KR100284000B1 - ATM Cell Address Translation and Routing Header Insertion Device for Asynchronous Transmission Mode Based Communication Devices - Google Patents

Abstract

The present invention relates to an ATM cell address translation and routing header insertion apparatus in an asynchronous transmission mode based communication apparatus, comprising a transmitter and a receiver. The receiver includes an address generator, a data storage, a header converter, an HEC converter, And a transmission management unit.

At this time, the address generator creates a predetermined address using a virtual path identifier (VPI) of the input ATM cell, and the data storage unit is an apparatus for storing address translation and routing information for the corresponding ATM cell. Outputs the data according to the address, and the header converter replaces the GFC information and VPI information of the input ATM cell with that of the data storage, pastes the cell routing header in the data, and outputs a predetermined cell enable bit. Output

In addition, the HEC converter checks the enable bit to determine whether the corresponding ATM cell is a valid cell, and calculates a header error check (HEC) byte for the data output from the header converter to insert the header error check interval. The transmission management unit checks whether the corresponding ATM cell is a valid cell by checking an activation bit, receives a signal indicating that there is space to receive data from a predetermined FIFO unit, and then sends a cell to the FIFO unit. Send it.

Description

A unit of translating address and adding routing headers of Asynchronous Transfer Mode cells in ATM base communication systems

The present invention relates to an address translation and routing header insertion device for an asynchronous transfer mode cell (hereinafter, referred to as an ATM cell), and more particularly to an OAM (Operation, Administration, Maintenance) cell. An ATM-based communication device comprising a predetermined maintenance function unit for generating / monitoring and a predetermined pre-input-output unit (FIFO unit) for regulating the flow of an ATM cell, the output being from a maintenance function unit. ATM cell in the ATM-based communication device that performs the function of transmitting the address translation and routing header after adding the address translation and routing header to the ATM cell or receiving the ATM cell from the pre-input-output unit A device for address translation and routing header insertion.

1 is a block diagram of a demand-density optical subscriber transmission device (Fiber Loop Carrier-Curb System: hereinafter referred to as FLC-C system) is an example of an ATM-based communication device, home-shopping, games, movies, etc. The service providers 130 providing the services are connected to the optical subscribers 140 through the ATM switch 100 and the FLC-C system 200.

The FLC-C system 200 is a FTTC (Fiber To The Curb) type service delivery platform, and its components are largely divided into a host digital terminal (HDT) 210 and an optical network unit (ONU). 220, which transmits service data through the optical path 230 from the host digital terminal 210 (HDT) to the optical terminator 220 (ONU) in order to provide telephone and video services to subscribers 140. In addition, each of the subscribers 140 from the optical terminator 220 (ONU) delivers standard telephone service and digital service using the existing telephone line 150.

At this time, the host digital terminal 210 (HDT) is installed in the telephone station, connects the DS1 (E) signal with the ATM-based broadband signal delivered from the broadband switching network, integrates and multiplexes the synchronous digital hierarchy, The optical terminator 220: ONU performs the function of optical transmission to the optical terminator 220 and the reverse function, and the optical terminator 220: ONU is installed in a distribution center in a dense residential area such as an apartment complex, and is connected to the host digital terminal 210 HD. Each subscriber signal is separated from the received optical signal according to a service, and a function of providing the subscriber and its reverse function is performed.

In addition, the FLC-C system 200 connects DS1 and DS1E signals from a public switched telephone network (110), and connects a digital video service from an ATM switch 100. The digital video service signal connection is connected to an ATM. Based on the Synchronous Transport Module-1 (STM-1) based on, and for routing to the optical terminator 220 (ONU), ATM cells are relocated and multiplexed to the corresponding STM-4 to terminate the optical To device 220 (ONU).

The element management system (EMS) 120 is an operator terminal, and is a device that performs functions such as failure, charging, configuration, performance, and security management according to a TMN (Telecommunication Management System) method.

