The tech press started buzzing earlier this month with reports that Facebook planned to add VoIP (voice over IP) calling to its Messenger app for the iPhone. The new feature officially arrived, when Facebook released an update for its app.
Source : CNN Money
Facebook's app transmits calls using your phone's broadband connection, whatever it is 3G, 4G or Wi-Fi. Instead of sucking up your monthly allotted voice minutes from your cellular carrier, it sucks up megabytes from your data plan. That's a boon for heavy talkers with unlimited data plans.
But it's not all roses just yet. For now, this is a pretty limited offering. Your phone won't alert you the way it does when you have a normal call: Facebook calls just show up as a push notification. And right now, you can only connect with a conversation partner who also has Messenger installed on their iPhone.
There's no way to ring up a Facebook friend who is logged in through the website, and there isn't any way to place a call to a ten-digit phone number. Calling is still absent from the Android and BlackBerry versions of the Messenger app.
There's a good reason for those omissions. The VoIP features in the Web version of Facebook were built using Skype's technologies, while the calling technology in Messenger is all Facebook. The ability to place and receive calls using traditional phone numbers requires telecommunications resources Facebook doesn't have (at the moment, at least).
For the time being, services such as Google Voice and Skype have a leg up, given their larger feature sets. But Facebook generally doesn't let anything remain in stasis for long. As we've seen in the past and caught a glimpse of yesterday with the Graph Search reveal Facebook likes to start small, and steadily flesh out its products. Expect the same with voice calling.