Spam over Internet Telephony (SPIT) is telephone spam over Internet telephony. These are unsolicited and dubious calls with advertising messages. The acronym SPIT is based on the English word for spit.
Since the cost of Internet telephony is extremely low, this market lends itself to spams, especially automated spams with recorded offers.
The contact or IP telephone addresses can be obtained by telephone spammers from the global online directory Telephone Number Mapping( ENUM). In this directory, the addresses of the most diverse communication services are standardized. ENUM links resources from telecommunications networks and the Internet and integrates telephone numbers into the Domain NameSystem( DNS). ENUM defines how a telephone number is mapped to a domain.