AT&T SYSTEM 25 Manual page 186

Setting Up a Third-Party Call
1
Turn on the data terminal.
2
Press
The Command Mode menu is displayed.
3
Select
The following prompt is displayed:
4
Enter the destination number, followed by
of the terminal for which the call is being set up (the source), as in the
following example:
NOTE:
27 characters can be entered.)
To set up a call from the associated PDC or DDC, it is not necessary to
enter the
enter only
5 Press
If the source terminal is a voice terminal, it receives "priority ringing, " (two short bursts
followed by one longer burst). This terminal alerts for three priority ring cycles.
If the source voice terminal is not answered within the three priority ring cycles, the call
is terminated and the following message is displayed:
lf the Third-Party Call Set Up feature is either totally restricted, or the station is restricted
to an associated PDC/DDC (and a different PDC or DDC was specified in Step 4 above),
the display message will be:
6
Pick up the handset of the source voice terminal and listen for ringing,
busy, etc..
The following message is displayed on the screen:
4-12 Data Terminal Features
and then press
[BREAK]
<Voice call> .
DIAL:
5551704 F 403
Spaces can be used before and after the F for readability. (Up to
and the associated PDC or DDC. For example, to call 5551704
F
5551704.
.
[RETURN]
NO ANSWER
DISCONNECTED
DENIED
CONFIRMED
DISCONNECTED
.
[RETURN]
and then the PDC or DDC
F