Clock is 4 minutes slow on IP phones

[jaywydra]

It is my understading that the phones sync to the Windows clock on the CCM. The Windows clock shows one time and the phones are running about 4 minutes behind. How can I synchronize the clocks?

Thanks,

Jason Wydra

[Aaron Harrison]

Is the time synchronised between all your callmanagers?

If you have an NTP source you can use there should be a file called ntp.conf in your Winnt directory... if you put the IP of an NTP server in there, then make sure the NTP windows service is running and the "Windows time" service is stopped (do these on all servers) you should then be synched up - your phones get the time from Callmanager, so one of your CMs must have the same time on it..

[p-dolbow]

Also check the time on all your CMs if you have more than one. The phones could be registering to a subscriber server who's clock may not be sync'd with the publisher. It's always a good idea to use NTP on all your systems to ensure that the time is accurate and synchronized.

-=Phil=-

[Erick Bergquist]

Could it be possible the phones have right time when they are reset, but after awhile the clock drifts?

Does anyone know if the phones update their time with the CCM after they are boot up through signalling/keepalive packets or by some other means?

[jaywydra]

I looked at the ntp.conf file on the CCM and it shows the local system as the clock source. 127.127.1.1. Also, the time is the same on both CCMs. Erick - I believe the phones periodically synch their time from the CCM. For testing purposes, I changed the time on CCM in the lab and watched my phone. After about 30 minutes it updated on its own.

Thanks,

Jason