KR100609685B1 - Apparatus for monitoring characteristics and quality of traffic in service in ATM network and method thereof - Google Patents

Abstract

In the ATM network according to the present invention, the apparatus for measuring the quality and quality of the traffic in service receives the traffic to be measured from the ATM network, converts the traffic into a first electrical signal if the traffic is an optical signal, and if the traffic is an electrical signal, performs impedance processing. At least one receiving unit for outputting a second electrical signal after the; A signal selector which receives at least one first electrical signal and a second electrical signal, respectively and selectively outputs one of the first electrical signals or one of the second electrical signals; And an analyzing unit configured to receive the first electrical signal or the second electrical signal and analyze an AAL type for each VCC to determine whether an ATM cell has an error. It is possible to analyze the signal status of specific optical / coaxial / twist pair line and the occurrence of traffic and error cell of ATM cell, so that the phenomenon and section can be identified immediately when a failure occurs, thereby improving the overall quality of service.

Line (optical, coaxial, twisted pair), no cutoff contacts, on-line quality of service measurements, ATM cell traffic characteristics

Description

Apparatus for monitoring characteristics and quality of traffic in service in ATM network and method according to the ATM network

1 is a block diagram illustrating an apparatus for measuring characteristics and quality of traffic in service in an ATM network according to the present invention.

Figure 2a is a view showing the configuration of an embodiment for providing a non-cutting contact of the optical line of the measuring device according to the present invention.

Figure 2b is a view showing the configuration of an embodiment for providing a non-cutting contact of the coaxial / twisted pair line of the measuring apparatus according to the present invention.

3 is a view for explaining a problem when the 2: 1 optical selector is configured in multiple stages.

4 is a diagram illustrating a problem in connecting a coaxial / twist pair line contact without a high impedance circuit.

5 is a diagram illustrating a criterion for defining an AAL type of a received ATM cell.

6 is a flowchart illustrating a procedure for calculating an AAL5 error cell for measuring a quality of service according to the present invention.

The present invention relates to an apparatus and method for measuring traffic characteristics and quality in service in an ATM network, and more particularly, to selectively measure a plurality of traffics without attenuation of traffic to be measured and without cutting off a line. An apparatus and a method thereof are provided.

Looking at the problem of measuring the traffic to be applied to the present invention for each signal as follows. First, we will look into the SDH and SONET series optical lines used in ATM networks.The optical lines combine low power and high sensitivity with light emitting / receiving elements with high power and high sensitivity to achieve no transmission distance. It can scale from tens of Km to hundreds of Km. The speed of the signal that can be transmitted through the optical fiber is composed of various forms. The conventional technical method for providing a disconnection point of an optical line is to distribute an optical signal to a splitter that distributes one signal to several ports, and then selects an optical signal to select a distributed line. This can be solved by configuring the selector in one or multiple stages. The optical signal selector has a function of outputting a specific optical signal to a terminal under the control of a control line among a plurality of optical signal inputs.

In this method, as the number of input terminals increases, the price increases rapidly, and it is difficult to manufacture, and when selecting among a large number of optical signal inputs, the optical signal selector can be configured in multiple stages as shown in FIG. Whenever a problem of attenuation of the optical signal occurs, it is difficult to apply. That is, when the optical signals input through the plurality of optical interfaces 301 are selected and output from the 2: 1 optical selectors 302 and 303, respectively, and the second 2: 1 optical selectors 305 are selected again (305). This is because attenuation occurs 304. Examples of such optical signals include signals mapped to STM-1 (155.520 Mbps) and STM-4 (622.028 Mbps) in the SDH (Synchrous Digital Hierarchy) level, and include OC-3 and OC-12 of SONET series.

Second, we look at the coaxial lines used in ATM networks. The coaxial line refers to a line composed of a core wire constituting a signal surrounded by a core wire having a ground potential. The coaxial line is a form in which a signal is amplified or noise is attenuated by applying a repeater at periodic distances. For coaxial lines, there are distributors like optical lines, but it is difficult to use when the exchange and transmitter in the same country are far apart due to the attenuation (0.5dB / contact point) of the terminal itself. There is inconvenience to move directly to the place. An example of this is a signal mapped to the DS3 (44.497 Mbps) class.

Now, the third is the twisted pair line used in ATM network. Twisted pair lines transmit symmetrical signals through two cores, and the two cores are twisted repeatedly. Twisted pair lines are primarily used for low-speed signals, and even splitters are not present for twisted pair lines, making it impossible to measure and monitor line conditions and signals and traffic data without cutting the line. Examples of these are signals mapped to DS1E (2.048 Mbps) and DS1 (1.544 Mbps) levels.

