Three Ways To Obtain The Mac Address Of A Phone; Why Can’t I Get A Dial Tone?; Why Doesn’t The Phone Ring?; Why Can’t I Receive Calls? - Yealink SIP-T21 E2 User Manual

User Guide for the SIP-T21(P) E2 IP Phone
How to obtain the MAC address of a phone when the phone is not powered on?

Three ways to obtain the MAC address of a phone:

You can ask your supplier for the shipping information sheet which includes MAC

addresses according to the corresponding PO (Purchase Order).
You can find the MAC address on the label of the carton box.

You can also find the MAC address from the phone's bar code on the back of the

phone.
Why can't I get a dial tone?
Check for any loose connections and that the phone has been installed properly.

For the installation instructions, refer to
Switch between the Handset, Headset (if present) and Hands-Free Speakerphone

to check whether the dial tone is present for one of the audio modes.
If the dial tone exists on another audio mode, connect a different handset or
headset to isolate the problem.
Why doesn't the phone ring?
Check the ringer volume on the phone. To adjust the ringer volume setting, press the
Volume key when the phone is on-hook and idle. For more information, refer to
on page 29.
Why can't I receive calls?
Check the SIP registration with your system administrator.

Check that DND (Do Not Disturb) mode is deactivated on your phone. Refer to

Not Disturb (DND)
Check that call forward is disabled on the phone. Refer to

85.
Check whether the caller number is stored in the blacklist directory. Refer to

Blacklist on page 43.
Why is my handset not working?
Check that the handset cord is fully connected to both the handset jack on the phone
and handset. Refer to
Why is my headset not working?
Check that the headset cord is fully connected to the headset jack on the phone.

Refer to Phone Installation
Check that the headset mode is activated. Refer to

150
Phone Installation
on page 81.
Phone Installation on page 13.
on page 13.
on page 13.
Call Forward on page
Headset Mode
Volume
Do