Network slicing is the crucial prerogative that allows end users and industries to thrive from 5G infrastructures, however, such a logical network component can deteriorate from security vulnerabilities that prevail within cloud environments and datacenters. The Quality of Experience in 5G is a metric that takes into consideration sets of factors, which play role in the definition of the end-to-end performance, which is indeed latency, packet processing, utilization of legacy protocols, old hardware, encryption, non-optimized network topologies, routing problems and multitude of other aspects. This research sheds light on the inherent networking stack performance issues that translate into 5G environments, in a use-case where encrypted VPN tunneling is used to secure the backhaul transport network between the 4G/5G cores and the frontend networks.