KR20030094971A - ATM path test apparatus and method by user packer - Google Patents

Abstract

PURPOSE: A device for diagnosing an ATM network by using a user packet is provided to form the user packet in cell type by using an ATM loop function and an echo function, and to analyze a received packet, thereby diagnosing an error caused in a processor. CONSTITUTION: Test layers(210,230) comprise as follows. Cell generators(213,233) create test packets for diagnosing a path between terminals, and transmit the test packets in cell type. Transmitters(217,237) transmit test cells to a destination terminal. Receivers(219,239) receive response cells retransmitted from the destination terminal. Cell analyzers(215,235) analyze the response cells, and diagnose an ATM network. Timers(211,231) measure transmission and reception time, and calculate time delay.

Description

ATM network test apparatus and method using user packet {ATM path test apparatus and method by user packer}

The present invention relates to a network management method in an Asynchronous Transfer Mode (ATM) system, and more particularly, to an ATM network diagnosis apparatus and method using a user packet for diagnosing an abnormality of a network path with a user packet.

Existing switching networks handled only voice-oriented services, but the introduction of accumulated program control and common line signaling enabled not only to provide various services, but also to improve economics and service quality through digitalization of exchanges. The ISDN service of 64Kbps system incorporating packet exchange is enabled.

However, as the user's demand for information and communication services is gradually advanced to the trend of advancement, diversification, and personalization, high speed and large capacity such as moving images are required. By satisfying the quality required for each of these various types of services and accommodating all services in a single, economical communication network, the exchange technology necessary for the broadband broadband information communication network (B-ISDN) that can process narrowband ISDN services and high-speed broadband video services without restriction. Based on ATM defined by the CONSultative Committee on International Telephone and Telegraphy (CITT), the company introduced the concept of virtual channel switching in the existing fixed channel switching scheme by complementing the advantages of circuit and packet switching.

ATM transfers information using a fixed length (53 bytes) information block called a cell by using the Asynchronous Time Division Multiplexing (ATDM) method. ATM is a conceptual method of packet transfer mode and synchronous transfer mode (STM). It is a new delivery mode in the middle position.

In the ATM method, channels are allocated only when necessary according to the presence or absence of information for each access channel, so that STM can increase transmission efficiency compared to a fixed channel assignment. However, there is a disadvantage that the processing function is complicated by the addition of the header.

The ATM network management is performed by using five layers of operation, administration and management (OAM) cell flows, and each layer's OAM cells have a pre-assigned cell header form.

In this case, the OAM refers to a network management function group that provides network fault indication, performance information, and data and diagnostic functions, and is an ATM forum regulation for a cell used to monitor a virtual circuit.

ATM network management, performed by sending OAM cells on an end-to-end or segment basis, provides performance monitoring to monitor the normal operation of network management objects continuously or periodically, and continuously or periodically. Defect detection to detect abnormal behavior of the network, system protection for isolation or removal of fixed objects, transmission of defects and monitoring information to deliver performance or failure information to managed objects, and determination of the location of failure objects. Positioning and the like.

The basic configuration of the OAM cell as described above is as shown in FIG.

1 is a diagram illustrating the structure of an OAM cell.

Referring to FIG. 1, the header of 5 octets, the OAM type field indicating the type according to the OAM function is 4 bits, the function type field indicating the function in each OAM type is 4 bits, and the function designation field is 45 octets. It consists of an unspecified 6-bit unspecified field and an 10-bit EDC field for error checking.

In particular, the OAM type field designates an OAM function such as fault management, performance management, activation / deactivation, and system management. According to the OAM type field, has a function type of an Alarm Indication Signal (AIS), a Remote Defect Indication (RDI), a continuity check, and a loopback according to the OAM type field, and occurs in an ATM network using the AIS signal and the RDI signal. Detects link faults and failures, and VPI / VCI management errors can be detected using loopback. A continuity test can be performed to check whether a connection is malfunctioning.

The network diagnosis function using the OAM cell is defined in the International Telecommunications Union-Telecommunication Standardization Sector (ITU-T) I.610 standard and checks the reliability of the physical layer.

However, as described above, the method of diagnosing an ATM path using an OAM cell can only test the physical layer, and there is an unknown problem in the case of a poor connection in the network or a connection error of an internal processor of the system terminal. Occurs.

In addition, the intermediate network should be configured according to a standardized principle, and intermediate processing routines should be included in the network board, and each processor should have an internal processing routine, that is, a routine capable of analyzing an OAM cell.

An object of the present invention is to use the ATM loop function and the echo function provided by the communication processor to transmit the user packet in the form of a cell, and to analyze the received packet to diagnose the error at the processor as well as the test at the physical layer. An object of the present invention is to provide an ATM network diagnosis apparatus and method using a user packet for verifying a section interval of each physical layer.

