Videoconferencing technology is a successful tool for expanding possibilities for collaborative and distance learning, while bridging the distance between the teacher and students, providing time and cost savings. Recently, the focus in literature and practice for quality requirements are shifting from deterministic behavior of the infrastructure in videoconferencing learning environments to students' Quality of Experience, as subjective measure that involves human dimensions. Hence, this study evaluates the impact of different Quality of Service mechanisms utilized in the infrastructure on students' Quality of Experience in videoconferencing learning environments. It involved 263 faculty students that participated in 42 learning sessions via videoconferencing during their academic activities, while the infrastructure was subjected to Quality of Service mechanism in the network, as well as application enhancement in the videoconferencing platform, or both. The performance counters from the technical equipment and results from the survey regarding students' perceived experience, showed definite Quality of Service to Quality of Experience correlation. When network and application Quality of Service were considered complementary, students' Quality of Experience was in average 18.5% higher compared to network and 15% to application Quality of Service implementations. Similarly, best technical performance was achieved when both mechanisms were consider as a whole, such as 34% decrease in average transmit delay compared to application and 62.5% to network Quality of Service mechanisms, etc. Finally, application controls had greater impact on perceived students' Quality of Experience than the network ones, which correlated to performance behavior of the infrastructure.