KR20000034429A - Subscriber interface module in asynchronous transmission mode exchanger - Google Patents

Abstract

PURPOSE: A subscriber interface module is provided so that the user can easily examine the connection and service state in an asynchronous transmission mode(ATM) exchanger. CONSTITUTION: A physical hierarchy process unit(210) extracts an ATM cell by decomposing a subscriber data from a subscriber, and forms a predetermined transmission format by mapping the ATM cell into a frame position, and connecting it with a maintenance/repair signal. An ATM hierarchy processing unit(220) receives the ATM cell from the physical hierarchy process unit(210), adds a routing tag thereto, and transmits it to a switch, and processes the ATM cell from the switch, and transmits it to the physical hierarchy process unit(210). A switch interface unit(230) interfaces the ATM hierarchy processing unit(220) with the switch network. A clock receiving unit(240) provides the received clock to the physical hierarchy processing unit(210) and the ATM hierarchy processing unit(220). A display unit(251) displays the subscriber connection state and/or the cell service state according to a control signal. A subscriber interface control unit(250) is connected to the physical hierarchy processing unit(210) and the ATM hierarchy processing unit(220), for providing a control signal for turning on the display unit(251), when the subscriber connection is performed.

Description

A SUBSCRIBER INTERFACE BOARD OF AN ATM EXCHANGE

The present invention relates to a subscriber matching device for an asynchronous delivery mode switch, and more particularly, to a subscriber matching device for easily displaying the connection and service status by an operator.

In general, an ATM switch is a system that performs a node function to connect an ATM network, an ATM network, or a subscriber to an ATM network when configuring a public network using an ATM method. A virtual channel (VC) switch according to its function And Virtual Path (VP) exchanges.

The ATM switching system is implemented with subscriber matching devices, switch networks, trunk line matching devices, and the processors that control them. The subscriber matching devices include UNI physical layer matching, ATM layer processing, signal cell and user cell separation transfer, header conversion, and OAM. In addition to processing, it performs traffic control function according to user parameter control (UPC). Subscriber matching devices can also include low- and medium-speed subscriber matching for existing subscriber services, as well as ATM subscribers. The low-speed subscriber matching provides DS1E (approximately 2.048 Mbps) level access, and the subscriber registration feature provides DS3 (approx. 44.736 Mbps) level of connectivity.

ATM switch networks are realized by multiple stages of unit switches capable of high-speed switching of hundreds of Mbits. ATM unit switches are divided into input buffers, output buffers, common memories, common buses, cross-point switches, and the like according to configuration.

ATM trunk line matching device performs NNI interface, physical layer processing, ATM layer processing, OAM processing, and the traffic control function works in conjunction with switch network. It also includes interworking functions with other networks such as existing telephone network, narrowband (N) -ISDN, packet network, frame relay network, etc.

However, in a conventional ATM switch, an operator inputs a command (MMC) through a human-machine interface (HMI) to determine whether an operator has a subscriber connection or is in service, and an operation and maintenance processor (OMP) or an operation server receives an MMC command. There is an inconvenient problem because you had to look up the results provided by searching the database.

Accordingly, an object of the present invention is to provide a subscriber matching device for an asynchronous delivery mode switch, in which an operator can easily understand the state of a connection and a cell service.

In order to achieve the above object, the present invention, by decomposing the subscriber data of the predetermined transmission format delivered from the subscriber to extract the ATM cell, mapping the ATM cell to the corresponding frame position and combined with the maintenance signal, the predetermined transmission format Physical layer processing unit to form a; An ATM layer processor for receiving an ATM cell from the physical layer processor and adding a routing tag to the switch and processing the ATM cell received from the switch and then transmitting the ATM cell to the physical layer; A clock receiver for providing a reception clock to the physical layer processing means and the ATM layer processing means; A switch matching unit for interfacing the ATM layer processing means with a switch network; Display means for displaying a subscriber connection state and a cell service state in accordance with a control signal; And a control signal connected to the physical layer processing unit and the ATM layer processing unit and connected through an IPC from an upper layer processor to turn on the display unit when a subscriber connection is established, and when the cell is normally transmitted through the connection. And a subscriber registration control means for causing the means to flash at a predetermined low speed and for causing the display means to flash at a predetermined highway when the cell is abnormally transmitted through the connection.

1 is a block diagram showing the configuration of an ATM switch to which the present invention is applied;

2 is a block diagram showing a subscriber matching device according to the present invention;

3 is a flowchart illustrating a procedure for displaying a connection state of a subscriber matching device according to the present invention;

4 is a flowchart illustrating a procedure for displaying a service state of a subscriber matching device according to the present invention.

