KR20030019990A - Voice over IP and voice over ATM interworking system - Google Patents

Abstract

PURPOSE: A VoIP(Voice over Internet Protocol) and VoATM(Voice over Asynchronous Transfer Mode) IWF(Interworking Function) system is provided to perform a call process between a VoIP and a VoATM having inter-different protocols. CONSTITUTION: A processor(30) performs an AAL5(ATM Adaptation Layer 5) SAR(Segmentation And Reassembly) function of control data capsulized in an AAL5, and performs operation and management functions for a call path setup with an ATM network(1). The processor(30) performs an IP packetization function for transmitting and receiving data associated with a VoIP call process with a VoIP processor(60) through an Ethernet interface, and controls lower function units including an ATM interface unit(10), an AAL2 processing unit(40), and a VoIP processing unit(50) through a DM-bus. The AAL2 processing unit(40) performs an AAL2 SAR function of voice data capsulized to an AAL2 in a VoATM interworking, separates received VoATM data, and transmits only intrinsic voice association data to the VoIP processing unit(50) through a compact PCI(Peripheral Component Interconnect) interface. The VoIP processing unit(50) capsulizes data received from the AAL2 processing unit(40) to the AAL2, generates an AAL2 ATM cell using a VPI/VCI(Virtual Path Identifier/Virtual Channel Identifier) value received from the processor(30) through the DM-bus, and packetizes received voice data as a VoIP packet. The VoIP processor(60) directly exchange a signal with an IP network, performs a telephone connection function and an ability exchange function, and performs the control of the VoIP processor(50) through the processor(30).

Description

Voice over IP and voice over ATM interworking system

The present invention relates to a VoIP and VoATM interworking system, and more particularly, a physical interface that is physically and functionally connected to a VoATM and VoIP network line so as to transmit a signal converted from each line, and a call generated in the heterogeneous network. A call control unit for converting and transmitting a control signal to match the counterpart network, controlling a media transmission / reception channel according to call processing resource management and call setup, and a data converting unit for converting a data packet format to match the counterpart network The present invention relates to an interworking system between VoIP and VoATM that allows VoIP and VoATM to interwork.

Currently, the evolution to Voice Over Packet networks is not a standard, but a voice data integration Internet protocol (VoIP) with different protocol stacks such as (a) and (b) of FIG. Two standards are under development: Voice over Internet Protocol (Voice) and Voice over Asynchronous Transfer Mode (VoATM).

Therefore, in order for voice subscribers using two different networks to talk to each other, there must be a medium capable of relaying in the middle.

Currently, the most practical way to mediate two networks is to connect VoIP subscribers 5 and VoATM subscribers 4 across a public switched telephone network (PSTN) 3, as shown in FIG.

However, in the above case, since the PSTN network 3 must be interposed between the ATM network 1 and the IP network 2, the call processing procedure is complicated, and only the packet network is used. Traffic efficiency, which is considered to be an advantage of doing so, is also reduced.

In addition, since there is no way to provide information exchange function for vocoding method between VoIP subscriber 5 and VoATM subscriber 4 through PSTN network 3, VoIP and VoATM gateway have different The use of a coding scheme results in a significant drop in speech quality.

In addition, when the network evolves into the next generation network (NGN), it is pointed out that the configuration of such a call becomes impossible assuming that all PSTNs disappear.

Accordingly, the present invention is to solve all the problems and disadvantages of the interworking system of the conventional VoIP network and VoATM network as described above, each physically and functionally connected to the network line of the ATM network for VoATM and IP network for VoIP A separate interface including a physical interface for transmitting signals converted into lines, a call control unit for controlling a media transmission / reception channel according to resource management and call setup, and a conversion unit for packetizing data to match the opposite network. An object of the present invention is to implement a call interworking system between VoIP and VoATM having different protocols.

1 shows a protocol stack,

(A) is the protocol stack structure of VoATM,

(B) is a protocol stack structure diagram of VoIP.

Figure 2 is a conventional VoIP and VoATM interworking structure diagram.

3 is a structure diagram of VoIP and VoATM subscriber interworking according to the present invention;

Figure 4 is a network diagram of a VoIP and VoATM interworking system according to the present invention.

5 is a flowchart showing a call processing procedure according to the present invention.

