The inherent needs of organizations to improve and amplify their technological platform entail large expenses with the goal to enhance their performance. Hence, they have to contemplate mechanisms of optimization and the improvement of their operational infrastructure. In this direction arises the need to guarantee the correct operation and non-degradation of the services provided by the platform during the periods with a significant load of work. This type of scenario is perfectly applicable to the field of VoIP technologies, where users generate elevated loads of work on critical points of the infrastructure, during the process of interaction with their peers. In this research work, we propose a solution for high availability, with the goal of maintaining the continuity of the operation of communication environments based on the SIP protocol in high load. We validate our proposal through numerous experiments. Also, we compare our solution with other classical VoIP scenarios and show the advantages of a high availability and fault tolerance architecture for organizations.

Attacks on networks which implement VoIP could lead to the degradation of the IP PBX performance, the interception of conversations, the theft of important and confidential information, and the generation of large expenses in any organization, if they do not have the correct security mechanisms. VoIP is based on existing layers and protocols and therefore inherits their security issues. In relation to signalization, different protocols have been proposed for VoIP. However, the Session Initiation Protocol (SIP) tends to be the favorite one because it is standardized by the IETF and has many features. Similarly to any other Internet protocol, SIP is susceptible to security threads, and can be involved in different kinds of attacks. In this paper, we propose three basic scenarios, representing common fundamental network architectures for VoIP, from which more complex systems can be built. We also establish a set of policies and guidelines focused on the aforementioned architectures, in order to mitigate security threads and provide more effective solutions for existing vulnerabilities in VoIP.