KR19990033490A - Apparatus and method for multimedia communication service - Google Patents

Abstract

A device that performs a multimedia service includes a server composed of a DB server managing computing information and a PBX server managing a table for telephone service in a network, and a single line of AMT of a computer and a telephone. Citi terminals that handle LAN signaling and voice signaling to perform data and voice services, switching hubs connected to Citi terminals with 25 UTPs to perform network expansion, and multiple public network interfaces It is composed of a multiservice switch that is connected between hubs and public networks and performs a gateway function by integrating voice and data of Citi terminals by a server.

Description

Apparatus and method for multimedia communication service

The present invention relates to an apparatus and method for a multimedia communication service, and more particularly to an apparatus and method for providing a multi-communication service by integrating voice and data.

Considering the general office environment, the corporate network is largely composed of a local area network (LAN) computer network providing computer communication services and a private branch exchange (PBX) telephone network providing telephone services. The LAN computer network and the PBX telephone network have evolved in different directions due to different switching schemes and transmission characteristics. The LAN computer network transmits a large amount of data in a non-real time in a packet-switched manner, while a PBX telephone network transmits voice data in real time in a circuit-switched manner. Each of the services provided by these two networks is a basic service in the corporate environment, and has been fixed as an essential element for the efficient work of the enterprise.

However, with the development of Asynchronous Transfer Mode (ATM) technology suitable for multimedia data transmission, the possibility of integrating voice (telephone service) and data (computer communication service) into one line is increasing. This is because ATM LAN switches, which can replace broadband and provide broadband data services, have already been developed and are being used. In addition, there is a growing need to integrate voice and data for the following reasons:

First, the demand for multimedia services is increasing. As communication technology and information industry are advanced, the demand for services that organically integrate voice, data, images, and moving pictures is increasing. Therefore, in order to provide various and efficient multimedia services economically in the future, a network infrastructure that integrates voice and data must be made.

Secondly, there is a single network request. At present, each network has to be installed and managed separately in order to receive both voice and data services. However, if the voice and data service are provided in one network, the management target is two to one. Therefore, it is economical in terms of management and maintenance, such as simple wiring and simple installation of a network in a building.

Accordingly, an object of the present invention is to provide a multi-service network capable of processing a multimedia service request as a single network.

Another object of the present invention is to provide an apparatus and method capable of integrating and processing a multimedia service in a multi-service network.

Another object of the present invention is to provide an apparatus and method having a multiservice enterprise network structure capable of performing voice and data services in a single network in a multiservice network.

In order to achieve the above object, the present invention provides a device for performing a multimedia service, comprising a server configured to manage computing information, a PBX server managing a table for a telephone service in a network, and a computer and a telephone. CNT terminals connected to a line to process ATM LAN signaling and voice signaling of the single line to perform data and voice services, and a switching hub connected to the Citi terminals to 25 UTPs to perform a network expansion function. And a multiservice switch having a plurality of public network interfaces and connected between the switching hubs and the public networks and performing a gateway function by integrating voice and data of the Citi terminals by the server. It is done.

1 is a diagram illustrating a structure of a multi-service network according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a structure for processing ISDN and ATM signaling in a multi-service network.

3 is a diagram illustrating a structure for processing AT signaling and a phone in a multi-service network;

4 is a diagram illustrating a service structure between a computer and a telephone in a multiple service network;

As described above, with the development of the information and communication industry, the demand for multimedia communication services of customers is increasing. In the future, the integration of voice and data for providing a complex communication service by integrating a telephone and a computer is required. Integrating telephony services and computer communications services into a single enterprise network enables the economical deployment of multimedia communications services.

An embodiment of the present invention relates to a multi-service network structure suitable for an enterprise environment, and provides a method of integrating a LAN computer network and a PBX telephone network, which have been separately developed, into a single network based on ATM technology. To this end, a method of configuring a multiservice enterprise network consisting of an ATM multiservice switch, a PC, a telephone, etc., a method of interworking a PSTN and a multiservice enterprise network, a user desktop environment composed of a PC and a telephone, and a multiservice The basic service scenarios of the service enterprise network will be described. The present invention realizes the function of PBX by interworking PSTN and ISDN networks based on ATM LAN switch, and effectively applies CTI (Computer Telephony Integration) technology.

