in FIG. Hereinafter, description will be given along the sequence number (S) shown in FIG.

[S11] First, as a step prior to the SVC connection, the service a interface control unit 21 of the CLAD device (# 2) 13 is set to, for example, a PVC connection channel identifier P.
Activate (ACTIVATE) with VC # 2a. That is, it is set so that only cells having the channel identifier PVC # 2a are transmitted and received. The channel identifier used here need not be the one assigned by the ATM switch 11. That is, the CLAD device (# 1) 12 and the CL
It may be determined locally with the AD device (# 2) 13.

As a result, the channel identifier PVC # containing the data from the user terminal 14 in the cell payload
The cell 2a is transmitted to the cell relay interface control unit 18 of the CLAD device (# 1) 12. However, CLA
The activation / deactivation instruction unit 16b of the D device (# 1) 12 is connected to the cell relay interface control unit 18
Is set to deactivate (DEACTIVATE) transmission / reception of cells having the channel identifier PVC # 2a. As a result, this cell is discarded. With this setting, the cell relay interface control unit 18 of the CLAD device (# 1) 12 sends the channel identifier PVC #
The cell having 2a is not transmitted to the CLAD device (# 2) 13. Therefore, data transmission from the CLAD device (# 1) 12 to the user terminal 14 is not performed.

[S12] Here, the ATM switch 11 and
User terminal 14 connected to CLAD device (# 2) 13
Assume that an SVC call connection has been requested. In that case,
By controlling the connection from the CLAD device (# 1) 12 or the ATM switch 11, the ATM switch 11 and the user terminal 14 are controlled.
The establishment of the SVC call connection with the CLAD device (# 1)
This is performed between the ATM switch 12 and the ATM switch 11. As a result, for example, the SVC connection channel SVC # 2a is allocated from the ATM exchange 11 to the user terminal 14.

With this allocation, the CLAD device (#
1) The 12 main control units 16 perform the channel identifier conversion table 1
6a, an SVC connection channel identifier SVC # 2a,
A PVC connection channel identifier PVC # 2a assigned to the same user terminal 14 is registered in association with the same.

[S13] With the establishment of the SVC call connection, C
The activation / deactivation instruction unit 16b provided in the main control unit 16 of the LAD device (# 1) 12 sends a PVC # 2a to the cell relay interface control unit 18.
Activate transmission / reception of cell with channel identifier of (ACTIVA
TE).

[S14] As a result of the activation (ACTIVATE) instruction, the cell having the channel identifier PVC # 2a is transmitted from the cell relay interface control unit 18 of the CLAD device (# 1) 12 to the CLAD device (# 2) 13. The cell having the channel identifier PVC # 2a transmitted from the CLAD device (# 2) 13
1) Reception can be performed by the 12 cell relay interface control units 18.

[S15] When the cell relay interface control unit 18 of the CLAD device (# 1) 12 receives a cell with the PVC connection channel identifier PVC # 2a set in the cell header from the user terminal 14, the main control is performed. Referring to the channel identifier conversion table 16a of the section 16, the PVC
Read the SVC channel identifier SVC # 2a corresponding to the connection channel identifier PVC # 2a. And PVC
The connection channel identifier PVC # 2a is transferred to the ATM interface control unit 17 instead of the SVC channel identifier SVC # 2a. On the other hand, the ATM interface control unit 1
7, the channel identifier S for the SVC connection is included in the cell header.
When a cell in which VC # 2a is set is sent, similarly, the channel identifier conversion table 16a of the main control unit 16 is referred to, and the PVC connection channel identifier corresponding to the SVC connection channel identifier SVC # 2a is similarly referred to. Reads PVC # 2a and sets the SVC connection channel identifier SVC # 2a to PVC.
Replace with the connection channel identifier PVC # 2a. Then, the cell in which the channel identifier is replaced is transmitted to the cell relay interface.

Note that the ATM exchange 11 starts transmitting and receiving cells having the channel identifier SVC # 2a when the SVC call connection is completed. As described above, the ATM switch 11
And user terminal 1 connected to CLAD device (# 2) 13
4 can transmit and receive data.

[S16] Next, the ATM switch 11 and C
Suppose that a request to release the SVC call connection with the user terminal 14 connected to the LAD device (# 2) 13 is made. In that case, the CLAD device (# 1) 12 or the ATM switch 11
, The SVC call connection between the ATM switch 11 and the user terminal 14 is released between the CLAD device (# 1) 12 and the ATM switch 11. At this point, the SVC connection channel SVC # 2a assigned from the ATM switch 11 to the user terminal 14 becomes invalid.

[S17] With the release of the SVC call connection, C
The activation / deactivation instruction unit 16b provided in the main control unit 16 of the LAD device (# 1) 12 sends a PVC # 2a to the cell relay interface control unit 18.
Deactivate transmission / reception of cells with the channel identifier of (DEAC
TIVATE).

[S18] With the release of the SVC call connection, C
The main control unit 16 of the LAD device (# 1) 12 deletes the correspondence data between the SVC connection channel identifier SVC # 2a and the PVC connection channel identifier PVC # 2a registered in the channel identifier conversion table 16a. In response to the deactivation instruction, the cell relay interface control unit 18 of the CLAD device (# 1) 12 stops transmitting and receiving cells having the PVC # 2a channel identifier.

The ATM switch 11 stops transmitting and receiving cells having the channel identifier SVC # 2a when the SVC call connection release is completed. As described above, the state returns to the state before the SVC call connection.