* Explanation of symbols for main parts of the drawings

210: physical layer processing unit 220: ATM layer processing unit

230: switch matching unit 240: clock receiving unit

250: subscriber registration control unit 251: LED

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

1 is a block diagram showing the configuration of a general ATM switch to which the present invention is applied. Referring to FIG. 1, an ATM switch may include a large number of ATM Local Switching / Subscriber subsystems (ALS / S) 110 and ATM Local Switching / Trunk subsystems (ALS / T); ), ATM Central Switching Subsystem (ACS) 130. In addition, the ALS / S 110 includes an access switching network module (ASNM) for accommodating the number of subscriber interface devices (SIMs 111 and 112) and the subscriber interface devices (SIMs 111 and 112). Module 113), the Call & Connection Control Processor (CCCP) 114 for controlling the subsystem, and the ALS / T 120 includes Trunk Interface Modules (TIMs) as many as the number of trunks. 121, 122), and an Access Switching Network Module (ASNM) 123 for accommodating the same, and a Call & Connection Control Processor (CCCP) 124 for controlling a subsystem.

The ACS 130 also includes an Interconnection Switch Network Module (ISNM) 131 and an Operation and Maintenance Processor (OMP: 132), which includes a disk 136, a cartridge tape ( CT: 137) and SCSI, and workstation (W / S: 140) and Ethernet.

Operation and maintenance related functions in the ATM switching system are mostly accommodated on the OMP 132, and the workstation (W / S: 140) is connected to the Ethernet so that the operator can check or control various states of the system. have.

2 is a detailed block diagram of a subscriber matching device according to the present invention. As shown in FIG. 2, the subscriber matching device includes a physical layer processing unit 210, an ATM layer processing unit 220, a switch matching unit 230, a clock receiving unit 240, and a subscriber matching control unit 250. The layer processor 210 includes an optical transmitter / receiver 211 and an STM1 frame unit 212. The ATM layer processor 220 includes a physical layer receiver interface 221, a routing performer 222, and output cell continuity. The inspection unit 224 and the physical layer transmission interface unit 223, the LED 251 is connected to the subscriber matching control unit 250.

The subscriber matching device terminates the STM-1 physical layer, extracts an ATM cell, and transmits a user cell and a signaling cell to a switch module (ASNM) by adding a routing tag according to the configuration of each connection, and extracts an OAM cell. Process. Meanwhile, the internal cell input from the switch module (ASNM) is separated from the user cell and the internal message cell, and the internal message cell is delivered to the subscriber matching controller 250, and the user cell is carried in the corresponding STM-1 frame and delivered to the subscriber line. It performs the function.

Referring to FIG. 2, the physical layer processing unit 210 receives an STM-1 frame signal from a subscriber, processes various maintenance signals included in the overhead of a frame, extracts an ATM cell, and extracts an ATM cell. To pass. In addition, the ATM cell received from the ATM layer processor 220 is loaded in the corresponding frame to configure the STM-1 frame together with the maintenance signal to the subscriber. That is, after converting the optical signal into an electrical signal to restore the data and the clock, the STM-1 frame is restored to process various maintenance signals included in the overhead of the frame, and the ATM layer processing unit extracts the ATM cell. 220, the ATM cell received from the ATM layer processor 220 is loaded in a frame, converted into an optical signal, and transmitted to the subscriber through the optical fiber.

The ATM layer processor 220 adds a routing tag to the ATM cell received from the physical layer processor 210, converts the routing tag into an internal cell, and transfers the converted cell to the switch matching unit 230. The internal cell received from the switch matching unit 230 is The ATM is converted into an ATM cell and transferred to the physical layer processor 210. That is, the ATM layer processor 220 includes a physical layer reception interface unit 221, a routing execution unit 222, a physical layer transmission interface unit 223, and an output cell continuity checker 224.

The physical layer receiving interface unit 221 extracts the VPI from the ATM cell inputted from the physical layer processing unit 210 and the ATM cell read from the loopback FIFO, searches the VP index table, reads the VP index, and then reads the corresponding VP index. Check whether the connection is a VP connection or a VC connection. In the case of a VP connection, use only the VP index, and in the case of a VC connection, search the connection ID table using the VP index and the VCI. After reading it, it is sent to the routing execution unit 222 together with the ATM cell.

The physical layer transmission interface unit 223 reads the user cell FIFO written by the switch matching unit 230 and the OAM cell FIFO written by the subscriber matching control unit 250 and writes the loopback FIFO when the loopback is not set.

The routing performing unit 222 searches the routing table using the connection ID received from the physical layer receiving interface unit 221, reads the output VPI, VCI, and routing tag for the corresponding connection, and reads 3 bytes of the input cell. Add a routing tag, replace the VPI and VCI of the input cell with the VPI and VCI read from the routing table, and write a 56-byte cell to the user FIFO. As such, the routing execution unit 222 requires a routing table. The routing table includes an output port, each cell type (determining whether it is an IPC cell or a USER cell), a busy cell, etc., when passing through each switch in an ATM switch. Have information

The output cell continuity checker 224 performs two processes at the same time. In one process, the VPI and VCI of the output cell are received from the physical layer interface units 221 and 223 to search the DPRAM to find the VP index, and use the VP index. Finds the connection ID, latches the connection ID and the CC threshold value input by the dip switch from the outside, increases the cell counter value of the CC table corresponding to the connection ID by 1, and clears the CC counter value to 0. Let's go. In addition, the subscriber matching controller 250 may know how many cells each connection has sent by the cell counter of the continuity checker 224.

