KR970002710B1 - Interfacing method of atm adaptation aal and call control layer in the atm switch - Google Patents

Abstract

A matching method between the ATM adaptive sublayer(AAL) and the subscriber call control sublayer(SCC) in the ATM where is a needful function when the subscriber call is controlled in the ATM switching system having the terminal to terminal configuration of the subscriber networks, is the signal procedure between the AAL layer and the Q.2931 call control layer, and executes the setting/removing the signal channel of the subscriber networks, the management of the set channel, and the connection with the call control processor.

Description

a. tea. A. in the ATM exchange system. tea. M. Matching method between adaptive sublayer (AAL) and call control layer

1 is a functional block diagram of an ATM switching system to which the present invention is applied.

2 is a flowchart illustrating a matching method between call control layers according to the present invention.

3 is a flowchart illustrating a procedure for transmitting and receiving signaling messages related to local calls in an ATM switching system.

The present invention relates to a matching method between an ATM adaptation layer (AAL) and a call control layer in an ATM (Asynchronous Transfer Mode) exchange system.

In the conventional narrowband ISDN exchanger, a signaling channel between subscriber networks is pre-allocated and fixed, and subscriber information is also fixed in units of 64 Kbps, thereby accommodating subscriber services by extending a bundle of units of 64 Kbps. However, in the broadband ISDN, the configuration of the signaling channel between subscriber networks can be made flexible so that the configuration can be released as needed. Therefore, in the prior art, the process of setting up and releasing a signal channel was not required. However, in an ATM switching system that realizes broadband service, a signal message for setting and releasing a signal channel and controlling a subscriber call transmitted through a set signal channel is provided as a call control function. You need a linking function.

The present invention devised to meet the above needs is a signal matching procedure between the AAL layer and the Q.2931 call control layer as a necessary function when / necessary to control a subscriber call in an ATM switching system in an end-to-end configuration between subscriber networks. The purpose of the present invention is to provide a method for establishing and releasing signal channels, managing channels, and matching between AALs and call control layers in an ATM switching system that is associated with a call control process.

In order to achieve the above object, the present invention provides a matching method between an ATM adaptation sublayer and a call control layer applied to an ATM switching system, wherein a subscriber signaling interface (SSI) block is configured with an AAL from a BSSCF (Broadband Service Specific Coordination Function) block. A first step of receiving an indication primitive, storing information set in a signal channel management table and notifying completion of signal channel establishment to a subscriber CAAL control block; After performing the first step, when the subscriber requests a call setup, the SSI block converts the received signal information into a structure for call control and transmits the signal to the SCC block, and the SCC block is a band for a rock lock and a connection identifier. A second step of transmitting an AAL data indication primitive to a terminal when the call progress message is transmitted to the SSC block and has a form of AAL data request primitive in the SSI block and transmitted to the BSSCF block; After performing the second step, the incoming call processing is requested, and the SCC incoming process requests the signal channel setting to the SSI block, and transmits an AAL setting request primitive from the SSI block to the BSSCF block, the terminal sets the AAL. Instructed by the indication primitive, and receives the AAL configuration confirmation primitive between the network and the terminal in the SSI block, stores the virtual path connection identifier / virtual channel connection identifier (VPCI / VCI) set in the signal channel management table and then the signal channel to the SCC block A third step of notifying of completion of the setting; After performing the third step, the call progress notification message is transmitted from the called party to the network according to the setup message transmission request, and after receiving the call progress message from the called party, the connection notification message is received to the SCC block in response to the called subscriber. A fourth step of completing the setting; And after performing the fourth step, when the call request is made by the subscriber, the resources occupied when the call is set up are completed and the call release is completed, and if there is no call in progress to the set signal channel in the network or the signal channel is required to be released, AAL And a fifth step of receiving the release decision primitive and returning the set signal channel to complete the release of the signal channel.

In the ATM, which transmits all information in units of cells, signal information between subscriber networks is also transmitted in units of cells, and a signal message is constructed and processed by assembling and distributing cells.

As the development of an ATM switching system requires the realization of a communication protocol useful for the high-speed broadband provided by ATM, signaling procedures between subscriber networks are required.

The signaling protocol structure between subscriber networks recommended by the International Telecommunications Union (ITU-T) for the realization of broadband integrated telecommunication network services is characterized by a physical layer performing a transmission level, an ATM layer processing a fixed length cell, and a higher layer. It is composed of A.A.L layer which converts to ATM and performs the reverse function according to service characteristics, and Q.2931 layer which establishes and releases subscriber call by interfacing with AAL layer.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a block diagram of an ATM switching system to which the present invention is applied, which is decentralized as an ATM Local Switching Subsystem (ALS) 1 and is a central switching subsystem (ACS) 2 Is interconnected by).

