KR100233677B1 - Incomming calls emulation method in atm switching system - Google Patents

Abstract

The present invention relates to a method of emulating a call for testing in a user transfer network (ATM) user-network interface (UNI).

This method of the present invention is provided with a plurality of subscriber switching subsystems (ALS) capable of accommodating a plurality of subscribers, and in an ATM switching system equipped with a processor for controlling the subscriber switching subsystem, when a test command is inputted, Determining (801) whether an incoming call emulation command is present; Generating a call setup message (802) if it is an emulation command; Inputting the calling number information into the generated call setup message (step 803); Generating 804 an incoming process by the number of calling parties; And killing all incoming processes if the emulation termination command is executed, and processing and displaying statistical data (805 to 808).

Therefore, the incoming call emulation method according to the present invention can generate a large number of incoming calls without using a separate test device for the testing of the ATM exchange, it is easy to test during maintenance.

Description

Incoming Call Emulation Method in ATM Switching System

The present invention relates to a method for emulating a call for testing in a user transfer network (ATM) user-network interface (ATM), in particular, using a DSS2 application program. A method of emulating an incoming call.

With the rapid development of the information society, users' communication service demands have increased, and the "B-ISDN" has emerged as the next-generation communication network.B-ISDN can accommodate not only narrow band but also various services of broadband regardless of band and speed. The ATM method, which is an asynchronous delivery mode, is used as the basic means of delivery.In order to process the ATM signal, standards such as Signaling AAL, Q.2931, and B-ISUP are being decided one after another.

That is, in the conventional ISDN (also referred to as narrowband (N) -ISDN), the transmission rate of a channel carrying user information was about 64 Kbps to about 2 Mbps, so it was difficult to satisfy broadband services such as moving pictures. On the other hand, B-ISDN can transmit data at high speed of 100Mbps or more, and can process various information sources such as voice, data, document, and video by using ATM technology.

In the conventional N-ISDN, a signaling method for realizing access control uses Digital Subscriber Signaling System 1 (DSS1) in the subscriber line section and No.7 common line signaling method in the inter-station relay section. "DSS1" implements the protocols of Layer 2 and Layer 3 on the D channel, also called Link Access Procedure on the D-channel (LAPD), and is recommended by ITU-T specifications Q.921 and Q.931. It became.

On the other hand, B-ISDN, which is currently being promoted, adopts Q.2931, which expands by adding functional elements of asynchronous transfer mode (ATM) to Q.931 as the signaling procedure of user network interface (UNI), and the network-node interface (NNI). B-ISUP (ISDN User Part) has been proposed as a signaling procedure.

The B-ISDN is implemented based on the ATM communication method, and a switch that can accommodate the subscriber of the ATM method is being developed. In order to test the subscriber call processing block in such an ATM exchange, a test apparatus that emulates an incoming call together with a device capable of generating a large number of calls was used separately.

By the way, there is a very inconvenient problem because the device for emulating the incoming call is very expensive, and you have to carry it with you during the test.

Accordingly, the present invention has been made to solve the above problems, and an object thereof is to provide a method for emulating an incoming call for testing in an ATM exchange.

The method of the present invention for achieving the above object, ATM switching system is provided with a plurality of subscriber exchange subsystem (ALS) that can accommodate a plurality of subscribers, and a processor for controlling the subscriber switching subsystem The method comprising: determining whether an incoming call emulation command is input when a test command is input; Generating a call setup message if it is an emulation command; Inputting calling number information into a generated call setup message; Creating an incoming process by the number of subscribers; And if the emulation end command, kills all incoming processes and processes and displays statistical data.

1 is a conceptual diagram illustrating a general ATM protocol reference model;

2 is a diagram illustrating a general B-ISDN call control protocol stack;

3 is a format diagram showing the structure of an ATM cell;

4 is a diagram illustrating an example of a call processing related message flow in an ATM user network interface (UNI);

5 illustrates a general format of a call processing related message in an ATM UNI;

6 shows a general format of the information element shown in FIG. 5;

7 is a diagram showing the structure of an ATM switch suitable for application of the present invention;

8 is a flowchart illustrating a method of emulating an incoming call at an ATM exchange in accordance with the present invention.