To this end, an embodiment of the present invention provides a structure and implementation method of a multi-service enterprise network (MUSE-Net) suitable for an enterprise environment based on ATM technology according to a multimedia service request. Here, the corporate network is a private network capable of an intranet configuration by being composed of terminals such as a PC, a telephone, a facsimile, a printer, a file server, a voice mail server, and various DB servers. Means. The enterprise network may appear in various forms depending on the purpose. In addition, in the embodiment of the present invention, the voice and data integration means that the voice channel and the data channel are set up through one physical line to enable simultaneous service, and the computing process of the voice stream is possible.

Referring to Figure 2, looks at the features and configuration of the multi-service enterprise network.

Referring to the characteristics of the multiservice enterprise network, a multiservice enterprise network refers to a multiservice enterprise network that provides a CT service environment by integrating voice and data into one line based on ATM technology. The multi-service means that various services are provided and are used because it means that various network services having different characteristics are provided in one network such as a telephone service and a computer communication service. It is distinguished from a multimedia service that provides data of different characteristics such as voice, data, image, moving picture, etc. as organically related to one service.

The multiservice enterprise network not only provides plain old telephone service (POTS) and computer communication services of the PBX telephone network and the LAN computer network, but also provides a desktop user environment in which a PC and a telephone are integrated. It is a network implemented to facilitate the implementation of CT multimedia. The requirements of the multiservice enterprise network are as follows.

First, it should include basic POTS and data service functions provided by the PBX telephone network and LAN computer network. The multiservice enterprise network should be designed to replace the current PBX and LAN networks.

Secondly, it should be a reliable network. At least the level provided by the PBX telephone network and the LAN computer network

In particular, PBX telephone network can provide side phone service by supplying power to terminal in network while LAN computer network does not supply power in network. impossible. In order to introduce a telephone service to a multi-service enterprise network based on the ATM LAN, a power problem must be solved.

Third, we need to provide a CT environment that integrates voice and data into one physical line and enables multimedia services. This means that the computing processing of the telephone voice stream must be possible and facilitates the implementation of multimedia services.

Fourth, in terms of service standards, it should be more economical than the PBX telephone network and LAN computer network.

The configuration of a multiservice enterprise network having the above characteristics will be described.

1 illustrates the configuration of a multiservice enterprise network. If a multi-service enterprise network is installed in a location such as a building, a single network provides various services such as a public switched telephone network (PSTN), an intranet, an ATM, and an integrated services digital network (ISDN) network. The ATM multiservice switch 111 serves as a gateway of a multiservice enterprise network. Over the long term, as the network evolves, the public network will be mixed with each other to provide unique services such as PSTN, Internet, ISDN, and ATM, and eventually, the ATM network that integrates voice and data will lead the public network. do. The ATM multi-service switch 111 performs an interface function for various public networks, but interworking between services is possible by integrating the multi-service enterprise network.

Server 112 may be various according to the purpose of the enterprise, but PBX server 152 with various functions of DB server 151 and PBX for computing information is representative. The PBX server 152 manages a mapping table of a telephone number, an Internet address, and a name of a desktop for a telephone service in an enterprise, and includes a function for supporting routing, conference call, etc. in the enterprise. . The PBX server 152 controlling the ATM multiservice switch 111 has a computer telephony integration (CTI) link as an interface between the switching area and the computing area.

The ATM switching hub 113 is for the expansion of multiservice enterprise networks. The switching hub 113 and the ATM multiservice switch 111 are connected at 155 Mbps, and most terminals such as a PC and various servers are connected at 25 Mbps UTP.

A representative terminal form of the multi-service enterprise network is an analog phone connected to a PC as shown in 115. At this time, even if the PC does not operate, basic telephone service should be provided. For this purpose, four of the 25 lines of UTP unused lines are used to power the phone. When the PC operates normally, various types of computing information such as caller information, phone history, and phone call time may be provided through the screen of the PC. 116 is a phone terminal using a sound card of a PC, 117 is a type equipped with a camera to enable video conferencing. In addition, more than two telephones may be connected to one PC, such as 114, and a telephone and a facsimile may be connected. In this case, one PC terminal is assigned one telephone number, which is called a one number service. You can receive calls from two people at the same time with one phone number. You can also use both the telephone and the facsimile with one phone number. This is because a plurality of virtual channels can be established between the ATM multiservice switch 111 and the PC. 118 is an Ethernet connection to a multiservice enterprise network. The Ethernet is a transmission line sharing type, and the sound quality of the telephone service is not guaranteed. However, as fast switching Ethernet is developed, sound quality can be improved if sufficient bandwidth is supported.

