KR100412974B1 - VTOA Gateway System and Method for Processing ISDN D-Channel Message in VTOA Gateway System - Google Patents

Abstract

The present invention relates to a Voice and Telephony Over ATM (VTOA) gateway system, and more particularly, to a VTOA gateway system for processing ISDN D channel messages using ATM Adaptation Layer type 5 (AAL 5) and to processing ISDN D channel messages in the system. It is about a method.

In the conventional VTOA gateway system, SSSAR and SSTED protocols for processing ISDN D channel messages such as control information or signals in conventional ATM Adaptation Layer type 2 (AAL 2) processing hardware for voice processing to process narrowband ISDN subscriber calls. There is a problem that the hardware performance is reduced by processing up to.

According to the present invention, the VTOA gateway system processes the ISDN D channel message using AAL 5, so that the hardware performance of the VTOA gateway system is stable and the software implementation is simplified.

Description

VTIO Gateway System and Method for Processing ISDN D-Channel Message in VTOA Gateway System

The present invention relates to a Voice and Telephony Over ATM (VTOA) gateway system, and more particularly, to a VTOA gateway system for processing ISDN D channel messages using ATM Adaptation Layer type 5 (AAL 5) and to processing ISDN D channel messages in the system. It is about a method.

In general, ISDN (Intergrated Service Digital Network) is a service that integrates and transmits analog data such as voice and digital data together through the same network. There are two classes of services in ISDN: Basic Rate Interface (BRI) services suitable for homes and small businesses, and Primary Rate Interface (PRI) services for large enterprises or large numbers of users.

Both BRI and PRI include multiple B channels and one D channel. The B channel carries main data for data and voice and other services, while the D channel carries control information and signals.

The BRI consists of two B channels at 64 Kbps and one D channel at 16 Kbps. Therefore, BRI users can receive services at speeds up to 128 Kbps.

The PRI consists of 23 D-channels and one D-channel with 64 Kbps speed using the T1 line in the United States and 30 B-channels and one D-channel using the E1 line in Europe. Therefore, PRI users can receive services at 1.544 Mbps on the T1 line and 2.048 Mbps on the E1 line. PRI uses the Q.931 protocol on the D channel.

Meanwhile, in the VTOA gateway system in which the above-described ISDN subscribers, particularly narrowband ISDN subscribers, are matched to a local exchange (LE) through an ATM (Asynchronous Transfer Mode) network, processing of ISDN D channel messages is essential.

Processing of conventional ISDN D channel messages is performed through Service Specific Segmentation And Reassembly sublayer (SSSAR) and Service Specific Transmission Error Detection sublayer (SSTED) protocols added over ATM Adaptation Layer type 2 (AAL 2).

1 is a diagram illustrating a protocol stack structure of a conventional VTOA gateway system, which is a protocol stack defined for providing a service to an ISDN subscriber through an ATM network (CP-IWF). Mutual matching device) and CO-IWF (Central Office Interworking Function (hereinafter referred to as 'second interworking device')) are matched with the ATM network as an ATM interface, and the ISDN terminal is the first mutual matching device. And User Network Interface (UN) matching, and the second mutual matching device matches the ISDN service node.

The first mutual matching device physically matches the ISDN terminal and the ATM network, and maps the high-level data link control (HDLC) frame used in Q.921 with SSSAR and SSTED of AAL 2 to map the ATM. To the network.

The second mutual matching device physically matches the ATM network and the ISDN service node, restores the HDLC frame of the ISDN terminal transmitted from the ATM network through the AAL 2, and delivers it to the ISDN service node.

Accordingly, Q.931 used in Layer 3 of the ISDN terminal and Q.921 used in Layer 2 are transmitted to the ISDN service node that is matched with the second matching device transparently through the ATM network.

However, in the above-described conventional VTOA gateway system, in order to process narrowband ISDN subscriber calls, the conventional AAL 2 processing hardware for voice processing processes SSSAR and SSTED protocols for processing ISDN D channel messages such as control information or signals. There was a problem in that hardware performance was degraded.

