KR20000056824A - Call Setup Method In ATM Network - Google Patents

Abstract

PURPOSE: A method for setting up calls in an asynchronous transfer mode(ATM) network is provided to set up a virtual path connection identity(VPCI) connection of an ATM level passing through many relay nodes, by passing through the relay nodes having high call setup request frequencies or by transceiving call setup messages for VPCI tunneling between a node designated by a network manager and other nodes. CONSTITUTION: A method for setting up calls in an asynchronous transfer mode(ATM) network comprises the steps of: passing through many relay nodes having high call setup frequencies, or setting up a virtual path connection identity(VPCI) connection of an ATM level passing through the relay nodes between a designated node and other nodes; analyzing a call setup message received from a terminal, and if the message is a call setup request from a terminal managed in a VPCI connection setup node, transmitting the message to a receiving node through the VPCI connection; and receiving the message to analyze the message, and transmitting a reception requesting message to the receiving terminal.

Description

Call Setup Method in ATM Network

The present invention relates to a call setup method in an ATM (Asynchronouse Transfer Mode) network. In particular, a virtual path connection indentify (VPCI) connection is established between a node and a node, and a call between terminals managed by each node through the established VPCI connection. The present invention relates to a call setup method in an ATM network for performing a setup operation.

In general, ATM network services are classified into a Connection Oriented (CO) service and a ConnectionLess (CL) service. The connected service is a service that establishes a connection between originating and receiving terminals in advance. SVC that decides VPI / VCI by call control sequence immediately before communication according to call setting request of originating terminal and PVC (Permanent Virtual Connection) service which fixedly allocates / VCI (Virtual Path Indentifier / Vitual Channel Indentifier) There is a Switched Virtual Connection service.

On the other hand, the ATM PVC service in the ATM network always establishes a virtual channel connection between users at the time of service contract and communicates using the established connection, and the VPI / VCI value for identifying the virtual channel is directly connected to the other party's path. The VPI / VCI value is called the User Network Interface (hereinafter referred to as 'UNI') and the Network Interface within the ATM Network (hereinafter referred to as 'NNI'). And destination party UNI are determined independently. For example, as shown in FIG. 1, when user A sends information to user B, it transmits to a cell having VPI / VCI = 1, but user B receives a cell value of VPI / VCI = 3. As such, ATM PVC service is provided only by the physical layer and ATM layer functions.

In addition, the ATM SVC service establishes a virtual channel between originating and receiving terminals by a call control procedure every time communication starts, and releases the virtual channel used at the end of communication. Every time you allocate dynamically. In this case, the call connection and disconnection is performed by the signaling protocol (Q.2931, etc.) for the UNI, and the signaling protocol (B-ISUP) for the NNI, so that communication with any party is possible. Network resources can be used efficiently because connections are established by specifying transmission quality and bandwidth.

Meanwhile, as shown in FIG. 2 attached between the terminal A and the terminal C in the conventional ATM network, when there are a plurality of nodes that provide an NNI, that is, a Broadband ISDN User Part (B-ISUP) protocol, the corresponding terminal is present. A call setup message processing operation according to a call setup request of A will be described with reference to FIG. 3.

First, when a call setup message (Setup) including all information necessary for call setup from terminal A to terminal C is transmitted to the originating node, the originating node analyzes the Q.2931 call setup message (Setup) transmitted from terminal A. Process, and generate an IAM1 (Initiate Address Message 1) message required for B-ISUP destination address according to the result, and transmit it to the corresponding relay node to request the relay line setting and continue to establish a call to the terminal A side. Send a Q.2931 Call Proceeding.

Then, the corresponding relay node analyzes and processes the received IAM1 message to set up the incoming line, and then sends a B-ISUP IAA1 (Initiate Address Allocation 1) message to the originating node to notify the incoming line setting and to the called node. A B-ISUP IAM2 message requesting the outgoing line is generated and transmitted to the called node.

Therefore, the called node analyzes and processes the received B-ISUP IAM2 message to set up the incoming line with the relay node, and then transmits the B-ISUP IAA2 message to the relay node to notify the incoming line setting, and the called terminal. When a C.2931 incoming request message (Setup) including information about the calling party terminal A is transmitted to C, a call progress message (Call Proceeding) indicating that the corresponding terminal C can continue to set up a call is sent to the called node. After the transmission, when the called party answers the call, it transmits a call connection message (Connect) indicating that the connection to the call has been established, to the called node.

