[cisco-voip] 3rd-gen and newer IP phones 5-10 seconds slow

[Bill Simon]

I removed the NTP options from DHCP for a group of phones and reset a 
couple.  I've been monitoring the console logs and have not seen any 
more NTP errors.  However the timing is still off.  I will monitor for a 
while and see if any more clues show up.

Wes Sisk wrote:
> How do you feel about removing the NTP reference from a group of phones 
> and monitoring them?
> That would prove we are looking in the appropriate direction.
> 
> /Wes
> 
> On Monday, May 11, 2009 10:06:17 AM, Bill Simon <bills at psu.edu> wrote:
>> The first information in the console logs after Friday's reboot of the 
>> phone:
>>
>> ERR 15:17:17.490496 NTP: Fri May  8 14:17:17 2009
>> ERR 16:00:00.000360 NTP: Fri May  8 15:00:00 2009
>>
>> A little later, an hourly report of NTP errors:
>>
>> ERR 17:00:00.004182 NTP: Fri May  8 16:00:00 2009
>> ERR 18:00:00.000777 NTP: Fri May  8 17:00:00 2009
>> ERR 19:00:00.000792 NTP: Fri May  8 18:00:00 2009
>> ERR 20:00:00.000735 NTP: Fri May  8 19:00:00 2009
>>
>> Eventually, this warning:
>>
>> ERR 03:00:00.000796 NTP: Sat May  9 02:00:00 2009
>> WRN 03:24:39.582697 NTP: Now using non-NTP clock reference.
>> ERR 04:00:00.000524 NTP: Sat May  9 03:00:00 2009
>> ERR 05:00:00.000750 NTP: Sat May  9 04:00:00 2009
>>
>> It looks like the phone is rejecting the time it's getting from NTP 
>> (source not shown in the logs) because it thinks there's an hour 
>> difference.  That makes no sense, because NTP is UTC and the local 
>> time is computed from the time zone setting.
>>
>> Jason Burns wrote:
>>> If you're really industrious you can download the phone console logs 
>>> from the phone web page and search through the logs for any mention 
>>> of ntp, drift, or sync.
>>>
>>> I would hope the phones print something in there when they sync to an 
>>> ntp source.
>>>
>>> On Sat, May 9, 2009 at 12:01 AM, Bill Simon <bills at psu.edu 
>>> <mailto:bills at psu.edu>> wrote:
>>>
>>>     Wait.  Hold up.  NTP servers are in our default options on the DHCP
>>>     server.
>>>
>>>     Would it take NTP servers from the DHCP options?
>>>
>>>     I have never read that the phones do that.
>>>
>>>     I can try experimenting with the phones' scope in DHCP on Monday if
>>>     this might be it.  Either removing the NTP options or pointing to
>>>     CUCM...
>>>
>>>
>>>     Bill Simon wrote:
>>>
>>>         I'm not aware of any method to direct a SCCP-firmware phone to
>>>         an NTP source.  I have seen the option in the XML config file
>>>         for a SIP load.
>>>
>>>         So, no, not trying to circumvent CM as the time source.  I'll
>>>         check out the bug you noted.
>>>
>>>         Thanks
>>>         Bill
>>>
>>>         Wes Sisk wrote:
>>>
>>>             We have had at least one report of this before.  That issue
>>>             appears associated to CSCsd54013.  I don't necessarily agree
>>>             with that.
>>>             My recollection (questionable?) of this issue is that when
>>>             3rd gen phone are provided NTP server they ignore time from
>>>             CM.  If the phones cannot sync from NTP source for any
>>>             reason then they drift.
>>>
>>>             Are you attempting to provide NTP source to the phones via
>>>             any means?
>>>
>>>             /Wes
>>>
>>>             On Friday, May 08, 2009 5:10:44 PM, Bill Simon
>>>             <bills at psu.edu <mailto:bills at psu.edu>> wrote:
>>>
>>>                 Running CM 4.1.3 with NTP configured on all servers to
>>>                 sync to two reliable NTP sources and peer with each
>>>                 other for verification.
>>>
>>>                 I run ntpq and check each server and all are synced up.
>>>
>>>                 My 7940s and 7960s are right on time.  But newer phones,
>>>                 7961, 7965 and 7906 are anywhere from 5 to 10 seconds 
>>> slow.
>>>
>>>                 I am aware that older phones used SCCP messages to sync
>>>                 time, and newer phones appear to use a different method.
>>>                  SIP firmware loads use NTP; what do SCCP firmwares use?
>>>
>>>                 Even after a **#** reset, the phone's time is lagged.
>>>
>>>                 Is this a defect of the Java-based firmware, or do I
>>>                 have another issue within the system causing the lag in
>>>                 the time displayed on the newer phones?