• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.9-15
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• 2013

Most of recent studies on data center networks are based on the assumption of symmetrical multi-rooted tree topologies such as a Fat-Tree. While packet scatter schemes are very effective for such a network topology, it is known that various failures can result in an asymmetric topology which degrades TCP performance. In this paper, we reexamine the effects of link failures on packet scatter schemes in Fat-Trees. Our simulation results show that in case of a single link failure in a large-scale Fat-Tree, packet reordering does not occur enough to degrade TCP performance. This implies that we do not necessarily need a complex scheme to make packet schemes robust to link failures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.33-41
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• 2011

This paper considers a topological optimization of a network design with mean packet delay and node connectivity constraints. The objective is to find the topological layout of links, at minimal cost. This Problem is known to be NP-hard. To efficiently solve the problem, a scatter search algorithm is proposed. An illustrative example is used to explain and test the proposal approach. Experimental results show evidence that the proposal approach performs more efficiently for finding a good solution or near optimal solution in comparison with a genetic approach.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.215-221
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• 2012

To address the bottleneck problem in data center networks, there have been several proposals for network architectures providing high path-diversity. In devising new schemes to utilize multiple paths, one must consider the effects on TCP performance because packet reordering can make TCP perform poorly. Therefore most schemes prevent packet reordering by sending packets through one of multiple available paths. In this study we show that packet reordering does not occur severely enough to have a significant impact on TCP performance when scattering packets through all available paths between a pair of hosts in Fat-Tree. Simulation results imply that it is possible to find a low-cost solution to the TCP performance problem for Fat-Tree-like topologies.