I have implemented peer to peer call using csipsimple where I am able to call any device which is connected to local network. It works fine for me. Now i want to make a conference call where more than one user can participate. Is it possible to make a conference call in local network using csipsimple? Or is there any other way? Please give me some advice. Thank you.
You don't want a VOIP type application for this, you want a gamer voice-chat application like Mumble . It's a very similar concept but designed to be used on LANs and for end users to run their own servers without requiring any internet access.
Mumble in particular is very easy to install on Windows, Android.