Voice over the internet can be used with existing Local Area Network infrastructure within an organisation such as DIT to cut down the communication costs within the campus premises. This paper presents how can VoIP intercom be set and the requirements of the system. Voice is very important method of communication and hence is important to make it cheap and easily available. In this work, a VLAN was created in the DIT LAN then an appliance IP-PBX was installed, the phones were connected to a nearest by backbone switch. With gateway of the phones being the IP-PBX and VLAN tagging of the respective connected switch ports, the phones were able to connect to the PBX. The analysis of the system during busy hour shows that the system reliable and suitable to be used if the concurrent calls do not exceed the maximum capacity of the PBX. It is on this basis that this paper tends to critically review this new technology VoIP, x-raying the different types. It further more discusses in detail the VoIP system, VoIP protocols, and a comparison of different VoIP protocols. The compression algorithm used to save network bandwidth in VoIP, advantages of VoIP and problems associated with VoIP implementation were also critically examined. It equally discussed the trend in VoIP security and Quality of Service challenges. It concludes by reiterating the need for a cheap, reliable and affordable means of communication that would not only maximize cost but keep abreast with the global technological change.