Synchronize Time with a Specific Source

A.

The correct answer is A. Add a Phone NTP Reference to the Date/Time Group.

Explanation: A Cisco SIP phone requires synchronization with a reliable source of time to ensure that the time displayed on the phone is accurate. Network Time Protocol (NTP) is used for this purpose, which allows the phone to synchronize its clock with a time server.

To configure NTP on a Cisco SIP phone, the following steps should be taken:

1. Configure the Date/Time Group: A Date/Time Group is a set of parameters that define the time zone, time format, and NTP server information for a group of devices. To configure a Date/Time Group, go to Call Manager Administration and select System > Date/Time Group. Create a new group or edit an existing one to specify the NTP server(s) to be used.

2. Assign the Date/Time Group to the Device Pool: A Device Pool is a set of parameters that define the characteristics of a group of devices, including the Date/Time Group. To assign the Date/Time Group to the Device Pool, go to Call Manager Administration and select System > Device Pool. Edit an existing pool or create a new one to specify the Date/Time Group to be used.

3. Assign the Device Pool to the Phone: To assign the Device Pool to the phone, go to Call Manager Administration and select Device > Phone. Edit an existing phone or create a new one to specify the Device Pool to be used.

Once the phone is assigned to a Device Pool with the correct Date/Time Group, it will automatically synchronize its clock with the NTP server(s) specified in the group. This ensures that the time displayed on the phone is accurate and synchronized with other devices on the network.

Option B (Assign the device to the correct region) is incorrect because region configuration is used for call admission control and does not affect time synchronization.

Option C (Change the Time Format from 24-hour to 12-hour) is incorrect because this setting only changes the way the time is displayed on the phone and does not affect time synchronization.

Option D (Change the Time Zone from America/Los_Angeles" to Etc/GMT+8) is incorrect because this setting only changes the time zone of the phone and does not affect time synchronization.