KR100233908B1 - Frame relay handler in isdn switch - Google Patents

Abstract

The present invention relates to a frame relay handler of an ISDN exchanger configured in a frame relay module, connected to a frame relay control board (1) via a local bus, and connected through a time switch (2) and a sub highway (3). A time switch matching section 13 connected to the switch 2 via the sub highway 3 and physically matched with the time switch 2 to receive frame data from the time switch 2; A link level processing unit 12 for processing LAPF protocol frame data of the time switch matching unit 11; A frame storage unit 13; A local bus matching unit 17 connected to the frame relay control board 1 through a local bus LBUS; A shared buffer 16 connected to the local bus matching unit 17 for buffering and outputting the first control signal from the frame relay control board, and for outputting the buffered input frame data to the local bus matching unit 17. )Wow; The frame data stored in the frame storage unit 13 is read and applied to the shared buffer 16 according to the first control signal from the shared buffer 16, and the frame data of the link level processing unit 12 is applied to the frame storage unit 13. A control unit 15 for outputting a second control signal for storing in the control unit; A memory arbitration unit 14 for storing the frame data of the link level processing unit 12 in the frame storage unit 13 according to the second control signal of the control unit 15 is provided.

Description

Frame Relay Handler for ISDN Exchange

The present invention relates to an ISDN switching system, and more particularly, to a frame relay handler configured in a frame relay module of an ISDN exchange.

Currently, most data networks operate based on packet transmission technology. Especially in public data networks, packet transmission technology based entirely on the X.25 standard is a natural international standard for both domestic and international networks. have.

Packet services within an ISDN exchange can be provided in two ways: Case A and Case B of the X.31 Recommendations. In the TDX-10 ISDN exchange, there is packet processing within the ISDN exchange, allowing subscribers to access B and D channels. The case B method can be used by using both services.

The TDX-10 packet switched service is provided through the structure as shown in FIG. 1, which does not distribute the packet handling subsystem, the packet handling subsystem, to each subscriber interface module, and all packet traffic is stored in the TDX-10. A centralized structure that is centralized and processed by an Access Switching Subsysem for Packet Switching (ASS-P) 1 through a TST switching network is achieved.

However, the TDX-10 ISDN packet-switched architecture uses X.25 protocol to perform complex processing such as error detection and recovery in order to guarantee end-to-end transmission quality. Therefore, in order to meet the service needs of users in the future, a better way of technology is required. (1) Since the flow control and error control are performed at the link layer of the packet protocol layer 2 and the layer 2 of the packet layer layer, there is a large transmission overhead in the network because the protocol overhead is too large.

(2) In-band signaling, which processes user information and control information in a layer 3 packet layer, is inflexible in adding a new service.

(3) During packet call processing, the virtual call is set up by a two-step procedure. That is, after performing channel allocation process by out-of-band control using D channel. A call for establishing a virtual circuit is required according to an in-band procedure on an allocated B or D channel. In this way, there is no flexibility to add new services.

(4) There is a limitation in speeding up the network because it is not suitable for high-speed data transmission service of 64 Kbps or more.

On the other hand, in recent information society, there is a demand for a protocol that can replace the existing X.25, which can transmit more information at high speed. Frame relay is proposed as an alternative. The existing packet protocol is designed to guarantee the end-to-end transmission quality due to the lack of the development of the initial communication path. Therefore, error detection, error recovery, flow control, etc. are performed in the data link layer. DTP (Data Transfer Protocol) of X.25 PLP (Packet Layer Protocol) was implemented.

However, due to the development of current transmission technology, the error occurrence rate is considerably lowered, thus minimizing various control functions in the data link layer. In the network, only the core functions of Layer 2 required for data transmission are implemented, and functions such as error recovery and flow control are performed. The frame relay enables short delay time and high speed transmission by allowing the user device to perform it when necessary. In fact, frame relay was proposed in 1986 as the evolutionary step of packet communication in ISDN, and is currently being spread worldwide for use in high-speed data communication.

