LTE, is the NGN that is all IP-based with improved capacity, speed and profit but it brings internet security risks in telecom networks which until now have been closed. It comes up with new vulnerabilities, has more attack surfaces and is more likely to be attacked in near future. Having wider security threats opens up new doors for intruders. The new infrastructure elements IMS, STP, SIGTRAN and SS7 network protocols have unpatched vulnerabilities and multiple entry points for DDOS, code execution, which can lead to disruption to customer’s voice and data privacy. Techniques to perform attacks like DDOS, packet & Voip sniffing , modification, application layer attacks will be discussed here.