Call Ringing and Call Busy (Engaged) Tone/Signal in VOIP Application

The task is to implement a Call Ringing and Call Busy (Engaged) tone/signal in a VOIP application. The Call Ringing tone is heard by the caller when the recipient's phone is ringing, and the Call Busy tone is heard by the caller when the recipient is busy on another call. When the line is busy, the existing call status on the call screen should change to 'Line Busy'. The tones are in MP3 format and need to loop from a private server.