In the second embodiment, the operation of the activate / deactivate instruction unit 16b and the cell relay interface control unit 18 causes unnecessary signals to be sent from the multi-stage connected CLAD devices to the ATM network. Can be avoided.

Next, a third embodiment will be described. FIG.
FIG. 9 is a diagram showing a configuration and an operation sequence of an ATM communication system according to a third embodiment. The third embodiment has basically the same configuration as the configuration in the second embodiment. Therefore, the same components will be denoted by the same reference characters, and the description thereof will be omitted, and only different portions will be described.

In the third embodiment, the CLAD device (#
2) An OAM cell analyzer 19a is added to the 13 main controller 16. The OAM cell analysis unit 19a is a CLAD device (#
2) Analyze the OAM cell received by 13 and activate / deactivate transmission / reception of a cell having a specific channel identifier (ACTIV)
ATE / DEACTIVATE) is recognized in the OAM cell.

Next, a procedure of SVC connection and connection release in the third embodiment will be described with reference to a sequence shown in FIG. Hereinafter, the sequence number (S) shown in FIG.
Write along.

[S21] The ATM switch 11 and the CLAD
It is assumed that an SVC call connection with the user terminal 14 connected to the device (# 2) 13 has been requested. In that case, CLAD
The connection control from the device (# 1) 12 or the ATM switch 11 establishes the SVC call connection between the ATM switch 11 and the user terminal 14, and the connection between the CLAD device (# 1) 12 and the A
The communication is performed with the TM exchange 11. With this, ATM
From the exchange 11 to the user terminal 14, for example, SVC
The connection channel SVC # 2a is allocated.

With this allocation, the CLAD device (#
1) The 12 main control units 16 perform the channel identifier conversion table 1
6a, an SVC connection channel identifier SVC # 2a,
A PVC connection channel identifier PVC # 2a assigned to the same user terminal 14 is registered in association with the same.

[S22] Here, the CLAD device (# 1)
12 is a PVC connection channel PVC #
Activation of the PVC connection channel PVC # 2a (ACTI
VATE) is transmitted. This O
In the OAM cell type column of the AM cell, "Activation (ACTIVAT
E) Instruction ”is set, and“ PVC channel identifier PVC # 2a ”is set in the information field.

[S23] With the establishment of the SVC call connection, C
The activation / deactivation instruction unit 16b provided in the main control unit 16 of the LAD device (# 1) 12 sends a PVC # 2a to the cell relay interface control unit 18.
Activate transmission / reception of cell with channel identifier of (ACTIVA
TE).

[S24] The CLAD device (# 2) 13
The OAM cell transmitted from the CLAD device (# 1) 12 is received, and the OAM analysis unit 19a provided in the main control unit 19 of the CLAD device (# 2) 13 analyzes the received OAM cell. When recognizing that the OAM cell instructs activation (ACTIVATE) of transmission / reception of a cell having a channel identifier of PVC # 2a, the OAM analysis unit 19a sends a PVC # 2
Activate transmission / reception of the cell having the channel identifier a (ACTI
VATE). The service a interface control unit 21 of the CLAD device (# 2) 13 starts transmission / reception of a cell having a channel identifier of PVC # 2a according to this instruction.

[S25] The cell relay interface control unit 18 of the CLAD device (# 1) 12
By the instruction from the deactivation instruction unit 16b, the PV
Transmission / reception of a cell having a channel identifier of C # 2a is started.

[S26] When the cell relay interface control unit 18 of the CLAD device (# 1) 12 receives from the user terminal 14 a cell in which the PVC connection channel identifier PVC # 2a is set in the cell header, the main control is performed. Referring to the channel identifier conversion table 16a of the section 16, the PVC
Read the SVC channel identifier SVC # 2a corresponding to the connection channel identifier PVC # 2a. And PVC
The connection channel identifier PVC # 2a is transferred to the ATM interface control unit 17 instead of the SVC channel identifier SVC # 2a. On the other hand, the ATM interface control unit 1
7, the channel identifier S for the SVC connection is included in the cell header.
When a cell in which VC # 2a is set is sent, similarly, the channel identifier conversion table 16a of the main control unit 16 is referred to, and the SVC connection channel identifier SVC # 2a and the corresponding PVC connection channel identifier are referred to. Reads PVC # 2a and sets the SVC connection channel identifier SVC # 2a to PVC.
Replace with the connection channel identifier PVC # 2a. Then, the cell in which the channel identifier is replaced is transmitted to the cell relay interface.

The ATM exchange 11 starts transmitting and receiving cells having the channel identifier SVC # 2a when the SVC call connection is completed. As described above, the ATM switch 11
And user terminal 1 connected to CLAD device (# 2) 13
4 can transmit and receive data.

[S27] Next, the ATM exchange 11 and C
Suppose that a request to release the SVC call connection with the user terminal 14 connected to the LAD device (# 2) 13 is made. In that case, the CLAD device (# 1) 12 or the ATM switch 11
, The SVC call connection between the ATM switch 11 and the user terminal 14 is released between the CLAD device (# 1) 12 and the ATM switch 11. At this point, the SVC connection channel SVC # 2a assigned from the ATM switch 11 to the user terminal 14 becomes invalid.

