9 research outputs found

    Packet loss optimization in router forwarding tasks based on the particle swarm algorithm

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    Software-defined networks (SDNs) are computer networks where parameters and devices are configured by software. Recently, artificial intelligence aspects have been used for SDN programs for various applications, including packet classification and forwarding according to the quality of service (QoS) requirements. The main problem is that when packets from different applications pass through computer networks, they have different QoS criteria. To meet the requirements of packets, routers classify these packets, add them to multiple weighting queue systems, and forward them according to their priorities. Multiple queue systems in routers usually use a class-based weighted round-robin (CBWRR) scheduling algorithm with pre-configured fixed weights for each priority queue. The problem is that the intensity of traffic in general and of each packet class occasionally changes. Therefore, in this work, we suggest using the particle swarm optimization algorithm to find the optimal weights for the weighted fair round-robin algorithm (WFRR) by considering the variable densities of the traffic. This work presents a framework to simulate router operations by determining the weights and schedule packets and forwarding them. The proposed algorithm to optimize the weights is compared with the conventional WFRR algorithm, and the results show that the particle swarm optimization for the weighted round-robin algorithm is more efficient than WFRR, especially in high-intensity traffic. Moreover, the average packet-loss ratio does not exceed 7%, and the proposed algorithms are better than the conventional CBWRR algorithm and the related work results

    Convergence: the next big step

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    Recently, web based multimedia services have gained popularity and have proven themselves to be viable means of communication. This has inspired the telecommunication service providers and network operators to reinvent themselves to try and provide value added IP centric services. There was need for a system which would allow new services to be introduced rapidly with reduced capital expense (CAPEX) and operational expense (OPEX) through increased efficiency in network utilization. Various organizations and standardization agencies have been working together to establish such a system. Internet Protocol Multimedia Subsystem (IMS) is a result of these efforts. IMS is an application level system. It is being developed by 3GPP (3rd Generation Partnership Project) and 3GPP2 (3rd Generation Partnership Project 2) in collaboration with IETF (Internet Engineering Task Force), ITU-T (International Telecommunication Union – Telecommunication Standardization Sector), and ETSI (European Telecommunications Standards Institute) etc. Initially, the main aim of IMS was to bring together the internet and the cellular world, but it has extended to include traditional wire line telecommunication systems as well. It utilizes existing internet protocols such as SIP (Session Initiation Protocol), AAA (Authentication, Authorization and Accounting protocol), and COPS (Common Open Policy Service) etc, and modifies them to meet the stringent requirements of reliable, real time communication systems. The advantages of IMS include easy service quality management (QoS), mobility management, service control and integration. At present a lot of attention is being paid to providing bundled up services in the home environment. Service providers have been successful in providing traditional telephony, high speed internet and cable services in a single package. But there is very little integration among these services. IMS can provide a way to integrate them as well as extend the possibility of various other services to be added to allow increased automation in the home environment. This thesis extends the concept of IMS to provide convergence and facilitate internetworking of the various bundled services available in the home environment; this may include but is not limited to communications (wired and wireless), entertainment, security etc. In this thesis, I present a converged home environment which has a number of elements providing a variety of communication and entertainment services. The proposed network would allow effective interworking of these elements, based on IMS architecture. My aim is to depict the possible advantages of using IMS to provide convergence, automation and integration at the residential level

    Case studies for developing globally responsible engineers

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    Document realitzat amb un ajut financer de la Unió Europea. Per poder accedir al material complementari per a docents dels 28 casos estudi que formen el llibre, activeu el "Document relacionat"Col·lecció de 28 casos estudi per a professors d'enginyeria: 1. Rural development and planning in LDCs: the “Gamba Deve – Licoma axis”,district of Caia, Mozambique 2. Reducing the impact of soil erosion and reservoir siltation on agricultural production and water availability: the case study of the Laaba catchment (Burkina Faso) 3. Trade and Mobility on the Rooftop of the World: Gravity Ropeways in Nepal 4. Sustainable Development of Agriculture and Food systems with regard to Water 5. Conservation agriculture: a complex avenue to conserve and improve soils 6. The national rural water supply and sanitation programme in Tanzania 7. Use of statistical tools in a development context. Analysis of variance (ANOVA) 8. Water supply system in Kojani Island (Zanzibar, Tanzania) 9. Faecal sludge management in Lusaka, Zambia 10. Water balance on the Central Rift Valley 11. Rural electrification in developing countries via autonomous micro-grids 12. Photovoltaics electrification in off-grid areas 13. Development of a MILP model to design wind-photovoltaic stand-alone electrification projects for isolated communities in developing countries 14. Estimation if indoor air pollution and health impacts due to biomass burning in rural Northern Ghana 15.Improved cookstoves assessment 16. Supporting the adoption of clean cookstoves and fuels: why won’t people adopt the perfect stove? 17. Do-it-yourself approach as appropriate technology for solar thermal system: the example of CDF Médina, Dakar (Senegal) 18. Essential oil extraction with concentrating solar thermal energy 19. Survival in the desert sun: cool food storage 20. Energy roadmap in Ghana and Botswana 21. Social & ethical issues in engineering 22. Radio communications systems in rural environments 23. A Diffserv transport network to bring 3G access to villages in the Amazon forest 24. Finding the poynting’s theorem in a health centre in San Pablo (Peru) 25. Tanzania, Water and health 26. Flood assessment and warning system 27. Technical aspects of municipal solid waste collection: case studies from East Africa 28. Plastic recyclingPeer ReviewedPostprint (published version

