Ubuntu – Video and Audio calls are not working in skype


I am using ubuntu 16.04. I installed the latest version of skype (V. It's working fine in text message, but when i make a video or audio call it showing me error "Your connection is too weak. Please try again later.". I am using high speed Ethernet connection. I tried in windows using same network connection, it's working fine.

I disabled the firewall, but nothing worked.
enter image description here