[S28] With the release of the SVC call connection, C
The activation / deactivation instruction unit 16b provided in the main control unit 16 of the LAD device (# 1) 12 sends a PVC # 2a to the cell relay interface control unit 18.
Deactivate transmission / reception of cells with the channel identifier of (DEAC
TIVATE).

[S29] With the release of the SVC call connection, C
The main control unit 16 of the LAD device (# 1) 12 deletes the correspondence data between the SVC connection channel identifier SVC # 2a and the PVC connection channel identifier PVC # 2a registered in the channel identifier conversion table 16a. In response to the deactivation instruction, the cell relay interface control unit 18 of the CLAD device (# 1) 12 stops transmitting and receiving cells having the PVC # 2a channel identifier.

The ATM switch 11 stops transmitting and receiving cells having the channel identifier SVC # 2a when the SVC call connection release is completed. [S30] Main controller 16 of CLAD device (# 1) 12
Transmits an OAM cell for instructing deactivation (DEACTIVATE) of the PVC connection channel PVC # 2a to the cell relay interface accommodating the PVC connection channel PVC # 2a. OA of this OAM cell
“Deactivate (DEACTIVATE) instruction” is set in the M cell type column, and “PVC connection channel identifier PVC # 2a” is set in the information field.

The CLAD device (# 2) 13 receives the OAM cell sent from the CLAD device (# 1) 12, and
The M analyzing unit 19a analyzes the received OAM cell. When recognizing that the OAM cell indicates the deactivation (DEACTIVATE) of transmission / reception of the cell having the channel identifier of PVC # 2a, the OAM analysis unit 19a determines that the service a
Deactivate transmission / reception of a cell having a channel identifier of PVC # 2a to the interface control unit 21 (DEACTIVA
TE). The service a interface control unit 21 of the CLAD device (# 2) 13 stops transmission and reception of the cell having the channel identifier of PVC # 2a according to this instruction.

As described above, the state returns to the state before the SVC call connection. In the third embodiment, the operation of the OAM cell analyzer 19a and the service a interface controller 21 allows
CLAD device (# 2) 13 to CLAD device (# 1) 1
It is possible to avoid sending unnecessary signals in two directions.

Next, a fourth embodiment will be described. FIG.
FIG. 14 is a diagram illustrating a configuration and an operation sequence of an ATM communication system according to a fourth embodiment.

ATM switch 3 in the fourth embodiment
1 has the same configuration as the ATM exchange 11 in the third embodiment shown in FIG.
1) 32 has the same configuration as the CLAD device (# 1) 12, and the CLAD device (# 3) 34 has the same configuration as the CLAD device (# 2).
13 has the same configuration.

The CLAD device (# 2) 33 in the fourth embodiment comprises a main control unit 36, an ATM interface control unit 37, and a cell relay interface control unit 38. The ATM interface control unit 37 and the cell relay interface control unit 38 have the same configurations as the ATM interface control unit 17 and the cell relay interface control unit 18 of the CLAD device (# 1) 12 in the third embodiment shown in FIG. . Main control unit 36
Is Activate / Deactivate
VATE) Instructing section 36a and OAM cell analyzing section 36b. Activate / deactivate indicator 36a
Has the same configuration as the activation / deactivation instruction unit 16b of the CLAD device (# 1) 12 in the third embodiment shown in FIG. 4, and includes an OAM cell analysis unit 36b.
Has the same configuration as the OAM cell analyzer 19a of the CLAD device (# 2) 13 in the third embodiment shown in FIG. The CLAD device (# 3) 34 has a user terminal 35
Is connected. The user terminal 35 has the same configuration as the user terminal 14 in the third embodiment shown in FIG.

Next, an SVC connection and connection release procedure in the fourth embodiment will be described with reference to a sequence shown in FIG. Hereinafter, the sequence number (S) shown in FIG.
Write along.

[S31] ATM exchange 31 and CLAD
It is assumed that an SVC call connection with the user terminal 35 connected to the device (# 3) 34 has been requested. In that case, CLAD
By the connection control from the device (# 1) 32 or the ATM switch 31, the establishment of the SVC call connection between the ATM switch 31 and the user terminal 35 is established by the CLAD device (# 1) 32 and the A terminal.
The communication is performed with the TM exchange 31. With this, ATM
From the exchange 31 to the user terminal 35, for example, SVC
The connection channel SVC # 3a is allocated.

With this allocation, the CLAD device (#
1) The main control unit of 32 stores S in the channel identifier conversion table.
The VC connection channel identifier SVC # 3a is registered in association with the PVC connection channel identifier PVC # 3a assigned to the same user terminal 14 in advance.

[S32] Here, the CLAD device (# 1)
The main control unit 32 is a PVC connection channel PVC # 3a
The OAM cell for instructing the activation (ACTIVATE) of the PVC connection channel PVC # 3a is transmitted to the CLAD device (# 2) 33 connected to the cell relay interface in which is accommodated. "Activation (ACTIVATE) instruction" is set in the OAM cell type column of the OAM cell, and "PVC connection channel identifier PVC # 3a" is set in the information field.

[S33] With the establishment of the SVC call connection, C
In the LAD device (# 1) 32, the activate / deactivate instruction unit provided in the main control unit activates (ACTIVATE) transmission / reception of a cell having a PVC # 3a channel identifier to the cell relay interface control unit. Make instructions.