1 is a diagram showing the structure of an OAM cell.

Figure 2 is a block diagram showing the configuration of an ATM network diagnostic apparatus using a user packet according to an embodiment of the present invention.

3 is a diagram illustrating a configuration of a test packet for diagnosing an ATM network using a user packet according to an exemplary embodiment of the present invention.

4 is a flowchart illustrating an operation procedure of an ATM network diagnosis method using a user packet according to an embodiment of the present invention.

<Brief description of the main parts of the drawings>

211 and 231: Timer 213 and 233: Cell generator

215, 235: cell analyzer 217, 237: transmitter

219, 239: receiver 210, 230: test layer

ATM network diagnostic apparatus using a user packet according to the present invention,

A cell generator for generating a test packet for diagnosing a path between terminals of an ATM system and transmitting the test packet in a cell form;

A transmitter for transmitting a test cell transmitted from the cell generator to a destination terminal through an ATM network, and a receiver for receiving a response cell retransmitted in the destination terminal;

A cell analyzer for diagnosing an ATM network by analyzing a response cell received by the receiver;

And a test layer including a timer for measuring time transmission and response time of the test cell and calculating a time delay.

Preferably, the test packet to form the test cell,

A value indicating that the packet is for testing, a sender address value, a receiver address value, a packet length value, a value indicating the type of test, a value indicating the sequence number of the test packet, and an error checking value Characterized in that comprises a.

In addition, the ATM network diagnostic method using a user packet,

Generating a test packet from a calling terminal to a destination terminal to be tested, converting the test packet into a test cell, and transmitting the test packet;

And waiting for a predetermined time for the response cell to the transmitted test cell, analyzing the received response cell, and determining whether there is an abnormality in the network.

Preferably, the terminal receiving the test cell,

Determining whether the test cell is a destination of the test cell, and analyzing the test cell when the track is the destination of the test cell;

And resending a response cell by using a reception address field of the test cell as a calling party terminal address.

Preferably, when receiving the test cell,

The method may further include looping back to the destination terminal when the destination of the test cell is the own station.

Preferably, if the response cell is not received for a predetermined time or if the network abnormality is determined by analyzing the response cell, it is determined whether the internal connection is normal by using a loop test in the terminal,

And determining whether there is an error in the physical layer by using an echo function of the counterpart terminal.

Preferably, when the response cell is not received for a predetermined time or when the abnormality of the network is determined by analyzing the response cell, when transmitting and receiving a cell through the network board between the two terminals, the network using a loop test of the network board It is characterized by determining whether there is an abnormality.

Preferably, when performing the test with respect to the path with all the connected terminals,

Each test packet is generated and transmitted according to a destination terminal of all paths.

The ATM network diagnosis apparatus and method using a user packet according to the present invention configured as described above will be described with reference to the accompanying drawings.

2 is a block diagram illustrating a configuration of an ATM network diagnosis apparatus using a user packet according to an exemplary embodiment of the present invention.

Referring to FIG. 2, an ATM terminal further includes test layers 1 and 2 (210 and 230) layers for network diagnosis between terminals on top of physical layers 1 and 2 and AAL5 1 and 2.

In particular, the test layers 1 and 2 (210 and 230) are cell generators 1 and 2 (213 and 233) for generating test packets for network diagnosis and transmitting them in a cell form, and the cell generators 1 and 2 ( Transmitters 1, 2 (217, 237) for sending the test cells transmitted from the 213, 233 to the destination terminal, Receivers 1, 2 (219, 239) for receiving the cell transmitted from the other terminal, and the receivers 1, 2 Cell analyzers 1, 2 (215, 235) for analyzing the cells received at (219, 239), and timers 1, 2 (211, 231) for measuring the time until the response of the transmitted test cell arrives. It is configured to include.

In order to diagnose a network between the ATM terminals configured as described above, when a test packet is generated by the cell generator 1 213 and transmitted in the form of a cell through the transmitter 1 217 (S201), another terminal is connected through the network board 250. (S203), when the other terminal receives the cell at the receiver 2239 and receives the packet and transmits the packet to the cell analyzer 2 235, the destination of the cell received by the cell analyzer 2 235 is owned. If it is determined that the destination is the own station, a response packet is sent to the transmission unit 2 (237) (S205), so as to be transmitted again to the first terminal that transmitted the test cell (S207, S209, S211).

In this case, the response packet transmits the received test packet as it is to the first terminal only.

In addition, the packet analysis unit 1 215 may analyze the response packet, that is, the returned packet, to diagnose the network state, and determine the time delay using the return time of the packet transmitted from the timer 1 211.

The configuration of the test packet is as follows.

3 is a diagram illustrating a configuration of a test packet for diagnosing an ATM network using a user packet according to an exemplary embodiment of the present invention.

