Direct dialling inward (DDI)

The DDI service enables a user to call a user on a private ISDN directly via the public ISDN, by using a public ISDN numbering plan. The DDI number is used by the private ISDN to progress the call to the destination user. The DDI service is possible on Basic and Primary Rate accesses in a point-to-point configuration.

Multiple subscriber numbers (MSN)

The MSN service provides the facility to assigning multiple numbers (not necessarily consecutive) to a single basic access (BRA). This enables the selection of one or multiple distinct terminals attached to the same access.

Terminal portability (TP)

The TP supplementary service provides users with the possibility of moving a CPE terminal from one S0-bus socket to another within one given Basic Access during the active state of a call, by suspending and resuming the call for a limited period of time. This feature is available to ISDN customers on BRA only.

Line Hunting on BRA services (LH)

LH enables incoming calls to a specific ISDN number to be distributed over a group of interfaces. The line hunting feature performs an automatic search for an idle line in a PBX hunting group in terminating traffic, the lines being seized in a fixed order (hunt sequence). This feature is available to ISDN customers on BRA.

Calling line identification presentation (CLIP)

The CLIP service provides the called user with the possibility of receiving the identification of the calling user. The identification is not always possible, e.g. when the calling user does not allow the presentation of his number, or in case of interworking with other networks. The complete number might also not be presented if the calling user is an extension off an ISDN PABX. This feature is available to ISDN customers on BRA and PRA.

Calling line identification restriction (CLIR)

The CLIR service enables the calling user to restrict presentation of its ISDN number at the called user. The invocation of the restriction is done on a call-by-call basis. This feature is available to ISDN customers on BRA and PRA.

Call waiting (CW)

The CW supplementary service provides a user with the option of being notified of another incoming call when all B-channels are in use. The user has the option to accept, reject or ignore the call within a limited period of time.

Call hold (CH)

The CH supplementary service allows the user to put a call on hold or to make or answer another call and at any stage resume the original call.

Call forwarding, (CF)

The CFU supplementary service permits the served user to have the exchange forward all incoming calls to the forwarded-to number.

3Party Conference (3Pty)

The Three party service enables a served user to establish, participate in and control a three-way conversation.