Finally, the signal status, traffic characteristics, and service quality of the service lines in the ATM network are examined. Conventionally, the signal state of the optical / coaxial / twist pair line connected to ATM exchanger is managed by the information collected by the receiving exchange, and the data traffic transmitted / received during the exchange can be managed by statistical data provided by the exchange. If the data traffic is not normally transmitted / received due to a failure or a switch failure, disconnect the transmission / reception or line of the test pattern, connect to the measuring equipment, and perform a test to identify the failure of the line or exchange. This method cannot be tested while the service is in normal operation, and it is impossible to identify the online service problem because the operator must manually connect the instrument and disconnect the line. In addition, even if the line is in a normal state, in order to improve the efficiency of ATM network resources, it is inevitably required to analyze the transmission and reception traffic characteristics and to stabilize the service quality.On-line service state is required for the traffic analysis and stabilization of the ATM node. It requires the measurement of ATM cell's transmit / receive ATM cell statistics, error cell extraction, circuit utilization and circuit state. However, statistical data provided by ATM exchangers can measure the exact quality (cell loss rate, cell error rate, misinserted cell error rate, etc.) and traffic patterns (peak cell rate, maximum burst size, burst tolerance, etc.) of the serviced line. Because there is no management capability, there is no way to measure and manage traffic patterns and quality of service on-line.

The technical problem to be solved by the present invention is to solve the above problems, the expensive price problem caused by applying the optical splitter and the optical signal selector of the optical line, the difficulty and signal attenuation problem, coaxial coaxiality in the multi-stage configuration of the selector It solves the problem of signal attenuation in multi-stage configuration of line splitter, cutting of twisted pair line for line monitoring, and extracts the signal status and traffic of transmission line connected to each switching period of ATM communication (switched) network. The present invention provides an apparatus and method for connecting a specific line to an instrument in an on-line state without cutting.

In order to achieve the above technical problem, an apparatus for measuring the characteristics and quality of traffic in service in an ATM network according to the present invention receives traffic to be measured from an ATM network, and converts the traffic into a first electric signal if the traffic is an optical signal. At least one receiver configured to output impedance as a second electrical signal after the impedance processing if the traffic is an electrical signal; A signal selector which receives at least one first electrical signal and a second electrical signal, respectively and selectively outputs one of the first electrical signals or one of the second electrical signals; And an analysis unit configured to receive the first electrical signal or the second electrical signal and analyze an AAL type for each VCC to determine whether an error occurs in an ATM cell.

According to an aspect of the present invention, there is provided a method of measuring characteristics and quality of traffic in service in an ATM network, the method comprising: receiving at least one traffic in service; Converting the traffic into a first electrical signal if the traffic is an optical signal, and connecting the parallel signal to a high impedance circuit if the traffic is an electrical signal, and amplifying the traffic into a second electrical signal; Selecting one of the at least one first electrical signal or one of a second electrical signal; And receiving the first electrical signal or the second electrical signal and analyzing an AAL type for each VCC to determine whether an ATM cell has an error.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to that, the outline of the present invention for each input signal will be described. In the case of an optical line, to solve the conventional technical problem, as shown in FIG. 2A, the optical signal is converted into an optical / electric signal, and the electrical signal is transmitted as an electrical / optical signal for transmitting to the input terminal of the exchange without loss, and the received electrical signal. Is applied by selecting the electrical signal selector 204, and converts the selected signal back to the corresponding signal to provide an apparatus.

In the case of the coaxial and twisted pair lines, there is an impedance matching problem for the contact connection as shown in FIG. 4. An apparatus for selecting through the analog selector 208 and amplifying and outputting the selected signal is provided.

And, under the above devices, it provides a method to measure / manage the quality of service by analyzing the ATM cell traffic patterns and errors of subscribers transmitted / received in the on-line state, which cannot be managed by statistical data provided by the ATM switch. .

After all, in the case of the optical line multi-input selection circuit through the apparatus and method according to the present invention, it is possible to configure the system at a low price and the attenuation problem caused by the multi-stage configuration, the attenuation problem of the splitter contact of the coaxial terminal, the twisted pair for the line monitoring It is possible to solve the conventional technical problems such as the disconnection of the line, and to measure / manage the real-time service quality and traffic type of the subscribers in the ATM network which did not exist in the past.

