FRITZ!Box 7390 – Service - Knowledge Base

FRITZ!Box 7390 – Service
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Using an ISDN PBX with the FRITZ!Box

If you connect your ISDN PBX to the FRITZ!Box, the devices connected to the PBX can use all of the telephone numbers that were entered in the FRITZ!Box.

Requirements / Restrictions

  • The ISDN telephone system must be suitable for use on an ISDN point-to-multipoint line.

Note:The configuration procedure and notes on functions given in this guide refer to the latest FRITZ!OS for your FRITZ!Box.

1 Configuring telephone numbers in the FRITZ!Box

First, configure all of your telephone numbers in the FRITZ!Box:

Configuring Internet telephone numbers

Configuring landline numbers

Configuring a mobile telephone number

2 Connecting the PBX to the FRITZ!Box

  • Connect the PBX to the "FON S0" port on your FRITZ!Box.

3 Configuring the PBX in the FRITZ!Box

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the "Configure New Device" button.
  4. Enable the option "ISDN PBX", click "Next", and follow the instructions. The Wizard takes you through the configuration of your PBX.

4 Configuring the extensions of your PBX

If you do not assign telephone numbers to the extensions of your PBX, then the main telephone number you configured in the FRITZ!Box is used to make outgoing calls. In addition, all of the extensions react to all incoming calls. Therefore, assign the desired telephone numbers to the extensions:

  • In the PBX, define which numbers the extensions should react to when you receive calls and which number should be used to make calls. Enter the numbers in the PBX the way they are displayed in the settings for the ISDN PBX in the FRITZ!Box user interface (see fig.). If you assign an Internet telephone number to an extension, and that number is identical to a landline number, then outgoing calls from this extension will be made over the Internet.

    Note:Sometimes a number may be too long for you to enter the complete number in the ISDN device. If this is the case, do not enter the entire number. Instead, enter as many of the last digits as possible.

    Fig.: Settings for the ISDN PBX in the FRITZ!Box user interface