KR19980037410A - How to provide a user-user switched virtual path connection on the calling user-network connection side - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

A method for providing a user-user switched virtual path connection in the calling user-network connection.

2. The technical problem to be solved by the invention

Before the subscriber of the broadband aggregation network requires the establishment of a virtual channel connection, the subscriber signaling protocol DSS2 is used to pre-establish a switched virtual path connection for the subscriber of the broadband aggregation network between the originating subscriber of his country and the destination subscriber of his or her country or another country. To make the virtual channel easy to set up.

3. Summary of Solution to Invention

The asynchronous transfer mode (ATM) switching system uses the user-user signaling procedure when the originating subscriber requests the establishment of a user-user switched virtual path connection that is received by the local or other subscriber in response to the request for establishing the switched virtual path connection. By using the preconfigured virtual path connection to establish the virtual channel connection, the signaling procedure for establishing the virtual channel in the network is not necessary since the connection between the calling and the called user is already established.

4. Important uses of the invention

Used to connect switched virtual paths between users in a broadband integrated telecommunication network.

Description

How to provide a user-user switched virtual path connection on the calling user-network connection side

The present invention provides a user-user exchange between an originating subscriber of a domestic switching system and an originating subscriber of a home country or a destination of another country in a broadband integrated services digital network (B-ISDN) in an asynchronous transmission mode (ATM). In case of requesting setup of User-User Switched Virtual Path Connection (UU-SVPC), outgoing and incoming call using DSS2 (Digital Service Signaling System Number 2), subscriber signaling protocol, at the calling user-network interface A method for establishing a user-user switched virtual path connection (UU-SVPC) between subscribers.

First, with reference to Figures 1 and 2 to help understand the terms used in the present invention and the present invention. First, the definition of the virtual path and the virtual channel is as follows.

The transparency connection that the ATM layer provides to the upper layer is called an ATM connection, which is connected between endpoints by a chain of connection elements. There are two types of ATM connections: Virtual Channel (VC) and Virtual Path (VP).

A virtual channel means a logical unidirectional coupling between link ends carrying an ATM cell, and a virtual path means a logical combination of virtual channels. One virtual channel identifier (VCI) is assigned to each virtual channel, and one virtual path identifier (VPI) is assigned to each virtual path. There may be different virtual channel links in a virtual path connection (VPC), which are distinguished from each other by the VCIs assigned to each. Meanwhile, some virtual channels belonging to different virtual paths may have the same VCI. Therefore, one virtual channel can be fully identified only by combining the corresponding VPI and VCI.

The following describes the definition of the virtual channel connection and the virtual path connection and possible setting methods.

Virtual Channel Connection (VCC) refers to a concatenation of virtual channel links to connect between points connected to an ATM Adaptation Layer (AAL). In this case, the virtual channel link refers to a unidirectional virtual connection path for transporting ATM cells between the point where the VCI is allocated and the point where the VCI is translated or released. The VCC may be provided via an exchange device, or may be provided as a permanent or semi-permanent connection.

Four methods are available to enable or disable VCC at the User-Network Interface (UN).

First, setting or clearing by reservation without going through a signaling procedure, which applies to a permanent or semi-permanent connection.

Second, use meta signaling. That is, the signal VC is set or released using the meta signal VC.

Third, using the user-network signaling procedure, this is a method of using the signal VCC to set or release the VCC for end-to-end communication.

Fourth, using a user-user signaling procedure, this is a method of using a signal VCC to set or release a VCC inside a preset VPC between two user-network interfaces.

Virtual path linking (VPC) refers to the concatenation of virtual path links to connect between the point at which the VPI is assigned and the point at which the VPI is translated or released. In this case, the virtual path link refers to a group of virtual channel links between a point at which the VPI is allocated and a point at which the VPI is translated or released. The VPC may be provided through an exchange device, or may be provided permanently or semi-permanently.

There are two ways to enable or disable VPCs between VPC endpoints.

First, a method of connecting or disconnecting without signaling procedure, in which case the VPC is set up or released by reservation.

Secondly, as a method of connecting or disconnecting as necessary, it is possible to connect or disconnect VPC by user control and network control.