Then, the called node generates a B-ISUP ANM1 (Answer Message 1) message as a call connection message (Connect) is received from the terminal C, and transmits the message to the corresponding relay node. When the ANM1 message is received, the corresponding ANM2 message is generated and transmitted to the originating node. Then, the originating node analyzes and processes the ANM2 message received from the relay node and sends a Q.2931 call connection message to the terminal A. By transmitting, call paths are formed between terminal A and terminal C respectively located at different nodes, that is, a destination node providing a network interface and a calling node, thereby providing communication services between each subscriber.

However, in the conventional ATM network as described above, a message transmitted and received between the originating node, the destination node, and the relay node to establish a call with the terminal C according to the originating request of the terminal A requesting an ISDN (Integrated Services Digital Network) service. At this time, each node checks the VPI / VCI included in the received UNI or NNI-related message, and selects an ATM layer that selects a path to the VPI / VCI of the corresponding output side physical link, and the corresponding physical link. A Signaling ATM Adaptation Layer (SAAL) layer that checks for normality, a Q.2931 layer that analyzes UNI related messages and reports the result to a Call Control layer or generates a message to be transmitted to a terminal; A call control layer for translating corresponding UNI or NNI related messages; There is an MTP3 layer responsible for routing NNI-related messages, and a B-ISUP layer that analyzes the corresponding NNI-related messages and reports the results to the call control layer, or generates a message to be sent to the next node. After the corresponding message is processed, the message is transmitted to the next node or the terminal, and thus the overall call setup time is delayed due to a long message processing time at each node.

That is, as shown in FIG. 2, the call setup with the terminal C according to the originating request of the terminal A is performed by the message processing in the layer 'Q.2931 → SAAL → ATM' of the terminal A and the 'ATM → SAAL' of the originating node. → Q.2931 → Call Control → B-ISUP → MTP3 → SAAL → ATM 'Message Processing and Relay Node's' ATM → SAAL → MTP3 → B-ISUP → Call Control → B-ISUP → MTP3 → SAAL → Message processing in the ATM 'layer, message processing in the' ATM → SAAL → MTP3 → B-ISUP → call control → Q.2931 → SAAL → ATM 'layer of the destination node and the' ATM → SAAL → Q. ' This is done through message handling procedures at layer 2931 '.

Therefore, in the corresponding ATM network, the call setup request frequency between the originating node and the destination node is high, and when passing through a plurality of relay nodes, there is a difficulty in routing management for determining a message transfer path between the nodes. By performing the message processing operation at each node, the call setup time between the calling terminal and the called terminal is further delayed, thereby degrading the quality of service for the subscriber.

In other words, in the conventional ATM network, there is a difficulty in routing management that determines a message forwarding path when a plurality of relay nodes are passed between originating and terminating terminals, and each node establishes a B-ISUP protocol for call establishment-related messages. There is a problem in that the overall call setup time is delayed by processing and transmitting to the next node.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a call setup message for VPCI tunneling between a node designated by a network manager and having a high call setup request frequency and a plurality of relay nodes. By transmitting and receiving, it is possible to establish a VPCI connection at the ATM level through a plurality of relay nodes between the nodes.

Another object of the present invention is to perform a call setup operation through a predetermined VPCI connection when a call setup request of a terminal managed by each node facilitates routing management in an ATM network and reduces overall call setup time. It is to make it possible.

1 is a diagram illustrating a multiple access state by VPI / VCI in a typical ATM PVC service.

2 is a diagram illustrating a message transfer path between a terminal A and a terminal C in a conventional ATM network.

3 is a diagram illustrating a call processing procedure between a terminal A and a terminal C in a conventional ATM network.

4 is a diagram illustrating a message transfer path between a terminal A and a terminal C in an ATM network according to the present invention.

A feature of the present invention for achieving the above object is, in the call setup method in the AMT network, the call setup request frequency is high and through a plurality of relay nodes, or relay node between the node and the node designated by the network manager Establishing a VPCI connection at the ATM level via the network; After analyzing / processing the call setup message received from the terminal, if the call setup request is made to the terminal managed by the node where the VPCI connection is established, the message is transmitted to the destination node through the VPCI connection of the ATM level via the relay node. Transmitting; And receiving and analyzing / processing the corresponding message, and transmitting the incoming request message to the called terminal.

On the other hand, in the process of establishing a VPCI connection of the ATM level, the originating node generates a call setup message for VPCI tunneling, exchanges the generated call setup message for VPCI tunneling with the relay node and the called node; It is characterized by establishing a VPCI connection at the ATM level via the relay node between the node and the destination node.

