BusinessPhone Communication Platform 5.1
Facilities

## New Zealand – Centrex hook flash over ISDN

## Definition

The feature offers the possibility to an ASB 150 02 user to establish a market specific ISDN feature ’hook flash’ during an ongoing external call. By this the user is able to hold the ongoing call, make an inquiry call and initiate other CENTREX features supported by the public ISDN, for example call alternation or call transfer.

The two external call setups and feature procedures are handled with one call reference ( one D-channel ) and one B-channel to the network side.

## Use

The primary purpose of this functionality is to provide external inquiry functionality by generating a ’hook flash’ in the ISDN: to hold on the external B-party and making an inquiry call to another external C-party. Thereafter retrieve from hold or alter between the two external parties.

## Operation

ASB15002 is connected to the public ISDN via a T-reference point as a stand-alone PBX.

#### Feature activation

By pressing the programmable function key ’external inquiry key’ (’R-key’) a market-specific ISDN ’hook flash’ is generated to the network side, the ongoing call is put on hold and the user gets a new register in the ISDN to start of the inquiry call.

#### Network feature acceptance/rejection

An accepted feature activation request is indicated with a possible dial tone and a received request prompt indication for the start of digit sending.

A rejected feature activation request is indicated with corresponding result tones and/or by not received request prompt indicator.

#### Digit sending and connection to C-party

Suffix digit dialling is TCD suffix category controlled (ACOS). The suffix digit sending method is ’out-band DTMF’.

#### Retrieve from inquiry and alternation

With the same user key procedures, generating ISDN ’hook flash’, the retrieve and/or alternation of the inquiry call is indicated to the ISDN.

#### Sending of facility code digits

During the inquiry call at speech state the possible dialled facility code digits are sent without suffix-TCD control. The sending is done with the same procedures as sending the inquiry called party digits, i.e as ’out-band DTMF’.

The action on these facility code digits are interpreted and handled on the premises of the cooperating network, e.g. to initiate a transfer of the inquiry call in the ISDN.

## Capacity / Limitations

This feature is only accessable on system telephones with programmable function key ’external inquiry’ (R-key).

The two call setups A-party- B-party and A-party-C-party are handled as one call connection. Thereby the internal call logging (CIL) and call metering registration (CM) will generate only one call log.

## Programming

External inquiry procedures from user side and control of suffix digit dialling follows the programming and parameter setting of Register recall in PSTN (445/155 34-ASB 150 02 Uen); commands: 0301, 0179, 0180, 1018.

1911 |  | Network signalling protocol

The signaling Protocol must be set to “New Zealand”

1973 |  | ISDN Stimulus services

Combine the New Zealand network protocol with stimulus service “Hook Flash”.

## Equipment

- At least FECU Index 1 for Release ASB 150 02 R13 or higher
- ISDN firmware BA/PRA on BTU-DP or BTU-B_ or MFU.

Revision: C © Ericsson Enterprise 2003