* Explanation of symbols for main parts of the drawings

10: exchange system 11: number translation processor (NTP)

12: Network Access Processor (INP) 13-1 to 13-n: Access Switching Processor (ASP)

14: Man Machine Processor (MMP) 15,232: Operation and Maintenance Processor (OMP)

17: personal computer 210: ATM local exchange / subscriber subsystem

220: ATM local exchange / trunk system 230: ATM central exchange subsystem

240: workstation (W / S) 233: cell multiplexing and demultiplexing block (CMDH)

234: S-bus matched communication block (SPCA) 235: ATM main processor block (AMPA)

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

First, the ATM method to which the present invention is applied will be briefly described to facilitate understanding of the present invention.

1 is a conceptual diagram illustrating an ATM protocol reference model, which is composed of a management plane, a control plane, and a user plane, and the management plane is divided into hierarchical management and plane management. Here, the plan management refers to the overall management of the system, and the hierarchical management refers to management of resources and usage variables and OAM information management.

In addition, the control plane manages call control and access control information, and the user plane manages the transfer of user information. Protocols of the control plane and user plane are divided into upper layer, ATM adaptation layer, ATM layer, and physical layer. The functions of each layer are shown in Table 1 below.

TABLE 1

Functions of Each Layer in the Protocol Criteria Model

As shown in Table 1, the ATM method is divided into vertical structures such as a physical layer, an ATM layer, an ATM adaptation layer (AAL), and a higher protocol layer, and the AAL layer is a segmentation and recombination sublayer (SAR). And Reassembly sublayer (CS) and Convergence Sublayer (CS) sublayer is divided again, the physical layer is divided into physical media (PM) and Transmission Convergence (TC) sublayer.

In addition, the user network interface (UNI) is implemented in Q.2931 in the third layer of the control plane to control the call and connection between the ATM network and the user. ITU-T proposed basic call / used by the User-Network Interface (UNI) Layer 3 for B-ISDN as a higher standard of Q.93B that extends ISQ's Layer 3 protocol, "Q.931". User Network Interface Layer 3 Specification for Basic Call / Connection Control. The network interface (NNI) is implemented as B-ISUP at layer 3 of the control plane, and the related ITU-T specifications are Q.2761 to Q.2764.

Next, look at the call control protocol standards of the B-ISDN to which the present invention is applied.

As shown in FIG. 2, the UNI call control protocol is defined as Q.2931 at the user network interface (UNI), and the service specific connection orientation protocol (SAAL SSCOP) of the signal AAL layer is Q.2130. And Q.2110, where the AAL Service Specific Coordination Function (SSCF) is set to I.363, the ATM layer is I.361, and the physical layer is I.432.

In addition, if you look at the specification at the network node interface (NNI), the user part (B-ISUP: B-ISDN User Part) is Q.2761 to Q.2764, and the message transfer part (B-MTP: B-ISDN Message Transfer Part). 3 is defined as Q.2210, SAAL SSCOP as Q.2140 and Q.2110, respectively, AAL SSCF layer as I.363, ATM layer as I.361, and physical layer as I.432. Comparing these protocols with the corresponding layers of OSI, Q.2931 and Q.2761 through Q.2764 correspond to OSI layer 3, SAAL SSCOP and AAL SSCF correspond to OSI layer 2, and ATM and physical layers are OSI. Corresponds to Layer 1.

That is, the Q.2931 message of Layer 3 is segmented by 48 bytes (hereinafter referred to as Octet) length through SSCOP, SSCF, CPCS of Signaling AAL 5, and then ATM layer. After the 5 byte header is added, the data is mapped and transmitted to a plurality of 53 byte ATM cells.

FIG. 3 is a diagram illustrating a general ATM cell format, which is divided into a 5-byte header and a 48-byte payload, and a 5-byte header structure used in a user interface (UNI) is shown in FIG. One byte consists of four bits of Generic Flow Control (GFC) and four bits of Virtual Path Identifier (VPI), and the second byte consists of four bits of Virtual Path Identifier (VPI) and four bits. It consists of a Virtual Channel Identifier (VCI), the third byte is composed of 8-bit virtual channel identifier (VCI), the fourth byte is a 4-bit virtual channel identifier (VCI) and 3 bits paid Payload Type (PT) and 1-bit Cell Loss Priority (CLP), and the fifth byte consists of 8-bit Header Error Control (HEC).