On the other hand, the host digital terminal 210 (HDT) receives the STM-1 signal from the ATM switch 100, processes the overhead included in the STM-1 signal, extracts the ATM cell, and extracts the corresponding optical transceiver (OTRU). The ATM transceiver 211 (ATRU), which transmits to the Optical Transmit-Receive Unit (212) and the reverse operation, the cell bus (213), the host digital terminal (HDT) 210 and the optical path of the ATM cell. And a plurality of optical transceivers 212 (OTRUs) and the like, which are in charge of the connection between the terminal units 220 (ONU).

2 is a configuration diagram of an ATM transceiver 211 (ATRU), and the functions of the components constituting the ATM transceiver 211 (ATRU) are as follows.

The optical connection unit 310 converts an STM-1 optical signal into an electrical signal, or converts an STM-1 electrical signal into an optical signal, which is input at a transmission rate of 155.52 Mbps (Mega bits per second) from the ATM exchanger 100. 100).

The signal processor 320 receives the STM-1 signal by reproducing data from the received signal, and processes each overhead included in the STM-1 signal, and processes the data in units of ATM cells.

The maintenance function unit 330 generates or inspects a maintenance cell (OAM cell) to perform maintenance, management, and maintenance functions. The maintenance cell 330 is inserted into the flow of the user cell and transmitted. Or, find and inspect a cell for maintenance among the received ATM cells.

The cell router unit 340 performs a routing operation to the cell bus 213, and the pre-input / outline unit 350 (FIFO) is a memory device used to adjust the flow of the cell for maintenance.

The transmission and reception operation of the ATM transceiver 211 (ATRU) configured as described above will be briefly described.

First, the reception operation of the ATM transceiver 211 (ATRU) will be described.

One ATM transceiver 211 (ATRU) receives the STM-1 optical signal transmitted from the ATM switch 100 via the optical transmission line 131 by using the optical connection unit 310 and receives the received STM-1. The optical signal is converted into an electrical signal and sent to the signal processor 320.

The signal processor 320 checks the communication state by searching for the player section overhead, the multiplexer section overhead, and the path overhead from the input STM-1 signal converted into an electrical signal from the optical connection unit 310, and performs the corresponding action. The ATM cells are extracted from the STM-1 signal and transmitted to the maintenance function unit 330.

The maintenance function unit 330 processes an alarm indication signal (AIS), a remote fault indication (RDI) process, and a continuity check on the ATM cells transmitted from the signal processor 320. CC (Continuity Check) processing and the like, and sends ATM cells and maintenance cells to the cell router 340. At this time, the transmitted cells are transmitted to the cell router 340 through the pre-input-output unit 350 (FIFO) to control the flow of the cell.

The cell router 340, which receives the ATM cell transmitted from the maintenance function unit 330 and the maintenance maintenance cell, outputs the cells to the cell bus 213, and the corresponding optical transceiver 212 (OTRU). Send to

The transmission operation of the ATM transceiver 211 (ATRU) will now be described.

From the optical transceiver 212 (OTRU) included in the host digital terminal 210 (HDT), ATM cells and maintenance cells transmitted through the cell bus 213 are received through the cell router unit 340. Is sent to the maintenance function unit 330. At this time, the transmitted cells are sent to the maintenance function unit 330 through the pre-input-output unit 350 (FIFO) to regulate the flow of the cell.

In the maintenance function unit 330, for the ATM cells transmitted through the cell router unit 340, for alarm indication signal (AIS) processing, remote failure indication (RDI) processing, continuity check (CC) processing, and the like. The maintenance maintenance cell is generated and transmitted to the signal processor 320.

The signal processor 320 inserts each overhead into the ATM cells and the maintenance cells that are input from the maintenance function unit 330 to form an STM-1 frame and transmits the STM-1 frame to the optical connection unit 310.

The optical connector 310 converts the STM-1 signal, which is an electrical digital signal received from the signal processor 320, into an optical signal and transmits the optical signal to the ATM switch 100 through the optical path 131.

In this case, before connecting to the cell router 340, the ATM cells from the maintenance function unit 330 of the ATM transceiver 211 (ATRU) may display a cell routing header (Cell) indicating a target device to which they are transmitted. Routing Header) should be added. That is, located between the maintenance function unit 330 and the pre-input-output unit 350 (FIFO), converts the address of the ATM cell output from the maintenance function unit 330, and inserts a cell routing header. The device 400 for transmitting the ATM cells output from the line input-line output unit 350 (FIFO) to the maintenance function unit 330 is required.

