Voice over IP and network convergence

As the IP network was primarily designed to carry data, it does not provide real-time guarantees but only provides best effort service, which is inadequate for voice communication. Upper layer protocols were designed to provide such guarantees. Further, as there are several vendors in the market implementing these protocols, conformance to standards and interoperability issues have become important with general VoIP (Voice over Internet Protocol) description noting VoIP advantages, disadvantages, problems with reliability and security.