I need make voice call between 2 mobile via local WIFI without Internet. I build server on PC via C#. the server will provide all mobile clients with the mobile IPs on network. the user will use mobile Application to connect with serve and fetch the IPs then select one IP to make voice call .
I need help or tutorial to build the APP allow make voice call between 2 device by Xamarin. If I can not use Xamarin , guide me on android studio