Sony Ipela PCS-XG80 Operating Instructions Manual page 87

Setup > ISDN > Number
The setting has been configured properly if the correct line number appears
in the Home menu.
2
Remote parties must configure in the same way.
Note
When connecting to the ISDN unit, use the ports in ascending order.
Yes: 1, 2, 3...
No: 1, 6, 5...
To connect to a remote party
Select "ISDN" under "Line I/F", enter the remote party's line number, and
dial.
For details on how to start a visual communication, see "Starting a
Connection by Calling a Remote Party" (page 88).
ISDN2
Area Code
A1
A2
B3
B2
C1
C2
Auto SPID
Save
Setting Up the Network Configurations
Local Number
Execute
Cancel
87