On queuing lengths in on-line switching
Journal article, 2005

Queues that temporarily store fixed-length packets are ubiquitous in network switches. Scheduling algorithms that prevent packet-loss are always desirable. Longest-Queue-First (LQF) is an on-line greedy algorithm widely exploited because of its simplicity and efficiency. In this paper, we give improved bounds on the competitive ratio of LQF in terms of the worst-case queuing length, parameterized with respect to the optimal queuing length of a clairvoyant adversary. This gives a better picture of LQF's performance under heavy traffic than the usual (unparameterized) competitive ratio. We also discuss randomization, and we conclude with some intriguing open problems regarding a two-dimensional generalization of the problem.

parameterized competitive ratio

online switching



Peter Damaschke

Chalmers, Computer Science and Engineering (Chalmers), Computing Science (Chalmers)

Zhen Zhou

Hong Kong University of Science and Technology

Theoretical Computer Science

0304-3975 (ISSN)

Vol. 339 2-3 333-343

Subject Categories

Computer and Information Science



More information