voice chatting app

Need to make a platform like Zello for instant talking PTT. User should be registered in a server (private/ public IP) Local server and clients to configure with any specific server, Wifi based, Internet based connection. Should create group up to 50 members, One to one and one to many communication possible Consider to save battery when idle, Should be active in idle condition like zello and should read ringer profile (volume can be customized based on ringer [login to view URL] it is mute it should be mute and if volume low it shold haeve low volume. Status: avail, Busy, Off. When phone communication it should be busy startup program Offline message limit setup for % mb and can be played back Use low bandwidth for audio compresion. Better for those ,who already done such project.