Modified DRR with Negative Deficit for Packet Scheduling in Routers
When multiple traffic flows contend for channel bandwidth, the scheduling algorithm regulating the access to that
channel plays a key role in ensuring that each flow obtains the required quality of service. Packet and flow scheduling
algorithms for packet networks has been a topic of interest for a long time since the very inception of communication
networks. In this paper, we propose improvement over Deficit Round Robin (DRR) algorithm in which we permit negative
deficit when deficit counter value is less than packet size. This reduces waiting time of packets in backlogged queues and
improves delay and throughput performance. The proposed algorithm is implemented in NS-2 using routers with CBR and
HTTP flows. Simulation results shows improvement in delay and throughput with little degradation in jitter.
Index terms- DRR, Quantum, Packet Scheduling, Fair queuing.