Which of the following occurs when you press the **# keypad sequence at the Settings menu on a Cisco IP
phone? (Select the best answer.)

A.
The phone will unlock the Settings menu options.

B.
The phone will be restored to the factory default settings.

C.
The phone will restart.

D.
The phone will reset.

E.
The phone will dial the voice mail pilot number

Explanation:
The IP phone’s settings will be unlocked if you press the **# keypad sequence at the Settings menu on a Cisco
IP phone. You can access the Settings menu by pressing the settings button on the phone’s keypad. You might
need to unlock the IP phone’s settings in order to make manual changes, such as manually deleting the
phone’s Certificate Trust List (CTL) file. CTL files are a component of a secure Cisco Unified Communications
Manager (UCM) configuration. They are used as part of the device, file, and signaling authentication process.
When a phone initializes, it downloads the CTL file from the Trivial File Transfer Protocol (TFTP) server.
You might need to delete a CTL file from an IP phone if you move the phone to a different UCM cluster or to
storage. You might also need to delete a CTL file from an IP phone if the secure cluster’s configuration
changes or you lose the security tokens with which the CTL was signed.
The phone will not reset when you press the **# keypad sequence from the Settings menu. The phone will reset
when you press the **#** keypad sequence at the Settings menu of a Cisco IP phone. An IP phone reset will
reinitialize the phone, which means that the phone will reboot, contact the Dynamic Host Configuration Protocol
(DHCP) server to obtain network configuration information, and then download its configuration file from the
TFTP server. The IP phone will also unregister and reregister with the Cisco call processor platform.
The phone will not restart when you press the **# keypad sequence at the Settingsmenu of a Cisco IP phone.
An IP phone restart is different from a reset because a restart does not contact the DHCP server. Instead, the
phone will store and reuse the network configuration information that was previously obtained from the DHCP
server. However, a restarted phone does connect to the TFTP server to download configuration updates. In
addition, the IP phone will unregister and reregister with the Cisco call processor platform. Because restarting
an IP phone circumvents the DHCP server, a restart brings the phone back to working order faster than a reset.
The phone will not be restored to the factory default settings when you press the **# keypad sequence at the
Settings menu of a Cisco IP phone. The method you use to restore a Cisco IP phone to factory default settings
varies by phone model. However, no Cisco IP phone can be restored to the factory default settings by pressingthe **# sequence at the Settings menu. When an IP phone is restored to the factory default settings, any
configuration changes that might be stored on the IP phone itself are restored to the factory default settings.
The phone will not dial the voice mail pilot number when you press the **# keypad sequence at the Settings
menu of a Cisco IP phone. To access voice mail from an IP phone, you should press the messages button on
the IP phone keypad. The IP phone should automatically dial the voice mail pilot number. If the phone’s
handset is on the hook, the voice mail system will use the IP phone’s builtin speaker to provide the audio for the
voice mail session.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/security/8_5_1/secugd/sec-851-cm/
secuauth.html#wp1077797