In order to construct such a network, an interworking between a PSTN and a multiservice enterprise network is required. And on the PC

There is a need to integrate and provide telephone and data services. The construction method of the multiservice enterprise network as described above is as follows. The integration of voice and data may be based on a circuit-switched PBX. In this case, it can be implemented using ISDN, but bandwidth is limited. Therefore, it is assumed in the embodiment of the present invention to build a multiservice enterprise network based on ATM LAN.

First, let's take a look at interworking operation of multiservice enterprise network. The ATM multiservice switch 111 has various public network interfaces. In the embodiment of the present invention, a PSTN and an ISDN for providing a telephone service will be described. The ATM multiservice switch 111 should be able to perform general PBX functions. Currently, the interface type between PBX and PSTN is mainly used when R2 signaling is applied to T1 and a loop trunk. However, the use of E1 trunks is on the rise, and signaling also uses common line signaling. It is also expected that ISDN services will increase in the future. Therefore, a description will be given assuming ISDN PRI (Primary Rate Interface) as a public network telephone service interface of a multi-service enterprise network according to an embodiment of the present invention.

2 is a diagram illustrating an ISDN and an ATM interface. The functionality illustrated in FIG. 2 is implemented in an ATM multiservice switch 111. Q.931 signaling terminates at ATM multiservice switch 111 and maps to Q.2931 signaling. When call setup with the terminal of the multiservice enterprise network is terminated, PCM voice data is made of an AAL1 type ATM cell. The AAL1 type effectively simulates a 64Kbps-based voice line of the PSTN. However, since the bandwidth is not enough and the delay factor is not large in the multiservice enterprise network, the sound quality is not significantly degraded even when the AAL5 type is used.

In the mapping function, an ATM cell is a virtual channel having different VPI / VCI values according to a destination for a slot including valid data among 23 timeslots (the number of timeslots except a signaling channel in the case of T1). The mapping takes place. In this case, delay may occur while filling an ATM cell. Since a multi-service enterprise network is a private network with a relatively sufficient bandwidth, a method of filling a portion of a cell is suitable for ensuring sound quality.

At this time, the mapping between the slot number and the virtual channel is performed during call setup. To this end, the ATM multiservice switch 111 fully interprets the call setup request of Q.931 (DSS1) to confirm the destination telephone number. For each phone number, there is a Permanent Virtual Channel (PVC) for voice channel and voice control channel, which informs the PC that the call is coming through the voice control channel. When fully connected through the voice control channel, when a CONNECT message of Q.931 is sent and a CONNECT ACK message is received, a corresponding time slot of the PVC voice channel corresponding to the telephone number and the ISDN interface is determined. Map it.

3 is a diagram for explaining a relationship between ATM signaling and a telephone in a PC to which a telephone is connected. The configuration of the left part of FIG. 3 is a signaling function used in an ATM LAN. The configuration of the right part of FIG. 3 is a function added to support the phone as it is connected to the PC. The main functions are a DSP (Digital Signal Processor) for extracting PCM data from the ATM cell and converting it to analog, and a DTMF (Dual Tone Multi-Frequency) unit for processing phone state and button information. The other party's telephone number generated by pressing the telephone button is collected and sent together when sending a call setup message. Thus, a phone number interpretation software component is included in the ATM multiservice adapter card processor. If the phone number is invalid, the ATM multiservice adapter card processor sends its own error message. These messages can be sent through the phone as a sound or through a PC screen.

Second, we look at the address mapping behavior. Three addresses are used in the multiservice enterprise network. The addresses are ATM addresses, Internet addresses, telephone numbers, and the like. The mapping between the ATM address and the Internet address is managed by LANE (LANE), and the mapping between the ATM address and the phone number is managed by the PBX server 152. Knowing one address

The other two types of addresses can be found, and these services are handled by PBX server 152. A mapping table of telephone numbers and ATM addresses exists in the ATM multiservice switch 111 and the PBX server 152, and the PBX server 152 manages these two tables consistently. The address used in the ATM multiservice switch 111 uses an ATM address regardless of the type of terminal, and a phone number is used in a telephone service area. The computing application area uses the Internet address.