FIG. 4 is a diagram illustrating an example of a call processing related message flow in an ATM user network interface (UNI), between a calling party (1), a network (2), and a called party. Indicates the call processing process.

First of all, a virtual channel connection (VCC) is always formed through a signaling adaptation layer (Signalling ALL) for call and connection control, and the payload (user) is transferred as call / access control messages flow through the virtual channel. data) As it controls the connection for forwarding, the message used for call / access control is the message for B-ISDN call / access control, and the call between N-ISDN and B-ISDN as shown in Table 2 below. There are messages used for access control, and messages used for global call references.

TABLE 2

Messages Used to Control B-ISDN Calls and Access

In FIG. 4, the messages in Table 2 generated according to Q.2931 are transmitted using the 'AAL-DATA-REQUEST' primitive of the signaling AAL (SAAL).

The originator (1) generates a "SETUP" message to set up the call, then transfers it to the network via the assigned signaling virtual channel (VCI = 5) and simultaneously starts the timer T303 and calls "Call." Initiated state. " In this case, the "Setup" message includes a call reference, various information elements required for call processing (for example, called part number, ATM user cell speed, broadband bearer capability, and quality of service parameters (QoS). Etc.). If there is no response for the time set by timer T303, the " setup " message is retransmitted, and if there is no response even after repeating the predetermined number of times, call processing is stopped.

After receiving the "Setup" message, the network 2 selects and assigns a valid connection identifier (VPCI / VCI), and then sends a "SETUP" message back to the called party 3 and then calls "CALL." PROCEEDING) "message to the sender (1). At this time, when the caller 1 receives the " call procedure " message, the caller 1 stops the timer T303, starts the timer T310, and enters an outgoing call procedure state.

The called party 3 receives the "Setup" message and then sends the "CALL PROCEEDING" and "ALERTING" messages to the network 2, which receives the alerting message. It is then delivered to the caller 1 and is in the "Call Delivered" state, and when the caller 1 receives the "alerting" message, it stops the timer T303 or T310 and enters the call deliberate state.

When the called party 3 generates a "CONNECT" message to allow the connection and transmits it to the network 2, the network 2 transmits it to the sender 1 as well as the "connect acknowledgment (CONNECT) ACK) " message to the called party 3 side, and receives a " connect acknowledgment " message from the sender 1;

Through the call processing process as described above, a communication path (connection) given as a connection identifier (VPCI / VCI) is formed between the caller 1 and the called party 2 so that data can be exchanged.

On the other hand, after the data transfer is finished or in transit, the user (recipient or caller) who wants to release the connection generates a "Release" message and starts the timer T308 to request the network to release the connection. When the "Release Request staste" state is received, the network disconnects the virtual channel upon receiving a "Release" message, and sends a "Release" message to the other party, informing them of the "RELEASE COMPLETE" message. Is passed to the release request and placed in the "NULL" state.

When the user (sender or called party) requesting the disconnection receives the "RELEASE COMPLETE" message, the timer T308 is stopped, the virtual channel, the call number, etc. are released and the status is "NULL". .

At this time, the user or network can generate a "STATUS ENQUIRY" message at any time to request information about the network or other user's status, and the user or network receiving the "STATUS ENQUIRY" message can Produce your status by generating a "STATUS" message.

5 is a diagram illustrating a general format of a call processing control related message in an ATM user interface (UNI), in which 1, ..., 8 at the top represent bits, and 1,2, ... 9, at the right side. etc indicates octets (bytes).

As shown in Figure 5, the first octet is a protocol discriminator, where Q.2931 is "0000,1001b", bits 8-5 of the second octet are "0000b", and bits 4-1 are The length of the call reference value is expressed in octets, and is generally "0011b". The third to fifth octets represent a call reference value, and in particular, if bit 8 of the third octet is a "0" as the call reference flag, it is from the side (typically, the originator) that generates the call reference. (from) Indicates the message to be sent, and "1" indicates the message to be sent to the party (typically the originator) that generates the call reference. The sixth and seventh octets indicate message type related information, and the messages are classified according to the sixth octet value.

Further, bit 8 of the seventh octet indicating message type related information is normally "1b" as an extension, bits 7 and 6 are "00b" as a spare, and bit 5 is "0b as a message type flag Flag. "Indicates that the message instruction field is not important, and" 1b "follows an explicit instruction. Bits 4 and 3 are spares with "0b" respectively, bits 2 and 1 are message action indicators (Msg. Action Indicator), if "00b" indicates a clear call, and "01b" gives up. And Discard and ignore, " 10b " represents Discard and report status, and " 11b " is reserved.