[S34] The CLAD device (# 2) 33
The OAM cell transmitted from the CLAD device (# 1) 32 is received, and the OAM analysis unit 36b provided in the main control unit 36 of the CLAD device (# 2) 33 analyzes the received OAM cell. When recognizing that the OAM cell indicates activation (ACTIVATE) of transmission / reception of a cell having a channel identifier of PVC # 3a, the OAM analysis unit 36b instructs the cell relay interface control unit 38 to transmit the PVC # 2a.
Activate transmission / reception of the cell having the channel identifier a (ACTI
VATE). The cell relay interface control unit 38 of the CLAD device (# 2) 33 starts transmission / reception of a cell having a channel identifier of PVC # 3a according to this instruction.

[S35] The OAM analyzer 36b
When it is recognized that the received OAM cell indicates the activation (ACTIVATE) of transmission / reception of the cell having the channel identifier of PVC # 3a, the main control unit 36 of the CLAD device (# 2) 33 It is determined whether there is a cell relay interface to which the connection channel PVC # 3a is allocated. In this case, since it exists, the CLAD device (# 3) 34 connected to the cell relay interface accommodating the PVC connection channel PVC # 3a.
Transmits an OAM cell for instructing the activation (ACTIVATE) of the PVC connection channel PVC # 3a.
In the OAM cell type column of this OAM cell, "Activation (AC
TIVATE) instruction ”is set, and“ PV ”is set in the information field.
The C connection channel identifier PVC # 3a "is set.

[S36] The CLAD device (# 3) 34
The OAM cell transmitted from the CLAD device (# 2) 33 is received, and the OAM analysis unit provided in the main control unit of the CLAD device (# 3) analyzes the received OAM cell. When recognizing that the OAM cell indicates the activation (ACTIVATE) of transmission / reception of the cell having the channel identifier of PVC # 3a, the OAM analysis unit notifies the service a interface control unit of the PVC # 3a. An instruction to activate (ACTIVATE) transmission / reception of a cell having a channel identifier is performed. The service-a interface control unit of the CLAD device (# 3) 34 starts transmission / reception of a cell having a channel identifier of PVC # 3a according to this instruction.

[S37] In the CLAD device (# 1) 32, the cell relay interface control unit responds to the instruction from the activate / deactivate instruction unit to set the PVC #
Transmission / reception of the cell having the channel identifier 3a is started.

[S38] In the CLAD device (# 1) 32, when the cell relay interface control unit receives, from the user terminal 35, a cell in which the PVC connection channel identifier PVC # 3a is set in the cell header, the main control is performed. The SVC channel identifier SVC # 3a corresponding to the PVC connection channel identifier PVC # 3a is read out with reference to the channel identifier conversion table of the section. Then, the PVC connection channel identifier PVC # 3a is replaced with the SVC channel identifier SVC.
# 3a is passed to the ATM interface control unit. On the other hand, when the ATM interface control unit sends a cell in which the SVC connection channel identifier SVC # 3a is set in the cell header, the SVC is similarly referred to by referring to the channel identifier conversion table of the main control unit. It reads the PVC connection channel identifier PVC # 3a corresponding to the connection channel identifier SVC # 3a, and replaces the SVC connection channel identifier SVC # 3a with the PVC connection channel identifier PVC.
Replace with # 3a. Then, the cell in which the channel identifier is replaced is transmitted to the cell relay interface.

The ATM exchange 31 starts transmitting and receiving cells having the channel identifier SVC # 3a when the SVC call connection is completed. As described above, the ATM switch 31
And user terminal 3 connected to CLAD device (# 3) 34
5 can transmit and receive data.

[S39] Next, the ATM switch 31 and C
It is assumed that a request to release the SVC call connection with the user terminal 35 connected to the LAD device (# 3) 34 is made. In that case, the CLAD device (# 1) 32 or the ATM switch 31
, The SVC call connection between the ATM switch 31 and the user terminal 35 is released between the CLAD device (# 1) 32 and the ATM switch 31. At this point, the SVC connection channel SVC # 3a assigned from the ATM switch 31 to the user terminal 35 becomes invalid.

[S40] With the release of the SVC call connection, C
In the LAD device (# 1) 32, the activate / deactivate instruction unit provided in the main control unit deactivates the transmission / reception of the cell having the PVC # 3a channel identifier to the cell relay interface control unit (DEACTIVATE). Give instructions.

[S41] With the release of the SVC call connection, C
In the main controller of the LAD device (# 1) 32, the SVC connection channel identifier SVC # 3a and the PVC connection channel identifier PVC # 3 registered in the channel identifier conversion table.
The correspondence data with a is deleted. Further, in response to the deactivation instruction, the cell relay interface control unit of the CLAD device (# 1) 32 stops transmission / reception of cells having the channel identifier of PVC # 3a.

The ATM switch 31 stops transmitting and receiving cells having the channel identifier SVC # 3a when the SVC call connection release is completed. [S42] In the CLAD device (# 1) 32, the main control unit sends a PVC connection channel to the CLAD device (# 2) 33 connected to the cell relay interface accommodating the PVC connection channel PVC # 3a. PVC #
OAM for indicating DEACTIVATE of 3a
Send the cell. In the OAM cell type column of this OAM cell, “DEACTIVATE instruction” is set, and in the information field, “PVC connection channel identifier PVC #
3a "is set.