((Explanation of symbols for main parts of drawing))

1. ATM network 2. IP network

PSTN Network 4. ATM subscriber

IP subscribers 6. VoATM Gateway

VoIP gateway 10. ATM interface

20. ATM MUX / DMX30. Processor

40. AAL2 processing unit 50. VoIP processing unit

60. VoIP Processor 100. Interworking System (IWF)

The object of the present invention is an VoIP interface composed of an ATM interface unit for interworking with an ATM network, an ATM control unit for ATM signal control, an IP interface unit for interworking with an IP network, and an IP control unit for IP signal control. Is achieved by the VoATM interworking system.

The present invention provides a physical interface that is physically and functionally connected to VoATM and VoIP network lines so as to transmit signals converted to each line, and converts and transmits call control signals generated in the heterogeneous networks to match the other network. It includes a call control unit for controlling the media transmission and reception channel according to call processing resource management and call setup, and a data conversion unit for performing the conversion function of the data packet format to match the partner network.

Details of the above object and technical configuration of the present invention and the effects thereof according to the present invention will be more clearly understood by the following detailed description through the accompanying drawings.

First, Figure 3 is a VoIP and VoATM subscriber interworking structure diagram according to the present invention, Figure 4 is a network configuration of the VoIP and VoATM interworking system according to the present invention.

As shown, the VoIP and VoATM interworking system (IWF system) 100 of the present invention is physically and functionally connected to the ATM network 1 and the IP network 2 so that the heterogeneous network is compatible to the ATM subscriber 4. And to provide a call path between the IP subscriber 5.

The VoIP and VoATM interworking system 100 of the present invention converts a physical interface to transmit a signal converted to each line and a call control signal generated in the heterogeneous network so as to be matched to a partner network and transmits and processes the call. And a call controller for controlling the transmission / reception channel of the media according to resource management and call setup, and a data packet processing unit for packet-formatting data to match the opposite network.

The VoIP and VoATM interworking system 100 of the present invention as described above will be described in more detail through the network configuration diagram shown in FIG. 4.

As shown, the VoIP and VoATM interworking system of the present invention includes an ATM interface unit 10, an ATM MUX / DMX 20, an AAL2 processing unit 40, a VoIP processing unit 50, a processor 30, and a VoIP. It consists of a processor 60.

The ATM interface unit 10 transmits and receives ATM data and control signals in conjunction with the ATM network 1 to convert voice data and control data received by the OPTIC into UTOPIA signals to the ATM MUX / DMX 20. Send and vice versa.

Next, the ATM MUX / DMX 20 retrieves the VPI / VCI value from the ATM signal received from the ATM interface unit 10 through the UTOPIA interface, and in the case of voice data, AAL2 through the HOT link. Processing unit 0 is sent to the processor 30 through the HOT link in the case of control data.

At this time, the ATM MUX / DMX 20 multiplexes the voice data and the control data received from the AAL2 processor 40 and the processor 30 through the HOT link to the ATM interface unit 10 through the UTOPIA interface. Send to.

Meanwhile, the control data transmitted / received through the HOT link between the processor 30 and the ATM MUX / DMX 20 are control data encapsulated in AAL5. Accordingly, the processor 30 must perform the AAL5 SAR function. And it performs the operation and management function for the call network establishment with the ATM network (1).

In addition, the processor 30 performs an IP packetization function to transmit and receive data related to VoIP call processing with the VoIP processor 60 through an Ethernet interface, and the ATM interface unit 10 and AAL2 in the system. The lower functional units including the processing unit 40 and the VoIP processing unit 50 are controlled through the DM-bus.

In VoATM interworking, voice data is encapsulated in AAL2. Therefore, the AAL2 processing unit 40 performs the AAL2 SAR function of disassembling and assembling the cell, and separates the received VoATM data and sends only pure voice related data to the VoIP processing unit 50 through the Compact PCI interface.

Next, the pure data received by the VoIP processing unit 50 is encapsulated in AAL2 and an AAL2 ATM cell is generated using the VPI / VCI value received through the DM-bus from the processor 30.

The VoIP processing unit 50 packetizes the pure voice data received from the AAL2 processing unit 40 into a VoIP packet having a protocol stack as shown in FIG. 1, and performs the reverse function.

