In recent years, many research efforts focus on relative differentiated service due to the increasing requirements on quality of service for time-sensitive applications. Most of the prior research relies on timestamping arriving packets or periodically monitoring the arrival traffic to arrange the service rate or priority for each class of packets. In this paper, we propose a new efficient and robust packet scheduling scheme, called ERP-DDRR. The ERP-DDRR scheduler not only can provide proportional delay differentiation under various traffic load conditions with very small overhead but also can be implemented in terabit networks. In addition, we propose a pipelining approach to further improve the performance of the ERP-DDRR scheduler. Simulation results show that the ERP-DDRR scheduler provides excellent short-term and long-term performance. The ERP-DDRR scheduler is an excellent alternative solution for future high-speed networks.