[S43] The CLAD device (# 2) 33
The OAM cell transmitted from the CLAD device (# 1) 32 is received, and the OAM analyzer 36b analyzes the received OAM cell. When recognizing that the OAM cell indicates the deactivation (DEACTIVATE) of transmission / reception of the cell having the channel identifier of PVC # 3a, the OAM analysis unit 36b sends the PVC to the cell relay interface control unit 38,
An instruction is given to deactivate (DEACTIVATE) transmission / reception of the cell having the channel identifier of # 3a.

In accordance with this instruction, the CLAD device (# 2) 3
In the cell relay interface control unit of No. 3, PVC # 3
The transmission / reception of the cell having the channel identifier a is stopped. [S44] In the CLAD device (# 2) 33, the main control unit 3
6 sends the PVC connection channel PVC to the CLAD device (# 3) 34 connected to the cell relay interface accommodating the PVC connection channel PVC # 3a.
OA for indicating # 3a deactivation (DEACTIVATE)
Transmit M cells. “Deactivate (DEACTIVATE) instruction” is set in the OAM cell type column of this OAM cell, and the “PVC connection channel identifier PVC” is set in the information field.
# 3a "is set.

In the CLAD device (# 3) 34, the CLAD
The OAM cell received from the device (# 2) 33 is
An AM analyzer analyzes the received OAM cell. That O
When recognizing that the AM cell instructs the deactivation (DEACTIVATE) of transmission / reception of the cell having the channel identifier of the PVC # 3a, the OAM analysis unit notifies the service a interface control unit of the PVC # 3a. An instruction is given to deactivate (DEACTIVATE) transmission / reception of a cell having a channel identifier. In response to this instruction, the service a interface control unit of the CLAD device (# 3) 34 stops transmission / reception of the cell having the channel identifier of PVC # 3a.

As described above, the state returns to the state before the SVC call connection. Next, a fifth embodiment will be described. FIG.
FIG. 3 is a diagram showing a configuration and an operation sequence of an ATM communication system according to the embodiment.

The fifth embodiment is basically the same as the fourth embodiment, but differs in the operation. The procedure of SVC connection and connection release in the fifth embodiment will be described with reference to the sequence shown in FIG. Hereinafter, description will be given along the sequence number (S) shown in FIG.

In the fifth embodiment, the main controller 42a of the CLAD device (# 1) 42 does not have a channel identifier conversion table. Further, the main control unit of each CLAD device determines the correspondence between the cell relay interface (line) and the service interface (line) connected to the downstream CLAD device in the CLAD device connected downstream of the own CLAD device. It is assumed that it is managed. More specifically, a serial number is assigned to each service interface existing in the entire system, and data corresponding to the serial number is created and the main control unit of each CLAD device holds the data.

[S51] ATM exchange 41 and CLAD
It is assumed that an SVC call connection with the user terminal 45 connected to the device (# 3) 44 has been requested. In that case, CLAD
By the connection control from the device (# 1) 42 or the ATM switch 41, the establishment of the SVC call connection between the ATM switch 41 and the user terminal 45 is established by the CLAD device (# 1) 42 and the A
The communication is performed with the TM exchange 41. With this, ATM
From the exchange 41 to the user terminal 45, for example, SVC
The connection channel SVC # 3a is allocated.

[S52] The main controller 42a of the CLAD device (# 1) 42 sends an SVC connection channel SVC # to the CLAD device (# 2) 43 connected to the user terminal 45.
An OAM cell for instructing activation (ACTIVATE) of 3a is transmitted. In the OAM cell type column of this OAM cell, "ACTIVATE instruction" is set, and in the information field, "channel identifier SVC # 3a for SVC connection" and the service a interface (line) for connecting the user terminal 45 are set. "Identification number" is set.

[S53] In the CLAD device (# 2) 43, the OAM cell analysis unit of the main control unit 43a sends the received OAM
The AM cell is analyzed, and the service a interface (line) of the set identification number is set to the own CLAD device (# 2).
If the cell relay interface is allocated to the cell relay interface accommodated in the cell relay interface 43 (the operation in the case where the cell relay interface is not allocated is basically the same as the operation of the CLAD device (# 3) 44 described below), the SVC is transmitted to the cell relay interface control unit 43c. The transmission / reception of the cell having the channel identifier of # 3a is activated. Cell relay interface control unit 43c
Starts transmission / reception of the cell having the channel identifier of SVC # 3a according to the activation instruction.

[S54] Also, the CLAD device (# 2) 4
In No. 3, as a result of the analysis by the OAM cell analysis unit of the main control unit 43a, the service a interface (line) of the set identification number is allocated to the cell relay interface accommodated in the own CLAD device (# 2) 43. If the CLA connected to the cell relay interface
The received OAM cell is transferred to the D device (# 3) 44.

[S55] In the CLAD device (# 3) 44, the OAM cell analyzer of the main controller 44a receives the received OAM cell.
The AM cell is analyzed, and the set identification number is extracted. The main control unit 44a instructs the service a interface control unit 44c corresponding to the service a interface of the identification number to activate transmission / reception of the cell having the channel identifier of SVC # 3a. The service-a interface control unit 44c responds to this instruction by using the SVC # 3
The transmission / reception of the cell having the channel identifier a is started.

[S56] In the CLAD device (# 1) 42, when the SVC call connection is established, the activate / deactivate instruction unit provided in the main control unit 42a sends the SVC # to the cell relay interface control unit 42c.
Activate transmission / reception of the cell having the channel identifier of 3a (AC
TIVATE).

[S57] The cell relay interface control unit 42c of the CLAD device (# 1) 42 starts transmission / reception of a cell having the channel identifier of SVC # 3a in response to the activation instruction.

