1,211 research outputs found

    A Survey on the Contributions of Software-Defined Networking to Traffic Engineering

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    Since the appearance of OpenFlow back in 2008, software-defined networking (SDN) has gained momentum. Although there are some discrepancies between the standards developing organizations working with SDN about what SDN is and how it is defined, they all outline traffic engineering (TE) as a key application. One of the most common objectives of TE is the congestion minimization, where techniques such as traffic splitting among multiple paths or advanced reservation systems are used. In such a scenario, this manuscript surveys the role of a comprehensive list of SDN protocols in TE solutions, in order to assess how these protocols can benefit TE. The SDN protocols have been categorized using the SDN architecture proposed by the open networking foundation, which differentiates among data-controller plane interfaces, application-controller plane interfaces, and management interfaces, in order to state how the interface type in which they operate influences TE. In addition, the impact of the SDN protocols on TE has been evaluated by comparing them with the path computation element (PCE)-based architecture. The PCE-based architecture has been selected to measure the impact of SDN on TE because it is the most novel TE architecture until the date, and because it already defines a set of metrics to measure the performance of TE solutions. We conclude that using the three types of interfaces simultaneously will result in more powerful and enhanced TE solutions, since they benefit TE in complementary ways.European Commission through the Horizon 2020 Research and Innovation Programme (GN4) under Grant 691567 Spanish Ministry of Economy and Competitiveness under the Secure Deployment of Services Over SDN and NFV-based Networks Project S&NSEC under Grant TEC2013-47960-C4-3-

    Investigating Basic Quality of Service Design Possibilities for Regis University Academic Research Network Edge Routers

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    The Regis University Academic Research Network (ARNe) had network resources, such as VoIP, that required preservation their ability to receive near real-time forwarding treatment across the network. Quality of Service (QoS) design ideas were examined from four actual implementations described in research cases. Additionally, research involving surveys from Cisco certified professionals was examined, and Cisco technical literature was examined. Case study methodology, involving the study of multiple cases, was the primary tactic utilized in this research. Examination and triangulation of data from the research indicated that ARNe would benefit from moving forward with a basic QoS design and implementation, integrating concepts identified in the data. Additionally, data supported that a basic QoS design and implementation on ARNe would provide Computer Science and Information Science students an opportunity to more fully appreciate QoS through further research and hands-on experience

    Datacenter Traffic Control: Understanding Techniques and Trade-offs

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    Datacenters provide cost-effective and flexible access to scalable compute and storage resources necessary for today's cloud computing needs. A typical datacenter is made up of thousands of servers connected with a large network and usually managed by one operator. To provide quality access to the variety of applications and services hosted on datacenters and maximize performance, it deems necessary to use datacenter networks effectively and efficiently. Datacenter traffic is often a mix of several classes with different priorities and requirements. This includes user-generated interactive traffic, traffic with deadlines, and long-running traffic. To this end, custom transport protocols and traffic management techniques have been developed to improve datacenter network performance. In this tutorial paper, we review the general architecture of datacenter networks, various topologies proposed for them, their traffic properties, general traffic control challenges in datacenters and general traffic control objectives. The purpose of this paper is to bring out the important characteristics of traffic control in datacenters and not to survey all existing solutions (as it is virtually impossible due to massive body of existing research). We hope to provide readers with a wide range of options and factors while considering a variety of traffic control mechanisms. We discuss various characteristics of datacenter traffic control including management schemes, transmission control, traffic shaping, prioritization, load balancing, multipathing, and traffic scheduling. Next, we point to several open challenges as well as new and interesting networking paradigms. At the end of this paper, we briefly review inter-datacenter networks that connect geographically dispersed datacenters which have been receiving increasing attention recently and pose interesting and novel research problems.Comment: Accepted for Publication in IEEE Communications Surveys and Tutorial

    Reducing Internet Latency : A Survey of Techniques and their Merit

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    Bob Briscoe, Anna Brunstrom, Andreas Petlund, David Hayes, David Ros, Ing-Jyh Tsang, Stein Gjessing, Gorry Fairhurst, Carsten Griwodz, Michael WelzlPeer reviewedPreprin