The following describes the definition of the application of virtual paths.

Virtual path (VP) is a generic term for a bundle of VC links, where all VC links in the bundle have the same endpoint. ATM cells are explicitly assigned a virtual path identifier (VPI) for the virtual path, which identifies a group of VC links that share the same VPC. Each time a VP is exchanged in an ATM network, a specific VPI is assigned. VP link refers to the unidirectional ability to transport an ATM cell between two ATM entities whose VPI values are translated. VP links are generated by assigning VPI values and terminate when VPIs are removed.

At the virtual path level, a VPC is provided for information transfer between user-user, user-network, and network-network. When the VC is exchanged, the VPC supporting the input VC link is terminated first, and a new VPC supporting the output VC link is created. The application of the virtual path is as follows.

First, a user-to-user VPC is set up between TB or SB reference points and provides users with a virtual path connection. ATM network elements transport all cells associated with these VPCs through the same route. The corresponding VPI values are translated in ATM network elements that provide cross linking or switching functions.

Second, the user-network VPC is set up between the TB or SB reference point and the network node and is used to collectively connect user devices to the network element.

Third, a network-to-network VPC is set up between two network nodes, which is applied to network traffic management or routing. At the network node where the VPC is terminated, the VCs in the VP are exchanged or cross-connected with the VCs in the other VP.

Subscriber signaling protocol DSS2 is a signaling protocol that originally defined signaling procedures for establishing switched virtual channel connections at the source and destination UNI. Since the switched virtual channel connection needs to establish a connection whenever the calling user requests it, it is necessary to repeatedly perform connection control such as network resource allocation and internal switch path. Therefore, if there is a need to establish a virtual channel connection for the same calling and called user, there is overhead to repeat the same operation. In addition, since the quality of service of the required virtual channel connection is different from the quality of the virtual channel connection already established in the transport link, to satisfy the new virtual channel connection while maintaining the service quality of the existing virtual channel connection, It takes a lot of time and effort for allocating network resources because it needs to calculate necessary network resources considering all virtual channels.

The above problem can be solved by setting up a virtual path connection. A virtual path connection can bundle ATM channels in the same route to switch ATM cells only with VPI, eliminating the need for connection control for virtual channels that require additional connections. In addition, since network resources are reserved in advance for the virtual path connection, when the virtual channel connection is established through the virtual path connection, the required network resource calculation can be efficiently performed, thus increasing the efficiency of network resource management.

In the past, the virtual path could be set only in the shape of a semi-permanent or permanent virtual path connection by the network manager without signaling procedure. Therefore, much information, time, and effort on the subscriber information and network shape were required for the virtual path setting. Therefore, there is a problem that a network administrator or user cannot immediately create a new route when needed.

To address this, DSS2 added signaling capabilities to establish a virtual path connection, which was added to the Bearer Class Field of the information element Broadband Bearer Capability (BBC) in the setup message that requires the virtual connection. It adds transparent VP service and ignores VCI in connection identifier (CID) information element and performs connection control on VPCI value.

The DSS2 performs the procedure of establishing a switched virtual path connection only when the bearer class is a transparent VP service, and the BCOB-A, BCOB-C, and BCOB- are not the transparent VP services. In case of X, the existing virtual channel connection establishment procedure is performed.

In order to distinguish the virtual path connection established by the signaling procedure from the virtual path connection established by the network management control or the network manager, it is defined as a switched virtual path connection.

A switched virtual path connection uses the subscriber signaling protocol DSS2 to preset a switched virtual path connection for a subscriber in a broadband aggregation network before the subscriber of the broadband aggregation network requires the establishment of a virtual channel connection. The purpose is to easily establish a virtual channel between the called subscribers. A switched virtual path connection may be established between a user and a user, a user and a network, and a network and a network. The present invention provides a user-user switched virtual path connection between an originating subscriber and a destination subscriber, especially at an interface between a calling user and a network. The purpose is to provide.

It uses the preconfigured virtual path connection between the calling and destination users to establish the virtual channel connection using the user-user signaling procedure, so that the network does not need the signaling procedure for establishing the virtual channel.

