The extreme need of advanced features rather than basic features in telephony are becoming increasingly popular within telecommunication corporations and consumers Voice over IP provides more advanced unified communications applications like Web and video conferencing which is transforming the classical telephony to a step forward during the competition of GSM market.
VoIP refers to a way to carry phone calls over an IP data network, whether on the Internet or your own internal network. A primary attraction of VoIP is its ability to help reduce expenses because telephone calls travel over the data network rather than the phone company's network.
IP telephony encompasses the full suite of VoIP enabled services including the interconnection of phones for communications; related services such as billing and dialing plans; and basic features such as conferencing, transfer, forward, and hold. These services might previously have been provided by a PBX.
IP communications includes business applications that enhance communications to enable features such as unified messaging, integrated contact centers, and rich media conferencing with voice, data, and video.
Unified communications takes IP communications a step further by using such technologies as Session Initiation Protocol (SIP) and presence along with mobility solutions to unify and simply all forms of communications, independent of location, time, or device.