Accordingly, the present invention was devised to meet the above necessity, attaches the corresponding cell routing header according to the virtual path identifier (VPI) of the ATM cell output from the maintenance function unit 330, and controls the general flow control (GFC). ) And after updating the virtual path identifier (VPI) information, the header error check (HEC) information is changed and transmitted to the pre-input-output unit 350 (FIFO). An object of the present invention is to provide an apparatus 400 for performing an operation of receiving an ATM cell from a pre-output unit 350 (FIFO) and sending it to the maintenance function unit 330.

In order to achieve the above object, an ATM cell address translation and routing header insertion device in an ATM-based communication device according to the present invention includes a virtual path identifier (VPI) of an ATM cell output from the maintenance function unit 330. An address generator for generating and outputting a predetermined address (address) by using; A data storage unit for storing predetermined address information and cell routing information for the corresponding ATM cell, and outputting corresponding data according to an address (address) generated from the address generator; Replace the general flow control (GFC) information and virtual path identifier (VPI) information of the ATM cell output from the maintenance function unit 330 with that of the data output from the data storage unit, and route the cells in the data. A header converter for attaching and outputting a header and outputting a predetermined cell activation bit; The HEC converter checks whether the corresponding ATM cell is a valid cell by checking the cell activation bit, and calculates and inserts a header error check (HEC) byte for the data output from the header converter. ; And checking whether the corresponding ATM cell is a valid cell by checking the cell activation bit, and receiving a predetermined signal (RACA) indicating that there is a space to receive data from the pre-input-output unit 350 (FIFO). A receiving unit comprising a transmission management unit for transmitting a signal RAWRENB to transmit a cell to the pre-input-line output unit 350 (FIFO); And a transmitter configured to receive a predetermined ATM cell from the pre-input-output unit 350 (FIFO) and send the predetermined ATM cell to the maintenance function unit 330.

At this time, when the transmitter receives a signal TACA indicating that there is a cell to be sent from the pre-input-output unit 350 (FIFO), the transmitter receives a signal from the pre-input-output unit 350 (FIFO). After receiving the response signal TARDENB to receive a signal, the pre-input-output unit 350 receives a predetermined synchronization signal TASOC indicating the start of the corresponding ATM cell from the FIFO. A reception operation for receiving TADAT, a signal TPWRENB indicating that there is a cell to be transmitted to the maintenance function unit 330, and indicating that there is a space to receive a cell from the maintenance function unit 330. After receiving the signal TPCA, it is possible to perform the transmission operation of transmitting the output cell data TPDAT together with a predetermined synchronization signal TPSOC indicating the start of the corresponding output cell data. .

1 is a configuration diagram of an FLC-C system;

2 is a block diagram of an ATM transceiver;

3 is a connection diagram of a device according to the invention,

4 is a block diagram of a receiver according to the present invention;

5 is a schematic diagram of the operation of the header converter.

* Explanation of symbols for main parts of the drawings

330: maintenance function unit 350: pre-input-output unit

410: transmitter 420: receiver

421: address generator 422: data storage

423: header converter 424: HEC converter

425: transmission management unit

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

3 is a connection diagram of the ATM cell address translation and routing header insertion apparatus 400 according to the present invention, which is a pre-input-line output unit which is a device for controlling the flow of the maintenance function unit 330 and the ATM cell ( 350: positioned between the FIFOs, the transmitter 410 and the receiver 420.

At this time, the receiving unit 420 attaches a corresponding cell routing header according to the virtual path identifier (VPI) of the ATM cell output from the maintenance function unit 330, and applies general flow control (GFC) information and the virtual path identifier (VPI). ) After updating the information, the header error check (HEC) information is changed and transmitted to the pre-input-pre-output unit 350 (FIFO).

In addition, the transmitter 410 receives the ATM cell from the pre-input-output unit 350 (FIFO) and transmits the ATM cell to the maintenance function function 330.

4 is a block diagram of a receiver 420 of an ATM cell address translation and routing header insertion apparatus according to the present invention, which includes an address generator 421, a data storage 422, a header converter 423, and an HEC converter ( 424, and a transmission manager 425.