The present invention has been made to solve the above problems, and its object is that the system that matches the conventional ATM network has AAL 5 processing capability, and therefore, AAL without additional hardware and software implementation for ISDN D channel message processing. By implementing a VTOA gateway system that processes ISDN D channel messages using 5, it separates voice processing and signal processing to stabilize the hardware performance of the VTOA gateway system and simplify the software implementation.

1 is a diagram illustrating a protocol stack structure of a conventional VTOA gateway system.

2 is a block diagram of a VTOA gateway system according to the present invention;

3 is a diagram illustrating a protocol stack structure of a VTOA gateway system according to the present invention.

4 is a flowchart for explaining the operation of the VTOA gateway system according to the present invention.

Explanation of symbols on the main parts of the drawings

10: ISDN terminal 20: first mutual matching device

21: ISDN subscriber matching unit 22: ATM matching unit

23: main processor 30: second mutual matching device

31: local exchange matching unit 32: ATM matching unit

33: main processor

A feature of the present invention for achieving the above object is to match with a plurality of ISDN terminal and ATM network, after receiving an ISDN channel message from the ISDN terminal, to generate an AAL 5 cell using the received ISDN channel message A first mutual matching device for transmitting to the ATM network or receiving an AAL 5 cell from the ATM network, extracting an ISDN channel message from the received AAL 5 cell and transmitting the extracted ISDN channel message to the ISDN terminal; Receives AAL 5 cells transmitted by the first mutual matching device through an ATM network, matches an ATM network and a local exchange, extracts ISDN channel messages from the received AAL 5 cells, and then uses the extracted ISDN channel messages. After generating frame data for the exchange and transmitting the frame data to the local exchange, or receiving the frame data for the local exchange from the local exchange, the AAL 5 cell is generated by using the ISDN channel message included in the received local exchange frame data. The present invention provides a VT gateway system comprising a second mutual matching device for transmitting to the first mutual matching device via an ATM network.

Here, the first mutual matching device is connected to a plurality of ISDN terminals, receives an ISDN channel message from the ISDN terminal and delivers the ISDN terminal identification information for identifying the ISDN terminal, or forwards the transferred ISDN channel message. An ISDN subscriber matching unit transmitting to the ISDN terminal; ATM matching, which is connected to an ATM network, generates an AAL 5 cell and transmits it to the ATM network using the transferred ISDN channel message, ISDN terminal identification information, and VPI / VCI information, or receives and forwards the AAL 5 cell from the ATM network. Wealth; After checking the VPI / VCI information of the ISDN channel message delivered by the ISDN subscriber matching unit, the ISDN channel message and the ISDN terminal identification information and VPI / VCI information to the ATM matching unit, or AAL 5 cell delivered by the ATM matching unit After checking the VPI / VCI information, the AAL 5 cell is characterized in that it comprises a main processor to extract the ISDN channel message and deliver it to the ISDN subscriber matching unit.

The second mutual matching device may be connected to an ATM network to receive and transmit an AAL 5 cell from an ATM network, or may generate an AAL 5 cell using the transferred ISDN channel message, ISDN terminal identification information, and VPI / VCI information. An ATM matching unit for transmitting to the ATM network; A local exchange matching unit connected to the local exchange to receive and transmit frame data for the regional exchange including the ISDN channel message from the local exchange through the local exchange matching port, or to transmit the forwarded regional exchange frame data to the local exchange; ; After confirming the VPI / VCI information of the AAL 5 cell delivered by the ATM matching unit, the frame data for the local exchange is generated using the ISDN channel message extracted from the AAL 5 cell and the port information of the local exchange matching port corresponding to the ISDN terminal. ISDN terminal corresponding to the ISDN channel message and the local exchange matching port after confirming the VPI / VCI information through the ISDN channel message of the regional exchange frame data delivered to the local exchange matching unit or the regional exchange matching unit And a main processor for transmitting identification information and VPI / VCI information to the ATM matching unit.

