In the context of IT knowledge, numbering is the assignment of a telecommunications or data service to a terminal device. A distinction must be made between numbering in fixed and mobile networks on the one hand and in IP networks on the other. In both cases, numbering is a sequence of digits structured in a specific way.
As far as numbering in fixed networks is concerned, this comprises the national country codes with the international prefixes, the local area code for regional assignments, and the terminal-specific numbers. In the case of mobile networks, this involves the country codes, the operating companies and the terminal numbers. The situation is different in IP networks, where the subscriber's IP address ensures unique assignment.
The numbering of telecommunications services and terminals corresponds to the numbering space standardized by the International Telecommunication Union( ITU). In voice networks, numbers are assigned in accordance with the ITU standard E.164. In addition to this numbering plan, there is also number portability for switching between operating companies and the UPT number, which stands for Universal Personal Telecommunications, for global communications.
In IP networks, numbering is also done by a sequence of digits for the IP address. Depending on the protocol version, the IPv4 address is a sequence of four digits separated by dots. This notation is called Dotted Decimal Notation. The IPv6 address was increased in the address range to 128 bits instead of the 32 bits for IPv4. Since the notation is extremely complex, the addressing system was changed from digits with the Domain NameSystem( DNS) to alphanumeric names such as ITWissen.info.