It will now be described in detail a preferred embodiment of the present invention in detail. 1 is a block diagram illustrating an apparatus for measuring the characteristics and quality of traffic in service in an ATM network according to the present invention, and FIG. 2a illustrates a configuration of an embodiment for providing a non-cutting point of an optical line in a measuring device according to the present invention. Drawing. And 2b is a view showing the configuration of an embodiment for providing a non-cutting contact of the coaxial / twisted pair line of the measuring apparatus according to the present invention.

The receivers 101-1 to 101-n have different configurations depending on the optical line and the normal line (coaxial and twisted pair lines), respectively. First, the receiver 101-k in the case of processing an optical signal will be described. The photoelectric conversion unit 201 receives a transmission side force of an exchanger or a transmission device by a general optical / electric conversion module device to confirm the existence of an optical signal and converts it into an electrical signal. The converted electric signal is transmitted to the all-optical signal converter 203 and the next signal selector 102 through the buffer unit 202 as a PECL (Pesudo Emitter Coupled Logic) signal. The all-optical converting unit 203 converts the received electrical signal into an optical signal and retransmits it to the optical input of the exchange (or transmission device). At this time, since the optical signal to be transmitted does not distribute the optical signal by a splitter or the like, no optical loss occurs and no attenuation occurs.

Now look at the case of a normal track (coaxial and twisted pair tracks), not a light path. This is shown in Figure 2b. The receiver 101-k is configured by connecting a high impedance circuit 204 in parallel to a general line as shown in FIG. 2B. Since the signal received from the connected high impedance circuit has a small amplitude due to the impedance ratio, the signal is amplified into an electrical signal having the same ratio as that of the line through the amplifier 207, and the amplified signal is an analog matrix for selecting an analog signal. 208).

The signal selector 102 receives signals transmitted from the plurality of receivers 101-1 to 101-n and selects a specific electric signal selected by the system controller 105. The electrical signal received and converted in the optical path is composed of a PECL signal for the reliable connection of the signal and selects a specific electrical signal through the digital signal selector 204. The configuration of the selector 204 is generally about 16: 1. When the receiver 101 is larger than that, the selector 204 can be expanded by configuring a first-stage electrical signal selection circuit in the photoelectric converter 201.

The electrical signals received on the normal line (coaxial and twisted pair lines) are composed of analog signals and select a specific electrical signal via analog signal selector 208. The selected signal is transmitted to the impedance matching unit 209 through the internal wiring of the system.

The selecting unit 102 for selecting an electric signal is operated by selecting a specific line of the control unit 105, and may select any specific line without reinstalling the measuring instrument. The selected electrical signal is also passed to the signal conversion 103.

The signal converter 103 is responsible for converting and receiving the received signals (optical line receiving electric signals and general lines (coaxial and twisted pair lines) receiving electric signals) into corresponding electric signals. That is, the optical signal reception electric signal is converted into an optical signal by the all-optical conversion circuit 205, and the general line (coaxial and twisted pair line) reception electric signal is transmitted through the prescribed impedance matching circuit. This converted and transmitted signal is connected to an external device (measurement device, etc.) or connected to the circuit analyzer so that the physical interface connection standards of STM-4 / 4c, STM-1, DS3, and DS1 / DS1E are satisfied. .

The circuit signal analyzer 104 monitors the physical state (frame state) of the received signal and the configuration bits of the overhead to monitor the signal synchronization state of the physical layer, and calculates the number of ATM cells transmitted and received by the payload unit. It is possible to extract statistics about maximum cell rate (PCR: Peak Cell Rate), sustained cell rate (SCR: Sustainable Cell Rate), and maximum burst cell size (MBS: Maximum Burst Size). Can be analyzed by VCC. These evicted data are only statistics on ATM cell traffic, and the presence or failure of an ATM cell is an important factor in evaluating the quality of the circuit. The present invention proposes a method for determining statistics and error cells of ATM cells of AAL1 and AAL5 types serviced in Korea. In the configuration as described above, the receiver 101 receives traffic in service (step 601). It is determined whether the traffic is an optical signal or a general line signal (coaxial or twisted pair line) (step 602), and if it is an optical signal, it is converted into an electric signal in a 101-k block, and if it is a normal line signal, it is high impedance processed and amplified ( Step 604). When a signal to be monitored for the converted signals is selected by the controller 105 (step 605), the AAL type is first determined to detect whether or not the received ATM cell is lost (step 606). If the sequence number is consecutive by checking the 8-byte value of the first field of the payload of AAL1, the AAL1 type ATM cell has a 3 bit header (SAR-PDU: Segmentation And Reassembly Protocol Data Unit) as shown in FIG. It consists of Modulo 8 and repeats continuously (501). Therefore, if the number of cells sequentially received with the specific VCC in the line signal analyzer 104 is not 3 Bit modulo 8, it is regarded as an error cell and performs cell processing such as cell loss, cell error, and number of misinserted cells. (Step 607).