Further another aspect of the present invention, the process of confirming the VPI / VCI information of the ISDN channel message received from the ISDN terminal; Generating an AAL 5 cell with the VPI / VCI information, identification information for identifying the ISDN terminal, and an ISDN channel message and transmitting the same to the ATM network; Receiving an AAL 5 cell from the ATM network, checking VPI / VCI information, and extracting an ISDN channel message; In the BTI gateway system comprising the step of generating the frame data for the regional exchange with the port information of the extracted ISDN channel message and the local exchange matching port corresponding to the ISDN terminal to the local exchange. It is to provide a method for processing ISDN D channel message.

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

In the VTOA gateway system according to the present invention, as shown in FIG. 2, a plurality of ISDN terminals 10 and a local exchange 40 are connected through an ATM network, and the ISDN terminal 10 is connected with the ISDN terminal 10. The first interworking device 20 is located between the ATM networks to transmit ISDN D channel messages from the ISDN terminal 10 to the ATM network through ISDN subscriber matching and ATM matching, and between the ATM network and the local exchange 40. The second interworking device 30 has a structure in which an ISDN D channel message is received from the ATM network and delivered to the local exchange 40 through ATM matching and local exchange matching.

The first mutual matching device 20 is composed of an ISDN subscriber matching unit 21, an ATM matching unit 22, and a main processor 23. The ISDN subscriber matching unit 21 is responsible for ISDN UNI (User Network Interface) matching with the ISDN terminal 10 and signaling of Layer 2, and the ATM matching unit 22 is physically matched with the ATM network and AAL 5 cells. The main processor 23 is responsible for message conversion and control between the ISDN subscriber matching unit 21 and the ATM matching unit 22 through IPC (InterProcess Communication) supported by an operating system (OS).

When the main processor 23 receives the ISDN D channel message from the ISDN terminal 10 through the ISDN subscriber matching unit 21, the ISDN D channel message is converted into an AAL 5 cell through the ATM matching unit 22 and transmitted to the ATM network. do.

The second mutual matching device 30 is composed of a local exchange matching unit 31, an ATM matching unit 32, and a main processor 33. The local exchange matching unit 31 is responsible for V5.2 matching with the local exchange 40, the ATM matching unit 32 is responsible for physical matching with the ATM network and processing of AAL 5 cells, and the main processor 33 is The IPC supported by the OS is responsible for message conversion and control between the local exchange matching unit 31 and the ATM matching unit 32.

The main processor 33 extracts the ISDN D channel message from the AAL 5 cell received from the ATM network through the ATM matching unit 32, and transmits the ISDN D channel message to the local exchange 40 through the local exchange matching unit 31. The ISDN D channel message sent to 40 is forwarded by ISDN subscriber call under the control of local exchange 40.

3 is a diagram illustrating a protocol stack structure of a VTOA gateway system having the above configuration.

The protocol stack of the ISDN terminal 10 includes a physical layer (PHYs) PHY, a link access protocol for ISDN D-Channel (LAPD) layer, and a Q.931 layer. In addition, the protocol stack of the first mutual matching device 20 that forms an ISDN terminal 10 with the ISDN terminal 10 includes a physical layer PHY, a LAPD layer, an ATM layer, and an AAL 5 (ATM Adaptation Layer 5) layer. And ATM, AAL 5 is layered on ATM.

The protocol stack of the local exchange 40 includes a physical layer (PHYs) PHY, a link access protocol for V5-interface (LAPV5) layer and a Q.931 layer. In the protocol stack of the second interworking device 30 that matches the local exchange with V5.2, there are a physical layer PHY, a LAPV5 layer, an ATM layer, and an AAL 5 layer, and LAPV5 and ATM are on the PHY, and AAL 5 is on the ATM. Is stratified.

