At the moment the demand for IP Telephony is increasing because of its scalability and efficient use of bandwidth. The main issues are security and quality of voice in IP Telephony .The study comprises previous research papers and, on the bases of those papers, comparison is made between two security techniques, IPSec VPN and MPLS VPN. The goal behind this study is to build an IP Telephony setup, with security for private branch network, which is an ISP. IP Telephony networks are currently facing issues regarding security and competent packet switching.

The comparison further describes that MPLS VPN technique is more scalable and efficient than IPSec VPN, which has been approved in implementation. In the implementation, one centralized call manager is configured to establish calls between different sites. To secure traffic over the internet which travels from one site to another other site, MPLS VPN is configured in MPLS domain. In order to increase the performance of IP Telephony, quality of service (QoS) is implemented. QoS provides thriving outcomes and it is also practically implemented in the lab. QoS enhances the flow of data by prioritizing the voice packets. At the end, it is concluded that MPLS VPN is more efficient and scalable than IPSec VPN, and shows better results, while completely supporting QoS.