scholarly journals Reliability Aware Multiple Path Installation in Software-Defined Networking

Electronics ◽  
2021 ◽  
Vol 10 (22) ◽  
pp. 2820
Author(s):  
Syed Mohsan Raza ◽  
Shohreh Ahvar ◽  
Rashid Amin ◽  
Mudassar Hussain

Link failures frequently occur in communication networks, which negatively impacts network services delivery. Compared to traditional distributed networks, Software-Defined Networking (SDN) provides numerous benefits for link robustness to avoid services unavailability. To cope with link failures, the existing SDN approaches compute multiple paths and install corresponding flow rules at network switches without considering the reliability value of the primary computed path. This increases computation time, traffic overhead and end-to-end packets delay. This paper proposes a new approach called Reliability Aware Multiple Path Flow Rule (RAF) that calculates links reliability and installs minimum flow rules for multiple paths based on the reliability value of the primary path. RAF has been simulated, evaluated and compared with the existing approaches. The simulation results show that RAF performs better than the existing approaches in terms of computation overhead at the controller and reduces end-to-end packet delay and traffic overhead for flow rules installation.

Author(s):  
V. Deeban Chakravarthy ◽  
B. Amutha

Due to the increase in the number of users on the internet and the number of applications that is available in the cloud makes Data Center Networking (DCN) has the backbone for computing. These data centre requires high operational cost and also experience the link failures and congestions often. Hence the solution is to use Software Defined Networking (SDN) based load balancer which improves the efficiency of the network by distributing the traffic across multiple paths to optimize the efficiency of the network. Traditional load balancers are very expensive and inflexible. These SDN load balancers do not require costly hardware and can be programmed, which it makes it easier to implement user-defined algorithms and load balancing strategies. In this paper, we have proposed an efficient load balancing technique by considering different parameters to maintain the load efficiently using Open FlowSwitches connected to ONOS controller.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Ting Zhang ◽  
Bin Liu

Software-Defined Networking (SDN) shows us a promising picture to deploy the demanding services in a fast and cost-effective way. Till now, most SDN use cases are deployed in enterprise/campus networks and data center networks. However, when applying SDN to the large-scale networks, such as Wide Area Network (WAN), the end-to-end delay of packet traversal is suspected to be very large and needs to be further investigated. Moreover, stringent time constraint is the cornerstone for real-time applications in SDN. Understanding the packet delay in SDN-based large networks is crucial for the proper design of switch architecture and the optimization of network algorithms such as flow control algorithms. In this paper, we present a thorough systematic exploration on the end-to-end delay in SDN which consists of multiple nodes, fully exposing the components which contribute to the long delay. We disclose that SDN switches cannot completely avoid the generation of flow setup even in proactive mode and conduct data mining on the probability of flow setup. We propose an analytical model for the end-to-end delay. This model takes into account the impact of the different rule installation time consumption on different switches. Considering the delay in switches contributes a large proportion to the entire delay, we conduct various measurements on the delay of a single switch. Results for the delay at different flow setup rates and with different rule priority patterns are presented. Furthermore, we study the impact on packet delay caused by ternary content addressable memory (TCAM) update. We measure parameters in the delay model and find that if SDN is deployed in all segments of WAN, the delay of packet traversal will be increased up to 27.95 times in the worst case in our experimental settings, compared with the delay in conventional network. Such high delay may eventually lead the end-to-end connections fail to complete if no additional measures are taken.


Author(s):  
Monday O. Eyinagho ◽  
Samuel O. Falaki

A large number of installed local area networks are sluggish in terms of speed of uploading and downloading of information. Researchers have, therefore, proposed the need for such networks to be designed with specified maximum end-to-end delay. This is because, if the maximum packet delay between any two nodes of a network is not known, it is impossible to provide a deterministic guarantee of worst case response times of packets’ flows. Therefore, the need for analytic and formal basis for designing such networks becomes very imperative. In this regard, this chapter has discussed the switched local area networks’ delay problem and related issues. It compared the two principal approaches for determining the end-to-end response times of flows in communication networks – stochastic approach and deterministic approach. The chapter goes on to demonstrate the superiority of the latter approach by using it to develop and validate the goodness of a general maximum delay packet switch model.


2013 ◽  
Vol 401-403 ◽  
pp. 1766-1771 ◽  
Author(s):  
Lan Kou ◽  
Si Rui Chen ◽  
Rui Wang

Multipath Transmission Control Protocol (MPTCP), a transport layer protocol, proposed by the IETF working group in 2009, can provide multipath communication end to end. It also can improve the utilization of network resources and network transmission reliability. However, that how to select multiple paths to improve the end to end overall throughput, and how to avoid the throughput declining by the performance difference, become the focus of this study. We propose a path selection strategy based on improved gray relational analysis, and set the optimal values of the QoS parameters for the selected paths as the reference sequence. According to the value of improved grey relational degree (IGRD) which is compared with reference sequence, we select the paths with better performance, smaller difference for transmission.