1 is a relation diagram of an asynchronous transmission mode (ATM) layer and a physical layer,

2 is a relationship diagram between a virtual path and a virtual channel;

3 is an overall structural diagram of an ATM switching system to which the present invention is applied;

4 is a main block diagram for performing establishment of a switched virtual path connection of an ATM switching system;

5A through 5G are flow charts for providing a user-user switched virtual path connection at an originating user-network connection side in accordance with the present invention.

In order to achieve the above object, the asynchronous transfer mode (ATM) switching system uses the DSS2 signaling protocol when a request for setting up a switched virtual path connection is required to set up a user-user switched virtual path connection that is received by a local or another subscriber. It provides a user-user exchange virtual path connection between the calling subscriber and the switching system at the calling user-network interface.

Therefore, when receiving the SETUP_ind message from the originating subscriber of the home country, the message is analyzed to request the establishment of the user-user switched virtual path connection, and the switching system connects the virtual path connection to the bandwidth and VPCI required by the originating subscriber. Allocate the necessary bands and VPCIs so that they can be set. After successfully allocating the band and the VPCI, it sends a Call Proceeding message to the calling subscriber and a SETUP_int message to the called party's subscriber connection control block or outgoing trunk connection control block.

When the SwLinkInfoRP message is received in response to the SETUP_int message, the routing tag information of the cell header is transmitted to the relevant block by using the internal switch link path information included in the message. Establish a user-user exchange virtual path connection for transmission of user data cells.

According to the above, when the CONNECT_int message is received from the called party subscriber connection control block or the outgoing relay line connection control block, the CONNECT_req message is transmitted to the originating subscriber of the local station. It is established and the state of the virtual path connection transitions to busy.

In addition, the subscriber connection control block that is in a busy state by the calling party or the calling party's RELEASE request performs the release of the virtual path connection, and the return and routing selection of the in-use band, VPCI, and internal switch link path. Delete the information.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. 3.

3 is an overall structural diagram of an asynchronous transmission mode switching system applied to the present invention.

In view of the above structure, the asynchronous transfer mode (ATM) switching system is basically an asynchronous transfer mode local switching subsystem (ALS) and an asynchronous transfer mode central switching subsystem (ACS), 2 It consists of two subsystems.

The Asynchronous Transfer Mode Local Switching Subsystem (ALS) is capable of operating as a Concentrator with a constant aggregation ratio together with the Asynchronous Transfer Mode Central Switching Subsystem (ACS).

Thus, the asynchronous transmission mode central switching subsystem (ACS) operates as a distribution device that performs the interconnection function between the asynchronous transmission mode local switching system (ALS).

In addition, the asynchronous transmission mode local switching subsystem (ALS) is network matching with the asynchronous transmission mode local switching subsystem / broadband integrated information network subscriber (ALS / BISDN Subscriber, ALS / S) for user registration of broadband integrated information network (BISDN) Asynchronous Transfer Mode Local Switching Subsystem / Wideband Telecommunications Trunk Line (ALS / BISDN Trunk, ALS / T) and Asynchronous Transfer Mode Local Switching Subsystem (ALS / BISDN Subscriber and Trunk, ALS) / ST).

As a concentrator according to the above, the asynchronous transmission mode local switching subsystem (ALS / S) has n * m, where n is 155 Mbps and the number of links on the switch (ACS) side is m. May have a collection fee.

Therefore, the asynchronous transmission mode central switching subsystem (ACS) performs caller number translation in case of own station and incoming call / connection in call / connection control, and in case of outgoing call / connection, route to each relay line. (route) Perform control.

In addition, the Asynchronous Transfer Mode Central Switching Subsystem (ACS) has an Operational Preservation Processor (OMP) for the operation and maintenance of the system as a whole. Perform control functions.

FIG. 4 is a main block structure diagram for setting up a switched virtual path connection of an asynchronous transfer mode (ATM) switching system according to the present invention. The entire virtual path connection establishment procedure will be described with reference to FIG.

When a request for a virtual path connection from an originating subscriber occurs, the asynchronous transmission mode local switching subsystem (ALS) detects it, performs the virtual path connection service, and translates the station number under the control of the originating asynchronous transmission mode local switching subsystem (ALS). Asynchronous transmission mode The central switching subsystem (ACS) makes a call number translation or outbound routing request.

