Securing VOIP networks via Transport protocols Layer

Voice over Internet Protocol (VoIP), is a technology that allows you to make voice calls using a broadband Internet connection instead of a regular (or analog) phone line. VoIP services have compelling technical advantages over circuit switching. VoIP networks are based more on an open architecture than that of their circuit-switched contemporaries. This open, standards-based architecture means that VoIP services are more interchangeable and more modular than that of a proprietary, monolithic voice switch. One can now select best-in-class products without being tied to one specific vendor. Open standards also translates into the realization of new services that one can rapidly develop and deploy rather than waiting for a particular vendor to develop a proprietary solution. Moreover, VoIP is suitable for CTI (Computer Telephony Integration) and other next-generation applications, which are insightful when looking to future networks that, provide enhanced services. VoIP traffic has a number of issues that should be carefully considered, such as traffic parameters and network design. Without such due diligence, one could be faced with service that does not function reliably or is severely degraded. These important considerations are Latency, Jitter, Bandwidth, Packet Loss, Reliability & Security. In this paper, the focus shall be on the Security aspect, its threat and measures to prevent it on various layers of the VOIP protocol. One of the common mistakes when approaching Voice over IP Security is to treat this technology and its applications like all other network-based applications and therefore use classical security measures. This approach fails to consider the fundamental property that makes VoIP different from classical network-aware technologies: Voice over IP is time critical. It demands Quality of Service (QoS) and is generally deployed over an environment where QoS does not exist as a standard feature. In this proposed research, we examine and investigate the concerns and requirements of VoIP security. After a detailed study of security issues and defense mechanisms, we focus on attacks and threats at Transport protocol layer and countermeasures to it that are essential for current and future VoIP implantations. Then, we analyze few popular industry best practices for securing VoIP networks and conclude this paper with further discussion on future research directions. This paper aims to direct future research efforts and to offer helpful guidelines for practitioners.