On the other hand, when the SVC call connection is completed, the ATM switch 41 starts transmission / reception of the cell having the channel identifier SVC # 3a. As described above, the ATM switch 41
And a user terminal 45 connected to the CLAD device (# 3) 44 via the service a interface.

[S58] Next, the ATM switch 41 and C
It is assumed that a request to release the SVC call connection with the user terminal 45 connected to the LAD device (# 3) 44 has been made. In that case, the CLAD device (# 1) 42 or the ATM switch 41
, The SVC call connection between the ATM switch 41 and the user terminal 45 is released between the CLAD device (# 1) 42 and the ATM switch 41. At this time, the SVC connection channel SVC # 3a assigned from the ATM switch 41 to the user terminal 45 becomes invalid.

[S59] With the release of the SVC call connection, C
In the LAD device (# 1) 42, the activate / deactivate instruction unit provided in the main control unit 42a sends an SVC # 3 to the cell relay interface control unit 42c.
Deactivate transmission / reception of the cell with the channel identifier of a (DE
ACTIVATE).

[S60] With the deactivation instruction, CLA is performed.
The cell relay interface control unit 42c of the D device (# 1) 42 stops transmission and reception of the cell having the channel identifier of SPVC # 3a.

Note that the ATM switch 41 stops transmitting and receiving cells having the channel identifier SVC # 3a when the SVC call connection release is completed. [S61] The CLAD device (# 1) 42 sends an SV to the CLAD device (# 2) 43 connected to the user terminal 45.
Deactivation of C connection channel SVC # 3a (DEACTIVAT
An OAM cell for instructing E) is transmitted. This OA
In the OAM cell type column of the M cell, "DEACTIVA
TE) instruction ”is set, and“ SVC connection channel identifier SVC # 3a ”and user terminal 45 are set in the information field.
Is set for the "identification number" of the service a interface (line) that connects.

[S62] The CLAD device (# 2) 43
The OAM analysis unit of the main control unit 43a receives the OAM cell transmitted from the CLAD device (# 1) 42, and
Analyze M cells. The OAM cell deactivates transmission / reception of a cell having a channel identifier of SVC # 3a (DEACTI
VAM), the OAM analysis unit instructs the cell relay interface control unit 43c to
An instruction to deactivate (DEACTIVATE) transmission / reception of a cell having a channel identifier of SVC # 3a is issued. Cell relay interface control unit 43c of CLAD device (# 2) 43
Then, the transmission and reception of the cell having the channel identifier of SVC # 3a are stopped according to this instruction.

[S63] In the CLAD device (# 2) 43, as a result of the analysis by the OAM cell analysis unit of the main control unit 43a, the service a interface (line) of the set identification number is changed to its own CLAD device (# 2). ) 43 is assigned to the cell relay interface accommodated in
The received OAM cell is transferred to the CLAD device (# 3) 44 connected to the cell relay interface.

In the CLAD device (# 3) 44, the CLAD
The OAM cell transmitted from the device (# 2) 43 is received, and the OAM analyzer of the main controller 44a analyzes the received OAM cell. When recognizing that the OAM cell instructs the deactivation (DEACTIVATE) of transmission / reception of the cell having the channel identifier of SVC # 3a, the OAM analysis unit sends the SVC #
An instruction to deactivate (DEACTIVATE) transmission and reception of the cell having the channel identifier of 3a is issued. CLAD device (# 3)
The service a interface control unit 44c of 44 stops transmission and reception of the cell having the channel identifier of SVC # 3a according to this instruction.

As described above, the state returns to the state before the SVC call connection. In any of the above-described embodiments, there is no response to the activation / deactivation (ACTIVATE / DEACTIVATE) instruction, but the next operation may be performed after waiting for the response.

[0118]

As described above, according to the present invention, the SVC
The connection establishing means executes point-to-point UNI signaling between the ATM switch and the own CLAD device to establish an SVC connection. With the establishment of this SVC connection, an ATM switch exchanges a channel identifier for SVC connection. The allocated channel identifier for SVC connection is assigned to the P terminal already assigned to the user terminal.
It is stored in the correspondence table in association with the VC connection channel identifier. Next, when the own CLAD device receives a cell from the ATM exchange, the first transfer means converts the SVC connection channel identifier included in the cell into a corresponding PVC connection channel identifier with reference to the correspondence table. , And transmits the converted cell to another CLAD device. When a cell is received from another CLAD device, the second transfer means converts the PVC connection channel identifier included in the cell into a corresponding SVC connection channel identifier with reference to the correspondence table 5, and performs the conversion. Send the post-cell to the ATM switch.

Thus, the SV sent from the ATM exchange is
A cell having a C channel identifier is transferred to a user terminal side PVC.
PV sent to the channel and also sent from the user terminal
The cell having the C channel identifier is transmitted to the SV
It is possible to transmit to the C channel. Therefore, AT
The SVC connection between the M exchange and each user terminal connected to each CLAD device can be simultaneously performed only by controlling the own CLAD device.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing a configuration and an operation sequence of the ATM communication system according to the first embodiment.

FIG. 3 is a diagram showing a configuration and an operation sequence of an ATM communication system according to a second embodiment.

FIG. 4 is a diagram showing a configuration and an operation sequence of an ATM communication system according to a third embodiment.

FIG. 5 is a diagram showing a configuration and an operation sequence of an ATM communication system according to a fourth embodiment.

