5.2.5 ISDN Extension Features
5.2.5.1 ISDN Extension
Description
An ISDN (BRI/PRI) port can be used for either trunk or extension connection. When extension connection is
enabled, ISDN terminal devices (e.g., ISDN telephone, G4 fax machine, PC) or a behind PBX can be connected
to the port.
If the ISDN port is in point-to-point (P-P) configuration, one terminal device can be connected to the port. If the
ISDN port is in point-to-multipoint (P-MP) configuration, a maximum of eight terminal devices can be connected
to the port. However, only a maximum of two devices can be used simultaneously.
Individual terminal devices on a behind PBX can be addressed with Multiple Subscriber Number (MSN).
The MSN consists of the ISDN extension number and an additional digit, 0 through 9 or 00 through 99.
[Example]
Conditions
• Subaddressing
Subaddressing is possible between ISDN terminal devices. The subaddress goes through the PBX to the
ISDN terminal devices directly.
• Call Transfer (PBX feature) is available only for ISDN extensions in P-MP configuration. (® 2.12.1 Call
Transfer)
466 Feature Guide
5.2.5 ISDN Extension Features