Browsing by Author "Chang, Guey-Yun"

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SDN-based dynamic multipath forwarding for inter-data center networking
(2019-01-10)
Wang, Yao-Chun
;
Lin, Ying-Dar
;
Chang, Guey-Yun
;
資訊工程學系
;
Department of Computer Science
Equal-cost multipath (ECMP)-based traffic engineering (TE) methods are commonly used in intra-data center (DC) networks to improve the transmission performance for east-west traffic (ie, traffic from server to server within a DC). However, applying ECMP on inter-DC wide area network (WAN) offers limited performance enhancement as a result of irregular network topology. Since TE can be intelligently and efficiently realized with software-defined networking (SDN), SDN-based multipath becomes a popular option. However, SDN suffers from scalability issue caused by limited ternary content-addressable memory (TCAM) size. In this paper, we propose an SDN-based TE method called dynamic flow-entry-saving multipath (DFSM) for inter-DC traffic forwarding. DFSM adopts source-destination-based multipath forwarding and latency-aware traffic splitting to reduce the consumption of flow entries and achieve load balancing. The evaluation results indicate that DFSM saves 15% to 30% of system flow entries in practical topologies and reduces the standard deviation of path latencies from 10% to 7% than do label-switched tunneling, and also reduces average latency by 10% to 48% by consuming 6% to 20% more flow entries than do ECMP in less-interconnected topologies. Note that the performance gain may not always be proportional to flow entry investment, with the interconnectivity between nodes being an important factor. The evaluation also indicates that per-flow provision consumes several times the flow entries consumed by DFSM but reduces latency by 10% at most. Besides, DFSM reduces the standard deviation of path latencies from 14% to 7% than do even traffic splitting.
SDN-Based Dynamic Multipath Forwarding for Inter-Data Center Networking
(2017-01-01)
Wang, Yao-Chun
;
Lin, Ying-Dar
;
Chang, Guey-Yun
;
資訊工程學系
;
Department of Computer Science
Since traffic engineering (TE) in Software Defined Networking (SDN) can be much more efficiently and intelligently implemented, Multipath in SDN becomes a new option. However, Ternary Content Addressable Memory (TCAM) size become the bottleneck of SDN. In this paper, we propose an SDN-based Dynamic Flowentry-Saving Multipath (DFSM) mechanism for inter-DC WAN traffic forwarding. DFSM adopts source-destination-based multipath forwarding and latency-aware flow-based traffic splitting to save flow entries and achieve better load balancing. Our evaluations indicate that DFSM saves 15% to 30% system flow entries in different topologies compared to label-based tunneling, and also reduces average latency by 10% to 48% by consuming 8% to 20% more flow entries than EqualCost Multipath (ECMP) in less-interconnected topologies. In addition, compared to even traffic splitting, DFSM reduces the standard deviation of path latencies from 14% to 7%.