Yealink SIP-T48G Administrator's Manual page 365

Configuring Basic Features
Parameters Permitted Values Default
Description:
Configures the desired line to apply the directed call pickup key.
For line keys:
X ranges from 1 to 29 (for SIP-T48G).
X ranges from 1 to 27 (for SIP-T46G/T29G).
X ranges from 1 to 15 (for SIP-T42G/T41P).
X ranges from 1 to 21 (for SIP-T27P).
X ranges from 1 to 3 (for SIP-T40P/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
For programable keys:
X=1-10, 12-14 (for SIP-T48G/T46G)
X=1-10, 13 (for SIP-T42G/T41P/T40P)
X=1-14 (for SIP-T29G/T27P)
X=1-10, 14 (for SIP-T23P/T23G/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).
Permitted Values:
1 to 16 (for SIP-T48G/T46G/T29G)
1 to 12 (for SIP-T42G)
1 to 6 (for SIP-T41P/T27P)
1 to 3 (for SIP-T40P/T23P/T23G)
1 to 2 (for SIP-T21(P) E2)
1-Line 1
2-Line 2
...
16-Line 16
Note: It is not applicable to SIP-T19(P) E2 and CP860 IP phones.
Example:
linekey.1.line = 1
Web User Interface:
DSSKey->Line Key/Programable Key->Line
Phone User Interface:
Menu->Features->DSS Keys->Line Key X->Account ID
Blank
linekey.X.value/ String within 99
345