1.21.1.11 ISDN ExtensionDescriptionAn ISDN (BRI/PRI) port can be used for either trunk or extension connection. When extension connection isenabled, ISDN terminal devices (e.g., ISDN telephone, G4 fax machine, PC) or a behind PBX can be connectedto the port.If the ISDN port is in point-to-point (P-P) configuration, one terminal device can be connected to the port. If theISDN port is in point-to-multipoint (P-MP) configuration, a maximum of eight terminal devices can be connectedto 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](131)Extn. No.: 13X (MSN)Extn. No.: 14XX (MSN)Extn. No.: 15XX(MSN)PBX(132) (139)......BehindPBX(1234)Extn. No.: 1234ISDN Port forEXTN. (P-MP)(1234) (1234)......1234:Up to eight terminalscan be connected tothe port and receivea call simultaneously.131–139:Up to eight terminalscan be connected tothe port.130:All terminals receivea call simultaneously.(1400) (1401) (1499)......1400–1499:Each terminalreceives a call.(Use the DDI/MSNfeature of thebehind PBX.)Idle ExtensionHunting is available.ISDN Port forEXTN. (P-P/P-MP)ISDN Port forEXTN. (P-P/P-MP)ISDN Port forEXTN. (P-MP)Conditions• SubaddressingSubaddressing is possible between ISDN terminal devices. The subaddress goes through the PBX to theISDN terminal devices directly.• Call Transfer (PBX feature) is available only for ISDN extensions in P-MP configuration. (® 1.12.1 CallTransfer)• ISDN extensions can belong to an incoming call distribution group (® 1.2.2 Incoming Call DistributionGroup Features) or idle extension hunting group (® 1.2.1 Idle Extension Hunting). In this case, an MSNcan be assigned.250 Feature Guide1.21.1 Integrated Services Digital Network (ISDN)