    SOFTWARE DEFINED CUSTOMIZATION OF NETWORK PROTOCOLS WITH LAYER 4.5

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    The rise of software defined networks, programmable data planes, and host level kernel programmability gives rise to highly specialized enterprise networks. One form of network specialization is protocol customization, which traditionally extends existing protocols with additional features, primarily for security and performance reasons. However, the current methodologies to deploy protocol customizations lack the agility to support rapidly changing customization needs. This dissertation designs and evaluates the first software-defined customization architecture capable of distributing and continuously managing protocol customizations within enterprise or datacenter networks. Our unifying architecture is capable of performing per-process customizations, embedding per-network security controls, and aiding the traversal of customized application flows through otherwise problematic middlebox devices. Through the design and evaluation of the customization architecture, we further our understanding of, and provide robust support for, application transparent protocol customizations. We conclude with the first ever demonstration of active application flow "hot-swapping" of protocol customizations, a capability not currently supported in operational networks.Office of Naval Research, Arlington, VA 22203Lieutenant Commander, United States NavyApproved for public release. Distribution is unlimited

    Telecommunications Networks

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    This book guides readers through the basics of rapidly emerging networks to more advanced concepts and future expectations of Telecommunications Networks. It identifies and examines the most pressing research issues in Telecommunications and it contains chapters written by leading researchers, academics and industry professionals. Telecommunications Networks - Current Status and Future Trends covers surveys of recent publications that investigate key areas of interest such as: IMS, eTOM, 3G/4G, optimization problems, modeling, simulation, quality of service, etc. This book, that is suitable for both PhD and master students, is organized into six sections: New Generation Networks, Quality of Services, Sensor Networks, Telecommunications, Traffic Engineering and Routing

    Telemedicine

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    Telemedicine is a rapidly evolving field as new technologies are implemented for example for the development of wireless sensors, quality data transmission. Using the Internet applications such as counseling, clinical consultation support and home care monitoring and management are more and more realized, which improves access to high level medical care in underserved areas. The 23 chapters of this book present manifold examples of telemedicine treating both theoretical and practical foundations and application scenarios

    On the Utility of Unregulated IP DiffServ Code Point (DSCP) Usage by End Systems

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    DiffServ was designed to implement service provider quality of service (QoS) policies, where routers change and react upon the DiffServ Code Point (DSCP) in the IP header. However, nowadays, applications are beginning to directly set the DSCP themselves, in the hope that this will yield a more appropriate service for their respective video, audio and data streams. WebRTC is a prime example of such an application. We present measurements, for both IPv4 and IPv6, of what happens to DSCP values along Internet paths after an end system has set them without any prior agreement between a customer and a service provider. We find that the DSCP is often changed or zeroed along the path, but detrimental effects from using the DSCP are extremely rare; moreover, DSCP values sometimes remain intact (potentially having an effect on traffic) for several AS hops. This positive result motivates an analysis of the potential latency impact from such DSCP usage, for which we present the first measurement results. We find that routers at approximately 3% of more than 100,000 links differentiate between the WebRTC DSCP values (EF, AF42 and CS1) and consistently reduce delay in comparison with probes carrying a zero value (CS0) under congestion. In contrast, routers at around 2% of these links increase the delay by a comparable amount under congestion, uniformly for EF, AF42 and CS1

    Net Neutrality and the Battle for the Open Internet

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    “Net neutrality,” a dry but crucial standard of openness in network access, began as a technical principle informing obscure policy debates but became the flashpoint for an all-out political battle for the future of communications and culture. Net Neutrality and the Battle for the Open Internet is a critical cultural history of net neutrality that reveals how this intentionally “boring” world of internet infrastructure and regulation hides a fascinating and pivotal sphere of power, with lessons for communication and media scholars, activists, and anyone interested in technology and politics. While previous studies and academic discussions of net neutrality have been dominated by legal, economic, and technical perspectives, Net Neutrality and the Battle for the Open Internet offers a humanities-based critical theoretical approach, telling the story of how activists and millions of everyday people, online and in the streets, were able to challenge the power of the phone and cable corporations that historically dominated communications policy-making to advance equality and justice in media and technology
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