Yealink SIP-T54S Administrator's Manual page 262

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
The following shows two line keys associated with a registered account 101:
When you customize multiple line keys to be associated with an account, you can configure the
IP phone whether to transfer a call or set up a conference call using a new line key.
Procedure
Multiple line keys per account can be configured using the following methods.
Central Provisioning
(Configuration File)
236
<y0000000000xx>.cfg
<MAC>.cfg
Configure auto linekeys.
Parameter:
features.auto_linekeys.enable
Configure whether to transfer a call using
a new line key on a phone basis.
Parameter:
phone_setting.call_appearance.transfer_vi
a_new_linekey
Configure whether to set up a conference
call using a new line key on a phone
basis.
Parameter:
phone_setting.call_appearance.conferenc
e_via_new_linekey
Configure the number of DSS keys to be
assigned automatically.
Parameter:
account.X.number_of_linekey
Configure whether to transfer a call using
a new line key on a per-line basis.
Parameter:
account.X.phone_setting.call_appearance.
transfer_via_new_linekey