BusinessPhone Communication Platform 5.1
Facilities

## Private Trunk Line

## Definition

Private trunk line means that a trunk line can only be utilised by an identified extension.

Incoming traffic via the same trunk calls the extension directly, either as individual answering position or external line key. The line can be transferred freely to another party.

## Use

A private trunk is used foremost when an extension user in an organisation (a company) has sufficient traffic to motivate his own trunk.

Like other trunks the private trunk can have multiple representation, e.g. on a secretary's telephone.

## Operation

### Incoming call on external line key

The lamp for the programmed trunk key is showing rapid flash.

1. Answer call by pressing key.

- Lamp flashes to confirm connection.

### Incoming call on Line 1

1. If trunk has been inserted as individual answering position, answer call by pressing key to call traffic function for own number.

### Outgoing call via external line key

1. Press programmed external line key.

- Lamp flashes to confirm connection.
- Dial tone received from public exchange.

### Outgoing call with directory number

1. Dial directory number of trunk.

- Lamp flashes to confirm connection.
- Dial tone received from public exchange.

## Capacity

All trunks can be programmed as private trunks.

## Limitations

A trunk that is to be available only to its “owner” for outgoing external traffic must be removed from route searching.

The trunk can be transferred to another party and is then inaccessible for its owner.

A private trunk line that calls own number can be diverted if it is not represented on an external line key.

Also a trunk that has been programmed as a private trunk line can be accessed if the individual directory number of the private trunk line is known.

All extensions possessing private trunk lines can form an own traffic group. This prevents the trunks from being accessed by extensions that do not possess private trunk lines.

Also private trunk lines are subjected to TCD-analysis and are dependent on the extension's category.

## Programming

0301 |  | Function of programmable key

Enter the function code = 12

0302 |  | Assiciated number

0303 |  | Ringing on incoming call

### Individual programming

The external line key can also be programmed via individual programming.

See document Facility Description - General (155 34-ASB 150 02 Uen).

Following command is only accessable via BMS:

3201 |  | Assigning an external line to a route

## Equipment

None

Revision: D © Ericsson Enterprise 2003