Rapid developments in information technologies have made these technologies indispensable elements of our lives with application areas such as e-government, e-commerce, e-health, e-learning. Particularly the global Covid-19 pandemic period has led to forced improvements in video conferencing applications, which enable users in different locations at the same time to communicate via video and audio over internet. Developments in technology, which cause the rapid increase of applications served over internet, also cause a significant increase in the number of devices connected to internet and the data traffic flowing over internet. As a result, the security needs of applications used over internet, such as video conferencing applications, are increasing in proportion to the increasing security threat risks. The use of firewall and VPN (Virtual Private Network) are the most basic security solutions for applications used over internet. A firewall is a device, which is positioned between a corporate network and the internet cloud, filtering incoming and outgoing traffic to and from the network according to defined rules. VPN, on the other hand, provides a secure point-to-point connection to a corporate network through the internet cloud. In this study, the effects of firewall and VPN usage in video conferencing applications were analyzed in terms of application performance. In video conferencing applications; since there is a real-time, bidirectional and large-scale data flow between the participants, delay and packet loss determine the performance of these applications. Analyzing how these applications perform when used with firewalls and VPN will guide further improvements in network protocols, components and related applications. In the study in which the simulation method was used, the data obtained from the simulation of different scenarios created with the OPNET tool were analyzed comparatively.