Joke Collection Website - Blessing messages - In recent days, I have received many short messages saying that individuals cannot lend, rent or sell calling cards at will. What should I do if I suddenly think of buying a mobile phone calling card?

In recent days, I have received many short messages saying that individuals cannot lend, rent or sell calling cards at will. What should I do if I suddenly think of buying a mobile phone calling card?

Either there is an automatic stop, or you go to the business hall to cancel. The mobile phone card has a contract and has to wait until it expires.

If you buy a calling card with your mobile phone, you can use it normally with your ID card. Don't rent, lend or sell calling cards.

Cancel it if you don't use it. After the cancellation, it has no effect on me.

Specifically, the functions of calling cards are mainly reflected in the following aspects. The data stored in the SIM card can be divided into four categories:

The first category is fixed storage data. This kind of data is written by SIM card center before the mobile phone is sold, including international mobile subscriber identification number (IMSI), authentication key (KI), authentication and encryption algorithm, etc.

The second category is temporarily stored network data. Such as location area identification code (LAI), mobile subscriber temporary identification code (TMSI) and public telephone network code without access.

The third category is related business codes, such as personal identification number (PIN), unlocking code (PUK), billing rate, etc.

The fourth category is the telephone book. Almost all the user's data are stored in SIM cards, so SIM cards are also called "subscriber data identification cards". SIM cards can be divided into big cards and small cards. Small cards are called "plug-in SIM cards", that is, chips on big cards.