JP7200162B2 - NETWORK TESTING DEVICE AND NETWORK TESTING METHOD - Google Patents

Description

The present invention relates to a network testing apparatus and a network testing method for performing various tests on network equipment and network lines such as routers, switching hubs, and transmission devices as devices under test (DUTs).

For example, network test apparatuses disclosed in Patent Literature 1 and Patent Literature 2 below are known as apparatuses for performing various tests on network devices and network lines such as routers, switching hubs, and transmission devices as objects to be measured.

In the network test equipment, a test signal generated in accordance with the communication standard of the device under test is input to the device under test, and the signal output from the device under test along with the input of this test signal is analyzed to perform various tests. It is carried out.

By the way, in a network test device, latency measurement is performed in order to know, for example, the delay amount of a network as a device under test, and time information is essential for this latency measurement. Latency means that when a data frame sent from the network test equipment to the device under test is received via the device under test, the data frame with the transmission time stamp is added with the reception time stamp at the time of reception, and the transmission time is calculated. It means the time taken from transmission to reception obtained by calculating the difference in reception time.

However, in the conventional network test equipment, the time information generator that generates time information generally uses an operating clock frequency with no fractions in order to avoid the calculation of the fractional part. Therefore, the operating clock frequency of the time information generating section is different from the operating clock frequency of the signal generating section that generates data frames and the signal measuring section that receives data frames from the device under test. Therefore, when storing the time information at the time of data frame transmission/reception in the data frame, the time information is generated at the operating clock frequency of the time information generating section, and the generated time information is set at the operating clock frequency of the signal generating section and the signal measuring section. I had to replace it.

Therefore, in a conventional network test apparatus, a handshake-type asynchronous reloading circuit is used to reload the clock of the time information and store the time information in the data frame. A method of storing time information at the time of data frame transmission/reception will be described below with reference to FIGS. Assume that the operating clock frequency of the time information generating section is C (Hz), and the operating clock frequency of the signal generating section and the signal measuring section is D (Hz).

[How to store time information when sending a data frame]
When storing the time information in the data frame generated by the signal generator, as shown in FIG. ST21). Next, the time information is held in order to replace the generated time information with the operating clock frequency D (Hz) of the signal generating section (ST22). Subsequently, using the held time information, the time is stamped when the data frame is generated (ST23). Then, the stamped time is stored in the data frame at the operating clock frequency D (Hz) of the signal generator (ST24).

[How to store time information when receiving a data frame]
When storing the time information in the data frame received by the signal measurement unit, as shown in FIG. ST31). Next, the time information is held in order to replace the generated time information with the operating clock frequency D (Hz) of the signal measuring section (ST32). Subsequently, using the held time information, the time is stamped when the data frame is received (ST33). Then, the stamped time is stored in the data frame at the operating clock frequency D (Hz) of the signal measuring section (ST34).

JP 2015-195468 A JP 2015-185861 A

However, in the conventional method, the time information is held at the operating clock frequency of the time information generating section by a handshake type asynchronous remounting circuit, and the hold start signal is used as the hold period by the signal generating section (or the signal measuring section). 2 clocks by the flip-flop circuit for synchronizing with the operating clock frequency of the part), 1 clock for latching time information with this synchronized hold start signal and generating a latch completion signal, and furthermore, this latch completion signal is used as time information. Two clocks are required for the flip-flop circuit for synchronizing with the operating clock frequency of the generator, and one clock is required for reholding the time information with this synchronized latch completion signal. As a result, the total resolution is reduced to about (3×operation clock frequency of time information generation unit)+(3×operation clock frequency of signal generation unit (or signal measurement unit))=60 nsec.

As described above, in the conventional method, clock reloading of time information is performed using a handshake-type asynchronous reloading circuit. The reliability of the time information stored in the data frame was lacking.

In addition, since the conventional method asynchronously transfers multiple bits of data (time information), skew occurs between bits, and the bits do not change for a certain period (until the data is latched at the frequency of the sampling side). Therefore, it was necessary to make the data constant.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a network test apparatus and a network test method capable of improving the resolution of time information.

