Recently Whatsapp introduced calling facility through internet. It seems very exciting for all whatsapp user. But unfortunately calling facility efficiently work on 3G and 4G data connection.
When you make a call using whatsapp, in 2G data connection and it will give worst calling quality . After that whatsapp send message that you have a missed call.
In India 70% users prefer to use 2G data connection rather than 3G , So if whatsapp resolve this problem in future it will be a great advantage for whatsapp and its users.
Thanks, Worked perfect.