Panasonic KX-TD500 System Reference Manual page 299

B. Treatment of the call placed by the extension or outside party
1. Direct Call
1-1.
* 1
* 2
The treatment of a call from the extension or outside party varies
depending on the conditions of the called extension.
The KX-TD500 system does not send codes (DTMF tones).
The following detailed information explains the treatment of a call from
the extension or outside party by the types of the call.
To an extension
Ext./CO
The type of call progress tones sent to the caller varies depending on the
status of the called extension/VPS as follows.
Call State
Ringback Tone * 1
Busy Tone
DND Tone
Answer
In case of outside calls (DIL 1:1, DISA,DID)
If an incoming outside call is not answered by the extension in a specified time
period (IRNA timer), it will be transferred to another destination. — IRNA
Refer to "6. Intercept Routing No Answer (IRNA)" and "7. IRNA and Station
Hunting" on pages 3-F-52 through 3-F-55 for further information.
In case of calls via DISA/DID
If a call via DISA/DID is directed to an extension in the DND mode, it will be
automatically redirected to another extension (including VPS extension) or an
attendant console assigned as the IRNA destination.
For further information, refer to Section 4-D-6.00, 5-B-4.00 "Do Not Disturb
(DND)".
3-F-39
Ext.1/VPS 1
Conditions
The Ext.1/VPS 1 is idle.
The Ext.1/VPS 1 is busy.
The Ext.1/VPS 1 is in the DND mode. *
The Ext.1/VPS 1 answers the call.
2