    Bandwidth management and quality of service

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    With the advent of bandwidth-hungry video and audio applications, demand for bandwidth is expected to exceed supply. Users will require more bandwidth and, as always, there are likely to be more users. As the Internet user base becomes more diverse, there is an increasing perception that Internet Service Providers (ISPs) should be able to differentiate between users, so that the specific needs of different types of users can be met. Differentiated services is seen as a possible solution to the bandwidth problem. Currently, however, the technology used on the Internet differentiates neither between users, nor between applications. The thesis focuses on current and anticipated bandwidth shortages on the Internet, and on the lack of a differentiated service. The aim is to identify methods of managing bandwidth and to investigate how these bandwidth management methods can be used to provide a differentiated service. The scope of the study is limited to networks using both Ethernet technology and the Internet Protocol (IP). Tile study is significant because it addresses current problems confronted by network managers. The key terms, Quality of Service (QoS) and bandwidth management, are defined. “QoS” is equated to a differentiating system. Bandwidth management is defined as any method of controlling and allocating bandwidth. Installing more capacity is taken to be a method of bandwidth management. The review of literature concentrates on Ethernet/IP networks. It begins with a detailed examination of definitions and interpretations of the term Quality of Service and shows how the meaning changed over the last decade. The review then examines congestion control, including a survey of queuing methods. Priority queuing implemented in hardware is examined in detail, followed by a review of the ReSource reserVation Protocol (RSVP) and a new version of IP (lPv6). Finally, the new standards IEEE 802.1p and IEEE 802.1Q are outlined, and parts of ISO/IEC 15802-3 are analysed. The Integrated Services Architecture (ISA), Differentiated Services (DiffServ) and MultiProtocol Label Switching (MPLS) are seen as providing a theoretical framework for QoS development. The Open Systems Interconnection Reference Model (OSI model) is chosen as the preferred framework for investigating bandwidth management because it is more comprehensive than the alternative US Department of Defence Model (DoD model). A case study of the Edith Cowan University (ECU) data network illustrates current practice in network management. It provides concrete examples of some of the problems, methods and solutions identified in the literary review. Bandwidth management methods are identified and categorised based on the OSI layers in which they operate. Suggestions are given as to how some of these bandwidth management methods are, or can be used within current QoS architectures. The experimental work consists of two series of tests on small, experimental LANs. The tests are aimed at evaluating the effectiveness of IEEE 802.1 p prioritisation. The results suggest that in small Local Area Networks (LANs) prioritisation provides no benefit when Ethernet switches are lightly loaded

    The Effects of Different Congestion Management Algorithms over VoIP Performance

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    QoS Provisioning in Converged Satellite and Terrestrial Networks: A Survey of the State-of-the-Art

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    It has been widely acknowledged that future networks will need to provide significantly more capacity than current ones in order to deal with the increasing traffic demands of the users. Particularly in regions where optical fibers are unlikely to be deployed due to economical constraints, this is a major challenge. One option to address this issue is to complement existing narrow-band terrestrial networks with additional satellite connections. Satellites cover huge areas, and recent developments have considerably increased the available capacity while decreasing the cost. However, geostationary satellite links have significantly different link characteristics than most terrestrial links, mainly due to the higher signal propagation time, which often renders them not suitable for delay intolerant traffic. This paper surveys the current state-of-the-art of satellite and terrestrial network convergence. We mainly focus on scenarios in which satellite networks complement existing terrestrial infrastructures, i.e., parallel satellite and terrestrial links exist, in order to provide high bandwidth connections while ideally achieving a similar end user quality-of-experience as in high bandwidth terrestrial networks. Thus, we identify the technical challenges associated with the convergence of satellite and terrestrial networks and analyze the related work. Based on this, we identify four key functional building blocks, which are essential to distribute traffic optimally between the terrestrial and the satellite networks. These are the traffic requirement identification function, the link characteristics identification function, as well as the traffic engineering function and the execution function. Afterwards, we survey current network architectures with respect to these key functional building blocks and perform a gap analysis, which shows that all analyzed network architectures require adaptations to effectively support converged satellite and terrestrial networks. Hence, we conclude by formulating several open research questions with respect to satellite and terrestrial network convergence.This work was supported by the BATS Research Project through the European Union Seventh Framework Programme under Contract 317533

    The Dynamics of Internet Traffic: Self-Similarity, Self-Organization, and Complex Phenomena

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    The Internet is the most complex system ever created in human history. Therefore, its dynamics and traffic unsurprisingly take on a rich variety of complex dynamics, self-organization, and other phenomena that have been researched for years. This paper is a review of the complex dynamics of Internet traffic. Departing from normal treatises, we will take a view from both the network engineering and physics perspectives showing the strengths and weaknesses as well as insights of both. In addition, many less covered phenomena such as traffic oscillations, large-scale effects of worm traffic, and comparisons of the Internet and biological models will be covered.Comment: 63 pages, 7 figures, 7 tables, submitted to Advances in Complex System
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