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

The ATM network according to the present invention provides an ATM SVC service for determining VPI / VCI according to a call control sequence immediately before communication according to a call establishment request of an originating terminal. In the corresponding ATM network, a call establishment request frequency between an originating node and a destination node is determined. Is high, and the call setup message for the VPCI (Virtual Path Connection Indentify) tunneling is exchanged between the originating node and the destination node through a plurality of relay nodes or by designation of the network manager. The VPCI connection is established via the relay node. That is, as the originating node transmits a call setup message for VPCI tunneling to the destination node, the VPCI connection is established between the corresponding originating node and the destination node, and logically adjacent nodes regardless of the number of relay nodes.

For example, in the case of having an ATM network configuration as shown in FIG. 4, a call setup message for VPCI tunneling generated at a corresponding originating node is transmitted to a called node in the same manner as the above call setup message processing operation at each node. A transport-level VPCI connection is established between the originating node and the destination node via the relay node.

Accordingly, when the calling node and the called node are recognized as virtually immediately adjacent nodes and request call setup from the terminal managed by the calling node to the terminal managed by the called node where the corresponding VPCI connection is established, the called node and the called node are called. The relay node, except the node, does not need to process the call establishment message, and can deliver the message to the next node through the VPCI connection of the preset ATM level.

Meanwhile, the call setup operation in the ATM network according to the present invention will be described in detail with reference to FIG. 4 as follows.

First, when a call setup message according to a call setup request is sent from a terminal A to an originating node managing itself, each layer of the corresponding originating node analyzes and processes the received call setup message and manages it at the called node where the VPCI connection is established. Check if the call establishment request to the terminal is requested.

If the VPCI connection is not a call setup request to the terminal managed by the set up destination node, the B-ISUP layer of the originating node generates an IAM message necessary for designating a destination address according to the call setup request, and then corresponds to a corresponding relay node. In this regard, the relay node and the called node analyze and process the received message according to a conventional call setup message processing operation to form a communication path between the corresponding terminal A and the called terminal to provide a communication service.

However, if the VPCI connection is a call setup request to the terminal managed by the established called node, that is, a call setup request to the terminal C, the B-ISUP layer of the corresponding originating node is required to designate a destination address according to the preset VPCI connection. After generating the IAM message, it is transmitted to the destination node through the relay node through the corresponding VPCI connection. At this time, the corresponding relay node does not need to process the message received through the VPCI connection and delivers it to the destination node through the VPCI connection of the preset ATM level.

Accordingly, the B-ISUP layer of the called node analyzes and processes the received IAM message and sends a Q.2931 call request message including information on the calling terminal A to the called terminal C, thereby receiving the call with the corresponding calling node. The call setup operation is performed through a predetermined VPCI connection between UE A and UE C located at each node, thereby reducing overall call setup time.

That is, the call setup with the terminal C according to the originating request of the terminal A, as shown in Figure 4, the message processing in the 'Q.2931 → SAAL → ATM' layer of the terminal A and the 'ATM → SAAL of the originating node → Q.2931 → Call control → B-ISUP → MTP3 → SAAL → ATM 'message processing, relay node's message relay at ATM layer, and destination node's ATM → SAAL → MTP3 → B-ISUP → Message processing in the call control-> Q.2931-> SAAL-> ATM "layer and the message processing procedure in the" ATM-> SAAL-> Q.2931 "layer of the terminal C.

Therefore, in the present invention, even when a plurality of relay nodes are established between an originating node and a destination node, if a first VPCI connection is established, each relay node does not determine a message forwarding path separately for subsequent call setup requests. It simply performs the message relay function, and the originating node can directly know the link state of the called node, so that routing management in the ATM network is easy.

If the VPCI tunneling between the originating node and the destination node is not necessary in the ATM network, the VPCI connection can be released by using a release message.

As described above, the present invention provides a high number of call setup requests in an ATM network, via a plurality of relay nodes, or by exchanging call setup messages for VPCI tunneling between nodes designated by a network manager. It is possible to establish a VPCI connection at the ATM level via the relay node.

In addition, when a call setup request of a terminal managed by each node is performed through a preset VPCI connection, routing management in an ATM network can be facilitated and the overall call setup time can be shortened.

Claims (2)

In the call setup method in the AT network, Establishing a VPCI connection at an ATM level via a plurality of relay nodes having a high call setup request frequency, or between a node designated by a network manager and a relay node; After analyzing / processing the call setup message received from the terminal, if the call setup request is made to the terminal managed by the node where the VPCI connection is established, the message is transmitted to the destination node through the VPCI connection of the ATM level via the relay node. Transmitting; Receiving and analyzing / processing the corresponding message, and transmitting the incoming request message to the called terminal. The method of claim 1, In the process of establishing a VPCI connection of the ATM level, the originating node generates a call establishment message for VPCI tunneling and exchanges the generated call establishment message for the VPCI tunneling with the relay node and the called node. And establishing a VPCI connection at the ATM level via the relay node between the destination node and the destination node.