The decoupling of control planes and forwarding planes in Software Defined Network (SDN) improves the flexibility of computer networks. However, the emergence of virtual switches brings potential security challenges. ...
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ISBN:
(纸本)9781538622803
The decoupling of control planes and forwarding planes in Software Defined Network (SDN) improves the flexibility of computer networks. However, the emergence of virtual switches brings potential security challenges. For data flows with strict requirement of security, an independent forwarding algorithm based on multidimensional spatial superposition model is proposed. When a new flow enters into the SDN network, under the control of network controller, a set of new forwarding rules for this flow are created, on which an isolated forwarding path is constructed in the forwarding plane. All data of this new flow will be forwarded along this independent logic path. This algorithm increases data safety. The simulation results show the proposed algorithm is valid and simple, which can satisfy the safe requirement of most applications.
In opportunistic networks, a successful message transmission between node pairs depends on the message size, the transmission speed and the connection duration time. This paper proposes a new message forwarding algori...
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In opportunistic networks, a successful message transmission between node pairs depends on the message size, the transmission speed and the connection duration time. This paper proposes a new message forwarding algorithm to improve the message delivery ratio and reduce the energy consumption. Previous encounter characteristics between nodes are used to estimate future connection duration time using a three point estimation method. Furthermore, the buffer utilization of nodes is used as a weight for the likelihoods to meet destinations according to the hop count of messages stored in the *** simulation results show that the proposed forwarding algorithm achieves higher delivery ratio and less overhead ratio than the other four popular routing *** addition, the proposed algorithm gains a better average residual energy performance among all the compared protocols.
Vehicular delay tolerant network (VDTN) technology uses vehicles on the road as moving nodes to deliver data from source to destination using several intermediate nodes. Efficient data dissemination in VDTN is a diffi...
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Vehicular delay tolerant network (VDTN) technology uses vehicles on the road as moving nodes to deliver data from source to destination using several intermediate nodes. Efficient data dissemination in VDTN is a difficult problem due to existing trade-offs between several metric variables such as delivery ratio, delay, and overhead ratio. Inclusion of important social network parameters (like community, social strength, trust, friendship, and selfishness) in computation of forwarding probability may help to improve the performance of a routing algorithm. However, different tuning of these parameters results in different outcomes for the metric variables. A proper balancing of these parameters may result in an optimized outcome solving the trade-off between the metric variables. Nonetheless, dependency of the variables on a number of social network parameters and their mutual trade-offs makes this a non-trivial optimization problem. In this paper, we propose a novel approach to optimize these trade-offs using multi-objective particle swarm optimization (MOPSO). The proposed approach provides a set of pareto-optimal solutions also known as non-dominating solutions. Further, based on the requirements of a target application scenario, a specific optimal solution out of the pareto-optimal solution set is delivered using artificial intelligence (AI) technique. The proposed methodology is simulated in a VDTN scenario using the opportunistic network environment (ONE) simulator and Matlab. Furthermore, based on the experimental results, an exhaustive analysis is provided about how the metric variables are affected by the involvement of the social-based parameters. The capabilities of the proposed approach are validated using a statistical comparative analysis of the results. In future, the outcome of the study may play a helpful role to decide the priorities of the network parameters while designing new data dissemination algorithms for VDTN.
Without STP and LLDP, we propose a new approach to find faster paths between the source and the destination and fully utilize the links between switches under the Software Defined Network paradigm. To find round-trip ...
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ISBN:
(纸本)9781538611012
Without STP and LLDP, we propose a new approach to find faster paths between the source and the destination and fully utilize the links between switches under the Software Defined Network paradigm. To find round-trip path with lighter load, we design a mechanism to compose special ARP packets for exploring the routing path and avoid broadcast storm by dropping late or duplicate packets. Meanwhile, the controller can carefully regulate other packets without affecting the behavior of the special packets. The evaluation results with the Clos-like network topology show that our approach can be used to improve the performance of transmission throughput. We believe our method is very suitable, especially, for a dynamic network environment, where links are up and down frequently. Our implementation can be seen as an instance showing the flexibility of SDN.
In this work, a novel data forwarding algorithm based on prediction method and optimization theory is proposed for improving the quality of service (QoS) in real-time applications, in particular over the multipath net...
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In this work, a novel data forwarding algorithm based on prediction method and optimization theory is proposed for improving the quality of service (QoS) in real-time applications, in particular over the multipath network. The proposed prediction method is based on the time-series models of observed trends over all available paths at each pre-determined time. This predictive information is then used as an input for the forwarding decision. The forwarding algorithm is meant to minimize the packet loss rate by adjusting the forwarding rate of packets over each path for next prediction period by PSO (particle swarm optimization). To avoid solutions that operate near the capacity of the links and shift flows to less utilized links where they can increase more freely, the optimization problem also introduce the cost function. Numerical experiments with packet loss rate-sensitive traffic show that the optimal objective converges quickly to the optimal values. It demonstrates that running the proposed algorithm over multipath network can be more efficient and more flexible than equal cost multipath protocol.
Delay Tolerant Networks (DTNs) are sparse mobile ad-hoc networks in which there is typically no complete path between the source and the destination. Data routing in DTNs is challenging, and has attracted much attenti...