FIG. 6 is a diagram showing a configuration and an operation sequence of an ATM communication system according to a fifth embodiment.

FIG. 7 shows a conventional AT in which a plurality of CLAD devices are connected in multiple stages.
FIG. 2 is a diagram illustrating an M communication system.

FIG. 8 is a diagram illustrating an internal configuration of a conventional CLAD device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 ATM exchange 2 CLAD device (own device) 3 Other CLAD device 4 User terminal 5 Correspondence table 6 SVC connection establishment means 7 First transfer means 8 Second transfer means 9 Storage means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takumi Iwatsuki 1-13-3 Higashisakura, Higashi-ku, Nagoya City, Aichi Prefecture Inside Fujitsu Nagoya Communication Systems Co., Ltd. (72) Inventor Hiroyuki Suzuki 1-13 Higashisakura, Higashi-ku, Nagoya City, Aichi Prefecture No. 3 Fujitsu Nagoya Communication System Co., Ltd.

Claims (8)

[Claims] 1. A cell disassembly / assembly device connected to an ATM exchange via an ATM interface and connected to at least one other cell disassembly / assembly device, comprising: a channel identifier for an SVC connection and a channel identifier for a PVC connection. And a correspondence table indicating a correspondence relationship between the ATM exchange and the own device, executing point-to-point UNI signaling to another cell disassembly device directly or indirectly connected to the own device. S between the specific user terminal accommodated and the ATM exchange
SVC connection establishing means for establishing a VC connection, SVC included in a cell transmitted from the ATM exchange,
A first transfer for converting the connection channel identifier into a corresponding PVC connection channel identifier with reference to the correspondence table, and transmitting the converted cell to another cell disassembly / assembly device directly connected to the own device; Means for converting a PVC connection channel identifier included in a cell transmitted from another cell disassembly / assembly device directly connected to the own device to a corresponding SVC connection channel identifier with reference to the correspondence table. And converting the converted cell into the ATM.
And a second transfer means for transmitting to the exchange. 2. The SVC connection establishing means according to claim 2,
There is further provided storage means for storing, in the correspondence table, an SVC connection channel identifier assigned from the ATM exchange when the connection is established, in association with a PVC connection channel identifier already assigned to the user terminal. The cell disassembly / assembly apparatus according to claim 1, wherein: 3. The method according to claim 1, wherein the establishing of the SVC connection by the SVC connection establishing means is performed by an external command, and the user terminal is a user terminal specified externally in the command. A cell disassembly / assembly apparatus as described in the above. 4. An AT is provided between the ATM switch and its own device.
An M interface, a self-device and a subordinate cell disassembly / assembly device connected by the same cell relay interface as the ATM interface, and the subordinate cell disassembly / assembly device and a user terminal accommodated in the subordinate cell disassembly / assembly device. 2. The cell disassembly / assembling apparatus according to claim 1, wherein the cell is connected by a service interface. 5. While the SVC connection is being established by the SVC connection establishing means, transmission and reception of cells having a PVC connection channel identifier assigned in advance to the user terminal are permitted, and the SVC connection is established. 2. The cell disassembly / assembling unit according to claim 1, further comprising transmission / reception permission / non-permission means for rejecting transmission / reception of a cell having a PVC connection channel identifier assigned to the user terminal in advance when there is no cell terminal. apparatus. 6. A plurality of cell disassembling and assembling apparatuses connected in tandem or in parallel by an ATM interface.
In an ATM communication system accommodated in an ATM network having a TM exchange, a correspondence table between an SVC connection channel identifier and a PVC connection channel identifier provided in a first cell disassembly / assembly device connected to the ATM exchange, A point-to-point UNI signaling is performed between the ATM switch and the first cell disassembly / disassembly apparatus to perform a second cell disassembly directly or indirectly connected to the first cell disassembly / assembly apparatus. SVC connection establishing means for establishing an SVC connection between a specific user terminal accommodated in the assembling apparatus and the ATM exchange; SVC connection provided in the first cell disassembly and assembling apparatus and provided by the SVC connection establishing means Is established, the second cell disassembly / assembly apparatus is provided with a PVC assigned in advance to the specific user terminal. When a permission signal for permitting the transmission / reception processing of the cell having the connection channel identifier is transmitted, and when the establishment of the SVC connection is canceled by the SVC connection establishment means, the second cell disassembly / assembly apparatus is sent to the second cell disassembly / apparatus. A permission / non-permission signal transmitting means for transmitting a permission / non-permission signal for prohibiting the transmission / reception processing, and a permission signal from the permission / non-permission signal transmitting means provided in the second cell disassembly / assembly apparatus. A transmission / reception processing unit for performing transmission / reception processing of a cell having a PVC connection channel identifier assigned in advance to the specific user terminal from the time point when the non-permission signal is received to the time point when the non-permission signal is received; Only when the SVC connection is established by the SVC connection establishing means provided in the cell disassembly / assembly apparatus,
Second transmission / reception permission means for permitting transmission / reception of a cell having a PVC connection channel identifier assigned to the specific user terminal in advance with the subordinate cell disassembly / assembly apparatus, and the first cell The SVC connection channel identifier included in the cell transmitted from the ATM exchange provided in the disassembly / assembly apparatus is referred to by the corresponding table to determine the corresponding PVC.
