Unfortunately, the modern mobile industry is built to a large extent on the basis of deception. Playing with the ignorance of their customers, the mobile monopolist’s offer them the services at unreasonably high prices. The subscriber has no possibility to determine what the price of the call includes and has no idea who in particular provides him whis this service.
Fundamentally, the fact that your call has to pass through several transit operators, before reaching the phone of the interlocutor, would not be so important if the whole chain of operators-intermediaries did not cost you a pretty penny.
The most cumbersome fact in this chain is a large mobile operator which network your call is addressed to, so-called «operator B». He gets incredible amount of money for sending the call to the person you are calling to.
Technically the mobile operator sends this call just as well he does it with his internal calls. But it will provide this service at three times higher price, because the call is «international»…