13 The zero phone number is an Internet phone. VoIP is to digitize the voice signal, compress, encode and package it, transmit it through the network, and then decompress it to restore the digital signal to sound for the other party to hear. So 13 zero is the code of VoIP.

Internet phone, also known as VOIP phone, is a direct call to the other party's fixed phone and mobile phone through the Internet, including domestic and international long-distance calls. The tariff is 65438+ 00% to 20% of the traditional phone bill. Macroscopically, it can be divided into software mobile phones and hardware mobile phones. Generally, you should be careful when answering internet phone calls, and beware of being cheated. VoIP can't capture the caller.

The telephone number is the number set by the telephone management department for the telephone. Generally, it consists of 7-8 digits (mobile phone number is 1 1 digit), with 5-6 digits in the early stage.

The designated number set by enterprises, organizations, factories, mines and institutions for internal communication such as fixed telephones or mobile phones is generally 4-8 digits in length. It is also equivalent to the number and name of each mobile phone.