关键词: 业务属性，服务质量，数据包调度，优先级排队

Abstract: The fast developing services in Internet pose challenges to the efficient transmission of various types of data, so an effective packet scheduling scheme is needed to meet the QoS constraints of heterogeneous services. In this article, the priority-queuing model was used to study the performances of various strategics based on delay sensitivity and par kets length. And the non-preemptive short packet first strategy was proved to result in the minimal overall delay. With different strategies for delay-sensitive and non-delay-sensitive services, an optimal priority-queuing model for the schedtr ling of multiple Internet services was designed based on above conclusions. The results from simulation experiments in NS-2 verified the superiority of the model. The results also demonstrated the features of packets queuing under different traffic scenarios and the law of variation for such performance indices as packet delivery ratio, throughput and average delay, which can be used to design effective measures for performance optimization.

Key words: Service properties, Quality of service, Packets scheduling, Priority-queuing