"VoIP" is a generic term in this case as they mean numbers that can be rented online by a customer directly, with little to no identity checks - sadly those are often used for fraud, though outright denying service on this basis alone is a dick move IMO.

Pretty much all telephony is VoIP for at least parts of the call chain, though there are still even analog circuits in place; here are some numbers that lead to analog switching gear: http://www.binrev.com/forums/index.php?/topic/48166-ukrainia...