AzureRTOS NetXduo SNTP Client Time synchronization issue with Windows 10 NTP server

yoji sato 281

We are currently developing an edge device that connects to AzureRTOS-based IoTHUB.

The device uses NetXduo's SNTP client for time synchronization,

Time synchronization with an NTP server on the Internet is successful.

However, in the time synchronization with the Windows 10 NTP server that we installed locally,
After starting the server (after starting the NTP service), time synchronization succeeds,
After running the NTP server for a while, time synchronization fails.

Capture NTP packets when time synchronization succeeds and when it fails
When I compared them, I found that there were some discrepancies in the information (Root Dispersion).
Could you please confirm if this difference can cause the time synchronization to fail?

Also, if possible, take measures to solve this problem. can you give me some advice?

LeelaRajeshSayana-MSFT 13,546 Reputation points

2023-01-30T23:10:03.1233333+00:00

Hello @yoji sato Thank you for posting the question. Community SME's on this topic or our team will review your scenario and circle back at the possible earliest time.
yoji sato 281 Reputation points

2023-02-02T01:06:05.6533333+00:00

Hello LeelaRajeshSayana-MSFT,

Thank you for responding to our inquiry.
After that, how is the status of this inquiry?
LeelaRajeshSayana-MSFT 13,546 Reputation points

2023-02-03T01:43:16.5466667+00:00

Hi @yoji sato apologies for the delay in providing a solution to this. We are still working on this internally with the team. We will update the thread as soon as we have more information on the error. I highly appreciate your patience.

Best regards,

Leela
yoji sato 281 Reputation points

2023-02-03T03:45:32.86+00:00

Hello LeelaRajeshSayana-MSFT,
Thank you for your reply.
We understand your situation.
We look forward to receiving your response.

Best regards, Yoji Sato
LeelaRajeshSayana-MSFT 13,546 Reputation points

2023-02-17T16:52:56.17+00:00

@yoji sato Greetings! I see that your questions have been answered below. Please let us know if you still need any clarifications or further assistance on this issue. Please do not forget to mark the answer as useful if the response is helpful so that it would benefit other community members facing the same issue.

Accepted answer

Bo Chen 596 Reputation points Microsoft Employee

2023-02-06T02:26:33.3+00:00

Hi @yoji sato Appreciate your patience. Root Dispersion indicates the nominal error relative to the primary reference source, this may cause the time synchronization to fail. Root Dispersion field can be set to a value corresponding to the maximum expected error of the clock, could you redefine NX_SNTP_CLIENT_MAX_ROOT_DISPERSION as 0 to disable this check and test again?
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2 people found this answer helpful.
yoji sato 281 Reputation points

2023-02-08T18:06:17.0766667+00:00

Hello, Bo Chen

Thank you for your reply.

By setting the value of "NX_SNTP_CLIENT_MAX_ROOT_DISPERSION" to 0 as per the information you provided Time synchronization with Windows 10 NTP server is now possible.

Therefore, please confirm the following two points.

The cause of this problem is that the time accuracy (Root Dispersion value) of the Windows 10 NTP server gradually deteriorates, so time synchronization is gradually becoming impossible?

As a fundamental countermeasure, is it correct to operate the Windows 10 NTP server side so that the time accuracy (Root Dispersion) can be maintained?

Best regards,

Yoji Sato

yoji sato 281 Reputation points

2023-02-08T18:09:45.07+00:00

Hello, Mr. Bo Chen

Thank you for your reply.

By setting the value of "NX_SNTP_CLIENT_MAX_ROOT_DISPERSION" to 0 as per the information you provided Time synchronization with Windows 10 NTP server is now possible.

Therefore, please confirm the following two points.

The cause of this problem is that the time accuracy (Root Dispersion value) of the Windows 10 NTP server gradually deteriorates, so time synchronization is gradually becoming impossible?

As a fundamental countermeasure, is it correct to operate the Windows 10 NTP server side so that the time accuracy (Root Dispersion) can be maintained?

Best regards,

Yoji Sato

Bo Chen 596 Reputation points Microsoft Employee

2023-02-10T07:40:51.0633333+00:00

Hi Joji Sato,

Good to know it works when setting the value of root dispersion to 0. The sum of root dispersion is called the root distance and is the total worse case timing error accumulated between the stratum 1 server and the client. You may refer to this website to understand it. For your questions. 1. I guess the cause of this problem is that adding Windows 10 NTP server between Stratum 1 server and client, the value of root dispersion increases. 2. Adding Windows 10 NTP server, we may need to update the value of time accuracy (Root Dispersion: NX_SNTP_CLIENT_MAX_ROOT_DISPERSION) for SNTP Client to accept.

Regards,

Bo

yoji sato 281 Reputation points

2023-02-23T03:09:42.61+00:00

Hello, Mr. Bo Chen

Sorry for the late reply.

We were able to understand the contents of your reply.
And we were able to deal with the problem as well.

Thank you for your support.
And we will close this inquiry.

Best regards,

Yoji Sato.
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1 additional answer

Bo Chen 596 Reputation points Microsoft Employee

2023-02-06T02:15:10.16+00:00

Hi @yoji sato Appreciate your patience. Root Dispersion indicates the nominal error relative to the primary reference source, this may cause the time synchronization to fail. Root Dispersion field can be set to a value corresponding to the maximum expected error of the clock itself. Could you redefine NX_SNTP_CLIENT_MAX_ROOT_DISPERSION as 0 to disable root dispersion check and test again? thanks.
Please sign in to rate this answer.
yoji sato 281 Reputation points

2023-02-23T03:10:42.2533333+00:00

Hello, Mr. Bo Chen

Sorry for the late reply.

We were able to understand the contents of your reply.
And we were able to deal with the problem as well.

Thank you for your support.
And we will close this inquiry.

Best regards,

Yoji Sato.
Sign in to comment