Abstract: We investigate the source domain's scheme of dynamically and intelligently pre-marking the streaming media packets before entering a DS-domain providing a relative differentiated service. The pre-marking scheme takes into account the packet content, the price limit for the transport of streaming media, and the traffic conditioning agreement. In this scheme, the sender cooperates with what we call media gateway (MG), which is a special node on the boundaries of the DS-domain. MG is responsible for meeting the traffic conditioning agreement while fully utilizing the received differentiated services for the quality of the streaming media. Our proposed QoS control scheme includes the following components: 1) the relative priority based indexing and categorization of streaming video content at the sender and 2) the dynamic feedforward QoS mapping of categorized index to DS grade at the proposed MG. With the proposed scheme, enhanced quality of streaming media applications is demonstrated.