Browsing by Author "Hsu, Yao-Tsung"

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Deploying QoS-assured Service Function Chains with Stochastic Prediction Models on VNF Latency
(2017-01-01)
Lei, Tsung-Han
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Hsu, Yao-Tsung
;
Wang, I-Chih
;
Wen, Charles H. -P.
;
電機工程學系
Current Network Function Virtualization (NFV) with Virtualized Network Functions (VNFs) running as virtual machines on commodity servers enables flexibility to Service Function Chaining (SFC). Specific applications may require Quality of Service (QoS) on end-to-end latency. However, the processing delay and the queuing delay of VNFs varies with virtual resource configurations (vCPU and vMemory), as well as physical usage (traffic amount, CPU utilization). Moreover, packet delays are randomly distributed, instead of a fixed value. To accurately model the latency distribution of one VNF, a prediction method using random-forest regression is proposed. Evaluation results show that our method can predict the latency distribution of the two sample VNFs with only 10% errors. On the basis of the model, a QoS-assured SFC deployment algorithm is also presented to guarantee end-to-end latency and bandwidth consumption of users. Experiments show that our algorithm enables high degree of scalability with polynomial runtime, and meanwhile maximizes user acceptance rates with 6% difference from the optimal solution from the mixed integer programming.
FASIC: A Fast-recovery, Adaptively Spanning In-band Control Plane in Software-Defined Network
(2017-01-01)
Su, Yu-Lun
;
Wang, I-Chih
;
Hsu, Yao-Tsung
;
Wen, Charles H. -P.
;
電機工程學系
To operate a reliable SDN network, the control plane should be robust in order to guarantee the correctness of traffic forwarding. For in-band control, the traffic flows along with the data plane without a dedicated control network. Thus, the failure of data plane may isolate the switches from control plane and lead to erroneous forwarding behavior. In this paper, we design a control plane, FASIC, which can bootstrap the control network autonomously and adaptively span the control plane with the control-link switching mechanism. By implementing our design with Open vSwitch (OVS), OpenDayLight OVSDB Integration (ODL-OVSDB) and Floodlight software, we demonstrate that FASIC is an in-band control solution which is feasible under support of the available SDN and OpenFlow resources. Compared with standard OVS, the experimental result shows that FASIC reduces 87.83% of control plane downtime under hard link failure and incurs zero downtime under congestion. The preemptive control-link switching can prevent the control-link failure when it suffers from heavy traffic load.