KR20190094499A - apparatus for testing load capacity of ptp/ntp server - Google Patents

Abstract

Disclosed is an apparatus for testing a load capacity of a precision time protocol (PTP) server. According to the present invention, an apparatus for testing a load capacity of a PTP/network time protocol (NTP) server comprises: a reference time information generating device for generating reference time information with higher precision than standard time information of the PTP/NTP server; a plurality of PTP/NTP simulators each having a different IP and accessing the PTP/NTP server to perform a time synchronization operation, applying a synchronization message having a time stamp based on the reference time information generated by the reference time information generating device to the PTP/NTP server during the time synchronization operation, and receiving a response message from the PTP/NTP server; and a load capacity measuring device for measuring load handling capacity of the PTP/NTP server with reference to the synchronization message sent from the plurality of PTP/NTP simulators and a corresponding response message.

Description

PTP / NTP server load test device {apparatus for testing load capacity of ptp / ntp server}

The present invention relates to a load test apparatus of a Precision Time Protocol (hereinafter referred to as PTP) / Network Time Protocol (hereinafter referred to as NTP) server, which is one of the network devices, in particular the same as the environment in which the PTP / NTP server operates. A PTP / NTP server load test apparatus that reduces test costs by providing test conditions.

PTP is an IEEE 1588 standard time transfer protocol that enables accurate synchronization between networks. This protocol supports time synchronization for all devices on an Ethernet network. When using hardware-generated time stamps, this guarantees nanosecond accuracy.

NTP is also a protocol used to synchronize clock times between networked computers. NTP will use Coordinated Universal Time (UTC) to synchronize computer clock times to less than 1/100 second.

Compared with the Network Time Protocol (NTP), PTP is included in the physical layer, making it a true hardware-based time stamping that enables precise time synchronization for all devices on an Ethernet network.

If one device is selected as the device generating the master clock (i.e. PTP / NTP server), this PTP / NTP server delivers time synchronization packets to all clients. The synchronization process begins as time synchronization packets are sent over the network. Every client calculates the time difference (delay) between its local time (or slave time) and the time (or master time) of the PTP / NTP server and adapts to this time difference step by step within 2μs.

For example, if a PTP / NTP server sends a PTP message announcing time 1:00:00 pm and also takes 1 second to reach the client, the client receiving the PTP message will set its local time to 1: 00:01 pm.

PTP / NTP server is connected to a large number of clients, it is very difficult to determine how many clients in the actual site, that is, the processing capacity of the PTP / NTP server.

PTP / NTP server load tester is to measure the processing capacity of such PTP / NTP server. It basically applies a lot of load to PTP / NTP server and checks the response to check whether there is a response delay. will be. Here, applying the load means that the PTP / NTP server authorizes a packet to be processed.

The load test of the conventional PTP / NTP server was to transfer a large load to one IP or to use a plurality of load interworking devices each having a unique IP.

Here, the method of increasing the load with one IP may determine the actual processing capability of the PTP / NTP server, but may not provide the same conditions as the environment in which the PTP / NTP server operates.

On the other hand, the method using a plurality of load interlocking device can provide the same conditions as the environment in which the PTP / NTP server is operated, but the test cost increases as the load interlocking device increases.

[Patent Documents]

KR 10-1009420 (registered Jan. 2011); Method and apparatus for synchronizing terminal time in integrated network

KR 10-1784408 (registered Sep. 27, 2017); Visual synchronization system

The present invention is designed to solve the problems of the prior art, using a single PTP / NTP server load test device, but the load test device is the same as using a plurality of different load interlock device by automatically generating a plurality of IP It is an object of the present invention to provide a PTP / NTP server load test apparatus that can obtain the effect.

PTP / NTP server load test apparatus according to the present invention for achieving the above object

In the PTP / NTP server load test apparatus for testing the department processing capability of the PTP / NTP server generating network standard time information,

A reference time information generator for generating reference time information with higher precision than standard time information of the PTP / NTP server;

A different IP is assigned to each PTP / NTP server to access the PTP / NTP server to perform a time synchronization operation, and during the time synchronization operation, the PTP receives a synchronization message having a time stamp based on reference time information generated by the reference time information generating device. A plurality of PTP / NTP simulators applied to / NTP servers and receiving response messages of the PTP server; And

A load capability measuring apparatus for measuring load handling capability of the PTP / NTP server with reference to a synchronization message sent from the plurality of PTP / NTP simulators and a corresponding response message;

It includes.