When a call request from a subscriber occurs, it is detected by a subscriber interface module (SIM) 3 in the ALS, and the subscriber signal cell is transmitted to a signaling control module (SCM) 4 through a switch. As the signal cell is assembled and transmitted to the call control module, the subscriber signal message is delivered.

Virtual Path Connection Identifier (VPCI) / Vurtual Channel Identification (VCI) and Bands in the outgoing ATM Local Switching Subsystem (ASCM) Access Switching Control Module (ASCM) After determining the terminating ALS, determine the destination ALS and set the switch path between the originating ALS (Access Switch Hardware) (6) and the ACS through the Central SWitch Harsware (7) and the terminating ALS. Subscriber call control is performed by performing incoming call processing.

Broadband Subscriber Physical Layer (BSPS) block that handles physical layer functions, Broadband Subscriber ATM Layer (BSAL) block that handles ATM layer functions, and AAL Signaling Handler (AASH) that handles the service common part on the AAL layer. (10) Block, AAL Signaling Handler (AASH) that processes service common part on AAL layer (10) Block, BSI (Broadband Signaling Interface) 11 that performs service dependency function of AAL layer, SSCF (Service Soecific Coordination) Function (BS) is implemented by the BSSCF (Broadband SSCF) 12 block.

In addition, the layer 3 function receives a SSI (Subscriber Signaling Interface) 13 block for matching between the AAL and the Q.2931 call control layer, and a SAC (Service) that analyzes the broadband service type by receiving a setup message from the SSI block. Analysis Control (14) block, SCC (Subscriber CAAL Control) (15) block that performs subscriber call processing by sending and receiving Q.2931 signal messages from SSI block, SSI block, CAC which allocates transmission band and channel to subscriber (Connection Admission Control) (16) block, NTC (17 Translation Block) to translate subscriber number, SRSC (Self-Routing Switch Control) 18 to perform switch path control, common to call control It consists of a CPAL (CAAL Processing System Library) 19 block that controls the library.

The following Table 1 shows the configuration of the signaling channel management table for subscriber call control. The signaling channel for subscriber call control is managed in the SSI block, and the signaling channel management table for setting / release upon request and setting of the signal channel is VPCI. (1), VCI (2), connection number (3) corresponding to VPCI / VCI (for managing the maximum number of tables in the system), and attributes for the state of the signal channel (4) .

In this table, the connection number has a sequential value as a binary coded decimal notation (BCD) value corresponding to the signal channel (VPCI / VCI). In addition, the VPCI and VCI values have a hexa value of 2 bytes, and the VCI value has a h'05 value in the case of an end-to-end signaling channel configuration between subscriber networks.

TABLE 1

The following table 2 is a table for the coordination process with the call control process, the connection number (1) corresponding to the corresponding signal channel when transmitting and receiving the setup (SETUP) message through the set signal channel ( Management is stored as 2 bytes BCD value, and the call reference value assigned as a unique value in the signal channel is stored in the call control process association table.

The call reference value corresponding to one connection number can have a maximum of 2048 values (4 byte hexa-values), so that the connection to the subscriber actually connected through the signaling channel in one link is 2048 at most. Therefore, the distinction of calls unique within the system can be seen by the VPCI / VCI call standard. When receiving a SETUP message or requesting to set up a called party, a process for performing subscriber call control independently for each call is generated and a call control process instance number (3) for processing a subscriber call having a specific call reference value in a signaling channel is generated. By storing the hex value of 4 bytes in the table, the subsequent message transmission and reception is transmitted to the call control process that processes the corresponding subscriber call.

When the set call is released, the process that performs the call control of the subscriber is stopped and the call reference value is returned to be available to other subscribers.

TABLE 2

2 is a flowchart illustrating a procedure for transmitting and receiving a signaling message related to a local call in an ATM switching system according to the present invention. The AAL layer function is initiated by transmitting an AAL_Establish_Request primitive in the Q.2931 layer of an originating terminal. Configure the AAL link for signaling.

The SSI block receives an AAL Establish Indication primitive with a virtual path connection identifier / VPCI / VCI set from the BSSCF block that performs the higher layer functions of the AAL (21). After storing information on the VPCI / VCI set in the channel management table, the SCC block notifies the completion of the signal channel setting (22).

Q.2931 signaling information for subscriber call processing is transmitted and received between the subscriber and the network by using the established signaling channel.When the subscriber requests call setup, the AAL data (AAL_Data) primitive is transmitted to the SSI block (23). After analyzing the received signal information, it is determined that the Q.2931 message type is a setup message. After verifying the error of the message type and each information element in the message, it is converted into a structure for call control and transmitted to the SCC block ( 24). The SCC block receives the band and the link identifier for the rock lock from the block managing the band and the link identifier in the link and transmits a CAAL_PROCEEDING message including the VPCI / VCI value to the SSI block (25). When the SSI block has an AAL data request (AAL_Data_Request) primitive type and transmits it to the BSSCF block (26), the AAL data book (AAL_Data_Indication) primitive is transmitted to the Q.2931 layer of the UE.