In order to achieve the above object, a network test apparatus according to claim 1 of the present invention inputs a data frame of a test signal generated corresponding to a communication standard of a device under test W to the device under test, In the network testing apparatus 1 that performs various test measurements based on the data frames received from the device under test in accordance with the input of the data frames of the test signal,
a time information generation unit 6 that generates time information;
The time information generated by the time information generating section operates at an operating clock frequency slower than the operating clock frequency of the time information generating section and generates a data frame of the test signal to be input to the device under test. is stored in the generated data frame, the leading bit at the time of generation of the data frame is detected as a transmission timing signal, and the transmission timing signal is replaced with the operating clock frequency of the time information generation unit 3. When,
It operates at the same operating clock frequency as the signal generator, receives the data frame of the signal from the device under test, and measures the various tests. a signal measuring unit 5 for detecting the leading bit at the time of reception of the data frame as a reception timing signal when storing in the received data frame, and replacing the reception timing signal with the operating clock frequency of the time information generation unit; , and
The time information generation unit stamps the time with a transmission timing signal that is replaced when the data frame is generated by the signal generation unit when storing the time information in the data frame generated by the signal generation unit; When the time information is stored in the data frame received by the signal measuring section, the time is stamped by the reception timing signal that is replaced when the data frame is received by the signal measuring section.

A network testing method according to claim 2 of the present invention includes a time information generating section 6 for generating time information, an operating clock frequency slower than the operating clock frequency of the time information generating section, and a device under test W. and a signal generating section 3 for generating a data frame of a test signal conforming to the communication standard of the above; A network testing method using a network testing device 1 equipped with a signal measuring unit 5 that performs measurements for various tests of an object,
When the time information generated by the time information generation unit is stored in the data frame generated by the signal generation unit, the head bit at the time of generation of the data frame is detected as a transmission timing signal, and the transmission timing signal is detected. a step of replacing the operating clock frequency of the time information generating unit;
When the time information generated by the time information generation unit is stored in the data frame received by the signal measurement unit, the first bit of the received data frame is detected as a reception timing signal , and the reception timing signal is detected. a step of replacing the operating clock frequency of the time information generating unit;
when time information is stored in the data frame generated by the signal generation unit, stamping the time with the transmission timing signal replaced when the data frame is generated by the signal generation unit;
a step of stamping the time with a reception timing signal that is replaced when the data frame is received by the signal measuring unit when storing the time information in the data frame received by the signal measuring unit. and

According to the present invention, since only the stamping timing is asynchronously replaced and stamped, the time information does not change, and the time information can be stored in the data frame without lowering the resolution of the time information.

1 is a block configuration diagram of a network testing device according to the present invention; FIG. 3(a) and 3(b) are flowcharts showing procedures of a method for storing time information at the time of data frame transmission/reception in the network testing device according to the present invention; 10(a) and 10(b) are flowcharts showing procedures of a method for storing time information at the time of data frame transmission/reception in a conventional network testing device;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail, referring attached drawings.

As shown in FIG. 1, the network test apparatus 1 of this embodiment includes an operation unit 2, a signal generation unit 3, an input/output unit 4, a signal measurement unit 5, a time information generation unit 6, a control unit 7, a display unit 8, and It is roughly configured with The network test apparatus 1 uses a network device such as a router, a switching hub, a transmission device, or a network line (for example, 100G, 400G Ethernet (registered trademark), etc.) as a device under test (DUT) W. A test signal generated according to the W communication standard is input to the device under test W, and various tests are performed based on the signal from the device under test W accompanying the input of the test signal.

The operation unit 2 includes operation knobs, various keys, switches, buttons, input devices such as a keyboard and a mouse having numeric keys and various setting keys, and a touch panel provided on the surface of the display unit 8. Consists of an input device. The operation unit 2 sets measurement conditions such as start and stop of various measurements of the device under test W, measurement intervals, etc., and sets the code format (NRZ (Non Return to Zero)/PAM) of the data frame transmitted to the device under test W. (Pulse Amplitude Modulation)), parameters for generating a data frame, and the like, are operated by the user when executing processing related to various measurements of the device under test W. FIG.

The signal generator 3 generates data frames of multiple lanes as test signals corresponding to the communication standard of the device under test W, and transmits the generated test signals of the data frames of the multiple lanes to the device under test via the input/output unit 4. Send to W. For example, with a clock frequency of 330 MHz×160 bits=52.8 Gbps as a data frame of one lane, a test signal of an 8-lane parallel data frame is generated.

The signal generator 3 operates at an operation clock frequency slower than the operation clock frequency of the time information generator 6, stores the time information generated by the time information generator 6 in a data frame, and generates data with a transmission time stamp. When forming a frame, a transmission timing signal (leading bit in data frame generation: 1 bit) is detected at the time of data frame generation, and the detected transmission timing signal is replaced with the operating clock frequency of the time information generation unit 6 .

