Scheduling for aggregated multiple asymmetrical links
Rony Patrice Putih · cIRcle (University of British Columbia) · 2009
Increase in demand for bandwidth has propelled the need for connecting two communication nodes with more than one physical link. Scheduling among these links must maintain Quality of Service (QoS) usually attained in the case of a single link connection. Previous single-server scheduling disciplines do not take into account properties inherent to multiple-server systems such as: packet re-ordering due to competition among packets of the same flow, and the ability to schedule more than one flow simultaneously due to division of total bandwidth among multiple servers / links. A multi-server system scheduling discipline, called the MSF2Q (Multiple Server Fair Queueing with bounded Fairness)[l], exploited the bandwidth division property using scheduling eligibility constraints to achieve better throughput fairness. However, MSF2Q assumes equal division of total bandwidth. In this thesis, we extend MSF Q to provide better fairness in throughput for multiple-server systems where each server is of a different (asymmetrical) rate. This new discipline, called MASF Q (Multiple Asymmetrical Server Fair Queueing with bounded Fairness), achieves the same theoretical delay bound and per-flow service discrepancy as MSF2Q. Simulation results are provided for performance comparison.