Just arrived in Antigua for 6 months. I have an Iphone 6 with US At&T, which has wifi calling. It works superb everywhere connected to the internet EXCEPT the villa we are renting. It is a slow connection, but we can do low quality streaming, so I would think it can handle voip calling. I have limited tech knowledge, but am convinced its' something/setting in the Claro router. The reason I think this is die to the fact that the wifi calling menu symbol just doesn't appear at all. Finally figured out how to log into the router, but everything is in Spanish. If I knew the setting/s that may block voip I could figure the router out, I think. ANY THOUGHTS OR SUGGESTIONS WOULD BE MORE THAN WELCOMED !!!!