PSTN

The public switched telephone network (PSTN ) is the network of the world's public circuit-switched telephone networks. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital in its core and includes mobile as well as fixed (plain old telephone service , POTS) telephones.

The PSTN is largely governed by technical standards created by the ITU-T , and uses E.163 /E.164 telephone numbers for addressing.

 

其中E.164等是一种号码规则，如可以sendE164(true/false)

E.164 is an ITU-T recommendation which defines the international public telecommunication numbering plan used in the PSTN and some other data networks .