IAX is a protocol created for video and VoIP transmission. It comes integrated with many staggering functionalities that help in improving problems as to SIP in VoIP. The IAX, in place of using real-time protocol (RTP), makes use of User Datagram Protocol (UDP) over a single Internet port (Port 4569) to receive and transmit media and signaling. IAX is also capable of making traversing of firewalls and makes use of much less overhead as compared to RTP. IAX also has the capacity of tripling the number of calls made using a single megabit when making use of the G.729 compression codec. Thus, the goal of IAX protocol, ever since its inception, has been to make VoIP correspondingly, so that even the least technical persons may be able to plug in a cost-effective IP phone and begin to make calls on it directly. As of now, there have been many a IAX VoIP based PC and mobile phone applications, making all your PC-to-Mobile and Mobile-to-Mobile, not only effortless, hassle-free, but cheaper than other calling services.