KR950014950B1 - Switching control unit of isdn termination device - Google Patents

Abstract

a control unit for controlling the switching function of D-channel data information; an interfacing unit for supplying an interface between a subscriber and the control unit; a reset unit for supplying a reset function; a D-channel switching unit for transferring pure D-channel information from an input/output unit to the control unit and the D-channel and switching information from the control unit to the input/output unit; a primary group D-channel switching unit for transferring the D-channel information from a primary group speed access switching unit to the control unit and the data of the control unit to the primary group speed access switching unit; a switching unit for inter-switching B-channel information of an S interfacing unit; and a clock synchronization generating unit for receiving a network synchronization reference clock from the primary group speed access switching unit via the primary group D-channel switching unit and generating a system clock synchronized to the network synchronization reference clock.

Description

Switching control device of ISDN network terminating device

1 is an overall configuration diagram of a network termination device to which the present invention is applied.

2 is a configuration diagram of a switching control device according to the present invention.

3 is a flowchart of data transmission between D-channel controllers.

* Explanation of symbols for main parts of the drawings

1 to 3: S interface unit 4: Switching control unit

5: input / output unit 6: main controller

7: primary group speed access matching unit 8: D-channel matching unit

9 control unit 10 primary group D-channel matching unit

11 serial interface 12 clock synchronization generating circuit

13 reset circuit 14 switching unit

The present invention, in the implementation of a comprehensive information communication network, a network termination that accommodates an ISDN (Integrated Service Digital Network) terminal and a terminal adapter (TERMINAL ADAPTER) (device for connecting a non-ISDN terminal to an ISDN network) as components of a subscriber side It transmits the information of 2B + D through the switching action to other subscribers connected by extension using the basic speed interface (2B + D) transmitted through the digital subscriber line between the subscriber-network in the device NT12, The switching control device performs the role of information transfer to the local exchange by switching to the local exchange using the primary group speed interface (3B + D).

Conventional techniques, which relate to switching in a private exchange function mainly for analog subscribers and digital subscribers, have tended to implement switching and control between the subscribers of a general information network or subscriber-network.

Accordingly, an object of the present invention is to provide a switching control device capable of quickly and accurately performing an overall switching function of a network termination device that performs only a function of a comprehensive information communication network.

In order to achieve the above object, the present invention, in the switching control device of the ISDN network termination device, comprising a microprocessor, the control to control the switching function of the D-channel data information using the built-in software Way ; Interfacing means for providing an interface between a subscriber and said control means; Reset means connected to the control means to provide a reset function; D-channel extracting pure D-channel information from the D-channel information input from an external input / output means and transmitting it to the control means, and transmitting the D-channel and switching related information transmitted from the control means to the input / output means. Matching means; A primary group D- that receives D-channel information from an external primary group speed access matching means and transmits the D-channel information to the control means, and transmits the data of the control means to the primary group speed access matching means; Channel matching means; Switching means for mutually switching external B interfacing means and B channel information of the primary group speed matching means according to the control of the control means; And generating a system clock synchronized with the network synchronizer reference clock by receiving the network synchronizer reference clock supplied from the primary group speed access matching unit through the primary group D-channel matching unit to provide synchronization in the system. A means is provided.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

1 is an overall block diagram of a network termination apparatus to which the present invention is applied, wherein 1 to 3 are S interface units, 4 is a switching controller, 5 is an input / output unit, 6 is a main control unit, and 7 is a primary group speed access matching unit. Indicates.

The S interface units 1 to 3 are subscriber-side interface booths of a general information communication network, and can directly connect a general information communication network telephone or a terminal adapter, and one S interface unit 1, 2 or 3 accommodates 8 subscribers. can do. In addition, by processing data on the subscriber side (2B + D), the 2B channel is allocated to a specific slot among 32 slots of the Pulse Code Modulation (PCM) highway, and the D-channel is performed by performing a Synchronous Data Link Control (SDLC) controller. It is transmitted to the input / output unit 5 in the form of an SDLC bus.

The input / output unit 5 functions to extract pure D-channel information of the D-channel of the SDLC bus type sent from the S interface unit 1 to 3 and transmit the extracted pure D-channel information to the main control unit 6. (6) analyzes the D-channel information transmitted from the input / output unit 5 to perform protocols of layers 2 and 3.

In addition, when the information passing through the layer 3 requires switching, the main controller 6 transmits the related information to the switching controller 4 in the form of an SDLC bus suitable for the switching controller 4, and the switching controller ( 4) performs functions such as extension switching, external switching, and three-way call switching according to the received information.

In external line switching, the switching control unit 4 serves to transmit and receive related control information via the D-channel transmission / reception line with the primary group speed access matching unit 7.

