How to configure Lync for Windows time Service (NTP)

Everyone who understands Lync knows how important it is to keep time synchronized between Lync clients and servers! Because of the MTLS and TLS protocol communication between the client and the server, it is necessary to ensure that the time difference between two communication nodes cannot be greater than 5 minutes. The challenge is greater for third-party video conferencing terminals like Polycom rmx and HDX. In fact, the Windows Server is actually an NTP server running the Windows Time service, which can keep the Lync server and Lync client time synchronized.

Domain control

When a server is promoted to domain control, it automatically runs the Windows Time service. We can stop or start the service with the following command:

net start W32Time
net stop W32Time

In addition to edge servers and reverse proxies, all other Lync servers that are members of the domain are automatically configured to synchronize with the domain control time. So for edge and reverse proxies, we should start the Windows Time service and set it to start automatically via MMC. But where does the time of domain control come from? By default, it is obtained through the system clock on the BIOS. You can see by following this command:

W32tm-query-configuration

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From the picture above we can note that this server is both an NTP server and an NTP Client. Under NtpClient you can see Inputprovider:1 (Local), which means that the server is querying the time source and using it to synchronize time. Under the type option we can see that it has a value of nt5ds, which is also the default setting for domain control. This means that it gets the time source in chronological order, first in the forest of the PDC emulator, followed by other domains in the forest, or the PDC emulator for the subdomain. The PDC emulator automatically acquires time from an external NTP server, such as ntp.pool.org. If not acquired, the local BIOS clock will be used.

In the NtpServer option below, you can see that the value of enables is set to 1, which means that it allows NTP to request. NTP listens for requests through UDP 123 ports.

You can see the time source in use by using the following command: W32tm/monitor, which displays the host name of the time source server you are using.

Configure an external, reliable time source

Because the BIOS clock is not very reliable, again we need to manually configure the PDC emulator to get the time from the external time source. In Asia, we can use the following time source, Http://www.pool.ntp.org/zone/asia. Here's an example of how to configure an external time source, as in sg.pool.ntp.org :

W32tm/config/update/manualpeerlist:sg.pool.ntp.org,0x1/syncfromflags:manual

Secondly

W32tm/resync/rediscover/nowait

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Then stop, restart the time service, the configuration will only take effect.

In this context, we should be able to synchronize time through a reliable time source throughout the Lync environment.

This article is from the "Tian Shengwan blog" blog, make sure to keep this source http://tiansw.blog.51cto.com/5894112/1629209

How to configure Lync for Windows time Service (NTP)