In response to this trend, the present inventor has filed an ISDN Access Switching Subsystem for ISDN (Application No.) as the same as the present invention. In this application, the Applicant states that each sus- tem system simultaneously accepts all subscriber access and trunk line connection modules, and No, 7 modules for other common line signaling services, packet modules for packet processing, and frame relay processing. A matching exchange subsystem of an ISDN exchange system including a frame relay module is presented, and the same filed for a frame relay module (application number) of an ISDN exchange.

The present inventor has proposed a configuration in which a plurality of frame relay handlers can exchange frame data under a frame relay control board in a frame module of the above-described ISDN exchange.

On the other hand, the present inventors have studied a more efficient device for the frame relay handlers of the frame module to perform the data exchange function in the above-described ISDN exchange system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above findings, and an object of the present invention is to provide a frame relay handler of an ISDN exchange that enables efficient exchange of frames in a flame relay module of an ISDN exchange system.

The frame relay handler of the ISDN exchange according to the present invention, which is configured in the frame relay module, is connected to a frame relay control board via a local bus, and is related to a frame relay handler of an ISDN exchange connected through a time switch and a sub highway. A time switch matching unit connected to the switch via the sub highway and physically matched with the time switch to receive frame data from the time switch; A link level processing unit for processing LAPF protocol frame data of the time switch matching unit; A frame storage unit; A local bus matching unit connected to the frame relay control board through a local bus; A shared buffer connected to the local bus matching unit to buffer and output the first control signal from the frame relay control board, and to buffer the input frame data and to apply the buffer data to the local bus matching unit; A control unit for reading frame data stored in the frame storage unit according to the first control signal from the shared buffer and applying the frame data to the shared buffer, and outputting a second control signal for storing the frame data of the link level processing unit in the frame storage unit; And a memory arbitration unit for storing the frame data of the link level processing unit in the frame storage unit according to the second control signal of the control unit.

1 is a schematic block diagram of a frame relay module configured with a frame relay handler of an ISDN exchange according to the present invention;

2 is a block diagram of a frame relay handler of an ISDN switch in accordance with the present invention.

<Description of the code | symbol about the principal part of drawing>

1: frame relay control board 2: time switch

11: time switch matching section 12: link level processing section

13 frame storage unit 14 memory arbitration unit

15 control unit 16: shared buffer

17: local bus matching unit

Those skilled in the art from the embodiments of the present invention described below will be able to more clearly understand the above and other objects and advantages of the present invention.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention.

FIG. 1 is a block diagram of a frame relay handling module 10 including a frame relay handler (FRH) of the present invention.

As shown, the frame relay module 10 controls the frame relay to perform the exchange function between the FRH (F1-Fn) and the plurality of FRH (F1-Fn) to perform link level processing on the frame relay data received from the subscriber. Board (Frame Relay Controller board; FRC) (1).

That is, the FRHs (F1-Fn) are connected to a time switch (TSW) 2 and a subhighway (SHW) 3 to receive a frame transmitted from the subscriber through the TSW 2, The received frame data is processed and frame exchange is performed with other FRHs (F1-Fn) under the control of the FRC (1). At this time, the FRC 1 is connected to the FRHs (F1-Fn) and the parallel bus 5 called L-BUS, and is configured to exchange data between the FRHs (F1-Fn).

In addition, the FRC 1 is connected to the message switch (MSCI) 6 through the U-Link (4), enabling data communication with other subsystems (ASS), and the higher telephony processor (Telephony Processor). TP) (7) can communicate with HDLC format to perform call processing or report operation and maintenance related information.

FIG. 2 shows a configuration in which FRHs (F1-Fn) exchange frame data with other FRHs (F1-Fn) in the FRM 10 of this configuration.