Incoming ALS information is received from the number translation function for incoming call processing, and the incoming call processing is requested from the SCC block in the originating ALS to the SCC block of the incoming ALS (27). Requires channel configuration to the SSI block.

When the AAL_Establish_Request primitive is sent from the SSI block to the BSSCF block (29), the Q.2931 layer function of the terminal is informed by the AAL_Establish_Indication primitive and between the network and the peer-to-peer. An AAL_Establish_Confirm primitive indicating an AAL connection establishment for a signal is received in the SSI block (30). The SSI block stores the VPCI / VCI set in the signal channel management table and notifies the SCC block of the completion of signal channel setting (31).

Upon receiving the setup message to the called subscriber through the established signaling channel (32), the ASI data request (AAL_Data_Request) primitive is configured in the SSI block and transmitted to the BSSCF block (33), indicating the AAL data to the Q.2931 layer of the called subscriber. The (AAL_Data_Indication) primitive is notified. A CAAL_PROCEEDING message is sent from the called party to the network through the AAL_Data primitive (34), and when receiving an AERTING from the called party, the incoming ALS is sent from the SCC block of the called ALS to the SCC block of the originating ALS. Upon notification of AERTING (35), the AAL data (AAL_Data) primitive notifying the AERTING is also transmitted (36) via the SSI and BSSCF blocks of the originating ALS.

When the CONNECT message is received through the BSSCF and the SSI block of the called subscriber as the SCC block (37), the incoming subscriber connection is notified to the SCC block of the originating ALS and the AAL data corresponding to the message is sent to the calling subscriber (AAL_Data). The primitive is received (38).

The call setup is completed by transmitting a CONNECT ACK message from the network or the subscriber receiving the CONNECT message (39).

When a request for release of a subscriber is received by the AAL data (AAL_Data) primitive, a request for release (RELEASE) is received (40). The call is completed by returning the occupied resources and sending a release completion notification (RELEASE_COMPLETE) message. (41).

If there is no ongoing call to the established signal channel in the network or the release of the signal channel is required, the signal channel release is initiated by transmitting an AAL release request (AAL_Release_Requesr) primitive from the SSI block to the BSSCF block (42). Upon receiving the AAL Release Confirm (AAL_Release_Confirm) primitive in response, the signal channel release is completed by returning the signal channel being set (43).

Accordingly, the present invention as described above is a function required for subscriber call control in an ATM switching system in an end-to-end configuration between subscriber networks, and is a signal matching procedure between the AAL layer and the Q.2931 call control layer. There is an effect that it is possible to provide a matching method between the AAL and the call control layer in the ATM switching system which performs the management method of the established channel and the cooperative process with the call control process.

Claims (1)

In a matching method between an ATM adaptation sublayer and a call control layer applied to an ATM switching system, a Subscriber Signaling Interface (SSI) block receives an AAL configuration indication primitive from a Broadband Service Specific Coordination Function (BSSCF) block, and uses a signaling channel management table. A first step (21, 22) of notifying completion of the signal channel setting to a Subscriber CAAL Control (SCC) block after storing the information set in FIG. After performing the first steps 21 and 22, when the subscriber requests call setup, the SSI block converts the received signal information into a structure for call control and transmits the received signal information to the SCC block, and the SCC block stores the lock lock. A second step (23 to 23) of transmitting the call progress message to the SSI block by receiving a bandwidth and a link identifier for the ASI data request primitive in the SSI block and forwarding the AAL data indication primitive to the terminal when the SSC block is transmitted to the BSSCF block; 26); After performing the second steps 23 to 6, an incoming process is requested, and the SCC incoming process requests a signal channel setting to the SSI block, and transmits an AAL setup request primitive from the SSI block to the BSSCF block. Is notified by the AAL configuration indication primitive, receives the AAL configuration confirmation primitive between the network and the terminal in the SSI block, stores the virtual path connection identifier / virtual channel connection identifier (VPCI / VCI) set in the signal channel management table, and then stores the SCC block. A third step (27 to 31) for notifying completion of the signal channel setting to the user; After performing the third step (27 to 31), the call progress notification message is transmitted from the called subscriber to the network according to the set message transmission request, and the connection notification message is displayed when the called subscriber responds after receiving the call progress message from the called subscriber. A fourth step (32 to 39) received by the SCC block to complete call setup; After performing the fourth step (32 to 39), when the call is requested by the subscriber, it returns the resources occupied when the call is set up and completes the call, and there is no call in progress to the set signal channel in the network or the release of the signal channel is performed. And a fifth step (40 to 43) in which the signal channel release is completed by receiving the AAL release confirmation primitive and returning the signal channel being set, if required. tea. A. in the ATM exchange system. tea. M. A matching method between the adaptive sublayer (AAL) and the call control layer.