The VoIP processor 60 is a processor that provides a call establishment function through the IP network 2 between the IWF 100 and the VoIP subscriber. The VoIP processor 60 performs a direct signal exchange (H.323 / SIP, etc.) with the IP network. It performs functions such as connection function and capability exchange, and control of the VoIP processing unit 50 is performed through the processor 30.

Next, FIG. 5 is a flowchart illustrating a call processing procedure according to the present invention, which shows the operation of the gateway when the VoATM subscriber 4 makes a call to the VoIP subscriber 5. FIG.

At this time, it is assumed that the call control protocol for VoIP is H.323.

First, the VoATM gateway 6 detects hook-off and dual tone multi-frequency (DTMF) signals from the subscriber, and in the ATM network 1 for AAL2 signaling between the VoATM and the IWF 100 using UNI signaling. Set up an end-to-end signaling path.

Next, AAL2 signaling is performed using the set path, AAL2 channel associated signaling (CAS) or common channel signaling (CCS) path is set through AAL2 path signaling, and DTMF or voice data vocoding is performed through AAL2 CAS / CCS signaling. vocoding) scheme and the like are provided to the IWF 100.

The IWF 100 establishes a TCP path for Q.931 signaling with the VoIP gateway or gatekeeper 7 using the information received through AAL2 CAS / CCS and performs the Q.931 signaling procedure through the established path. Perform

At this time, in the Q.931 call setup procedure, the subscriber and the AAL2 media path of the VoATM gateway 6 are also set, and a transport address for H.245 channel open is also received.

After opening the H.245 channel as described above, if the RTP / RTCP channel for capability exchange and media stream transmission for the vocoding scheme is set, the IWF 100 connects the existing AAL2 media path and the RTP path to the voice call. Set.

Accordingly, the VoIP and VoATM network interworking system of the present invention allows the connection between the VoIP subscriber and the VoATM subscriber to be made smoothly, the call processing procedure is simplified, and the capability exchange for the vocoding scheme is provided, thus the possibility of voice quality degradation. It can be reduced, and in the future it can be provided a voice communication service without the PSTN network.

Claims (1)

In the system to be compatible between the ATM network (1) and the IP network (2), Send and receive ATM data and control signals by interworking with ATM network (1), convert data received by OPTIC into UTOPIA signal and transmit to ATM MUX / DMX (20), and receive by UTOPIA from ATM MUX / DMX (20) An ATM interface unit 10 for converting the data into an OPTIC signal and transmitting the same to the ATM network 1; The VPI / VCI value is retrieved from the ATM signal received from the ATM interface unit 10 via the UTOPIA interface, and voice data is transmitted to the AAL2 processor 40 through the HOT link, and the control data is transmitted to the processor 30 through the HOT link. An ATM MUX / DMX (20) for multiplexing voice data and control data received from the AAL2 processor (40) and the processor (30) and sending them to the ATM interface unit (10) through a UTOPIA interface; Performs AAL5 SAR function, which is a function of disassembling and assembling control data encapsulated in AAL5, which is the data transmitted / received with the ATM MUX / DMX 20, performs an operation and management function for establishing a call route with the ATM network 1, Performs IP packetization function to transmit and receive data related to call processing with the VoIP processor 60 through the Ethernet interface, and includes an ATM interface unit 10, an AAL2 processor 40, and a VoIP processor 50 in the system. A processor 30 for controlling the lower functional units through a DM-bus; An AAL2 processing unit 40 performing an AAL2 SAR function of voice data encapsulated by AAL2 when the VoATM is interworked, separating the received VoATM data, and sending only pure voice related data to the VoIP processing unit 50 through the Compact PCI interface; Encapsulates the data received from the AAL2 processing unit 40 into AAL2, generates an AAL2 ATM cell using the VPI / VCI value received from the processor 30 via DM-bus, and receives the received voice data into a VoIP packet. VoIP processing unit 50 to make a voice; A processor that provides a call setup function through an IP network between an IWF and a VoIP subscriber, and performs a function such as a telephone connection function and a capability exchange by directly exchanging a signal with an IP network, and controlling the VoIP processing unit 50. VoIP processor 60 to perform through processor 30; VoIP and VoATM interworking system, characterized in that consisting of.