[janwhite]

i saw a few online store sold a type of prepaid SIM, called "travelSIM" or "PassportSIM", all of them claims that "the SIM is Free to receive Incoming Calls in over 50 countries", is it ture?

i wonder how can they do that, who knows the platform provider of such free roaming solutions?

ps. most of the primary number(or active number) is +44(Isle of Man) or +372, are these area any special terms in telecom industry?

thank you guys!