Since the ATM cells of the AAL5 type 503 do not have continuous information like the cells of the AAL1 type, the number of cells constituting one frame is identified using the start / end bits of PT (Payload Type) of the ATM cell header. At this time, the number of known cells is defined as RCC (Receive Cell Count). Using the length of the frame trailer, it is possible to calculate the number of effective cells constituting one frame. In this case, the PAD should be taken into consideration and the effective number of cells is defined as LCC (Length Cell Count). This can be expressed as the quotient + 1 of LCC = (Length + 7) / 48. After calculating the CRC and the RCC of the AAL5 frame, if the CRC is normal, the process is processed as a normal cell (step 609). If the CRC is abnormal, the LCC and the ACC to be described below are calculated and processed according to each case (step 610). In the case of a normally received frame, the RCC and the LCC are the same, and cell loss, cell error, and error cell number can be extracted using ACC (Abnormal Cell Count = RCC-LCC), which is a difference between two non-identical variables.

를 셀 손실로, 그리고 셀 에러로 처리하고 RCC 는 정상 셀로 처리한다(611단계)1) Cell Loss: This is the case where ACC is negative and is obtained by the following equation.

Is treated as a cell loss and a cell error, and the RCC is treated as a normal cell (step 611).

를 오삽입 셀로, 그리고 셀 에러로 처리하고 RCC는 정상 셀로 처리한다(612단계).2) Mis-Insertion Cell: This is the case where ACC is positive and is calculated by the following equation.

Is treated as a misinserted cell and a cell error, and the RCC is treated as a normal cell (step 612).

3) Errored Cell: Corresponds to the CRC error of the frame. It is assumed that an error cell has occurred and the error cell can be estimated by adding the absolute value of ACC to this value and calculated as in Equation 3 below. The RCC processes the normal cell (step 613).

As described above, the AAL type determination and analysis of the error cell is a measure of the cell transmitted and received in the on-line state, unlike the fixed ATM cell by the instrument, and the error interval is easily measured when the ATM node is configured in multiple stages. Can be judged.

ATM lines transmit and receive data in units of ATM cells. By calculating the ATM cell to be transmitted and received, it is possible to extract the maximum cell rate (PCR), the sustained cell rate (SCR) and the maximum burst cell size (MBS).

The controller 105 manages the states of all components such as the receiver 101, the signal selector 102, the signal converter 103, and the signal analyzer 104 that constitute the system. It controls the signal selection unit 102 and the signal conversion unit 103 for connecting the signal of the line to the general measurement equipment (not shown) and the signal analysis unit 104 and externally provides a LAN and a console interface. The operator who manages the system can control and manage the system through the Internet network 107 locally (Local, 106) and remote (Remote, 107) through the control unit 105.

In the ATM network according to the present invention, the method of measuring the characteristics and quality of the traffic in service may also be embodied as computer readable codes on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, hard disk, floppy disk, flash memory, optical data storage device, and also carrier wave (e.g. transmission over the Internet). It is also included to be implemented in the form of. The computer readable recording medium can also be distributed over computer systems connected over a computer network so that the computer readable code is stored and executed in a distributed fashion. Also, the font ROM data structure according to the present invention can be read by a computer on a recording medium such as a computer readable ROM, RAM, CD-ROM, magnetic tape, hard disk, floppy disk, flash memory, optical data storage device, and the like. It can be implemented as code.

As described above, according to the apparatus for measuring the characteristics and quality of traffic in service in the ATM network according to the present invention, and a method thereof, a system for selectively providing a contact point in a disconnection state for on-line monitoring of an optical line is configured. As a result, it is possible to solve the expensive price problem and the attenuation problem in the case of providing a single part such as an optical selector.

In addition, it is possible to configure a system that selectively provides a contact in a no-cut state for on-line monitoring of coaxial / twist pair lines, which can solve the problem of attenuation and impossibility of remote control when a single coaxial splitter can be provided. .

In addition, it is possible to analyze the signal status of a specific optical / coaxial / twist pair line and the occurrence of traffic and error cells in ATM cells without interrupting service on the lines connected between ATM nodes. Can improve.