Third, we look at the quality of service (hereinafter referred to as QoS). Until now, it has been a QoS problem for voice that has made it difficult to integrate voice in data networks. While the voice data is sensitive to time delay, it has a characteristic that it is not greatly affected by some data loss. The multi-service enterprise network is based on ATM LAN technology, and delay factors that may occur during voice service include packetization delay, mapping function delay, and transfer delay.

The packetization delay is a time delay that occurs while waiting to fill 48 bytes when the CT terminal converts the voice sampling data into an ATM cell. The mapping delay is a time delay that occurs when collecting PCM data from the PSTN to create an ATM cell. However, the multi-service enterprise network is a private network with at least 25 Mbps allocated to each terminal, and there is no need to fill the ATM cells because there is no need to secure bandwidth even at the expense of sound quality. The transmission delay indicates a delay caused by buffering at the switch node during transmission. In the multiservice enterprise network, since the maximum number of nodes through which PCM data passes is not significant, the effect is not large.

In addition, a synchronization problem may occur when multiplexing PCM data created in a multiservice enterprise network terminal to a time slot on the PSTN side. For example, 24 channels of PCM data may arrive late at Tx T1. Since voice data is not greatly affected by some loss, there may be a way to create and send empty data or to reserve one piece of PCM data at all times.

Fourth, look at the CT service environment.

One of the greatest features of a multiservice enterprise network is that it can be provided in conjunction with a telephone service computer. In the meantime, the computer-telephone link service was provided by linking PBX and LAN with CTI technology, and used it for a specific purpose such as a call center or help desk. However, since the service implementation is complicated and expensive as described above, it is difficult to use in a general office environment.

Efforts to combine computing and switching environments have been around for a long time, and the Computer Supported Telephony Application (CSTA) of the European Computer Manufacturers Association (ECMA) has been standardizing CTI technology for this. [ECMA-179, "Service for Computer Supported Telecommunications Applications Phase I "ECMA CSTA, June 1992]. Currently, Versit and the Enterprise Computer Telephony Forum (ECTF) are also standardizing on CTI. [ECTF, "Architecture Framework Rev 1.0", 1996].

As a software platform for realizing the CTI, Novell's Telephony Service Application Programming Interface (TSAPI) and First-Party Call forms that support Third-Party Call forms are used. Supported by Microsoft, Microsoft's TAPI (Telephone Application Programming Interface, starting with 2.0 can support third-party call types) is a typical example. In the multi-service enterprise network, since the PC and the phone are directly connected, the TAPI supporting the text-party call is suitable for controlling the phone from the PC.

The CT service is provided by a CT application developed on the CT platform as shown in FIG. The CT platform is composed of a telephone control part, a communication service part and a part supporting distributed processing. The distributed processing portion may use a common object request broker architecture (CORBA), which is currently widely studied, the communication service portion may apply TCP / IP, and the telephone control portion may apply TAPI. The server 112

The CT platform on the side includes a switch control section, enabling multiservice switches to implement PBX functionality used internally within the enterprise.

Fifthly, the multi-service enterprise network is an integrated network of voice and data. Since the phone service is dependent on the PC, the phone service is impossible when the PC malfunctions or power is not supplied to the PC. To solve this problem, power must be supplied from the network. In a multi-service enterprise network according to an embodiment of the present invention, power is supplied using four unused lines of 25M UTP. In addition, the ATM multimedia adapter card installed in the PC must be designed to operate independently of the PC. The ATM multimedia adapter card has its own processor and can support a simple signaling function and a DSP function for performing a telephone service even when a PC is not operating.

The service execution process of the multiservice enterprise network will be described.

It looks at the process of providing a telephone service in conjunction with the PSTN in the multi-service enterprise network. Q.931 signaling is used for the PSTN, and Q.2931 is used for ATM signaling in the multiservice enterprise network. The ATM multiservice switch 111 and the CT terminal have at least two PVC channels. One is for voice channel for PCM data stream and the other is for voice channel control. The voice channel and the voice control channel are basically generated as soon as the CT terminal is connected to the network, and a voice channel can be additionally set as necessary. This method is to provide an effective POTS service regardless of the operating state of the PC. The details of message mapping of Q.931 and Q.2931 are omitted, and the overall flow is examined qualitatively.

First, let's take a look at the case of incoming call from PSTN.

