Cloud based Voice over Internet protocol (VoIP), is a new type of communication that uses Internet protocol to transfer the data packets which contains the audio data. For the past 20 years there has been an intensive research going on this field since this makes the calling system much cheaper than those taking place over PSTN (Public Switched Telephone Network). VoIP has been mainly taking place through cloud computing and this feature has its own issues but even has its own pros. This feature over cloud is facing many challenges in the terms of quality of services and security. This paper also describes the research or the development taking place in field of secured discussions. The network components and architecture have been discussed; the components described are call processors, gateways and many more. Different attacks possible on the VoIP have been discussed which include spoofing and SPIT. There are different VoIP solutions and they are based on either peer-to-peer (P2P) protocol or Session Initiation Protocol (SIP). In this paper, we have analysed about some of the essential security issues on cloud based VoIP for preventing the adaptive anomaly attacks and some other security issues of cloud computing by applying the algorithmic simulation in hadoop clusters.