2020 ◽  
Vol 4 (2) ◽  
pp. 147-156
Author(s):  
Zahraa Saleh ◽  
Qahhar Qadir

Mobile traffic volumes have grown exponentially because of the increase in services and applications. Traditional networks are complex to manage because the forwarding, control, and management planes are all bundled together and, thus, administrators are supposed to deploy high-level policies, as each vendor has its own configuration methods. Software-Defined Networking (SDN) is considered the future paradigm of communication networks. It decouples control logic from its underlying hardware, thereby promoting logically centralized network control and making the network more programmable and easy to configure. Low-power wireless technologies are moving toward a multitenant and multiapplication Internet of Things (IoT), which requires an architecture with scalable, reliable, and configured solutions. However, employing an SDN-based centralized architecture in the environment of a low-power wireless IoT network introduces significant challenges, such as difficult-to-control traffic, unreliable links, network contention, and high associated overheads that can significantly affect the performance of the network. This paper is a contribution toward a performance evaluation for the use of SDN in wireless networking by evaluating the latency, packet drop ratio (PDR), data extraction rate (DER), and overheads. The results show that SDN adds a high percentage of overheads to the network, which is about 43% of the 57% user packets, and the DER drops when the number of mesh nodes are increased, in addition to the high loss that was observed for packets that traveled over more hops.


Author(s):  
Stefan Schmid ◽  
Nicolas Schnepf ◽  
Jiří Srba

AbstractTo ensure a high availability, communication networks provide resilient routing mechanisms that quickly change routes upon failures. However, a fundamental algorithmic question underlying such mechanisms is hardly understood: how to verify whether a given network reroutes flows along feasible paths, without violating capacity constraints, for up to k link failures? We chart the algorithmic complexity landscape of resilient routing under link failures, considering shortest path routing based on link weights as e.g. deployed in the ECMP protocol. We study two models: a pessimistic model where flows interfere in a worst-case manner along equal-cost shortest paths, and an optimistic model where flows are routed in a best-case manner, and we present a complete picture of the algorithmic complexities. We further propose a strategic search algorithm that checks only the critical failure scenarios while still providing correctness guarantees. Our experimental evaluation on a benchmark of Internet and datacenter topologies confirms an improved performance of our strategic search by several orders of magnitude.


2021 ◽  
Author(s):  
◽  
Caleb Gordon

<p>In measurement and control systems there is often a need to synchronise distributed clocks. Traditionally, synchronisation has been achieved using a dedicated medium to convey time information, typically using the IRIG-B serial protocol. The precision time protocol (IEEE 1588) has been designed as an improvement to current methods of synchronisation within a distributed network of devices. IEEE 1588 is a message based protocol that can be implemented across packet based networks including, but not limited to, Ethernet. Standard Ethernet switches introduce a variable delay to packets that inhibits path delay measurements. Transparent switches have been introduced to measure and adjust for packet delay, thus removing the negative effects that these variations cause.  This thesis describes the hardware and firmware design of an IEEE 1588 transparent end-to-end Ethernet switch for Tekron International Ltd based in Lower Hutt, New Zealand. This switch has the ability to monitor all Ethernet traffic, identify IEEE 1588 timing packets, measure the delay that these packets experience while passing through the switch, and account for this delay by adjusting a time-interval field of the packet as it is leaving the switch. This process takes place at the operational speed of the port, and without introducing significant delay. Time-interval measurements can be made using a high-precision timestamp unit with a resolution of 1 ns. The total jitter introduced by this measurement process is just 4.5 ns through a single switch.</p>


2019 ◽  
Vol 9 (10) ◽  
pp. 2081 ◽  
Author(s):  
Hua Wang ◽  
Yongli Zhao ◽  
Avishek Nag

As an important support for quantum communication, quantum key distribution (QKD) networks have achieved a relatively mature level of development, and they face higher requirements for multi-user end-to-end networking capabilities. Thus, QKD networks need an effective management plane to control and coordinate with the QKD resources. As a promising technology, software defined networking (SDN) can separate the control and management of QKD networks from the actual forwarding of the quantum keys. This paper systematically introduces QKD networks enabled by SDN, by elaborating on its overall architecture, related interfaces, and protocols. Then, three-use cases are provided as important paradigms with their corresponding schemes and simulation performances.


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