Yealink SIP-T23P User Manual page 136

User Guide for the SIP-T23/T23P/T23G IP Phone
How to obtain the MAC address of a phone when the phone is not powered on?
Three ways you can 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) or 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 that the ringer volume on the phone. To adjust the ringer volume setting, press
the Volume key when the phone is idle. For more information, refer to
26.
Why can't I receive calls?
Check that the SIP registration with your system administrator.

Check that the DND (Do Not Disturb) mode is deactivated on the phone. Refer to

Do Not Disturb (DND)
Check that call forward is disabled on the phone. Refer to

81.
Check whether the caller number is stored in the blacklist directory. Refer to

Blacklist on page 40.
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

126
Phone Installation
on page 77.
Phone Installation on page 11.
on page 11.
on page 11.
Volume on page
Call Forward on page
Headset Mode