TY - GEN
T1 - Improved competitive performance bounds for CIOQ switches
AU - Kesselman, Alex
AU - Kogan, Kirill
AU - Segal, Michael
PY - 2008/1/1
Y1 - 2008/1/1
N2 - Combined input and output queued (CIOQ) architectures with a moderate fabric speedup S > 1 have come to play a major role in the design of high performance switches. In this paper we study CIOQ switches with First-In-First-Out (FIFO) buffers providing Quality of Service (QoS) guarantees. The goal of the switch policy is to maximize the total value of packets sent out of the switch. We analyze the performance of a switch policy by means of competitive analysis, where a uniform performance guarantee is provided for all traffic patterns. Azar and Richter [8] proposed an algorithm β-PG (Preemptive Greedy with a preemption factor of β) that is 8-competitive for an arbitrary speedup value when β= 3. We improve upon their result by showing that this algorithm achieves a competitive ratio of 7.5 and 7.47 for β= 3 and β= 2.8, respectively. Basically, we demonstrate that β-PG is at most β2+2β/β-1 and at least β2-β+1/β-1-competitive.
AB - Combined input and output queued (CIOQ) architectures with a moderate fabric speedup S > 1 have come to play a major role in the design of high performance switches. In this paper we study CIOQ switches with First-In-First-Out (FIFO) buffers providing Quality of Service (QoS) guarantees. The goal of the switch policy is to maximize the total value of packets sent out of the switch. We analyze the performance of a switch policy by means of competitive analysis, where a uniform performance guarantee is provided for all traffic patterns. Azar and Richter [8] proposed an algorithm β-PG (Preemptive Greedy with a preemption factor of β) that is 8-competitive for an arbitrary speedup value when β= 3. We improve upon their result by showing that this algorithm achieves a competitive ratio of 7.5 and 7.47 for β= 3 and β= 2.8, respectively. Basically, we demonstrate that β-PG is at most β2+2β/β-1 and at least β2-β+1/β-1-competitive.
UR - http://www.scopus.com/inward/record.url?scp=57749202433&partnerID=8YFLogxK
U2 - 10.1007/978-3-540-87744-8_48
DO - 10.1007/978-3-540-87744-8_48
M3 - Conference contribution
AN - SCOPUS:57749202433
SN - 3540877436
SN - 9783540877431
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 577
EP - 588
BT - Algorithms - ESA 2008 - 16th Annual European Symposium, Proceedings
PB - Springer Verlag
T2 - 16th Annual European Symposium on Algorithms, ESA 2008
Y2 - 15 September 2008 through 17 September 2008
ER -