The first group speed access matching unit 7 uses a CEPT (Conference of European Post and Telecommunications Adimistration) method and a T1 method as an interface method for establishing a transmission line with a private switching network for a local switching network or other comprehensive information communication network. . Then, thirty B-channels provided by the primary group speed access matching unit 7 are transmitted to a switch in the switching control unit 4 which performs the switching function of the entire system via a switch therein.

2 is a configuration diagram of a switching control device according to the present invention, 8 is a D-channel matching unit, 9 is a control unit, 10 is a primary group D-channel matching unit, 11 is a serial interface unit, 12 is a clock synchronization generating circuit, 13 denotes a reset circuit, and 14 denotes a switching unit.

The control unit 9 consists of an 8-bit microprocessor, and as a peripheral circuit there is a reset circuit 13 and a serial interface unit 11 for monitoring the state of the system with the serial port of the computer.

Configures the control unit 9, manages the reset circuit 13, the serial interface unit 11, and hardware on the board, and executes a protocol related to the D-channel information by using built-in software, and controls the switch accordingly. Briefly, the characteristics of the microprocessor (CPU) in charge of the function are as follows.

Ports 0 and 2 are addresses and data input / output ports connected to external ROM, RAM, etc., respectively, and port 1 is a port for performing GSC (Global Serial Channel). , Port 3 is an input / output port that performs LSC (Local Serial Channel) to handle serial interface. Port 5 is connected with a critical fault signal, and port 6 is for listening to the process number installed on the back panel. The two external interrupt pins serve as SDLC-enabled interrupts for the interrupt of the switching chip and the interface with the D-channel matcher 8.

Two other direct memory access (DMA) and two timers are built in, so DMA is used for fast transmission and reception of D-channel data, one timer is used as a serial interface timer of 9600bps, and the other timer is We use as timer.

Other memory configurations and software functions are as follows.

The memory consists of one ROM and one RAM, and the system software and call control software are installed in the ROM to perform system initialization, buffer management, D-channel transmission and reception, and switching. In addition, a buffer such as Rx and Tx is provided in the RAM for temporary storage and transmission of transmission / reception channel data, and for storage of variables and program data.

The reset circuit 13 is implemented by an 8-pin timer integrated circuit (IC) to perform a reset function, and the serial interface unit 11 is implemented by using an RS232C interface chip.

The switching unit 14 switches the B-channel information of the S interface unit 1 to 3 and the primary group speed access matching unit 7 through the PCM highway using a memory and a time switch to output the result to the PCM highway. It performs functions such as extension calls, external calls, and conference calls.

The D-channel matching unit 8 extracts pure D-channel information from the D-channel information transmitted in the SDLC form from the input / output unit 5 and delivers the pure D-channel information to the control unit 9 through the GSC, and in the control unit 9 It is responsible for transmitting the D-channel and switching related information to the input and output unit 5 after determining the state of the line.

The primary group D-channel matching unit 10 delivers the D-channel information extracted by the D-channel controller in the primary group speed access matching unit 7 to a specific frame structure, and delivers it to the control unit 9 through interruption. Accordingly, the control unit 9 processes the data and transmits the data to the primary group D-channel matching unit 10 if there is data to be transmitted to the primary group speed access matching unit 7, and the primary group D-channel matching unit 10. Receives the data and passes it to the primary group speed access matching unit 7.

The serial interface unit 11 provides an interface between the external personal computer (PC) and the control unit 9 using the RS232C function to enable the control and testing of the system on the personal computer (PC) monitor.

The clock synchronizing generation circuit 12 generates a system clock in which 8K kHz, a network synchronizer reference clock supplied from the primary group speed access matching unit 7, is supplied through the primary group D-channel matching unit 10 and synchronized thereto. By supplying each component in the system to synchronize, and if the state that the network reference clock is not available, it generates the system synchronization clock itself and supplies the clock for the subscriber end.

Looking at the detailed operation of the present invention of the configuration as described above are as follows.

When the power is supplied, the process of initializing the board itself is first performed, and if there is an error in the ROM or RAM, the error status is displayed on the LED when an error occurs. If there is no message, it waits until a message from layer 3 arrives or receives D-channel information through an interrupt of the control unit 9 from the primary group D-channel matching unit 10.

During the standby state, on the subscriber side, when the setup information of the layer 3 of the D-channel via the S interface units 1 to 3 comes up, the D-channel matching unit 8 sends the information to the control unit 9. The controller 9 stores the data in a data buffer in RAM.

Then, the call control software module inside the control unit 9 reads and analyzes the data buffer in the polling order, and then examines the state of the D-channel matching unit 8 to inquire whether data transmission is possible. The inquired D-channel matching section 8 notifies the control section 9 of the availability of the interrupt when the transmission line is in an idle state, so that the control section 9 transmits specific protocol information to the layer 3.