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ISBN:
(纸本)9781479953448
Delay Tolerant Networks (DTNs) are sparse mobile ad-hoc networks in which there is typically no complete path between the source and the destination. Data routing in DTNs is challenging, and has attracted much attention from the research community. Although many routing schemes have been proposed, they do not address the fairness issue in data delivery to different destination nodes. In this paper, we propose a novel socially-aware routing strategy that optimizes both fairness and throughput. We combine controlled data "spraying" at the source node and single-copy routing at the intermediate nodes. A replication decision is made based on the delivery probability computed over the most probable path in the social contact graph. Furthermore, at intermediate nodes, we sort arriving data into different queues. We then propose a two-level data forwarding strategy that optimizes fairness using round-robin at the first level and throughput using priority scheduling at the second level. Through extensive simulation studies using a real-world mobility trace, we show that our scheme achieves a high delivery ratio, low delay, and low replication overhead.
In the past few years, more and more researchers have paid close attention to the emerging field of delay tolerant networks (DTNs), in which network often partitions and end-to-end paths do not exist nearly all the ti...
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In the past few years, more and more researchers have paid close attention to the emerging field of delay tolerant networks (DTNs), in which network often partitions and end-to-end paths do not exist nearly all the time. To cope with these challenges, most routing protocols employ the "store-carry-forward" strategy to transmit messages. However, the difficulty of this strategy is how to choose the best relay node and determine the best time to forward messages. Fortunately, social relations among nodes can be used to address these problems. In this paper, we present a comprehensive survey of recent social-aware routing protocols, which offer an insight into how to utilize social relationships to design efficient and applicable routing algorithms in DTNs. First, we review the major practical applications of DTNs. Then, we focus on understanding social ties between nodes and investigating some design-related issues of social-based routing approaches, e. g., the ways to obtain social relations among nodes, the metrics and approaches to identify the characteristics of social ties, the strategies to optimize social-aware routing protocols, and the suitable mobility traces to evaluate these protocols. We also create a taxonomy for social-aware routing protocols according to the sources of social relations. Finally, we outline several open issues and research challenges.
Unstructured peer-to-peer (P2P) overlay networks with two-layer hierarchy, comprising an upper layer of super-peers and an underlying layer of ordinary peers, are used to improve the performance of large-scale P2P app...
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Unstructured peer-to-peer (P2P) overlay networks with two-layer hierarchy, comprising an upper layer of super-peers and an underlying layer of ordinary peers, are used to improve the performance of large-scale P2P applications like content distribution and storage. In order to deal with continuous growth of participating peers, a scalable and efficient super-peer overlay topology is essential. However, there is relatively little research conducted on constructing such super-peer overlay topology. In the existed solutions, the number of connections required to be maintained by a super-peer is in direct proportion to the total number of super-peers. For super large-scale P2P applications, i.e. the number of participating peer is over 1,000,000, these solutions are not scalable and impractical. Therefore, in this paper, we propose a scalable hierarchical unstructured P2P system in which a self-similar square network graph (SSNG) is proposed to construct and maintain the super-peer overlay topology adaptively. The SSNG topology is a constant-degree topology in which each node maintains a constant number of neighbor nodes. Moreover, a simple and efficient message forwarding algorithm is presented to ensure each super-peer to receive just one flooding message. The analytical results showed that the proposed SSNG-based overlay is more scalable and efficient than the perfect difference graph (PDG)-based overlay proposed in the literature.
In the Internet today, multipath routing is proved a popular technique that improves reliability and robustness of data delivery;however, current forwarding algorithm over multipath network have problems such as lacki...
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ISBN:
(纸本)9780769538433
In the Internet today, multipath routing is proved a popular technique that improves reliability and robustness of data delivery;however, current forwarding algorithm over multipath network have problems such as lacking of preparing for sudden spikes. This paper proposes a new forwarding algorithm, which is based on time series prediction and PSO (particle swarm optimization). We describe how the algorithm dynamically predicts loss levels over all available network paths and adjust the allocation proportion of packets for next prediction period by the adaptive PSO. We present our simulation work using NS-2 to show the superiority of our algorithm over equality splitting algorithm.
Unstructured peer-to-peer (P2P) systems with two-layer hierarchy, comprising an upper layer of super-peers and an underlying layer of ordinary peers, are used to improve the performance of large-scale P2P systems. In ...
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ISBN:
(纸本)9780769545769
Unstructured peer-to-peer (P2P) systems with two-layer hierarchy, comprising an upper layer of super-peers and an underlying layer of ordinary peers, are used to improve the performance of large-scale P2P systems. In order to deal with continuous growth of participating peers, a scalable super-peer overlay topology with a lower diameter is essential. However, there is relatively little research conducted on constructing a scalable super-peer overlay topology. In the existing solutions, the number of connections that super-peers need to maintain is in direct proportion to the total number of super-peers which makes the solutions not scalable as well as not practical. Therefore, in this paper, we propose a scalable hierarchical unstructured P2P system which using a self-similar square network graph (SSNG) to construct and maintain the super-peer overlay topology dynamically. Moreover, a forwarding mechanism over SSNG is presented to enable each super-peer to receive just one flooding message. The analytical results show that the proposed SSNG-based overlay is more scalable and efficient than the perfect difference graph (PDG)-based overlay proposed in the literature.
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