national subscriber number

ITU RecommendationE.164 defines the structure of international telephone numbers. It consists of the country code, local area code and subscriber number.

The national subscriber number consists of the local area code and the subscriber number. This corresponds to the last two telephone numbers of E.164. The national subscriber numbers are assigned by the RegTP. For example, the RegTP has designated the number range (0)32 for Internet telephony.

Due to their geographical independence, the national subscriber numbers open up new service features for service providers and can be retained in the case of mobile IP as well as in the case of a move. Service providers can offer NTR numbers nationwide without having to rely on number assignment in the local network area.