Firstly, when a setup message is input from the PSTN, the ATM multiservice switch 111 analyzes the message to confirm the destination telephone number. Secondly, the ATM multiservice switch 111 finds a destination ATM address by referring to a mapping table of phone numbers and ATM addresses managed internally. Given the destination ATM address, the VPI / VCI values of the already established PVC voice channel and voice control channel can be known. Thirdly, the voice control channel is notified to the CT terminal that the call has come. This is done by sending a phone call message, which may include the caller's phone number or the customer's ID. Fourthly, the CT terminal receiving the call reception message can operate in various ways depending on the PC configuration. There are three ways to do this, for example, by simply ringing the phone connected to a PC to provide voice service over the phone, running the PC's voice storage program and getting ready to receive voice mail. If the caller ID is included, the customer service program on the PC can interact with the server to display the caller's information on the screen. Fifth, when the receiver of the CT terminal picks up the receiver or prepares to store the voice mail, the CT terminal transmits a connection message through the voice control channel to the ATM multi-service switch. Sixth, the ATM multiservice switch 111 receiving the connection message sends a connection message to the PSTN side, and connects the time slot of the PSTN side with the VPI / VCI of the voice channel. Seventhly, a PCM data stream is transmitted through a voice channel.

The following describes the operation of calling a telephone user of the PSTN side from the CT terminal. In this case, you can make a call by holding the handset and pressing the other party's phone number button or by running a program on your PC. Here, we will take a look at how to use general telephone service.

When you first pick up the handset, the ATM multiservice adapter card detects the hookoff condition and plays a tone. When you hear the call, press the other party's phone number. Secondly, the other party's phone number is collected and sent to the ATM multiservice switch through the voice control channel already set up in the outgoing message. Third, the ATM multiservice switch 111 operates a phone number interpretation algorithm to determine whether to connect to the PSTN network or to an internal telephone. Fourth, calls that need to connect to the PSTN network are signaled through a setup message in Q.931.

Send and wait for a response. Fifth, the call to be connected to the internal telephone repeats the function from the second process. Sixth, when the connection response message arrives from the result of the fourth process, the connection time slot with the PSTN and the voice channel of the call originator are established and the connection response message is transmitted to the CT terminal.

As described above, an embodiment of the present invention provides a structure of a multi-service enterprise network capable of effectively providing a multimedia service by integrating voice and data in an enterprise environment. The multi-service enterprise network defined in the embodiment of the present invention is a multi-service private enterprise network that can provide services such as PSTN, Internet, ATM backbone, etc. in a single line in a desktop environment in which a telephone is connected to a computer. , Network configuration, and POTS service scenarios in multiservice enterprise networks.

Network operators are promoting voice and data integration from the public network in order to pursue economic advantages from the point of view of transmission and management, but general service users require multimedia communication services, and link PBX and LAN networks with CTI technology. Developed a network. The multiservice enterprise network is a private network designed to satisfy the above two viewpoints.

Claims (3)

In the apparatus for performing a multimedia service, A server comprising a DB server managing computing information, a PBX server managing a table for a telephone service in a network, Citi terminals which are connected to a computer and a telephone line and perform data and voice services by processing ATM LAN signaling and voice signaling of the single line; Switching hubs connected to the Citi terminals to 25 UTPs and performing network expansion functions; And a multiservice switch having a plurality of public network interfaces and connected between the switching hubs and the public networks and performing a gateway function by integrating voice and data of the Citi terminals by the server. Device for performing multimedia services. In a multimedia processing method of a multi-service enterprise network that performs a multimedia service by integrating a voice network and a data network into a single network, When receiving the setup message from the public network, analyzing the received message by the multiservice switch and confirming the destination telephone number; Searching for a destination AVM address based on the phone number and checking a BP / VC value of a set PBC voice channel and a voice control channel; Notifying an incoming call to the Citi terminal through a voice control channel of the destination telephone; Waiting for reception of a connection message generated through a voice channel in response to the Citi terminal; Outputting a connection message to the public network upon receiving the connection message, and connecting a time slot of the public network to a VP / VC of a voice channel; And receiving a PCM data stream through the voice channel. In a multimedia processing method of a multi-service enterprise network that performs a multimedia service by integrating a voice network and a data network into a single network, Receiving a message through a voice control channel when the Citi terminal requests a call; Analyzing the telephone number in the received message and determining whether to connect to the public network; Transmitting a signal through a setup message of the CUE 931 when waiting for a public connection, and waiting for a response; When the connection response message is received from the public network, establishes a connection time slot and a voice channel connection of the calling party, and transmits the connection response message to the Citi terminal.