If authorized (contact System Support), you can set ISDN functions via code dialing in some countries. 

Press the key. The LED lights up. 

Confirm. 

Enter the code. 

Enter the number of the trunk you wish to use (contact System Support). 

Entering a code for required ISDN function. 

Contact your network provider to find out which ISDN functions can be code-controlled in your country.  Siemens AG shall not be liable for damages/costs which may be incurred by fraudulent activities or remote operation (e.g. toll fraud).