Browsing by Author "Hossain, Md. Shohrab"

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Performance Modeling and Analysis of TCP Connections over Software Defined Networks
(2017-01-01)
Lai, Yuan-Cheng
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Ali, Ahsan
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Hassan, Md. Mahadi
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Hossain, Md. Shohrab
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Lin, Ying-Dar
Software Defined Networking (SDN) decouples the control plane from the data plane, thereby enhancing flexibility in network management. Earlier works on SDN modeling only focused on packet-level arrivals without considering flow-level arrivals. However, a model without considering flow-level arrivals cannot correctly reflect the probability of sending packets to the controller. In this paper, we propose an analytical model of SDN considering flow-level (TCP connection) arrivals and packet-level arrivals simultaneously. We use an analytical method termed as 4D state model, which uses four-dimensional states. We have derived the state transition rates of the model and also the packet delay and packet loss probability. We have conducted numerical analysis and extensive simulations. Our results show good matches, which verify the suitability and correctness of our analysis. Error ratios of the analytical results for 4D state model and M/M/1 model against simulation results are also given. Results show that for data packet delays, 4D state can achieve error ratios of 1.16 similar to 3.30%, which is much better than 8.57 similar to 35.7% attained by M/M/1 model, which only considers packet-level arrivals.
Performance Modeling of SDN with NFV under or aside the Controller
(2017-01-01)
Fahmin, Ahmed
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Lai, Yuan-Cheng
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Hossain, Md. Shohrab
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Lin, Ying-Dar
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Saha, Dipon
Software Defined Networking (SDN) emphasizes the separation of data and control plane while network function virtualization (NFV) decouples network function from underlying hardware. Combining SDN with NFV would have many benefits, but the problem is how to integrate them. There are two possible architectures for such integration: the controller interacts with virtualized network functions (VNFs) or the switch interacts with VNFs. In this paper, the former is referred to as NFV under the controller (NFV_C) while the latter is called NFV aside the controller (NFV_AC). To the best of our knowledge, there is no analytical model for mathematically investigating the performance of such architectures. This paper therefore aims to carry out analytical modeling of SDN with NFV under or aside the controller. We model and analyze these two SDN+NFV architectures using M/M/1 queuing model and validate our analysis with various simulations. Results show that the analytical results well match the simulation results. Also a packet delay reduction of 54.67% can be achieved for NFV_AC over NFV_C, meaning that NFV_AC is a better architecture for integrating SDN with NFV.