WhatsApp voice call functionality has been activated for most Android users have the most current version of the application in the device. Over the weekend, most users activate the features. To obtain it, you need to have at least a play store or from WhatsApp website 2.11.531 version 2.11.528.
According to AndroidPolice, voice-calling could be be activated by receiving a call from someone who already has the voice-calling feature. One the user receives a call they can see three tabs instead of recent chats, namely Calls, Chats and Contacts. The call tab showed incoming, outgoing and missed calls. Unfortunately however, it seems like the invite system has been deactivated by WhatsApp for the moment.
Whatsapp Calling feature is only for those who have the latest version of the app, even though you call your friend sor familly the feature will not get activated for them.
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Although this feature was not without its shortcomings. There is a definite lag much like Viber, which makes it a more frustrating and confusing conversations, because of the time it takes for one party to hear what the other is saying.
Another problem which has been spotted is regarding the echo of a users voice. When the calling feature has been activated in an appartment or building, echos of the users voice could be heard. This echo played back after some delay and it was also what the person at the receiving end was hearing. But, this echo issue was not occuring when a user is on the go.
The beep sound is another problem user have sighted during ongoing calls. Users have stated that they are hearing a beep sound during a call, which is because of the incoming Whatsapp message. If you face any such problems do share with us in the commendt box below.