The asynchronous transmission mode central switching subsystem (ACS) receiving the above routing request designates an incoming asynchronous transmission mode local switching subsystem (ALS). The designated incoming asynchronous transmission mode local switching system (ALS) selects the optimal internal switch link path and notifies the originating asynchronous transmission mode local switching subsystem (ALS) and the incoming call of its own subscriber or another station. Make a virtual routing request to the switching system. The outgoing asynchronous transmission mode local exchange subsystem (ALS) informed of optimal internal switch link path information establishes a virtual path connection within the system. At this time, the outgoing asynchronous transmission mode local switching subsystem (ALS) counts user data cells that pass through the virtual path in the busy state, and after the call is completed, the asynchronous transmission mode central switching subsystem (ACS) with the service type requested by the user. Billing data is sent), and the originating / receiving asynchronous transmission mode local exchange subsystem (ALS) restores the call / connection data to an idle state.

4 shows a main call / connection processing block for performing the virtual path connection control procedure as described above, and description of each block is as follows.

First, the System Library block includes a Switch Link Resource Handling Function Block (SLRHF), a Number Translation in ALS Function (NTLF), and a Subscriber Link Resource Management Block (User Link Resource). Handling Function (ULRHF) and Network Link Resource Handling Function (NLRHF).

The switch link resource management processing block (SLRHF) is a block for generating internal switch link path setting and route designation tag information of an asynchronous transmission mode cell header, and the station number translation block NTLF is A block for performing a destination station translation, a subscriber link resource management block (ULRHF) is a block for processing band allocation and band management of a subscriber link at the user-network interface, and a network link resource management processing block (NLRHF) is a network. A block for handling band allocation and band management of a relay line link at a network interface (NNI).

In addition, the Broadband Signaling Interface Function (BSIF) serves to control and manage a signaling connection for reliable transmission of B-ISDN call / connection control messages. The subscriber service specific coordination function block (SSCF) is a coordination function between the broadband signal access processing block (BSIF) and the user connection interface function (UCIF) for delivering subscriber signal messages. Do this. The subscriber connection access block (UCIF) performs a connection function of a subscriber signaling message. The subscriber connection control block (UCCF) performs subscriber call / connection control.

The trunk service specific coordination function is a coordination between the broadband signal access processing block (BSIF) and the MTP-3 signaling message handling function (SMHF) to deliver the trunk line signaling message. Perform the function. MTP Signal Message Processing Block (SMHF) Performs the MTP-3 function in No.7 signaling.

The trunk connection interface block (TCIF) performs an MTP signaling message transfer function between the MTP signaling message processing block (SMHF) and the network connection control block (Network Connection Control Function).

Trunk Connection Control Function (TCCF) block performs B / ISDN User Part (BISUP) call / connection control.

In addition, there are a Number Translation in ACS for Called Party Number Translation and a Routing Control Function (RTCF) block that performs routing control.

5A-5F are flow diagrams for providing a switched virtual path connection between a user at an originating user-network interface in accordance with the present invention.

Referring to the drawings, a detailed procedure for providing a user-user exchange virtual path connection will be described.

FIG. 5A illustrates a procedure of creating a child process for performing establishment of a switched virtual path connection between a user in a UCCF main process (UCCF_main) of a subscriber connection control block (UCCF).

In FIG. 5B, FIG. 5F shows that the originating subscriber virtual path connection control sub-process generated by the UCCF_main process of the subscriber connection control block provides a switched virtual path connection between the user and the user. The procedure is shown.

Referring to the above procedure, the main process (UCCF_main) of the subscriber connection control block (1) receiving the call / connection setup request (SETUP) message from the originating subscriber of the local station analyzes the call / connection setup request message (2). The BS (Bearer Class) information element of the Broadband Bearer Capability (BBC) information element is a virtual path (VP), and the connection identifier (CID) information element is a virtual path connection identifier (Virtual Path Connection Identifier). If only the VPCI) is included, it is determined that the establishment of the user-user switched virtual path connection is requested, and the calling subscriber virtual path connection subprocess (UCCF_vporg) is generated (3).

