Certain special numbers (emergency numbers, toll-free or particularly expensive service numbers) can be subjected to special treatment by the call router.
- For example, this ensures that emergency numbers for the police or fire department are always secured, even if the subscribers do not dial the correct preceding dialing signal for outside line access. With the standard settings, the emergency numbers "110" and "112" are configured in such a way that they can be dialed correctly with or without the preceding "0".
- For toll-free numbers such as "0800", a direct connection via ISDN is usually selected in order to use the toll-free land-line to land-line connection.