The input/output unit 4 transmits test signal data frames between the signal generating unit 3 and the device under test W, and receives test signal data frames between the device under test W and the signal measuring unit 5 . The input/output unit 4 includes an optical transceiver module such as QSFP-DD, CFP8, or OSFP, and includes an E/O converter and an O/E converter for mutually converting electrical signals and optical signals.

For example, when a QSFP DD (DR4, LR4, FR4) optical transceiver module is adopted, the 8-lane parallel electrical signal generated by the signal generator 3 is converted into a 4-lane parallel optical signal, 4-lane parallel optical signals from W are converted into 8-lane parallel electrical signals.

When a QSFP DD (LR8, FR8, SR8) optical transceiver module is adopted, the 8-lane parallel electrical signal generated by the signal generator 3 is converted into a 4-lane parallel optical signal, and the 8-lane parallel optical signals from the object W are converted into 8-lane parallel electric signals.

The signal measurement unit 5 performs various measurements including error detection based on the data frame of the electrical signal converted by the optical transceiver module of the input/output unit 4 . For example, when performing error detection, the signal measuring unit 5 receives a data frame (for example, 160-bit data) of an electrical signal transmitted to the device under test W at a setting timing preset by the operation unit 2, and an input/output unit Synchronization with the data frame (for example, 160-bit data) of the electric signal from the optical transceiver module No. 4 is performed, and bit comparison is performed to detect the presence or absence of an error. That is, the signal measurement unit 5 compares the bits of the data frame transmitted to the device under test W and the data frame received from the device under test W from the optical transceiver module of the input/output unit 4. If the two match, there is no error: 0, and if they do not match, the error is detected as 1.

The setting timing is set in advance by the operation unit 2 on a setting screen (not shown) of the display unit 8, for example. These are the timing at which the object W generates the trigger signal, the timing at which the trigger signal is generated by the user's instruction (for example, button operation), and the timing at which the error is detected.

The signal measuring unit 5 operates at an operating clock frequency slower than the operating clock frequency of the time information generating unit 6, stores the time information generated by the time information generating unit 6 in a data frame, and generates data with a transmission time stamp. When forming a frame, a reception timing signal (first bit when receiving a data frame: 1 bit) is detected, and the operation clock frequency of the time information generator 6 is replaced with the detected reception timing signal.

The time information generation unit 6 generates time information by stamping the time when generating or receiving a data frame, and operates at an operating clock frequency faster than that of the signal generating unit 3 and the signal measuring unit 5. do. For the signal of the operating clock frequency of the time information generator 6, for example, a signal of a highly accurate oscillator or a signal synchronized with GPS (Global Positioning System) is used. The time information generation unit 6 stores the time information in the data frame generated by the signal generation unit 3 to generate a data frame with a transmission time stamp. The time is stamped with a timing signal (the first bit of the data frame when the data frame is generated).

Further, when the time information generating unit 6 stores the time information in the data frame received by the signal measuring unit 5 to generate a data frame with a reception time stamp, the data frame is replaced when the signal measuring unit 5 receives the data frame. The time is stamped with the received timing signal (the first bit of the data frame when the data frame is received).

The control unit 7 is composed of, for example, a microcomputer including a CPU, ROM, RAM, etc., and performs integrated control of each unit that constitutes the network testing apparatus. generation control, data frame transmission/reception control in the input/output unit 4, time stamping control in the time information generation unit 6, time information storage control and operation in the data frame in the signal generation unit 3 and the signal measurement unit 5 It performs switching control of the switching unit 13 based on the settings of the operation unit 2, various measurement controls of the signal measuring unit 5 based on the settings of the operation unit 2, display control of setting screens and measurement results on the display unit 8, and the like.

The display unit 8 is composed of a display device such as liquid crystal or electroluminescence (EL), and displays setting screens for performing various tests based on the operation of the operation unit 2, and various measurements in the signal measurement unit 5. Display the results, etc.

Next, as an operation of the network testing apparatus 1 configured as described above, a method of storing time information at the time of data frame transmission/reception will be described with reference to the flow charts of FIGS. The operating clock frequency of the time information generating section 6 is A (Hz), and the operating clock frequency of the signal generating section 3 and the signal measuring section 5 is B (Hz) (<A (Hz)).

[How to store time information when sending a data frame]
As shown in FIG. 2(a), when the signal generator 3 generates the data frame, it detects the leading bit (1 bit) of the data frame as a transmission timing signal (ST1). Then, the detected transmission timing signal is replaced with the operating clock frequency A (Hz) of the time information generator 6 (ST2).