However, the call / connection establishment request message may have a Class of Delivery (BS) of Broadband Forwarding Capability (BBC) information element, a Broadband Connection Oriented Bearer Service (A), and a Broadband Connected Forwarding Service (C). (Broadband Connection Oriented Bearer Service-C (BCOB-C)) or Broadband Connection Oriented Bearer Service-X (BCOB-X), and the Connection Identifier (CID) information element is associated with the Virtual Path Connection Identifier (VPCI). In the case of including the virtual channel identifier (VCI), it is determined that the virtual channel connection is set up, and thus, an originating subscriber VC UCCF child process (UCCF_vcorg) is generated (4).

The generated subprocess (UCCF_vporg) receives a virtual path connection setup (main-child SETUP, SETUP_mc) message from the main process (UCCF_main) (5) after checking available network resources (6), If the band and the Virtual Path Connection Identifier (VPCI) can be accommodated, then call forwarding message (CALL PROCEEDING) is sent to the calling subscriber (7). However, if the request of the originating subscriber cannot be accepted, the RELEASE COMPLETE message is delivered to the originating subscriber and the secondary process (UCCF_vporg) terminates.

After sending the call progress message to the calling subscriber, the sub process UCCF_vporg selects the called local exchange subsystem (ALS) by calling the system library of the station translation block (NTLF) to translate the called party. Station number translation result (8) If the country code is found, the called party number translation block (NTCF) is requested to translate the called party number (9). The location information of the called party can be known as a result of the called party number translation. If it is determined that the relay number is a relay number, a request for outgoing route is requested to the routing control block (RTCF) (10). As a result of the routing request, the outgoing route information and the signaling point code (SPC) information of the incoming exchange system can be known.

After performing the above procedure, the system library of the switch link resource management processing block (SLRHF) is called to reserve the internal switch link path between the calling local switching subsystem (ALS) and the called local switching subsystem (ALS). 11).

If all of the above procedures are successfully performed, the calling party process (UCCF_vporg), if the translation of the station number is a local call, then the internal call / connection including internal switch link information reserved by the main process (UCCF_main) of the called party's subscriber connection control block. It transmits a setup request (Internal SETUP to UCCF, SETUPu_int) message (12) and transitions to a switch link information response message waiting state (Await_SwLinkInfoRP; 13). The called party main process (UCCF_main) that has received the internal call / connection setup request (SETUPu_int) message performs the same procedure as the calling party main process to create a destination VP UCCF child process (UCCF_vpdes). Let's do it.

If the station translation result is a relay call, the calling party process (UCCF_vporg) requests an internal call / connection setup request including internal switch link information reserved as the main process (TCCF_main) of the terminating trunk relay control link. TCCF, SETUPt_int) message is transferred (14), and transitions to the switch link information response message wait state (Await_SwLinkInfoRP) (13). The called party main process (TCCF_main) that has received the internal call / connection setup request (SETUPt_int) message performs the same procedure as the calling party main process to perform the outgoing VP TCCF child process (TCCF_vpogt). Creates

When the calling party process UCCF_vporg receives the switch link information response message SwLinkInfoRP including the switch path information selected from the called party process (UCCF_vpdes or TCCF_vpogt) in the switch link information response message waiting state (Await_SwLinkInfoRP) (15), the switch The system library of the link resource management processing block (SLRHF) is called to establish an internal switch path of the virtual path connection (16). The calling unit process UCCF_vporg transmits a message including a virtual path identifier (VPI) and information for user parameter control (UPC) to a subscriber interface module controller (SIMC) (17, 18) After receiving the response, it transitions to the call connection completion wait state (Await_CONNECT) (20).

The calling party process (UCCF_vporg) receives an internal CONNECT (CONNECT_int) message from the called party process (UCCF_vpdes or TCCF_vpogt) in the call connection completion wait state (Await_CONNECT) (21). After the call connection completion (CONNECT_req) message is notified that the establishment of the switched virtual path connection is completed between the calling party and the called party (22), the state transitions to the conversation state (23). From then on, the user data cell is transferred between the two subscribers via the established virtual path connection.