Then, if the connection between the subscribers or the subscriber network is made by the control of the switching unit 14, the D-channel controller and the PCM highway interface function unit in the S interface units 1 to 3 specify the B1 and B2 channels on the subscriber side. It is loaded in one of the 32 slots on the PCM Highway. The B1 and B2 channels mounted on the PCM highway are connected to the switching unit 14, and these are switched and transmitted to specific slots that are switched by performing the D-channel protocol.

Next, the data transmission and switching procedure by the primary group D-channel matching unit 10 will be described.

First, in order to transmit the CEPT-based 30B + D primary group speed access data from the primary group D-channel matcher 10 to the switching controller 4, from the D-channel controller in the primary group speed access matcher 7. D-channel information is transmitted to the primary group D-channel matching unit 10 at a speed of 4 Mb / s or more, and the D-channel controller in the primary group D-channel matching unit 10 delivers this to the controller 9 as an interrupt. To perform the D-channel protocol.

Then, when the primary group speed access matching unit 7 loads 30B on the PCM highway, the control unit 9 causes the switching unit 14 to perform the switching function by the D-channel which previously received the data of the allocated slot. Do it.

3 is a flowchart of a data transmission / reception process procedure between the D-channel controllers, (a) is a processing flowchart relating to transmission, and (b) is a processing flowchart relating to reception.

First, referring to (a), the processing procedure according to the transmission is performed. When transmitting the information of the D-channel to the primary group speed access matching unit 7, it is checked whether the transmission buffer is empty (20). The D-channel controller notifies the controller 9 of the interrupt and checks whether an interrupt for this has occurred (21), and the controller 9 writes 32 bytes into the transmission FIFO (First In First Out) buffer (22).

The D-channel controller performs the transfer as soon as the buffer fills, verifies that it is the end of the message (23), requests and returns to send the next 32 bytes if the message is not end (24), and controls if it is the end of the message. Interrupts to (9) to inform the end of the transfer procedure and ends (25).

Referring to (b), the processing procedure related to the reception is examined by checking whether the reception buffer is full (26), if it is full, reading 32 bytes (27) checking whether the end of the message (28) is completed or not. Generates an interrupt and exits (29), otherwise returns to the beginning.

On the other hand, during the transmission and reception of the above-mentioned D-channel data, the serial interface unit 11 transmits the overall operating characteristics and state information of the system to the RS232C interface of the external personal computer (PC) through the serial port of the control unit 9. It is responsible for changing the level to enable communication.

In addition, the clock synchronizing generation circuit 12 receives an 8KkHz FRS (Frame Request Signal) clock from the primary group speed access matching unit 7 and generates a system clock which is synchronized with the clock. If the clock is truncated, it plays a role in supplying the system with a self-generated clock to synchronize and switch between subscribers.

Therefore, the present invention configured and operated as described above is dualized by a method of processing D-channel information, and the burden of software polling and the like of the main control unit by processing between D-channel controllers supporting SDLC with high-speed communication of 4 Mb / s or more. It has the effect of reducing the speed and ensuring the fast processing speed of switching. In particular, if only the high-speed transmission line between the D-channel controller is used, it is possible to drastically improve the D-channel information transmission.

Claims (2)

A switching control device of an integrated network (ISDN) network terminating device, comprising: control means (9) configured of a microprocessor and controlling switching function of D-channel data information by using embedded software; Interfacing means (11) for providing an interface between a subscriber and said control means (9); Reset means (13) connected to said control means (9) to provide a reset function; Pure D-channel information is extracted from the D-channel information input from the external input / output means 5 and transmitted to the control means 9, and the D-channel and switching related information transmitted from the control means 9 are transmitted. D-channel matching means (8) for transmitting to said input / output means (5); Under the control of the control means 9, the D-channel information is received from an external primary group speed access matching means 7 and transmitted to the control means 9, and the data of the control means 9 is transmitted to the 1. Primary group D-channel matching means 10 for transmitting to the group speed access matching means 7; Switching means (14) for mutually switching B-channel information of the external S interfacing means (1 to 3) and the primary group speed matching means (7) according to the control of the control means (9); And generating a system clock synchronized with the network synchronizer reference clock by receiving the network synchronizer reference clock supplied from the primary group speed access matching unit 7 through the primary group D-channel matching unit 10. Switching control device characterized in that it comprises a clock synchronization generating means (12) for providing. 2. The switching control apparatus according to claim 1, wherein the clock synchronizing means (12) is configured to generate a system synchronizing clock by itself to provide synchronization in the system when the clock synchronizing means (12) is not provided.