Economic Viability of Software Defined Networking (SDN)

Economical and operational facets of networks drive the necessity for significant changes towards fundamentals of networking architectures. Recently, the momentum of programmable networking attempts illustrates the significance of economic aspects of network technologies. Software Defined Networking (SDN) has got the attention of researchers from both academia and industry as a means to decrease network costs and generate revenue for service providers due to features it promises in networking. In this article, we investigate how programmable network architectures, i.e. SDN technology, affect the network economics compared to traditional network architectures, i.e. MPLS technology. We define two metrics, Unit Service Cost Scalability and Cost-to-Service, to evaluate how SDN architecture performs compared to MPLS architecture. Also, we present mathematical models to calculate certain cost parts of a network. In addition, we compare different popular SDN control plane models, Centralized Control Plane (CCP), Distributed Control Plane (DCP), and Hierarchical Control Plane (HCP), to understand the economic impact of them with regards to the defined metrics. We use video traffic with different patterns for the comparison. This work aims at being a useful primer to providing insights regarding which technology and control plane model are appropriate for a specific service, i.e. video, for network owners to plan their investments

A framework for economic analysis of network architectures

Indiana University-Purdue University Indianapolis (IUPUI)This thesis firstly surveys and summarizes the state-of-the-art studies from two research areas in Software De fined Networking (SDN) architecture: (i) control plane scalability and (ii) Quality of Service (QoS)-related problems. It also outlines the potential challenges and open problems that need to be addressed further for more scalable SDN control planes and better and complete QoS abilities in SDN networks. The thesis secondly presents a hierarchical SDN design along with an inter-AS QoS-guaranteed routing approach. This design addresses the scalability problems of control plane and privacy concerns of inter-AS QoS routing philosophies in SDN. After exploring the roots of control plane scalability problems in SDN, the thesis then proposes a metric to quantitatively evaluate the control plane scalability in SDN. Later, the thesis presents a general framework for economic analysis of network architectures and designs. To this end, the thesis defines and utilizes two metrics, Unit Service Cost Scalability and Cost-to-Service, to evaluate how SDN architecture performs compared to MPLS architecture in terms of unit cost for a service and cost of introducing a new service along with giving mathematical models to calculate Capital Expenditures (CAPEX) and Operational Expenditures (OPEX) of a network. Moreover, the thesis studies the problem of optimal final pricing for services by proposing an optimal pricing scheme for a service request with QoS in SDN environment while aiming to maximize benefits of both service providers and customers. Finally, the thesis investigates how programmable network architectures, i.e. SDN, affect the network economics compared to traditional network architectures, i.e. MPLS, in case of failures along with exploring the economic impact of failures in different SDN control plane models

Economic Analysis of Software Defined Networking (SDN) Under Various Network Failure Scenarios

Failures are inevitable in an operational network. They can happen anytime in different sizes and components of a network. They impact the network economics regarding CAPEX (Capital Expenditure), OPEX (Operational Expenditure), revenue lost due to service provisioning cut and so on. In order to mitigate the damages resulting from these failures, reactions of network architectures and designs are crucial for the future of the network. Recently, Software Defined Networking (SDN) has got the attention of researchers from both academia and industry as a means in order to increase network availability and reliability due to features, such as centralized automated control and global network view, it promises in networking. To this end, we explore the effects of programmable network architectures, i.e. SDN technology, and traditional network architectures, i.e. MPLS (Multiprotocol Label Switching) technology, on network economics by exploiting Number of Satisfied Service Requests and our predefined Unit Service Cost Scalability metrics under network failure scenarios: i) a random single data plane link failure and ii) a random controller (i.e. control plane) failure. To the best of our knowledge, this study is the first to consider a comparison of a programmable network architecture, i.e. SDN, along with different control plane models, Centralized (Single) Control Plane (CCP), Distributed (Flat) Control Plane (DCP), and Hierarchical Control Plane (HCP), and a non-programmable network architecture, i.e. MPLS, regarding network economics in case of network failures

Vibration analysis of a tire in ground contact under varied conditions

The effect of three different factors, which are inflation pressure, vertical load and coefficient of friction on the natural frequencies of a tire (175/70 R13) has been studied. A three dimensional tire model is constructed, using four different material properties and parts in the tire. Mechanical properties of the composite parts are evaluated. After investigating the free vibration, contact analysis is carried out. A concrete block and the tire are modelled together, using three different coefficients of friction. Experiments are run under certain conditions to check the accuracy of the numerical model. The natural frequencies are measured to describe free vibration and vibration of the tire contacted by ground, using a damping monitoring method. It is seen, that experimental and numerical results are in good agreement. On the other hand, investigating the impact of three different factors together is quite difficult on the natural frequencies. When some of these factors are assumed to be constant and the variables are taken one by one, it is easier to assess the effects.http://www.ptmts.org.pl/jtam/index.php/jtamam2018Mechanical and Aeronautical Engineerin