AAL 5 supports connection-oriented services with variable rates, which reduces bandwidth overhead, simplifies processing requirements, and simplifies implementation.

The operation of processing the ISDN D channel message in the VTOA gateway system having the above configuration will be described in detail with reference to FIG. 4 as follows.

First, the operation of the VTOA gateway system for processing the ISDN D channel message to be delivered from the ISDN terminal 10 toward the local exchange 40, the ISDN subscriber receiving the ISDN D channel message from the specific ISDN terminal 10 The matching unit 21 transmits the ISDN D channel message to the main processor 23 through the IPC together with the ISDN terminal identification information for identifying the ISDN terminal 10.

Then, the main processor 23 receives the ISDN D channel message (step S41), and checks whether a PVC (Permanent Virtual Circuit) for AAL 5 exists in the database (step S42).

At this time, the PVC for AAL 5 is stored in a provisioning form in a database when the system is set up to process ISDN D channel messages, and the PVC information includes VPI (Virtual Path Identifier) / VCI (Virtual Circuit Identifier) connected to the ATM network. Information is included.

The main processor 23 transmits the VPI / VCI information and the ISDN terminal identification information and the ISDN D channel message identified through the PVC to the ATM matching unit 22, and the ATM matching unit 22 sends the VPI / VCI information and the ISDN. The AAL 5 cell is generated from the terminal identification information and the ISDN D channel message and transmitted to the ATM network (step S43).

At this time, the ATM matching unit 22 performs a Common Part Convergence Sublayer (CPCS) function of AAL 5.

Then, the ATM matching unit 32 of the second mutual matching device 30 receives the AAL 5 cells transmitted by the first mutual matching device 20 through the ATM network and transmits the same to the main processor 33.

Therefore, the main processor 33 checks whether it is an ISDN D channel message through the VPI / VCI information of the AAL 5 cell received from the ATM matching unit 32 (steps S44, S45), and if it is not an ISDN D channel message. In step S49, the ISDN D channel message is extracted from the received AAL 5 cell (step S46), the ISDN terminal identification information is checked, and the ISDN terminal 10 is checked. The corresponding local exchange matching port is checked (step S47).

After generating the regional exchange frame data, that is, the LAPV5 (Link Access Protocol for V5-interface) frame data using the confirmed local exchange matching port information and the ISDN D channel message, the local exchange matching unit 31 is generated. And transfer to local exchanger 40 via step S48.

On the other hand, the operation of the VTOA gateway system for processing the ISDN D channel message sent from the local exchange 40 to the ISDN terminal 10 is as follows.

First, when the ISDN D channel message is transmitted from the local exchange 40 in the form of a LAPV5 frame, the local exchange matching unit 31 performs an ISDN with ISDN terminal identification information for identifying the ISDN terminal 10 corresponding to the local exchange matching port. The D channel message is transmitted to the main processor 33 through the IPC.

Then, the main processor 33 receives the ISDN D channel message (step S41), checks whether the PVC for AAL 5 exists in the database (step S42), and then checks the VPI / VCI through the PVC for AAL 5. The information, the ISDN terminal identification information, and the ISDN D channel message are transmitted to the ATM matching unit 32, and the ATM matching unit 32 generates an AAL 5 cell using the above information and transmits the same to the ATM network (step S43).

Then, the ATM matching unit 22 of the first mutual matching device 20 receives the AAL 5 cells transmitted by the second mutual matching device 30 through the ATM network and transmits the received AAL 5 cells to the main processor 23.

Accordingly, the main processor 23 checks the VPI / VCI in the AAL 5 cell received from the ATM matching unit 22 to confirm whether it is an ISDN D channel message (steps S44, S45), and in the case of an ISDN D channel message, the AAL received. In step 5, the ISDN D channel message is extracted (step S46).

After generating the LAPD frame data using the extracted ISDN D channel message and the ISDN terminal identification information, the LAPD frame data is transmitted to the ISDN subscriber matching unit 21 and transferred to the ISDN terminal 10 through ISDN UNI matching (step). S47, S48).

