Phone NTP References - why use them?

[James Hawkins]

Hi,

The CUCM Admin Guide contains the following text about Phone NTP References.

If you want to do so, you can configure phone Network Time Protocol (NTP) references in Cisco Unified Communications Manager Administration to ensure that a phone that is running SIP gets its date and time from the NTP server. If all NTP servers do not respond, the phone that is running SIP uses the date header in the 200 OK response to the REGISTER message for the date and time.

The "If you want to do so" statement seems pretty ambiguous. SIP phones seem to be able to get date and time info just fine from the 200 OK response so I am wondering why Phone NTP References are required. They would just seem to create additional traffic on the network (which could be significant for large deployments) but I assume that there must be some benefit to using them.

Can anyone answer this question?

[BiaMeslin]

Hello all,

My customer has the same concern as James, and I was looking to see if is t hat possible to change/increase the time interval the phone sends an NTP query packet to NTP server. From my customer environment, it seems it is send the query each 30 seconds. I could not find any document mentioned if it is possible to modify that.

Thanks anregards,