Mumbai: There is no official word about this from the world’s largest social networking site Facebook Inc., but many users who have the upgraded WhatsApp installed on their Android phones can now make voice calls to their friends or contacts who also have the app.

This development makes India’s over-a-decade long debate over Voice over Internet Protocol, or VoIP—the ability to make a voice call over the Internet—almost redundant since most companies anyway use a closed user group (CUG) network for VoIP calls which is legal. However, it will surely give Indian telecom services companies that are already burdened with high spectrum charges more cause for heartburn as they worry about a dent in their data revenue from over-the-top, or OTT, services providers like WhatsApp, WeChat, Line and Hike.

OTT refers to delivery of instant messaging, video, audio and other media over an open Internet connection directly to user, without the need for carriage negotiations and without any infrastructure investment on the part of the provider. They have numbers that telcos need to reckon with.

WhatsApp, which was acquired by Facebook for $19 billion in February 2014, had 700 million global users as of March, according to online statistics company Statista Inc. Of these, an estimated 10% users are from India. Facebook Messenger, on its part, has 600 million global users. Facebook.com itself has around 1.3 billion global users and about 110 million in the country. 

As of now, a voice call made from WhatsApp will depend on the bandwidth that your data plan offers. It is similar to how you would use similar OTT applications and services like Skype, that is now a Microsoft Corp. product, Facebook Messenger or even Google Hangouts. But how long will the party last? Much will depend on how India’s telecom regulator handles the debate of security and telcos losing potential revenue to OTT services providers.

Whatapp’s voice calling feature has been launched at a time when the Telecom Regulatory Authority of India, or Trai, is seeking comments on its consultation paper on ‘Regulatory Framework for Over-the-top (OTT) services’ that it released on 27 March. All comments and counter comments have to reach Trai by 8 May.