In addition, the embodiments according to the present invention are not limited to the above-described embodiments, and various alternatives, modifications, and changes can be made within the scope apparent to those skilled in the art.

As described above, the present invention enables the VTOA gateway system to process the ISDN D channel message using AAL 5, so that the hardware performance of the VTOA gateway system is stable and the software implementation is simplified.

Claims (4)

After receiving an ISDN channel message from the ISDN terminal after matching with a plurality of ISDN terminals and ATM networks, an AAL 5 cell is generated using the received ISDN channel message and transmitted to the ATM network, or AAL 5 cells from the ATM network. A first mutual matching device for extracting an ISDN channel message from the received AAL 5 cell and transmitting the extracted ISDN channel message to the ISDN terminal; Receives AAL 5 cells transmitted by the first mutual matching device through an ATM network, matches an ATM network and a local exchange, extracts ISDN channel messages from the received AAL 5 cells, and then uses the extracted ISDN channel messages. After generating frame data for the exchange and transmitting the frame data to the local exchange, or receiving the frame data for the local exchange from the local exchange, the AAL 5 cell is generated by using the ISDN channel message included in the received local exchange frame data. And a second mutual matching device for transmitting to the first mutual matching device via an ATM network. The method of claim 1, The first mutual matching device is connected to a plurality of ISDN terminals, receives an ISDN channel message from an ISDN terminal, delivers the ISDN terminal identification information for identifying the ISDN terminal, or transfers the transferred ISDN channel message to the corresponding ISDN. An ISDN subscriber matching unit transmitting to the terminal; ATM matching, which is connected to an ATM network, generates an AAL 5 cell using the transmitted ISDN channel message, ISDN terminal identification information, and VPI / VCI information and transmits it to the ATM network, or receives and delivers an AAL 5 cell from the ATM network. Wealth; After checking the VPI / VCI information of the ISDN channel message delivered by the ISDN subscriber matching unit, the ISDN channel message and the ISDN terminal identification information and VPI / VCI information to the ATM matching unit, or AAL 5 cell delivered by the ATM matching unit And a main processor for extracting the ISDN channel message from the AAL 5 cell and transferring the ISDN channel message to the ISDN subscriber matching unit after checking the VPI / VCI information of the VPI / VCI information. The method of claim 1, The second mutual matching device, connected to an ATM network, receives and transmits an AAL 5 cell from an ATM network, or generates an AAL 5 cell by using the transferred ISDN channel message, ISDN terminal identification information, and VPI / VCI information. An ATM matching unit transmitting to a network; A local exchange matching unit connected to the local exchange to receive and transmit frame data for the regional exchange including the ISDN channel message from the local exchange through the local exchange matching port, or to transmit the forwarded regional exchange frame data to the local exchange; ; After confirming the VPI / VCI information of the AAL 5 cell delivered by the ATM matching unit, the frame data for the local exchange is generated using the ISDN channel message extracted from the AAL 5 cell and the port information of the local exchange matching port corresponding to the ISDN terminal. ISDN terminal corresponding to the ISDN channel message and the local exchange matching port after confirming the VPI / VCI information through the ISDN channel message of the regional exchange frame data delivered to the local exchange matching unit or the regional exchange matching unit And a main processor for transmitting identification information and VPI / VCI information to the ATM matching unit. Checking the VPI / VCI information of the ISDN channel message received from the ISDN terminal; Generating an AAL 5 cell with the VPI / VCI information, identification information for identifying the ISDN terminal, and an ISDN channel message and transmitting the same to the ATM network; Receiving an AAL 5 cell from the ATM network, checking VPI / VCI information, and extracting an ISDN channel message; In the BTI gateway system comprising the step of generating the frame data for the regional exchange with the port information of the extracted ISDN channel message and the local exchange matching port corresponding to the ISDN terminal to the local exchange. How to handle ISDN D-Channel message.