Referring to FIG. 3, a test packet includes a field indicating four octets indicating that the current packet is a test packet, and includes a source address field for sending a packet, a destination address field for a destination, and an entire packet. A field indicating length information and a field indicating a type of test indicating whether the packet is to be tested for connectivity or functional check are each composed of 4 octets, a data field containing dummy data of a test packet, and a sent test. In order to check whether the packets are sequentially received, a field having sequence information assigned to each packet and a CRC field for error checking are included.

The test packet is converted into the cell type used in the ATM network and transmitted to the destination.

4 is a flowchart illustrating an operation procedure of an ATM network diagnosis method using a user packet according to an exemplary embodiment of the present invention.

Referring to FIG. 4, a test packet is created and transmitted in a test layer 1 210 of an originating terminal for a network test. First, it is determined whether to test a path between one destination terminal or test all connected paths. In step S401, in order to perform a path test between one destination terminal, that is, a point to point test, a test packet is configured using the reception address field of the test packet as a reception terminal (S403) and transmitted (S405).

In addition, for testing all connected paths, that is, point to multi test, a packet having a different destination address is configured according to the final destination of each path (S403) and transmitted (S405).

The test packet transmitted from the above is converted into a cell form and transmitted to a destination along an ATM network, and the terminal receiving the test packet determines whether the local station is the destination of the test packet (S407). Loops to the destination (S409), and if the destination of the test packet of the own station, the cell analysis unit analyzes the cell (S411) to determine whether the packet is transmitted, whether or not the path is normal, and analyzes the time information with the counterpart terminal. Communication delay can be seen.

In addition, after analyzing the test packet, the test packet is transmitted again to the calling terminal that sent the first test packet in the form of a response packet (S413) so that the terminal may attempt to test the path state by analyzing the normality of the path and time information. do.

On the other hand, the originating terminal that transmits the test packet waits for a response packet for a certain time, and if a response packet is not received for a predetermined time, determines that there is an error in the path, so that the processor in the terminal is normal and the internal connection is normal. Check using the test function (a).

In addition, if the test packet is transmitted through the network board, the connection state may be checked using a loop of the network board (b), and even the physical layer error of the other party may be checked using the echo function of the other terminal terminal processor (c). ).

As described above, the ATM network diagnosis apparatus and method using the user packet according to the present invention, by making and transmitting the user packet as a packet for the test, to diagnose the network, the diagnosis of the physical layer, as well as the loopback function and echo of the communication processor By using the function, the connection error in the terminal and the physical layer error check of the other terminal, as well as the physical layer of each section can be confirmed the error.

Claims (8)

A cell generator for generating a test packet for diagnosing a path between terminals of an ATM system and transmitting the test packet in a cell form; A transmitter for transmitting a test cell transmitted from the cell generator to a destination terminal through an ATM network, and a receiver for receiving a response cell retransmitted in the destination terminal; A cell analyzer for diagnosing an ATM network by analyzing a response cell received by the receiver; Device for diagnosing ATM using user packets, characterized in that it comprises a test layer comprising a timer for measuring the time delay of the transmission and response time of the test cell. The test packet of claim 1, wherein the test packet for forming the test cell comprises: A value indicating that the packet is for testing, a sender address value, a receiver address value, a packet length value, a value indicating the type of test, a value indicating the sequence number of the test packet, and an error checking value ATM network diagnostic apparatus using a user packet, characterized in that comprises a. Generating a test packet from a calling terminal to a destination terminal to be tested, converting the test packet into a test cell form, and transmitting the test packet; Waiting for a response cell for the transmitted test cell for a predetermined time, analyzing the received response cell, and determining whether there is an abnormality in the network. The method of claim 3, wherein the terminal receiving the test cell, Determining whether the test cell is a destination of the test cell, and analyzing the test cell when the track is the destination of the test cell; And retransmitting a response cell by using a reception address field of the test cell as a calling party terminal address, and retransmitting the response cell. The method of claim 3, wherein upon receiving the test cell, Determining whether the destination of the test cell is the own station, and if the station is not the local station, looping back to the destination terminal. The method of claim 3, wherein if the response cell is not received for a predetermined time or if an abnormality of the network is determined by analyzing the response cell, it is determined whether the internal connection is normal by using a loop test in the terminal. The ATM network diagnostic method using a user packet, characterized in that further comprising determining the presence or absence of errors in the physical layer using the echo function of the other terminal. 7. The method of claim 6, wherein when a cell is transmitted / received through the network board between the two terminals, it is determined whether there is a network error by using a loop test of the network board. The method of claim 3, wherein the test is performed on a path with all connected terminals. ATM network diagnostic method using a user packet, characterized in that to make and transmit each test packet according to the destination terminal of all paths.