Integrated Services Digital Network (ISDN) is a digital switching and transmission network. ISDN transmits voice, data, and image in digital format. ISDN lines can be connected to public line (CO line) or private line (QSIG).

ISDN Interface and Configuration

Interface Type

Description

Port Mode

Primary Rate Interface (PRI)

Provides twenty-three 64 kbps B channels for communication and one 64 kbps D channel for signaling (23B + D).

CO Line, QSIG–Master, QSIG–Slave

ISDN Supplementary Services for Public Network

Service

Description

Details in

Direct Inward Dialing (DID)

Directs a call with a DID number to the preprogrammed destination.

• 1.1.1.3 Direct Inward Dialing (DID)

Calling Line Identification Presentation (CLIP)

Sends the caller's telephone number to the network when making a call. The called party can see the number on his or her telephone display before answering the call.

• 1.19.1.2 Calling Line Identification Presentation (CLIP)

Calling Line Identification Restriction (CLIR)

Prevents the caller's CLI from being presented to the called party.

Caller ID

The PBX receives Caller ID information, such as the caller's name and telephone number, when a call is sent from the network. A display proprietary telephone (PT) user can see this information before answering the call.

• 1.16.1 Caller ID

Private Networking Connection (QSIG)

Private networking with QSIG is possible using an ISDN line. Each ISDN port must be programmed so that each ISDN line has a "master" connection and a "slave" connection.

•

En bloc
The PBX sends all of dialed digits at once after the extension user completes dialing. The PBX recognizes the end of dialing as follows:

—

When the extension user dials "#", if programmed

—

When the extension user dials a preprogrammed telephone number

—

When the inter-digit time expires

•

Extension Number
An extension number can be assigned to each ISDN port.

•

Network Type
Each ISDN port can be set to the requirements of each country/area.

•

L1 Active Mode and L2 Data Link Mode
The active mode of Layer 1 (L1) and the data link mode of Layer 2 (L2) can be selected individually (Permanent or Call by Call) for each ISDN port.

•

TEI Assignment Mode
The Terminal Endpoint Identifier (TEI) assignment mode can be selected for each ISDN port.

•

Bearer Mode
The bearer mode can be assigned for each ISDN port.

The PBX can send a preprogrammed telephone number to the network when an extension user makes a call. The called party can see the number on his or her telephone display before answering the call.

[Example]

CLIP Number
Telephone numbers sent to the network for Calling Line Identification Presentation (CLIP) can be assigned as follows:

•	A CLIP number for each ISDN port (subscriber's number)
•	A CLIP number for each extension ( CLIP Number [606])
•	A CLIP number for each incoming call distribution (ICD) group

Each extension can select to use the CLIP number either assigned to the ISDN port or to the extension. The CLIP number for the ICD group is used when making a call by pressing the G-DN button.

Calling Line Identification Restriction (CLIR)
It is possible for each extension to prevent the sending of its telephone number to the network by pressing the CLIR button or entering the CLIR feature number.

•	The availability of this feature is dependent on the contract with the telephone company.
•	The CLIP number for the connected ISDN port can be used for ISDN terminal devices which cannot be assigned their own CLIP number, such as doorphones.
•	CLIR Assignment for Each Port CLIR feature can be enabled or disabled for each ISDN port of the PBX.
•	CLIR Button It is possible to switch between CLIP and CLIR by pressing the CLIR button. Any flexible button can be customized as the CLIR button.
•	The CLIP number must match the telephone number provided by the telephone company. Otherwise it will be ignored or replaced by another number.
•	When using a private network, the extension number assigned for each extension through system programming ( Extension Number [003]) is sent for CLIP. ( 1.26.2.2 Calling/Connected Line Identification Presentation (CLIP/COLP) and Calling/Connected Name Identification Presentation (CNIP/CONP)–by QSIG)