The release procedure of the virtual path connection may be performed at the request of the calling or called party. In the case where the virtual path connection release procedure is performed at the request of the originating subscriber, the originating subscriber starts by sending a call / disconnection request (RELEASE_req) message to the originating sub-process (UCCF_vporg). Receiving a call / disconnection request (RELEASE_ind) message from the originating subscriber (UCCF_vporg) (24) checks whether a virtual channel connection exists within the virtual path connection (25) before disconnecting the virtual path connection (25). If there is a virtual channel connection, the virtual channel connection is first released and then the virtual path connection is released. The calling party process (UCCF_vporg) calls the system library of the switch link resource management processing block (SLRHF) to release the internal switch path corresponding to the virtual path connection (26) and delete the virtual path identifier to the subscriber access module controller (SIMC). (27). Then, a call / disconnection request (Internal RELEASE, RELEASE_int) message requesting the release of the virtual path connection to the called sub-process (UCCF_vpdes or TCCF_vpdes) is transmitted (28), and a call notifying the calling subscriber that the release of the virtual path connection is completed. After notifying the RELEASE COMPLETE_req message (29), the user-user switched virtual path connection established at the calling user-network interface is released and the calling party process terminates.

In the case of performing the release procedure of the virtual path connection at the request of the called party, the called party starts by sending a call / release request (RELEASE_req) message to the called sub-process (UCCF_vpdes or TCCF_vpogt). The called party process (UCCF_vpdes or TCCF_vpogt) that has received the call / disconnection request (RELEASE_ind) message from the called party sends the call / disconnection request (RELEASE_int) message to the calling party process (UCCF_vporg) after disconnecting the virtual path. . The calling party process (UCCF_vporg) that receives the call / disconnect request (RELEASE_int) message (30) checks whether a virtual channel connection exists within the virtual path connection (31) before disconnecting the virtual path connection (31) and as a result the virtual channel connection. If present, the virtual channel connection is released first, and then the release procedure of the virtual path connection is started (32). The called party process (UCCF_vpdes or TCCF_vpogt) calls the system library of the switch link resource management processing block (SLRHF) to release the internal switch path corresponding to the virtual path connection (33) and connect the virtual path to the subscriber access module controller (SIMC). Request deletion of the identifier (34). In operation 35, the call / reconnection request message (RELEASE_req) requesting the release of the virtual path connection is transmitted to the calling subscriber, and the state transitions to the call / connection disconnection message waiting state (Await_Release Complete). After receiving the call / reconnection completion message (37) indicating that the disconnection of the virtual path connection is completed from the calling subscriber (37), the user-user switched virtual path connection established at the calling user-network interface is released and the calling party is released. The subprocess terminates.

The present invention described above is capable of various substitutions, modifications, and changes within the scope without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains, and thus is limited to the above-described embodiments and drawings. It is not.

As described above, the method for providing a user-user switched virtual path connection in the caller-side user-network connection surface of the present invention uses a user signaling protocol (DSS2) to establish a user-user switched virtual path connection between the calling subscriber and the calling exchange system. By performing the virtual path establishment procedure for the required local or relay call, it is possible to provide a user-user switched virtual path connection between the calling party and the called party. It has the effect of providing ATM service to recipient subscribers in its own country or in other countries with regard to the transmission mode (ATM) service request.

Claims (8)