As shown, the FRH includes a time switch matching section 11, a link level processing section 12, a frame storage memory section 13, a memory arbitration section 14, a control section 15, a shared buffer 16, and a local bus matching. The part 17 is provided.

In this configuration, the time switch matching unit 11 is connected through the TSW 2 and the sub highway 3 to be physically matched with the TWS 2 to exchange frame data and to perform a rate adaption (RA) function. Consists of. In this embodiment, data from 64 Kbps to 1.092 Mbps can be transmitted between the TSW 2 and the FRH (F1-Fn).

The time switch matching section 11 is connected to the link level processing section 12, and the link level processing section 12 performs the LAPF protocol processing on the fast reception frame data of the subscriber whose time order is preserved through the TSW 2; And, it can be stored in the frame memory 13 by the mediation of the memory arbitration unit (14). In addition, the link level processor 12 performs a CRC check on the physical layer, and also performs a multiplexed demultiplexing function of a frame.

The frame storage unit 13 stores the frame data from the link level processing unit 12 under the control of the memory arbitration unit 14, and stores the frame data received from another FRH (F1-Fn) for transmission to the subscriber. It performs the function.

At this time, FRH (F1-Fn) uses the local bus (LBUS) and MSCI (6) present in the module to exchange frame data. That is, the controller 15 is connected through the FRC 1, the local bus matching unit 17, and the shared buffer 17, and the controller 15 controls the frame storage unit 13 under the control of the FRC 1. In this case, the frame data stored in the subframe is exchanged between FRH (F1-Fn) through the local bus.

At this time, when the frame data in the frame storage unit 13 is to be transmitted to the FRH (F1-Fn) of another sub system, the FRC 1 transfers the data in the frame storage unit 13 to the local bus ( LBUS) is performed by applying to the MSCI (6).

Here, the local bus (LBUS) is composed of a parallel bus of 16 bits, there is a mutual interrupt line to use the data transmission and reception interrupt. The local bus matching unit 17 is for matching the local bus LBUS and the shared buffer 16 in this manner, and the shared buffer 6 stores data transmitted and received between the local bus matching unit 17 and the control unit 15. For buffering.

Meanwhile, as described above, the controller 15 causes the memory arbitration unit 14 to store frame data in the memory storage unit 13 or to read the stored frame data under the control of the FRC 1. In addition to the function to output to 17), the following functions are further performed. That is, the controller 15 has an operating system having real-time disk management, memory management, time management, and the like to perform smooth functions in the FRH (F1-Fn), and performs general control, error detection, and congestion control functions in the board. . In the congestion control, the traffic is congested to monitor the congestion situation in which the frame being transmitted is lost, or the performance degradation and transmission delay occur. Error detection is to discard the frame when an error occurs during frame transmission.

By configuring the frame relay handler as in the present invention, there is an effect that the frame data can be easily exchanged between the frame relay handler and the frame relay module in the ISDN exchange system.

Claims (1)

As a frame relay handler of an ISDN exchanger configured in a frame relay module, connected to the frame relay control board 1 via a local bus, and connected through a time switch 2 and a sub highway 3, A time switch matching section (13) connected to the time switch (2) via a sub highway (3) and physically matched with the time switch (2) to receive frame data from the time switch (2); A link level processor (12) for processing LAPF protocol frame data of the time switch matching unit (11); A frame storage unit 13; A local bus matching unit (17) for matching the frame relay control board (1) and the local bus (LBUS); Sharing and buffering the first control signal of the frame relay control board 1 applied through the local bus matching unit 17, and buffering the input frame data to the local bus matching unit 17. A buffer 16; The frame data stored in the frame storage unit 13 is read and applied to the shared buffer 16 according to the first control signal from the shared buffer 16, and the frame data of the link level processor 12 is read. A control unit 15 for outputting a second control signal for storing in the frame storage unit 13; And a memory arbitration unit (14) for storing the frame data of the link level processing unit (12) in the frame storage unit (13) in accordance with a second control signal of the control unit (15).

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