Recently, user perception has been receiving increasingly much attention of service providers, operators, manufactures and researchers. They are interested to know how the users perceive the quality of multimedia streaming services. To avoid the fatigue of subjective testing, they are interested to model the Quality of Experience (QoE) based on Quality of Service (QoS) and other measurable parameters. However, these parameters to estimate the QoE may differ per service. In this paper, we propose a conceptual model of QoE in parallel with the classical internet architecture hourglass model. Moreover conditions are highlighted under which QoE can be evaluated objectively from QoS without entailing other factors. The main is goal to understand the factors that are playing a significant role for QoE. We also discuss and explain the role of the application on QoE.