In addition, the eighth and ninth octets may indicate a message length and may have a maximum length of 64K (2 ¹⁶ ) octets, followed by an information element of variable length from the tenth octet (etc). .

6 is a diagram illustrating a general format of an information element (IE) included in an ATM UNI message, in which 1, ..., 8 at the top represent bits, and 1, 2,. 5, etc represents an octet (byte).

In FIG. 6, the first octet is an information element identifier, and information elements are classified according to the value.

In addition, in the second octet, bit 8 is "1b" as an extension, bits 7 and 6 are coding standards, and bits 5 to 1 are IE Instruction Fields. In the IE command field, bit 5 is a flag, and bits 3 to 1 are IE action indicators (IE Action Ind.), For example, "000b" indicates a clear call, and "110b" indicates message abandonment and status reporting. (Discard message, and report status). The third and fourth octets indicate a length of information element (L), and the contents of the information element follow the fifth octet (etc).

On the other hand, the structure of a general ATM switch suitable for the present invention is largely shown in Figure 7, ATM local switching / subscriber (ALS / S: ATM Local Switching / Subscriber subsystem; 210), ATM local exchange / trunk ( ALS / T: ATM Local Switching / Trunk subsystem (220), ATM Central Switching Subsystem (ACS) 230.

In addition, the ALS / S 210 includes as many Subscriber Interface Modules (SIMs) 211 and 212 as the number of subscribers, and an Access Switching Network Module (ASNM) to accommodate the SIMs 211 and 212. Call & Connection Control Processor (CCCP: 214) for controlling the system, ALS / T 220 is a trunk interface module (TIM: 221, 222) and accommodates as many trunks An Access Switching Network Module (ASNM) 223 and a Call & Connection Control Processor (CCCP) 224 for controlling a subsystem.

In addition, the ACS 230 includes an interconnection switch network module (ISNM) and an operation preservation processor (OMP: 232), and the OMP 232 is a cell multiplexing and demultiplexing block (CMDH: Cell). Mux / Demux H / W Assembly, SCA interface processor communication board assembly (SPCA) 234, ATM main processor board assembly (AMPA), and AMPA (235) Disk 236, cartridge tape (CT: 237), and the like.

The SPCA 234 is composed of a control memory, a SAR layer chip, an EPROM, a taxi transmitter, and a taxi receiver to connect the S-bus device to the exchange system in a TAXI manner.

Operation and maintenance related functions in the ATM switching system are mostly accommodated on the OMP 232, and the AMPA 235 and the workstation (W / S: 240) are connected to the Ethernet 242 to allow the operator to control various states of the system. It can be checked or controlled.

Next, the call generation method according to the present invention based on the above understanding as follows.

According to the present invention, a method for emulating an incoming call includes, as shown in FIG. 8, a step 801 of determining whether an incoming call emulation command is input when a test command is input; Generating a call setup message (802) if it is an emulation command; Inputting the calling number information into the generated call setup message (step 803); Generating 804 an incoming process by the number of calling parties; And killing all incoming processes if it is an emulation termination command, processing and displaying statistical data (805 to 808).

In order to evaluate the performance of the subscriber block, if an incoming call emulation start command is input, a call setup message is generated. Since the call setup message has a format as described above and requires call number information, the appropriate call number information is inserted into the generated message. Then, the incoming process is created.

If the emulation end command is input, the incoming process is killed and then statistically processed, and the processed result is displayed. In this way, the traffic processed through the incoming call emulation can be used to evaluate the performance of the subscriber block.

As described above, the incoming call emulation method according to the present invention can generate a large number of incoming calls without using a separate test device for the test of the ATM exchange, it is easy to test during maintenance.

Claims (1)

In the ATM switching system having a plurality of subscriber switching subsystems (ALS) capable of accommodating a plurality of subscribers, and having a processor for controlling the subscriber switching subsystem, Determining whether an incoming call emulation command is input if a test command is input; Generating a call setup message if it is an emulation command; Inputting calling number information into a generated call setup message; Creating an incoming process by the number of originating subscribers; And If the emulation terminate command, kills all incoming processes, and processes and displays statistical data.