IP Phones get time from Subscriber, not from DTG

Answered Question
Jul 23rd, 2008
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Hi,

I've got a small Call Manager 4.2(3) cluster, that contains 1 Pub and 1 Sub.

Cluster is configured with default device pool, that using manually inserted Date/Time group.

There is one Call Manager group is configured, where Sub is the 1st priority, Pub is the 2nd priority.

As a result, IP Phones, associated with default device pool, are registered with Sub, i.e. as I need.


The problem is in that IP Phones got their time value and format (except separator) from Subscriber,

while they registered to Subcriber. They do not take time from date/time group of their device pool.

It's very, very strange.


I've tried to reconfigure Call Manager Group by assigning the 1st priority (1st place in list)

for Pub, and second one for Sub. After resetting all becomes fine. Again reverted back

(Pub-Sub to Sub-Pub) and the problem returns.


Any advice will be highly appreciated.

Correct Answer by Chad Stachowicz about 8 years 8 months ago

aoklawan,


Those date time groups are just timezones. It obviously has to compare it to something, and it does that by comparing it to the local time of the boxes. Therefore if you servers are in different regions and are not NTP sync'd, when the phones register to different subscribers you will get different time. How do you think DTG Groups work? Magic? Also if you think it has nothing to do with the local server time why would anyone Cisco releasing DST patches?


Tobvian as I said originally check you correlation of your particular DTG to your subscriber OS, its ALWAYS going to rely somewhat on the subscriber OS!!



Chad

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Chad Stachowicz Thu, 07/24/2008 - 16:06
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Go to each Call Manager and check that their local times are correct. It pulls the Dat Time Group against the local time on the boxes!


I am guessing the time on the subscriber or DST was never applied, or possibly the time zone is incorrect!


HTH, Please rate useful posts.


Chad

Tobivan_Helden_2 Mon, 07/28/2008 - 23:41
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Chad,


AFAIK IP Phones shouldn't get their time value and format from Subscriber at all.


It seems to me it's a bug. Can someone confirm ?

Ayodeji Okanlawon Tue, 07/29/2008 - 01:05
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Chad,


IP phones pull their time off the DTG not the servers. You can have your server in a totaly different time zome from your phones.

Tobivan_Helden_2 Tue, 08/12/2008 - 23:26
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Gentlemen,

Any help you can provide with this question ?


How to force IP Phones that are registered to CM Subscriber

to get theirs time format and value not from Subscriber OS,

but from Date/Time Group from CM configuration ?

Correct Answer
Chad Stachowicz Tue, 08/12/2008 - 23:53
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aoklawan,


Those date time groups are just timezones. It obviously has to compare it to something, and it does that by comparing it to the local time of the boxes. Therefore if you servers are in different regions and are not NTP sync'd, when the phones register to different subscribers you will get different time. How do you think DTG Groups work? Magic? Also if you think it has nothing to do with the local server time why would anyone Cisco releasing DST patches?


Tobvian as I said originally check you correlation of your particular DTG to your subscriber OS, its ALWAYS going to rely somewhat on the subscriber OS!!



Chad

Tobivan_Helden_2 Tue, 08/19/2008 - 00:40
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Chad,


It seems to me you are right.

CM's DTG is a really just a shifting mechanism.


Thank you.

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