The switch matching unit 230 converts the internal cells received from the ATM layer processing unit 220 into serial data and transmits them through the switch link. The internal message cells are transmitted to the subscriber matching control unit 230 among the cells received from the switch network. do. That is, the switch matching unit 230 includes an unloaded switch link interface unit, an output header converting unit, and a CRC performing unit. In the switch link interface unit, if there is a user cell, the switch link unit is converted into 64 bytes and sent to the switch link. If not, the IPC cell with the CRC added is made into 64 bytes and sent to the switch link. In addition, 64 byte cells are classified as IPC / OAM or user cells from the switch link side, and the user cells are sent to the header conversion unit, and the IPC / OAM cells are sent to the CRC execution unit. The output header converter receives the user cell from the switch link interface, extracts the MCN and sends it to DPRAM in the case of multicasting, reads the VPI and VCI accordingly, and performs VPI conversion only when the connection type is 0, and VPI when the connection type is 1 Convert all / VCIs. In the case of not multicasting, only the upper 3 bytes of 56 bytes are removed without any conversion, and 53 bytes are generated and sent to the physical layer transmission interface unit 223. The CRC Execution Unit checks CRC32 only for the cell where "CET" is "11" for the received cell, makes the 64 byte cell 56 bytes, and performs CRC10 when the CET is "0" for the user cell read from the FIFO. If CET is "11", perform CRC32.

The clock receiver 240 receives the system clock, distributes it to the ATM layer processor 220 and the switch matching unit 230, synthesizes a clock, and transfers the clock to the physical layer processor 210. That is, the clock receiver 240 receives a system clock having a frequency of 23.474 MHz from the local clock generation unit (not shown) as an ECL differential signal and uses the 23.474 MHz used by the ATM layer processing unit 220 and the switch link matching unit 230. The TTL clock is distributed, and the 19.44 MHz reference clock used for data transmission and reception with the subscriber is synthesized and transmitted to the physical layer processor 210.

The subscriber matching controller 250 performs various OAM functions and connection management functions of the subscriber matching device, and communicates with an upper processor through an internal message. The subscriber matching control unit is composed of a single chip controller and a decoder circuit for selecting ROM, RAM, registers and tables to perform operation management of each unit. In particular, in the present invention, the subscriber matching control unit 250 controls the LED 251 lighting according to the state of the connection and the cell transmission state so that the operator can easily know the state of the subscriber matching device.

3 is a flowchart illustrating a procedure of displaying a connection state of a subscriber matching device according to the present invention, and FIG. 4 is a flowchart illustrating a procedure of displaying a cell service state of a subscriber matching device according to the present invention.

Referring to FIG. 3, in step 301, the subscriber connection registration is checked, and in step 302, the subscriber matching controller 250 generates an LED light signal according to the state of the subscriber connection. In operation 303, the LED 251 is turned on according to the generated signal.

Referring to FIG. 4, in step 401, it is determined whether a subscriber cell is transmitted, and if a cell is being transmitted, it is determined in step 402 whether the cell is normal. In step 402, if the cell is normal, the LED on / off timer is set to 2 seconds in step 403, respectively. In step 404, the LED 251 is turned on or off according to the operation of the set on / off timer.

If it is determined in step 402 that the cell is abnormal, the on / off timers are set to 0.5 seconds in step 405, respectively, so that the LED 251 is turned on / off at 0.5 second intervals in step 404.

As such, it is possible to know the state of the cell by controlling the on / off rate of the LED according to the service state of the subscriber cell.

As described above, according to the present invention, the operator can visually determine the service state of the subscriber matching device, the subscriber connection state, etc. from the outside of the system, so that the operator can easily grasp the state of the subscriber and quickly recognizes the abnormality of the subscriber. There is an effect that can be taken.

Claims (1)

A physical layer processing unit for decomposing subscriber data of a predetermined transmission format delivered from the subscriber, extracting an ATM cell, mapping the ATM cell to a corresponding frame position, and combining the maintenance signal with a maintenance signal to form a predetermined transmission format; An ATM layer processor for receiving an ATM cell from the physical layer processor and adding a routing tag to the switch and processing the ATM cell received from the switch and then transmitting the ATM cell to the physical layer; A switch matching unit for interfacing the ATM layer processing means with a switch network; A clock receiver for providing a reception clock to the physical layer processing means and the ATM layer processing means; Display means for displaying a subscriber connection state and a cell service state in accordance with a control signal; And The control unit is connected to the physical layer processor and the ATM layer processor, and is connected through an IPC from an upper layer processor to provide a control signal for turning on the display unit when a subscriber connection is established. When the cell is normally transmitted through the connection, the display unit And subscriber registration control means for causing the display means to flash at a predetermined highway when the cell blinks at a predetermined low speed, and the cell is abnormally transmitted through the connection.