Mangoe

Mangoe is a Mobile VoIP dialer application that allows to make VoIP calls from any of the Android devices and it uses 3G/Edge/Wi-Fi Internet connectivity.It is developed based on the requirements of VoIP Providers business needs
Features :-
It uses SIP protocol based for signaling.
Supports G729,PCMU, PCMA codecs.
Runs Behind NAT or private IP.
User Friendly Interface.
Auto Sync of Balance.
Real Time Sip status messages.
Call History.
Address book integration.
It has very efficient implementation of jitter buffer to play voice smoothly.
Silent suppression and comfort noise generation has been used to reduce the bandwidth usage, and this makes the dialer more efficient in making VoIP calls.
Integrates with mobiles phonebook and auto detects (+) sign when contact is picked from phonebook.