Issue with Time Synchronization on Cisco Unified Communications Manager with Network Time Protocol Server

Document ID: 111973

Updated: May 19, 2010

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Problem

Introduction

This document discusses how to troubleshoot the Network Time Protocol (NTP) error for which time on the IP phones does not get synchronized with the time on the CUCM publisher server, which uses an external clock, for example, an NTP server, such as a router.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on Cisco Unified Communications Manager version 5.x.

Note: All IP Phones use NTP protocol in order to synchronize time with the publisher.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Problem

NTP does not work correctly on Cisco Unified Communications Manger Publisher. The clock is tied to the BIOS internal clock on the server (computer hardware clock) and not the NTP server. If you change the batteries on the motherboard, it still shows off by five minutes.

Note: The time cannot be changed because NTP is currently configured. You need to remove all the configured NTP servers in order manually adjust the time.

Solution

The phones show the wrong time, which is most likely due to misconfiguration. NTP server feeds UTC (GMT) time to clients in order to provide consistency around the world. You have to manipulate it to the local time. Check these steps in order to resolve the issue.

Choose OS Administration > Settings > NTP Server in order to navigate to the Cisco Unified Operating System Admin web interface.
Check that a reference IP address system-wide for a NTP server is configured.

Access the SSH of the CUCM and run the utils ntp status command.

admin:utils ntp status

ntpd (pid 11045) is running...

      remote           refid      st t when poll reach   delay   offset jitter

============================================================================
==

*127.127.1.0     127.127.1.0     10 l   23   64  377    0.000    0.000 0.004

 192.168.10.7    10.1.2.3     2 u   38   64  377    0.895  362571 .108.191

 
synchronised to NTP server (192.168.10.7) at stratum 11

   time correct to within 34 ms

   polling server every 64 s

 
Current time in UTC is : Mon Feb 22 16:43:57 UTC 2010

Current time in America/Chicago is : Mon Feb 22 10:43:57 CST 2010

admin:

The output shows that the CUCM is synchronized to 192.168.10.7.

Access the SSH of the CUCM and run the utils ntp config command.

admin:utils ntp config
 
This node is configured to synchronize with one of the following NTP
server(s):

  192.168.10.7

Since the NTP Source is the router, check the NTP configuration on the router.

ntp clock-period 17208228

ntp server 172.16.1.2 prefer

ntp server 10.1.1.1

ntp server 10.1.2.3

Navigate to the Cisco Unified Operating System Admin web interface and check for OS Administration > Settings > Time.
Remove the NTP from the OS and use the manual configuration in order to setup TIME on the CUCM.
Now after manual configuration, CUCM displays the correct time but the phone is still shows off by five minutes.

Note: BIOS displayed the wrong time and that was the time the phones displayed.
Run the utils network capture port 123 command in order to troubleshoot this issue.

The output displayed the correct time information and correct NTP reference.
Add the NTP master 4 command on the Router.
Remove the NTP IP address from the server and then restart the Publisher. Then read the NTP server IP address.
After you have configured NTP, it can take hours to synchronize based on the time difference between the publisher and NTP source.
On CUCM Admin > System > Date/Time Group, you can configure different groups in order to reflect different time zones. Then you can associate a date/time group to different device pools. Hence, different phones in different device pools can have different local times.