926 research outputs found
Design and Development of the Reactive BGP peering in Software-Defined Routing Exchanges
The Software-Defined Networking (SDN) is considered to be an improved solution for applying flexible control and operation recently in the network. Its characteristics include centralized management, global view, as well as fast adjustment and adaptation. Many experimental and research networks have already migrated to the SDN-enabled architecture. As the global network continues to grow in a fast pace, how to use SDN to improve the networking fields becomes a popular topic in research. One of the interesting topics is to enable routing exchanges among the SDN-enabled network and production networks. However, considering that many production networks are still operated on legacy architecture, the enabled SDN routing functionalities have to support hybrid mode in operation. In this paper, we propose a routing exchange mechanism by enabling reactive BGP peering actions among the SDN and legacy network components. The results of experiments show that our SDN controller is able to mask as an Autonomous System (AS) to exchange routing information with other BGP routers
Design and Implementation of Monitoring Schemes for Software-Defined Routing over a Federated Multi-domain SDN Testbed
Emerging Software-Defined Networking (SDN) paradigm has been widely affecting most networking fields. However, the real-world SDN application for inter-domain routing management is still limited since the routing exchange among wide-area networks is quite complicate due to the extreme scale of global Internet connectivity. Several SDN-leveraged routing ideas are being proposed to improve the routing exchange among wide-area networks. Thus, in this paper, an on-going experience for experimenting and validating the inter-domain routing proposals over OF@TEIN federated testbed in Asia is shared. By focusing on the design and implementation of monitoring deployment for visibility support, we try to identify practical key points and provide improved monitoring for validating the performance and anomaly of the exchange. Other design considerations are also discussed together with possible future research directions
Planning and Implantation of NetFPGA Platform on Network Emulation Testbed
The concepts of cloud computing and Internet applications have expanded gradually and have become more and more important. Researchers need a new, high-speed network to build experimental environments for testing new network protocolswithout affecting existing traffic. In this paper, we describe a way to integrate NetFPGA platform, OpenFlow concept and NetFPGA reference designs into anetwork testbed to improve the packet processing speed and the dynamic adjustability for network emulation experiments. Furthermore, combined with Tunneling and VPLS, the proposed network testbed can be connected to distributed network, thus providing researchers a traffic-controllable and NIC-programmable experimental networking testbed in intra-communicating part
A Flow-based Method to Measure Traffic Statistics in Software Defined Network
Since software defined network became a revolution of network, many new developments and deployments are put forward. Device operating in software defined network environment will need a controller to store control policy. As a result of flow is one of traffic presentation units in software defined network, hence, this paper proposed a prototype of flow-based method to measure traffic statistics which can be used in OpenFlow network. By analysis of flow table, active flows which managed by controller can be listed, and information of each flow can be presented with developed module on the controller. After gathered port statistics from OpenFlow switch and entries in flow table, information of each flow can be presented on a developed graphic interface. By using this method, Traffic statistics of each flow may be more adaptive and realizable for measurement for observation
Toward Inter-Connection on OpenFlow Research Networks
With the advance of Future Internet technologies, many research issues andideas are growing fast in recent years. In the field of network virtualization, softwaredefined network becomes a common topic on network research. In Taiwan, manyinstitutes and laboratories of universities already built their bench-scale testbed forresearch and educational use with OpenFlow protocol. As time goes by, stitchingexperimental networks is a growing trend to fulfill requirements for large scaleemulation. Hence, this paper revealed a progressing deployment which connectsdifferent experimental networks with centralized control policy. The objective is tobuild an integrated research network with a proposed solution which utilizesOpenFlow protocol to deal with the inter-connections. With a centralized controllerand implemented architecture, the deployment not only solves the limitation of VLANtag number in network but also improves the flexibility of configuration. This designcould be a solution for the realistic constraints of network environment in Taiwan, andit also supports the possibility of stitching regional experimental networks fornetworking research
Electrocardiographic and cardiometabolic risk markers of left ventricular diastolic dysfunction in physically active adults: CHIEF heart study
AimThis study was aimed to investigate the association of cardiometabolic and ECG markers with left ventricular diastolic dysfunction (LVDD) in physically active Asian young adults, which has not been clarified in prior studies.Methods and resultsA total of 2,019 men aged 18–43 years were included from the military in Taiwan. All the subjects underwent anthropometric, hemodynamic, and blood metabolic marker measurements. Physical fitness was investigated by time for a 3,000-m run. LVDD was defined by presence of either one of the three echocardiographic criteria: (1) mitral inflow E/A ratio < 0.8 with a peak E velocity of > 50 cm/s, (2) tissue Doppler lateral mitral annulus e′ <10 cm/s, and (3) E/e′ ratio > 14. Multiple logistic regressions with adjustments for age, physical fitness, and pulse rate were conducted to determine the association of cardiometabolic and ECG markers with LVDD. The prevalence of LVDD was estimated to be 4.16% (N = 84). Of the cardiometabolic markers, central obesity, defined as waist circumference ≥ 90 cm, was the only independent marker of LVDD [odds ratio (OR) and 95% confidence interval: 2.97 (1.63–5.41)]. There were no association for hypertension, prediabetes, and dyslipidemia. Of the ECG markers, left atrial enlargement and incomplete right bundle branch block/intraventricular conduction delay were the independent ECG markers of LVDD [OR: 2.98 (1.28–6.94) and 1.94 (1.09–3.47), respectively]. There was borderline association for Cornell-based left ventricular hypertrophy and inferior T wave inversion [OR: 1.94 (0.97–3.63) and 2.44 (0.98–6.08), respectively].ConclusionIn the physically active Asian young male adults, central obesity and some ECG markers for left heart abnormalities were useful to identify LVDD
Critical illness-related corticosteroid insufficiency in patients with severe acute biliary pancreatitis: a prospective cohort study
Moderate Ethanol Pre-treatment Mitigates ICH-Induced Injury via ER Stress Modulation in Rats
Intracerebral hemorrhage (ICH) is a life-threatening type of stroke that disrupts the normal neurological function of the brain. Clinical studies have reported a non-linear J-shaped association between alcohol consumption levels and the occurrence of cerebral stroke. Specifically, alcohol intoxication increases stroke incidence, while moderate alcohol pre-conditioning decreases stroke frequency and improves outcomes. Although alcohol pre-consumption is likely a crucial player in ICH, the underlying mechanism remains unclear. We performed 1-h alcohol pre-conditioning followed by ICH induction in Sprague-Dawley (SD) rats to investigate the role of alcohol pre-conditioning in ICH. Interestingly, behavioral test analysis found that ethanol intoxication (3 g/kg) aggravated ICH-induced neurological deficits, but moderate ethanol pre-conditioning (0.75 g/kg) ameliorated ICH-induced neurological deficits by reducing the oxidative stress and proinflammatory cytokines release. Moreover, we found that moderate ethanol pretreatment improved the striatal endoplasmic reticulum (ER) homeostasis by increasing the chaperone protein expression and reducing oxidative stress and apoptosis caused by ICH. Our findings show that the mechanism regulated by moderate ethanol pre-conditioning might be beneficial for ICH, indicating the importance of ER homeostasis, oxidative stress, and differential cytokines release in ICH
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