Bharti Airtel customers will now have to pay more -- Rs 10,000 per GB on 2G network -- for making calls on Skype, Viber or other apps, as the operator has decided to charge extra for VoIP service (voice calls over Internet).

"All internet/data packs or plans (through which customer can avail discounted rate) shall only be valid for internet browsing and will exclude VoIP (both incoming/ outgoing). VoIP over data connectivity would be charged at standard data rates of 4p/10 KB (3G service) and 10p/10 KB (2G service)," Airtel said on its website.

Based on standard rates, usage of each GB of data for VoIP on 3G network will cost about Rs 4,000 and while the same on 2G netwrok will cost about Rs 10,000.

Under schemes, Airtel sells 1GB of 3G data for Rs 249 and 1GB of 2G internet for Rs 175.

This is the first time in the country that any mobile operator is charging separately for VoIP service.

"We have made some revisions in the composition of our data packs, and will offer VoIP (Voice over internet protocol) connectivity through an independent pack that will be launched shortly. Our customers can continue enjoying voice calls over data connectivity by opting for this VoIP pack, or simply use VoIP services on pay-as-you-go basis," Airtel said in a statement.

Mobile operators have long been demanding the over the top (OTT) players like WhatsApp, Line, Skype among others should be brought under regulation.

India Infosec Consortium, which deals into cyber security and internet governance related issues, criticised the move of the telecom major.

"The telecom operators plans of segregating VoIP calls data and charging exponentially higher rates on them smells of sheer greed in its concepts itself. This will be against basic concepts of net neutrality. The very essence of technology and low cost internet telephony needs to be cherished and protected," IIC CEO Jiten Jain said.