Here, the reference time information generating device

Generates a reference clock with a higher precision than the clock of the PTP / NTP server;

The PTP / NTP simulator may transmit and receive a synchronization message and a response message in synchronization with a reference clock.

Here, the load capacity measuring device analyzes the received message for each IP and calculates a transfer time and time error between the PTP / NTP server and the PTP / NTP server load test device.

Here, the load capacity measuring apparatus calculates the load capacity of the PTP / NTP server by referring to the propagation time and time error calculated for each IP.

Here, the load capacity measuring device calculates the suitability by comparing the measured value with the international standard.

In this case, each of the PTP / NTP simulator preferably includes a latch for detecting the time stamp information of the transmitted and received messages.

The PTP / NTP server load test apparatus according to the present invention can obtain the same effect as using a plurality of different load interworking apparatus by automatically generating a plurality of IP.

The PTP / NTP server load test apparatus of the present invention transmits a synchronization message simultaneously to the PTP / NTP server and analyzes the response to the synchronization message to determine how much processing delay occurs in the PTP / NTP server. A single load tester simulates the actual environment of the PTP / NTP server.

1 shows a configuration of a PTP / NTP server load test apparatus according to the present invention.
2 is a timing diagram illustrating a time synchronization operation between a PTP / NTP server and a PTP / NTP simulator.
3A to 3B are examples showing the results of measuring load capacity.
4A to 4C are examples of screens showing the results of measuring time accuracy.
5 shows an example of a screen displaying a result of measuring network delay.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 shows a configuration of a PTP / NTP server load test apparatus according to the present invention.

1, the PTP / NTP server load test apparatus 100 according to the present invention includes a reference time information generator 102 and a plurality of PTP / NTP simulators 104-1 to 104-n load capability measuring apparatuses ( 106).

The reference signal generator 102 generates reference time information with higher precision than standard time information generated from the PTP / NTP server 200 to be measured.

The reference time information basically generates reference time information by a PLL operation by an internal clock. In addition, the reference signal generator 102 may generate reference time information using a GPS signal input from the GPS receiver 300 or a cesium clock signal input from the cesium oscillator 400.

For high precision characterization, the PTP / NTP server load test apparatus 100 should have more accurate reference time information than the standard time information of the PTP / NTP server 200. It is also desirable to have a reference clock with a higher precision than the master clock of the PTP / NTP server 200.

To this end, the reference time information generator 102 generates the reference time information and the reference clock using an internal clock, a GPS signal generated by the GPS receiver 300, or a cesium clock generated by the cesium oscillator 400.

As is well known, time information and clocks can be extracted from the GPS signal.

On the other hand, the cesium clock generated by the cesium oscillator 400 is <1 * 10e ^-11 or more. In fact, the GPS receiver 300 also has a cesium oscillator.

Each of the plurality of PTP / NTP simulators 104-1 to 104-n generates a synchronization message having different IPs and applies them to the PTP / NTP server 200. This synchronization message refers to a message for time synchronization. The synchronization message is transmitted in synchronization with the reference clock generated by the reference time information generator 102. At this time, the synchronization message includes a time stamp having reference time information generated by the reference time information generating device 102. Here, the synchronization message is transmitted in a packet. A packet is a unit of information transmission in a network.

In addition, each of the plurality of PTP / NTP simulators 104-1 to 104-n receives a response message returned from the PTP / NTP server 200. Here, the response message is also transmitted in a packet.

Each of the plurality of PTP / NTP simulators 104-1 to 104-n is given a different IP, and each of them generates a packet having a synchronization message having an IP assigned to the PTP / NTP server 200. To send.

For precise measurement, the time staff information of the transmitted and received messages is detected in hardware at the last input / output end of each PTP / NTP simulator 104-1 to 104-n. Latch may be used to detect time staff information.

The PTP / NTP server 200 transmits a response message to the received synchronization message to each of the plurality of PTP / NTP simulators 104-1 to 104-n.

2 is a timing diagram illustrating a time synchronization operation between a PTP / NTP server and a PTP / NTP simulator.

(1) The PTP / NTP server 200 transmits a synchronization message. The time when the synchronization message leaves the PTP / NTP server 200 is tagged with a time stamp t1.

(2) The PTP / NTP simulators 104-1 to 104-n receive a synchronization message. This reception time is t2.

(3) The PTP / NTP simulators 104-1 to 104-n transmit Delay_Req messages. The time when this message starts the PTP / NTP simulators 104-1 to 104-n is t3, and the time when the PTP / NTP server 200 receives this message is t4.

