Specifications

User Guide SIP-T28P IP Phone
116
check whether 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 does the phone not ring?
Check the ringer volume on your phone. To adjust the ringer volume setting, press the
Volume key when the phone is on-hook and idle. For more information, refer to Volume
on page 27.
Why can I not receive calls?
 Check the SIP registration with your system administrator.
 Check DND (Do Not Disturb) mode is turned off on your phone. Refer to Do Not
Disturb (DND) on page 69.
 Check call forward feature is disabled on the phone. Refer to Call Forward on page
72.
 Check whether the caller number is stored in the blacklist directory. Refer to Blacklist
on page 34.
Why is my handset not working?
Check to ensure that the handset cord is fully connected to both the handset jack on the
phone and handset. Refer to Phone Installation on page 13.
Why is my headset not working?
 Check to ensure that the headset cord is fully connected to the headset jack on the
phone. Refer to Phone Installation on page 13.
 Check to ensure that the headset mode is activated. Refer to Headset
Activation/Deactivation on page 41.
 Check to ensure that the headset volume is adjusted to an appropriate level. Refer
to Volume on page 27.
What will happen if I connect both PoE cable and power adapter? Which has the
priority?
The phones manufactured before February 2010 use the power adapter preferentially,
otherwise the phones use PoE preferentially.
How to change the user password?
You can change the user password via web user interface:
1. Click on Security->Password.
2. Enter the current user password in the Current Password field.