25-08-2017, 09:32 PM
VoIP or Voice over Internet protocol is a technology for transferring voice by the means of internet protocol. Compared to public telephone network service, its main advantages remain in its very low cost. Many VoIP providers exist on the web (such as Skype, Ekiga, X-lite and so on), and give us free services: chat, call, and video-conference. It also allows us to call any phone number in the world from a machine connected to internet. Our discussion in this document is focused on VoIP, in its restricted sense, that is to say, the voice transferring mechanism over internet protocol. In this document we have briefly described the architecture, working, features, advantages and disadvantages of VoIP. We have also discussed the network protocol stack of VoIP which contains TCP/UDP,IP, RTP,RTCP,MGCP, H.323/SIP and its working in brief. We have described about a device called VoIP Phone used for VoIP calls and which possess the functionalities like VoIP. Another extension to VoIP named Mobile VoIP or mVoIP has also been discussed which provides mobility to VoIP. In any way, we think that in the future, VoIP will take the place of the current public telephone network because numerical gadgets are now invading the world market.