In the Asynchronous Transfer Mode (ATM) system, the originating user-network is configured to establish the virtual connection between the called party or the receiving subscriber of another station in response to the request for establishing the user-user exchanged virtual path connection required by the originating subscriber of the local station. In the method of providing a user-to-user switched virtual path connection on the connection side, If the result of analyzing the call / connection setup request (SETUP_ind) message received from the originating subscriber of the own station requires the connection of the local call or the relay call exchange virtual path, the originating subscriber virtual path connection control part process or the outgoing relay line virtual path connection A first step of creating a control subprocess, If the originating subscriber virtual path connection control subprocess generated from step 1 receives a call / connection setup request (SETUP_mc) requesting a switched virtual path connection from the main process of the subscriber connection control block, the requested virtual path connection Allocating a band and virtual path connection identifier (VPCI); After performing the second step, the destination station number is translated to determine whether it is a national call or a relay call, and after reserving an internal switch link path, an internal call / connection setup request (SETUPu_int or SETUPt_int) message is controlled by the called subscriber or outgoing relay line connection control. A third step of delivering to the block, A fourth step of setting a path for transmission of a user information cell using switch link information received from a called subscriber or outgoing relay line virtual path connection control unit process after performing the third step; After receiving the internal call connection complete (CONNECT_int) message from the incoming or outgoing sub-process, send the call connection complete (CONNECT_req) message to notify the calling subscriber that the establishment of the switched virtual path connection between the calling party and the called party is completed. A fifth step of making the state of the route connection busy; A sixth step of performing a procedure of releasing the on-call virtual path connection by a request for releasing the virtual path of the calling subscriber after performing the fifth step; and And a seventh step of performing the procedure of releasing the busy virtual path connection according to the request of releasing the virtual path of the called subscriber after performing the fifth step. . The method of claim 1, The first step is, When the main process of the subscriber connection control block that receives the call / connection setup request (SETUP_ind) message from the originating subscriber of the local station requests the establishment of the switched virtual path connection as a result of the message analysis, it generates an outgoing subscriber virtual path connection subprocess. To provide a user-to-user switched virtual path connection. The method of claim 1, The second step, Call the system library of the user link resource management processing block (ULRHF) to allocate the requested bandwidth and virtual path connection identifier (VPCI) to the virtual path connection requested by the calling subscriber virtual path connection control process, and then CALL PROCEEDING_req) A method for providing a user-to-user switched virtual path connection, characterized by delivering a message to an originating subscriber. The method of claim 1, The third step, If the destination station translation result is a local number, the destination number is translated to find the incoming local switching subsystem (ALS) and subscriber transport link, and to reserve the internal switch link path information between the originating and destination local switching subsystem, Forwards an internal call / connection setup request (SETUPu_int) message requesting setup to the main process of the called party's subscriber connection control block, or If the destination number translation results in a relay call, it requests the designation of a route to be relayed to a large country, finds the incoming local exchange subsystem (ALS) and the outgoing relay line link, and switches the internal switch link between the originating and destination local exchange subsystem. Between the user and the user characterized in that it reserves information and passes an internal call / connection setup request (SETUPt_int) message requesting the establishment of a virtual path connection to the main process of the relay trunk connection control block. How to provide switched virtual path connections. The method of claim 1, The fourth step, Internal switch link for transmission of a user information cell by receiving a switch link information response message including internal switch link path information selected by a switch link resource management processing block (SLRHF) from a called subscriber or outgoing relay line virtual path connection control subprocess. A method for providing a user-user switched virtual path connection, comprising establishing a path and transferring a virtual path identifier (VPI) and user parameter control information to a subscriber access module controller. The method of claim 1, The fifth step, A call connection complete (CONNECT_req) that receives an internal call connection complete (CONNECT_int) message from an incoming or outgoing subprocess, notifying the calling subscriber that a request for establishing a user-user switched virtual path connection between the calling subscriber and the calling exchange system has been completed. ) A method for providing a user-to-user switched virtual path connection by sending a message to put a status of the virtual path connection on a call. The method of claim 1, The sixth step, A procedure for releasing a virtual path connection in a call at the request of an originating subscriber, and after receiving a call / disconnection request (RELEASE_ind) message from the originating subscriber, deleting an internal switch link path and a virtual path connection identifier (VPCI) in use. Of a user-to-user switched virtual path connection that performs an internal call / disconnect request (RELEASE_int) message to an incoming subscriber or outgoing trunk line connection control subprocess and informs the calling subscriber of a call / disconnection complete (RELEASE COMPLETE_req) message. How to Provide. The method of claim 1, The seventh step, A procedure for disconnecting a virtual path in a call at the request of a called subscriber, and receiving an internal call / disconnection request (RELEASE_int) message from a called subscriber or outgoing relay part process, and then connecting an active internal switch link path to a virtual path. A method of providing a user-user switched virtual path connection that performs deletion of an identifier (VPCI), forwards a call / disconnection request (RELEASE_req) message to an originating subscriber, and receives a call / disconnection complete (RELEASE COMPLETE_req) message from an originating subscriber. .