A first transfer unit for converting the converted cell identifier into a connection channel identifier and transmitting the converted cell to a subordinate cell disassembly / assembly apparatus; and a first transfer unit provided in the first cell disassembly / assembly apparatus for transmission from the subordinate cell disassembly / assembly apparatus A second transfer unit that converts the PVC connection channel identifier included in the converted cell into a corresponding SVC connection channel identifier with reference to the correspondence table, and transmits the converted cell to the ATM switch. An ATM communication system comprising: 7. A plurality of cell disassembly / assembly apparatuses connected in tandem or in parallel by an ATM interface,
In an ATM communication system accommodated in an ATM network having a TM exchange, a correspondence table between an SVC connection channel identifier and a PVC connection channel identifier provided in a first cell disassembly / assembly device connected to the ATM exchange, Performing point-to-point UNI signaling between the ATM exchange and the first cell disassembly / assembly device to provide the first cell disassembly / assembly device with at least a second
An SVC connection establishing means for establishing an SVC connection between a specific user terminal accommodated in a third cell disassembly / assembly device indirectly via the cell disassembly / assembly device and the ATM exchange; When the SVC connection is established by the SVC connection establishing means provided in the first cell disassembly / assembly apparatus, a PVC connection previously allocated to the specific user terminal is assigned to the second cell disassembly / assembly apparatus. A permission signal for permitting the transmission / reception processing of the cell having the dedicated channel identifier, and when the establishment of the SVC connection is released by the SVC connection establishing means, the second cell disassembly / assembly apparatus is A permission disapproval signal transmitting means for transmitting a disapproval signal for disabling the transmission / reception processing; and a permission disapproval signal provided in the second cell disassembly / assembly apparatus. First transmission / reception processing for performing transmission / reception processing of a cell having a PVC connection channel identifier assigned in advance to the specific user terminal from a time point when the permission signal is received from the communication means to a time point when the non-permission signal is received. Means, provided in the second cell disassembly / assembly apparatus, for relaying permission signals and non-permission signals sent from the first cell disassembly / assembly apparatus to subordinate cell disassembly / assembly apparatuses; Is provided in the cell disassembly and assembly apparatus, from the time when the permission signal relayed and transmitted from the first cell disassembly and assembly apparatus is received until the time when the disapproval signal is received,
PVC pre-assigned to the specific user terminal
Second transmission / reception processing means for performing transmission / reception processing of a cell having a connection channel identifier, provided in the first cell disassembly / assembly apparatus, only while the SVC connection is established by the SVC connection establishment means,
Third transmission / reception permission means for permitting transmission / reception of a cell having a PVC connection channel identifier assigned to the specific user terminal in advance with the subordinate cell disassembly / assembly apparatus, and the first cell The SVC connection channel identifier included in the cell transmitted from the ATM exchange provided in the disassembly / assembly apparatus is referred to by the corresponding table to determine the corresponding PVC.
A first transfer unit for converting the converted cell identifier into a connection channel identifier and transmitting the converted cell to a subordinate cell disassembly / assembly apparatus; and a first transfer unit provided in the first cell disassembly / assembly apparatus for transmission from the subordinate cell disassembly / assembly apparatus A second transfer unit that converts the PVC connection channel identifier included in the converted cell into a corresponding SVC connection channel identifier with reference to the correspondence table, and transmits the converted cell to the ATM switch. An ATM communication system comprising: 8. A plurality of cell disassembly / assembly apparatuses connected in tandem or in parallel by an ATM interface,
An ATM communication system accommodated in an ATM network having a TM exchange, wherein a point-to-point UNI signaling is executed between the ATM exchange and the first cell disassembly / assembly apparatus, and the first cell disassembly / assembly apparatus is executed. At least the second
An SVC connection establishing means for establishing an SVC connection between a specific user terminal accommodated in a third cell disassembly / assembly device indirectly via the cell disassembly / assembly device and the ATM exchange; When the SVC connection is established by the SVC connection establishing means provided in the first cell disassembly / assembly apparatus, the SVC connection channel assigned to the specific user terminal is transmitted to the second cell disassembly / assembly apparatus. When a permission signal for permitting transmission / reception processing of the cell having the identifier is transmitted, and when the establishment of the SVC connection is released by the SVC connection establishing means, the transmission / reception of the transmission / reception to the second cell disassembly / assembly apparatus is performed. A permission / non-permission signal transmitting means for transmitting a permission / non-permission signal for prohibiting the execution of the process; First transmission / reception processing means for performing transmission / reception processing of a cell having a channel identifier for SVC connection allocated to the specific user terminal, from a time point at which a permission signal is received to a time point at which a non-permission signal is received; A relay unit provided in the second cell disassembly / assembly apparatus, for relaying the permission signal and the non-permission signal sent from the first cell disassembly / assembly apparatus to a subordinate cell disassembly / assembly apparatus; and the third cell disassembly / assembly. Provided in the apparatus, from the time when the permission signal transmitted from the first cell disassembly apparatus is relayed to the time when the non-permission signal is received,
Second transmission / reception processing means for performing transmission / reception processing of a cell having an SVC connection channel identifier assigned to the specific user terminal; and SVC connection provided in the first cell disassembly / assembly apparatus, wherein the SVC connection is established by the SVC connection establishment means. Only while is established
Third transmission / reception permitting means for permitting transmission / reception of a cell having an SVC connection channel identifier assigned to the specific user terminal, which is performed with the subordinate cell disassembly / assembly apparatus. ATM communication system.