When the address generator 421 receives a signal RPCA indicating that there is a cell to be transmitted from the maintenance function unit 330, the address generator 421 receives a signal RRPDENB to accept the cell from now on. Send it to.

Then, the maintenance function unit 330 transmits a synchronization signal indicating the start of the cell to be sent. In one embodiment, the maintenance function unit 330 transmits a signal (RPSOC) that is activated in synchronization with the first bit of the cell to be transmitted as a synchronization signal. Can be. The address generator 421 receives the ATM cell data RPDAT output from the maintenance function unit 330 by using the synchronization signal RPSOC.

When the address generator 421 receives the ATM cell data output from the maintenance function unit 330, the corresponding address (TADD) of the data storage unit 422 from the virtual path identifier (VPI) of the header part of the received ATM cell. ) And print it out.

The address TADD is created by multiplying the value of the virtual path identifier (VPI) by 3, and multiplying the data by the data storage unit 422 with respect to one virtual path identifier is performed in units of 3 bytes. Because it is data. The created address TADD is sent to the data storage unit 422.

The data storage unit 422 is a component that stores predetermined data, and outputs the data to the header converter 423 according to the address TADD output from the address generator 421. At this time, the data storage unit 422 is preferably implemented using a dual port RAM (DPRAM), an embodiment of the data (translation data) format stored in the data storage unit 422 is shown in Table 1 below. As shown, it can have a data structure of 3 bytes.

VPI A X X X GFC B P C R R R R R

As shown in Table 1 above, the data stored in the data storage unit 422 has a virtual path identifier (VPI) information of 1 byte, a bit (A) indicating whether the corresponding connection (Activation) of 1 bit (Active) ), Four bits of general flow control information (GFC), one byte of cell routing header information, and three bits of dance bit (X).

In this case, one byte of cell routing information includes one-bit broadcasting / point-to-point separator, one-bit port identifier (P), five-bit routing destination address information (R), and a routing destination. It consists of one bit odd parity check (C) bit for address information.

That is, three bytes of data correspond to a virtual path identifier (VPI) of one cell sent from the maintenance function unit 330, which is a virtual path identifier (VPI) value of an ATM cell received from the address generator 421. That's why we get the address by triple.

The header converting unit 423 controls the flow of data in the data storage unit 422 using the general flow control (GFC) information and the virtual path identifier (VPI) information of the ATM cell outputted from the maintenance function unit 330. GFC) information and virtual path identifier (VPI) information are replaced, and a cell routing header is added to the HEC conversion unit 424.

FIG. 5 is a schematic diagram of the operation of the header converter 423, and the operation of the header converter 423 will be described in detail with reference to the drawing.

First, the header converter 423 receives corresponding data from the ATM cell (RPDAT) and the data storage unit 422 from the maintenance function unit 330. At this time, this data is the data of the structure shown in Table 1 shown above.

Then, the cell routing header 514 of the data received from the data storage unit 422 is attached to the 53-byte ATM cell received from the maintenance function unit 330, and the general flow control information 515 of the received ATM cell. And the virtual path identifier information 516 are replaced with the general flow control information 513 and the virtual path identifier information 511 of the data received from the data storage unit 422.

Then, since the cell routing header 514 is attached to the 53-byte ATM cell, 54 bytes of data are generated. The data RPOUT is outputted to the HEC converter 424, and at the same time, a predetermined activation bit ( Output A) through a separate signal line.

The HEC converter 424 checks whether an active cell is output by checking the enable bit A output from the header converter 423, and checks the header error check (HEC) byte for the data from the header converter 423. Calculate and insert into the HEC section of the corresponding ATM cell.

In addition, by being activated in synchronization with the first bit of the output cell, a predetermined synchronization signal RASOC indicating that data output is started is output, and data RADAT to which a cell routing header is added is output.

The transmission manager 425 checks whether an active cell is output by checking the activation bit A output from the header converter 423, and notifies that there is a space to receive data from the pre-input-pre-output unit 350 (FIFO). After receiving the signal (RACA), a signal (RAWRENB) to send a cell to the pre-input line output unit 350 (FIFO).

