As the adaptive streaming technology becomes the mainstream solution for online video service and 4G broadband service becomes very accessible, for mobile service providers, having a performance model integrating adaptive streaming and elastic traffic becomes a necessity. We aim to build an adaptive streaming model by using flow-dynamics and to examine the streaming performance. Our model takes both the codec limitation and integration of elastic data into account, which assist the operators to understand the trade-offs among different metrics such as deficit rate, mean codec rate and mean elastic throughput when different configurations and prioritization factors are chosen. The simulation results obtained with the real statistics of Orange mobile network demonstrated the maximum traffic intensity under certain QoS constraints and its corresponding optimal prioritization factor.