(4) The PTP / NTP server 200 responds with a Delay_Resp message with a timestamp t4.

Each of the plurality of PTP / NTP simulators 104-1 to 104-n transmits a synchronization message generated by the PTP / NTP simulator 104-1 to the load capability measuring device 106.

The load capacity measuring apparatus 106 analyzes the messages received from the plurality of PTP / NTP simulators 104-1 to 104-n to generate a measurement value for a pre-selected measurement item.

Representative metrics include network delay and accuracy of PTP / NTP server time.

Network delay

1.1 Time from the PTP / NTP server 200 to the PTP / NTP simulators 104-1 to 104n (forward delay; master to slave delay)

The difference between the time transmitted from the PTP / NTP server 200 and the time received from the PTP / NTP simulators 104-1 to 104n is calculated.

1.2 Time from PTP / NTP simulator 104-1 to 104n to PTP / NTP server 200 (backward delay; slave to master delay)

The difference between the time the packet is sent by the PTP / NTP simulators 104-1 to 104n and the time received by the PTP / NTP server 200 is calculated.

1.3 Network Delay

Time to come from PTP / NTP simulator 104-1 to 104n to PTP / NTP server 200 in item 1.1 and PTP / NTP server 200 to PTP / NTP simulator 104-1 to 104n in item 1.2. Calculate the average with the time to go to the network delay (network delay).

2. Accuracy of PTP / NTP Server Time

The PTP / NTP server load capability test apparatus 100 compares the time (standard time) of the PTP / NTP server 200 with its own time (reference time) to determine whether the PTP / NTP server 200 has the correct time. The accuracy of the standard time that the PTP / NTP server 200 has is determined.

In the case of the PTP / NTP server 200, the accuracy of the required server time varies depending on the type of client connected thereto.

<500 * 10e ^-6 / sec for normal pc

If only frequency is synchronized <100 * 10e ^-6 / sec

<10 * 10e ^-6 / sec when out of phase synchronization

In case of interworking with existing communication equipment <5 * 10e ^-6 / sec

NTP, on the other hand, usually needs to be <10 * 10e ^-3 / sec.

The load capacity measuring device 106 analyzes the load processing capability of the PTP / NTP server 200 to be measured by referring to the measured value.

The function of the load capability measuring apparatus 106 is as follows.

1. Setup and evaluation of the number of IP generations

1.1 Setup function: Function for evaluating how many clients the PTP / NTP server 200 can provide visual information to

  Ex) 1 ~ 1000, 1500

  A time synchronization operation is performed with the PTP / NTP server by using the set number of PTP / NTP simulators 104-1 to 104-n.

1.2 Evaluation: Verify that the time synchronization operation for all PTP / NTP simulators 104-1 to 104-n is properly performed from the PTP / NTP server 200 during the measurement time.

    E.g,

    100% received

    Mark as 95% receive

    Incoming Packets / Outgoing Packets

The load capability of the PTP / NTP server 200 can be determined using the result calculated as described above.

3A to 3B are examples showing the results of measuring load capacity.

It is very important to evaluate how many clients the PTP / NTP server 100 can accommodate.

The load capacity measuring device 106 counts all the response messages (or packets) received for the synchronization messages delivered by the PTP / NTPs 104-1 to 104-n.

Referring to FIG. 3A, when a synchronization message is transmitted to 100 IPs, it can be seen that all messages (synchronization message and response message) are normally transmitted and received at RX / TX = 600/600 = 100%.

Meanwhile, referring to FIG. 3B, the response rate from the PTP / NTP server 200 decreases to RX / TX = 1160/2505 = 46.3% when the synchronization message is transmitted to 500 IPs.

2. Measure whether the time of PTP / NTP server 200 to be measured is correct

2.1 Display time accuracy chart to check whether the time of PTP / NTP server 200 provides precise time without change as load increases

First, whether the time of the PTP / NTP server 200 is accurate should measure the exact characteristics of the server by applying only one load IP. By doing so, it is determined how accurate the time the PTP / NTP server 200 has and then how much is affected by increasing the load IP (ie, PTP / NTP simulator). As the load increases, the measurement is the same as 1.2 (Load synchronization characteristic test).

4A to 4C are examples of screens showing the results of measuring time accuracy.

For precise measurement, the time staff information of the transmitted / received messages is preferably latched in hardware at the last input / output terminal of each PTP / NTP simulator 104-1 to 104-n. Detecting in software can result in delays processed by software. Detecting by hardware eliminates the delay time that occurs during software processing.