On the other hand, the predetermined reference clock signal REFCLK is supplied from the outside means a clock signal required for the operation of each component of the receiver 420, the reset signal RESET is the address generator 421, the data storage unit ( 422), an external signal for resetting the HEC converter 424 and the transmission manager 425.

The transmitter 410 is responsible for receiving an ATM cell from the pre-input-output unit 350 (FIFO) and sending it to the maintenance function unit 330.

Specifically, when a signal TACA indicating that there is a cell to be sent currently is received from the pre-input line output unit 350 (FIFO), a signal TARDENB to receive the cell from the pre-input line output unit 350 (FIFO). Send) After receiving the synchronization signal TASOC indicating the start of the input cell by activating in synchronization with the first bit of the cell from the pre-input-output unit 350 (FIFO), it receives the ATM cell data TADAT by using the same. .

In addition, when the transmitting unit 410 receives the ATM cell from the pre-input-out line unit FIFO 350, it transmits a signal (TPWRENB) indicating that there is a cell to be transmitted to the maintenance function unit 330, and the maintenance function unit. In response to the signal TPCA indicating that there is a space to receive the cell from 330. In addition, by being activated in synchronization with the first bit of the cell, the synchronization signal TPSOC and ATM cell data TPDAT indicating the start of the cell are sent to the maintenance function unit 330.

As described above, when the present invention is used, the maintenance function unit 330 for generating / monitoring a predetermined maintenance cell used for an ATM-based communication device and a pre-input for adjusting the flow of an ATM cell Located between the line output unit 350 (FIFO), it is possible to perform the address translation and cell routing header insertion function for the ATM cell, there is an effect that facilitates the manufacture of ATM-based communication device.

Claims (2)

A predetermined maintenance function unit 330 for generating / monitoring an asynchronous transfer mode cell (ATM cell) for predetermined maintenance management (OAM) and a predetermined pre-input-output unit for regulating the flow of ATM cells ( 350: Asynchronous communication mode (ATM) based communication device configured to include a FIFO, the predetermined address (VPI) using the virtual path identifier (VPI) of the ATM cell output from the maintenance function unit 330 An address generator for generating and outputting an address); A data storage unit for storing predetermined address information and cell routing information for the corresponding ATM cell, and outputting corresponding data according to an address (address) generated from the address generator; Replace the general flow control (GFC) information and virtual path identifier (VPI) information of the ATM cell output from the maintenance function unit 330 with that of the data output from the data storage unit, and route the cells in the data. A header converter for attaching and outputting a header and outputting a predetermined cell activation bit; The HEC converter checks whether the corresponding ATM cell is a valid cell by checking the cell activation bit, and calculates and inserts a header error check (HEC) byte for the data output from the header converter. ; And After checking the cell activation bit to determine whether the corresponding ATM cell is a valid cell, and receiving a predetermined signal (RACA) indicating that there is a space to receive data from the pre-input-output unit 350 (FIFO) A receiver configured to transmit a signal (RAWRENB) for transmitting a cell to the pre-input / output unit 350 (FIFO); And Asynchronous transmission mode-based communication, characterized in that it comprises a transmitter for performing a function for receiving a predetermined ATM cell from the pre-input-line output unit 350 (FIFO) and sends it to the maintenance function unit 330 Apparatus for ATM cell address translation and routing header insertion. The line input / output unit 350 of claim 1, when the transmitter receives a signal TACA indicating that there is a cell to be sent from the line input / output unit 350 (FIFO). After receiving a response signal (TARDENB) to receive a cell, and receives a predetermined synchronization signal (TASOC) indicating the start of the ATM cell from the pre-input-output unit (FIFO) 350, this input is used. A receiving operation for receiving cell data (TADAT), After sending a signal (TPWRENB) indicating that there is a cell to be transmitted to the maintenance function unit 330, and receives a signal (TPCA) indicating that there is a space to receive the cell from the maintenance function unit 330, ATM cell address in an asynchronous transmission mode based communication device, characterized in that it is configured to perform a transmission operation for transmitting the output cell data (TPDAT) together with a predetermined synchronization signal (TPSOC) indicating the start of the corresponding output cell data. Translation and routing header insertion device.