Originally Posted by
gfunkdave
Yes, you're both right. Verizon's Messages app is a special case where they apparently encapsulate the data that traditionally go over the cellular network into IP.
Except that Verizon's Message+ when sending over Wifi/IP is not actually SMS. It is IM. SMS is actually a protocol that cannot be run over IP. You can receive an SMS message and re-encapsulate it into an IP-based IM, but at that point it is no longer SMS. Strictly speaking of course.