4A shows an example of selecting K, ITU-T g.823, from among international standards.

In FIG. 4A, a maximum time interval error (MTE) represents a maximum time error measured during an observation time. It can be seen that the measured values are compared with international standards to indicate compliance.

Referring to FIG. 4A, an increase in time difference due to time delay of a PTP / NTP server measured as IP increases.

As a result, as shown in FIG. 4B, the measurement result based on ITU-T G.823 is FAIL.

It is important to note that it is suitable when one of the ITU-T G.8271 Table II.1 is applied as shown in FIG. 4C.

By providing these indicators, it may be more reasonable to determine whether the PTP / NTP server 200 is suitable for the environment in which it is used.

3. Calculation and display of PTP / NTP server 200 and network delay to be measured

3.1 Verify that there is no degradation in server response time as load increases

    Display latency charts from the server-> measuring devices

    Display latency chart of measuring device-> server device

When multiple clients request information to the PTP / NTP server 200 at the same time, there is a delay in processing time in the PTP / NTP server 200 and may not respond at all.

The PTP / NTP server load test apparatus 100 of the present invention simultaneously transmits a synchronization message to the PTP / NTP server 200 and analyzes the response to the synchronization message to a certain extent in the PTP / NTP server 200. By determining whether a processing delay occurs, the single load test apparatus 100 simulates the actual environment of the PTP / NTP server 200.

5 shows an example of a screen displaying a result of measuring network delay.

Referring to FIG. 5, it can be seen that the network delays for each of the total of 6022 PTP / NTP simulators 0 to 6061 are displayed, and the maximum / minimum values of the network delays are displayed.

PTP / NTP server load test apparatus according to the present invention can be applied almost the same to NTP as well as PTP.

The way PTP and NTP work is slightly different

1.1.1 In the case of PTP, the PTP / NTP server load tester communicates with the PTP / NTP server by transmitting mutual information. You decide how many times per second you want to spend.

1.1.2 The PTP / NTP Server sends time and other information to the PTP / NTP Server Load Tester.

1.1.3 PTP / NTP server load tester requests network delay

1.1.4 The PTP / NTP server responds

1.1.5 The PTP / NTP server load tester calculates the time to set its own time. (The PTP / NTP server load tester compares the server's time with its own time and provides information.)

In contrast, NTP is simpler.

1.2.1 For NTP, the load tester requests time to the server (NTP server)

1.2.2 The NTP server responds

1.2.3 The load tester calculates the time received from the NTP server and adjusts its time.

(Here, the load tester compares the time of NTP server with its own time and provides information)

100 ... PTP / NTP Server Load Capacity Test Device
Reference time information device 104-1 to 104-n ... PTP / NTP simulator
106 ... Load capacity measuring device

Claims (6)

In the PTP / NTP server load test apparatus for testing the department processing capability of the Precision Time Protocol (PTP) / Network Time Protocol (NTP) server for generating network standard time information,
A reference time information generator for generating reference time information with higher precision than standard time information of the PTP / NTP server;
A different IP is assigned to each PTP / NTP server to access the PTP / NTP server to perform a time synchronization operation, and during the time synchronization operation, the PTP receives a synchronization message having a time stamp based on reference time information generated by the reference time information generating device. A plurality of PTP / NTP simulators applied to / NTP servers and receiving response messages of the PTP server; And
A load capability measuring apparatus for measuring load handling capability of the PTP / NTP server with reference to a synchronization message sent from the plurality of PTP / NTP simulators and a corresponding response message;
PTP / NTP server load test apparatus comprising a.
The apparatus of claim 1, wherein the reference time information generating device comprises:
Generates a reference clock with a higher precision than the clock of the PTP / NTP server;
And the PTP / NTP simulator is configured to transmit and receive a synchronization message and a response message in synchronization with a reference clock.
The PTP / NTP of claim 2, wherein the load capacity measuring device analyzes a message received for each IP to calculate a transmission time and a time error between the PTP / NTP server and the PTP / NTP server load test device. Server load test device.
The PTP / NTP server load test apparatus of claim 3, wherein the load capacity measuring apparatus calculates a load capability of the PTP / NTP server by referring to a transmission time and a time error calculated for each IP.
The PTP / NTP server load test apparatus according to claim 4, wherein the load capacity measuring apparatus compares the measured value with an international standard to calculate compliance with the international standard.
The apparatus of claim 1, wherein each of the PTP / NTP simulators includes a latch for detecting time staff information of a message to be transmitted and received.

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