Finally, in the system configuration of the present invention, the signal state and data traffic of a specific optical / coaxial / twist pair line are selectively connected to the instrument and monitored in the state of normal service without disconnecting the line connected between the ATM switch and the transmission device. Remote and local control and management can be used to check the status of abnormal tracks or connected exchanges on-line instantly, increasing the efficiency of service and track operation / maintenance and improving service quality. have.

Claims (10)

At least one receiver which receives the traffic to be measured from an ATM network and converts the traffic into a first electrical signal if the traffic is an optical signal, and outputs a second electrical signal after performing impedance processing if the traffic is an electrical signal; A signal selector which receives at least one first electrical signal and a second electrical signal, respectively and selectively outputs one of the first electrical signals or one of the second electrical signals; And A characteristic and quality measurement of traffic in service in an ATM network, comprising: an analysis unit receiving the first electrical signal or the second electrical signal and analyzing an AAL type for each VCC to determine whether an error occurs in an ATM cell Device. The method of claim 1, wherein the receiving unit A photoelectric conversion unit converting the optical signal into the first electrical signal; A buffer unit separating and outputting the first electrical signal output by the photoelectric conversion unit into two identical electrical signals; And And a photoelectric conversion unit converting one first electrical signal of the output of the buffer unit into an optical signal and returning the optical signal to the ATM network. The method of claim 2, wherein the first electrical signal is A device for measuring the characteristics and quality of traffic in service in an ATM network, which is a PECL signal. The method of claim 1, wherein the receiving unit A high impedance unit outputting an electrical signal in which the electrical signal is attenuated by connecting a high impedance in parallel to a line to which the electrical signal is input; And And amplifying unit for amplifying the attenuated electric signal. The method of claim 1, wherein the analysis unit An AAL type determining unit for determining the AAL type and outputting the received ATM cells to the AAL 1 determining unit and the AAL 5 determining unit, respectively; An AAL1 determining unit determining that an AAL1 type ATM cell has a characteristic VCC and that a cell number which is sequentially received is not a 3 bit modulo 8 and is an error cell; And The AAL5 determining unit for calculating the number of cells constituting one frame and the number of valid cells and calculating the cell loss, the cell error, and the number of error cells based on the difference in the case of AAL5; and Quality measuring device. The method of claim 1, wherein the measuring device And a signal converting unit converting the first electrical signal into an optical signal and outputting the optical signal, or outputting the second electrical signal by performing impedance matching with an external device. Quality measuring device. (a) receiving at least one or more traffic in service; (b) converting the traffic into a first electrical signal if the traffic is an optical signal, and connecting the parallel signal to a high impedance circuit if the traffic is an electrical signal, and amplifying the traffic into a second electrical signal; (c) selecting one of the at least one first electrical signal or one of a second electrical signal; And (d) receiving the first electrical signal or the second electrical signal and analyzing the AAL type for each VCC to determine whether an error occurs in an ATM cell; the characteristics of traffic in service in an ATM network, comprising: How to measure quality. The method of claim 7, wherein step (b) And converting the optical signal into the first electrical signal, separating the converted first electrical signal into two identical first electrical signals and generating one of the first electrical signals into an optical signal. Method for measuring the characteristics and quality of traffic in service in the ATM network, characterized in that. The method of claim 7, wherein step (d) (d1) determining an AAL type to determine whether the received ATM cell is AAL 1 or AAL 5; (d2) if it is determined as AAL1, determining that the ATM cell has a characteristic VCC and is an error cell if the number of cells sequentially received is not 3-bit modulo 8; And (d3) In the case of AAL5, if CRC error occurs by performing CRC check, the number of cells constituting one frame and the number of valid cells are calculated, and cell loss, cell error, and error cell count are calculated based on the difference. Method for measuring the characteristics and quality of traffic in service in the ATM network comprising a. The method of claim 9, wherein step (d3) (d31) If the value obtained by subtracting the number of valid cells from the number of cells constituting the one frame (hereinafter referred to as "abnormal cell number") is negative, the abnormal cell number is treated as a cell loss and a cell error, and the received cell is normal. Treating with; (d32) if the abnormal cell number is positive, processing the abnormal cell number as a misinserted cell and a cell error and processing the received cell as normal; (d33) if the number of abnormal cells is zero, processing as a cell error and processing the received cells as normal; characteristics and quality measurement method of the traffic in service in the ATM network comprising a.

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