Modeliranje strukturnih jednadžbi na temelju veza između povjerenja nastavnika u menadžment, predanosti menadžmentu, zadovoljstva menadžmentom i namjere napuštanja organizacije

This study aims to determine the relationships among teachers’ trust in the manager, commitment to the manager, satisfaction with the manager and teachers’ intent to leave. The data was collected on the sample of 478 primary school teachers using self-report scales. Two alternative structural models were examined: one proposed that satisfaction with the manager causes commitment, while the other one proposed that commitment causes satisfaction. Both alternative models yielded exactly the same good fit indices. According to the first model, the teachers’ trust in manager predicts their satisfaction with manager and commitment to manager positively, while trust in manager negatively predicts their intent to leave through the mediating effect of satisfaction with manager. According to the second model, teachers’ trust in manager positively predicts their satisfaction with manager and commitment to manager, while trust in manager negatively predicts the teachers’ intent to leave through the mediating effects of commitment to manager and satisfaction with manager.Cilj ovoga istraživanja je odrediti veze između povjerenja zaposlenika u menadžera, predanosti menadžeru, zadovoljstva menadžerom i namjere nastavnika da napuste ustanovu u kojoj rade. Podaci su prikupljeni na uzorku od 478 nastavnika osnovne škole koji su upotrebljavali skale samoprocjene. Ispitana su i dva drugačija strukturna modela: jedan koji tvrdi da zadovoljstvo menadžmentom vodi predanosti i drugi koji tvrdi da predanost menadžmentu vodi zadovoljstvu. Oba modela pokazala su jednako dobre indekse pogodnosti. Prema prvome modelu povjerenje nastavnika u menadžera pozitivno utječe na njihovo zadovoljstvo menadžerom i predanost menadžeru, dok to isto povjerenje u menadžera umanjuje njihovu namjeru da napuste organizaciju, kroz medijacijski učinak zadovoljstva menadžerom. Prema drugome modelu, povjerenje nastavnika u menadžera pozitivno utječe na njihovo zadovoljstvo menadžerom i na predanost menadžeru, dok povjerenje u menadžera umanjuje njihovu namjeru da napuste organizaciju, kroz medijacijski učinak predanosti menadžeru i zadovoljstva menadžerom

Two Cases of an Unusual Childhood Aortic Dissection Resulting in Death

Pediatric aortic dissection is an emergency condition that is difficult to diagnose and is associated with high morbidity and mortality. To draw attention to this issue, we present two male cases diagnosed with aortic dissection because of an autopsy. A 16-year-old man with severe new-onset chest pain had an unremarkable physical examination, electrocardiography, and laboratory values. Aortic dissection was not detected on non-contrast computed tomography or echocardiography. Type A aortic dissection was discovered during the patient's autopsy. In the second case, a 10-year-old male patient complained of fever, vomiting, and abdominal pain. The physical examination and biochemical tests were unremarkable. Type B aortic dissection was discovered during the autopsy. Genetic and congenital causes predisposing to aortic dissection and hypertension or a history of trauma were not detected in either patient. Aortic dissection, which is very rare in children, should be considered in cases of persistent chest pain, and rapid diagnosis with contrast-enhanced tomography is vital

Economic Impact Analysis of Control Plane Architectures in Software Defined Networking (SDN)

Economical and operational facets of networks drive the necessity for significant changes towards fundamentals of networking architectures. Recently, the momentum of programmable networking attempts illustrates the significance of economic aspects of network technologies. Software Defined Networking (SDN) has got the attention of researchers from both academia and industry as a means to decrease network costs and generate revenue for service providers due to features it promises in networking. In this article, we perform an economic analysis of SDN about different popular SDN control plane architectures: Centralized Control Plane (CCP), Distributed Control Plane with Local View (DCP_LV), and Hierarchical Control Plane (HCP) model. In particular, we investigate the economic impact of these control plane architectures about the unit cost for a service with bandwidth QoS parameter as well as Total Cost of Ownership (TCO) and network revenue for network owners under different traffic patterns. We characterize the unit cost for a service concerning CAPEX, OPEX, and workload of a network in a certain time period and apply the calculation methods in different SDN control plane models. Our experiments and analysis show that CCP model shows the highest TCO while DCP_LV model results in lowest amount among them. In addition, HCP model shows the lowest unit cost for a service among all models while CCP gives the highest cost for the same service tier. This work aims at being a useful primer to providing insights regarding the economic impact of control plane architectures in SDN for network researchers and owners to plan their investments