phone time not synchronized in the same cluster

[Guo Fang Sherlock Wu]

All phones are connected to CUCM cluster through SCCP and all phones in the same timezone. However there will be some timing differences (less than 10 seconds) on a few phones. After reset those phones, the clock will be synchronized again. Any idea on this? Thanks.

[Joseph Martini]

Interesting, here's how SCCP phones get their time.  When the phone registers it will get it's time from the CUCM it's registered with.  After placing a phone call the phone again when the call ends will be sent a SCCP message with the current time according to the CUCM server the phone is registered to.  Also each night (I forget when but it's in the middle of the night) each phone will be sent a SCCP message with the current time.  The problem could be drift on the phones themselves if they're not being used that often to continually get the correct time from CUCM.  Let me know if this information helps at all.  Do the problem phones not make many calls during the day?

[acampbell]

Thanks for this information Joe.

I tried to find this on google etc

Regards

Alex

[Guo Fang Sherlock Wu]

Thanks Joe. I am also suspect that the phone may not be used quite often. I also did some test in my lab and was able to see that the CUCM publisher will send a time update to the phone when an on hook/end call event occurs. I also noticed that my customer's publisher is synchronized to a stratum 5 NTP server. I am not so sure if there could be any relationship with this issue as i noticed that in the SRND document cisco recommends synchronizing the publisher with stratum 1 ntp server.

By the way, do you still remember the sccp message being sent during middle night is from phone to cucm or the opposite? If it is from phone to the cucm, will cucm send reply to the phone if it detects that the phone's timing is not accurate?

[michael-luo · Accepted solution]

As far as I know there's no such a 'midnight' thing.  (unless we're talking about midnight cowgirls?    )

When the phone first reigstered to CUCM, it'll send TimeDateReq message to CUCM.

11:53:11.854 |StationInit: (0000001) TimeDateReq.|1,100,56,1.25^142.100.64.16^cipchq1

Then CUCM will respond with DefineTimeDate.

11:53:11.855 |StationD:    (0000001) DefineTimeDate timeDateInfo=9/22/2011 16:53:11,4 systemTime=1316710391.|1,100,56,1.25^142.100.64.16^cipchq1

Then, whenever there's a SCCP event (such as offhook), the CUCM will send DefineTimeDate.

As far as the direction, 'StationInit' is from phone to CUCM.  'StationD' is from CUCM to phone.

Hope this helps!

Michael