Does Link Scheduling Matter on Long Paths?

• Published in: 2010 IEEE 30th International Conference on Distributed Computing Systems pp. 199 - 208
• Main Authors: Liebeherr, J, Ghiassi-Farrokhfal, Y, Burchard, A
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2010
• Subjects: Added delay; Algorithm design and analysis; Bandwidth; Calculus; Computer networks; end-to-end delays; Internet; link scheduling; Measurement; network calculus; Processor scheduling; Scheduling algorithm; Telecommunication traffic
• ISBN: 142447261X; 9781424472611
• ISSN: 1063-6927
• DOI: 10.1109/ICDCS.2010.62

We seek to provide an analytical answer whether the impact of the selection of link scheduling algorithms diminishes on long network paths. The answer is provided through a detailed multi-node delay analysis, which is applicable to a broad class of scheduling algorithms, and which can account for statistical multiplexing. The analysis is enabled by two contributions: (1) We derive a function that can characterize the available bandwidth at a node for various scheduling algorithms. The function has an accuracy that recovers necessary and sufficient conditions for satisfying worst-case delay bounds at a single node, (2) We obtain end-to-end delay bounds by providing an explicit solution to an optimization problem, in which the service received at multiple nodes is subsumed into a single function. By presenting a unified analysis that captures the properties of a broad group of schedulers in a single parameter, we can provide insight how the choice of scheduling algorithms impacts end-to-end delay bounds. An important finding of this paper is that some schedulers show noticeable performance differences which persist in a network setting with long paths.