The earliest deadline first scheduling with active buffer management for real-time traffic in the internet

Abstract

We study the problem of QoS guarantee for differentiated services. A two-level hierarchical scheduling framework is deployed for the separation of the QoS metrics. Due to the desirable property of minimizing the maximum packet lateness, the Earliest Deadline First (EDF) scheduling is adopted to provide the in-class scheduling for the time-sensitive traffic. We propose to employ an EDF scheduler combined with an active buffer management scheme (CHOKe) to improve the fairness of resource allocation and to maintain a good delay performance for all real-time applications. Simulation results show that the proposed scheme can achieve a better delay performance and make a more fair bandwidth allocation between the real-time TCP and UDP connections than the First Come First Serve (FCFS) scheduling with the Drop-Tail buffer management which is commonly deployed in the traditional IP router.