Yealink SIP-T54S Administrator's Manual page 416

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
If it is set to 1 (Enabled), the IP phone can automatically answer an incoming call.
Note: It is only applicable to CP860 and CP920 IP phones. The IP phone cannot
automatically answer the incoming call during a call even if auto answer is enabled.
Web User Interface:
Account->Basic->Auto Answer
Phone User Interface:
Menu->Features->Auto Answer->Status
pstn.account.X.auto_answer_mute_enable
(X ranges from 1 to 2)
Description:
Enables or disables auto answer mute feature for PSTN account X.
0-Disabled
1-Enabled
If it is set to 1 (Enabled), the IP phone will mute the microphone when an incoming call is
automatically answered, and then the other party cannot hear you.
Note: It is only applicable to CP860/CP920 IP phones. It works only if the values of
parameters "pstn.account.X.auto_answer" and "features.allow_mute" are set to 1 (Enabled).
Web User Interface:
Account->Basic->Auto Answer Mute
Phone User Interface:
Menu->Features->Auto Answer->Auto Answer Mute
To configure auto answer via web user interface:
Click on Account->Basic.
1.
Select the desired account from the pull-down list of Account.
2.
390
Parameters Permitted Values
0 or 1
Default
0