Next, the time information generator 6 stamps the time with the transmission timing signal (first bit of the data frame when the data frame is generated) that has been transposed to the operating clock frequency A (Hz) of the time information generator 6 ( ST3).

Then, the stamped time is stored in the data frame at the operating clock frequency B (Hz) of the signal generator 3 (ST4). This results in a data frame with a transmission timestamp.

[How to store time information when receiving a data frame]
As shown in FIG. 2(b), upon receiving the data frame, the signal measuring section 5 detects the leading bit (1 bit) of the data frame as a reception timing signal (ST11). Then, the detected reception timing signal is replaced with the operating clock frequency A (Hz) of the time information generator 6 (ST12).

Next, the time information generating unit 6 stamps the time with the reception timing signal (first bit of the data frame when the data frame is received) that has been transposed to the operating clock frequency A (Hz) of the time information generating unit 6 ( ST13).

Then, the stamped time is stored in the data frame at the operating clock frequency B (Hz) of the signal measuring section 5 (ST14). This results in a data frame with a reception timestamp.

As described above, according to the present embodiment, since only the stamping timing is stamped by performing asynchronous replacement, the time information does not change, and the time information is stored in the data frame without lowering the resolution of the time information. can do. Specifically, according to the present embodiment, the resolution is reduced from 60 nsec to 10 nsec compared to the conventional method using the handshake-type asynchronous remounting circuit shown in FIGS. It is possible to improve the resolution of the data frame generation time and the data frame reception time.

Further, the time information generator 6 can store more accurate time information in the data frame by improving the operating clock frequency according to the capability of the device (FPGA: field-programmable gate array) used. .

Although the best mode of the network testing device and network testing method according to the present invention has been described above, the present invention is not limited by the description and drawings according to this mode. In other words, it goes without saying that other forms, embodiments, operation techniques, etc. made by persons skilled in the art based on this form are all included in the scope of the present invention.

REFERENCE SIGNS LIST 1 network test device 2 operation unit 3 signal generation unit 4 input/output unit 5 signal measurement unit 6 time information generation unit 7 control unit 8 display unit W device under test (DUT)

Claims (2)

A data frame of a test signal generated corresponding to the communication standard of the device under test (W) is input to the device under test, and a data frame is received from the device under test in accordance with the input of the data frame of the test signal. In a network test device (1) that performs various test measurements based on
a time information generator (6) for generating time information;
The time information generated by the time information generating section operates at an operating clock frequency slower than the operating clock frequency of the time information generating section and generates a data frame of the test signal to be input to the device under test. is stored in the generated data frame, a signal generation unit ( 3) and
It operates at the same operating clock frequency as the signal generator, receives the data frame of the signal from the device under test, and measures the various tests. When storing in the received data frame, a signal measurement unit (5) detects the first bit of the received data frame as a reception timing signal , and replaces the reception timing signal with the operating clock frequency of the time information generation unit. ) and
The time information generation unit stamps the time with a transmission timing signal that is replaced when the data frame is generated by the signal generation unit when storing the time information in the data frame generated by the signal generation unit; A network testing apparatus characterized in that, when storing time information in a data frame received by the signal measuring unit, the time is stamped by a reception timing signal that is replaced when the data frame is received by the signal measuring unit. . A time information generating section (6) for generating time information, and a data frame of a test signal operating at an operating clock frequency slower than the operating clock frequency of the time information generating section and conforming to the communication standard of the device under test (W). and a signal that operates at the same operating clock frequency as the signal generator, receives a data frame of a signal from the device under test, and measures various tests of the device under test. A network testing method using a network testing device (1) comprising a measuring unit (5),
When the time information generated by the time information generation unit is stored in the data frame generated by the signal generation unit, the head bit at the time of generation of the data frame is detected as a transmission timing signal, and the transmission timing signal is detected. a step of replacing the operating clock frequency of the time information generating unit;
When the time information generated by the time information generation unit is stored in the data frame received by the signal measurement unit, the first bit of the received data frame is detected as a reception timing signal , and the reception timing signal is detected. a step of replacing the operating clock frequency of the time information generating unit;
when time information is stored in the data frame generated by the signal generation unit, stamping the time with the transmission timing signal replaced when the data frame is generated by the signal generation unit;
a step of stamping the time with a reception timing signal that is replaced when the data frame is received by the signal measuring unit when storing the time information in the data frame received by the signal measuring unit. network test method.

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