Yealink SIP-T2 SERIES Administrator's Manual page 567

Parameters
X ranges from 1 to 3 (for SIP-T40P/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
For ext keys:
X ranges from 1 to 6, Y ranges from 1 to 20, 22 to 40 (Ext key 21 cannot be
configured).
Note: It is not applicable to SIP-T19(P) E2 and CP860 IP phones.
Web User Interface:
DSSKey->Line Key->Label
Phone User Interface:
Menu->Features->DSS Keys->Line Key X->Label
To configure a BLF key via web user interface:
1. Click on DSSKey->Line Key.
2. In the desired DSS key field, select BLF from the pull-down list of Type.
3. Enter the phone number or extension you want to monitor in the Value field.
4. Select the desired line from the pull-down list of Line.
5. (Optional.) Enter the string that will appear on the LCD screen in the Label field.
6. (Optional.) Enter the directed call pickup code in the Extension field.
7. Click Confirm to accept the change.
To configure visual alert and audio alert for BLF pickup via web user interface:
1. Click on Features->Call Pickup.
2. Select the desired value from the pull-down list of Visual Alert for BLF Pickup.
Configuring Advanced Features
Permitted
Default
Values
545