To ensure that an emergency call (110, 112, ...) is delivered to the right control centre, it is necessary to communicate information about the location of the person making the emergency call. Due to the legal requirements of the Technical Guideline Emergency Call Connections in Version 1.0, only information of the network connection point may be used for this purpose. For this, we use the exchange line of the extension. The set-up for desk telephones must be carried out accordingly:

• A local incoming trunk line must be set up with the location and country of the terminal.
• The location and country of the terminal device must match the location and country of the trunk line.

For Desktop App, Web App and Mobile App, there is the possibility of "nomadic use".

Therefore, reliable transmission of the location cannot be guaranteed for these apps as shown in the Service Description. If an assignment to a location can be made based on the configuration of the preferred trunk line of an extension and the call numbers associated with the extension, the preferred trunk line is used to transmit the emergency call. If this is not possible, the first German call number block of the system is transmitted with the central number.