| Summary: | 碩士 === 國立臺灣大學 === 電信工程學研究所 === 90 === A scheduling algorithm for performance guarantees in integrated services networks is proposed. We adopt the concept of Dynamic Programming (DP), specifically the Viterbi Algorithm
(VA), and the framework of Service Curve based Earliest Deadline first (SCED), to build up our scheduling policy, named Trellis Queueing (TQ). Since Non-Preemptive Earliest Deadline
First (NPEDF), the basis of TQ, possesses the optimality of schedulability, we intend to inherit this desirable property from it and make further improvement of its fairness.
A similar previous work is what Worst-case Fair Weighted Fair Queueing (WF2Q) did to Weighted Fair Queueing (WFQ).
We focus the analysis of TQ on a single-link case. Fairness for EDF-based schedulers is defined, burstiness of TQ under both theoretical and practical environments are discussed, and a new method of updating service curves is proposed. By inference utilizing Network Calculus and simulation results, TQ can serve diverse types of flows appropriately by scheduling guaranteed flows smoothly and allocating residual bandwidth for best-effort flows fairly.
While TQ itself can be implemented in pseudo-polynomial time, we further propose an approximated TQ in terms of the delay-bound tightness (DBT) index. The approximated TQ runs in polynomial sorting time, and it approximates the optimal
solution by a factor of 2.
|
|---|
