The Internet has led to the creation of a digital society, where (almost) everything is connected and is accessible from anywhere. However, despite their widespread adoption, traditional IP networks are complex and very hard to manage. It is both difficult to configure the network according to predefined policies, and to reconfigure it to respond to faults, load, and changes. To make matters even more difficult, current networks are also vertically integrated: the control and data planes are bundled together. Software-defined networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns, introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper, we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound application programming interfaces (APIs), network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms—with a focus on aspects such as resiliency, scalability, performance, security, and dependability—as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

https://publications.uni.lu/bitstream/10993/20596/1/survey_on_SDN.pdf

Software-Defined Networking: A Comprehensive Survey

Software-Defined Networking (SDN) is an emerging paradigm that promises to change this state of affairs, by breaking vertical integration, separating the network's control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. The separation of concerns introduced between the definition of network policies, their implementation in switching hardware, and the forwarding of traffic, is key to the desired flexibility: by breaking the network control problem into tractable pieces, SDN makes it easier to create and introduce new abstractions in networking, simplifying network management and facilitating network evolution. In this paper we present a comprehensive survey on SDN. We start by introducing the motivation for SDN, explain its main concepts and how it differs from traditional networking, its roots, and the standardization activities regarding this novel paradigm. Next, we present the key building blocks of an SDN infrastructure using a bottom-up, layered approach. We provide an in-depth analysis of the hardware infrastructure, southbound and northbound APIs, network virtualization layers, network operating systems (SDN controllers), network programming languages, and network applications. We also look at cross-layer problems such as debugging and troubleshooting. In an effort to anticipate the future evolution of this new paradigm, we discuss the main ongoing research efforts and challenges of SDN. In particular, we address the design of switches and control platforms -- with a focus on aspects such as resiliency, scalability, performance, security and dependability -- as well as new opportunities for carrier transport networks and cloud providers. Last but not least, we analyze the position of SDN as a key enabler of a software-defined environment.

C4.5: Programs for Machine Learning (書評)

At some point in the future, how far out we do not exactly know, wireless access to the Internet will outstrip all other forms of access bringing the freedom of mobility to the way we access the we...

ACM SIGCOMM computer communication review

Flow monitoring has become a prevalent method for monitoring traffic in high-speed networks By focusing on the analysis of flows, rather than individual packets, it is often said to be more scalable than traditional packet-based traffic analysis Flow monitoring embraces the complete chain of packet observation, flow export using protocols such as NetFlow and IPFIX, data collection, and data analysis In contrast to what is often assumed, all stages of flow monitoring are closely intertwined Each of these stages therefore has to be thoroughly understood, before being able to perform sound flow measurements Otherwise, flow data artifacts and data loss can be the consequence, potentially without being observed This paper is the first of its kind to provide an integrated tutorial on all stages of a flow monitoring setup As shown throughout this paper, flow monitoring has evolved from the early 1990s into a powerful tool, and additional functionality will certainly be added in the future We show, for example, how the previously opposing approaches of deep packet inspection and flow monitoring have been united into novel monitoring approaches

/pdf/flow-monitoring-explained-from-packet-capture-to-data-55ebj7g9hl.pdf

Flow Monitoring Explained: From Packet Capture to Data Analysis With NetFlow and IPFIX

This paper presents the results of an investigation into the application flow control technique utilised by YouTube. We reveal and describe the basic properties of YouTube application flow control, which we term block sending, and show that it is widely used by YouTube servers. We also examine how the block sending algorithm interacts with the flow control provided by TCP and reveal that the block sending approach was responsible for over 40% of packet loss events in YouTube flows in a residential DSL dataset and the retransmission of over 1% of all YouTube data sent after the application flow control began. We conclude by suggesting that changing YouTube block sending to be less bursty would improve the performance and reduce the bandwidth usage of YouTube video streams.

/pdf/application-flow-control-in-youtube-video-streams-57mxb6ngsz.pdf

Application flow control in YouTube video streams

This paper introduces libtrace, an open-source software library for reading and writing network packet traces. Libtrace offers performance and usability enhancements compared to other libraries that are currently used. We describe the main features of libtrace and demonstrate how the libtrace programming API enables users to easily develop portable trace analysis tools without needing to consider the details of the capture format, file compression or intermediate protocol headers. We compare the performance of libtrace against other trace processing libraries to show that libtrace offers the best compromise between development effort and program run time. As a result, we conclude that libtrace is a valuable contribution to the passive measurement community that will aid the development of better and more reliable trace analysis and network monitoring tools.

/pdf/libtrace-a-packet-capture-and-analysis-library-mz8h385qh5.pdf

Libtrace: a packet capture and analysis library

Software Defined Networking (SDN) is an active area for network research, with many organizations exploring the opportunities provided by the decoupling of network control from packet forwarding However, questions remain over the operation of such systems in production In order to build operational confidence, we built Cardigan -a distributed router using OpenFlow-and deployed it at a public Internet exchange Cardigan applies a routing as a service abstraction to a RouteFlow controlled IP network in an effort to reduce operational complexity The implementation and deployment efforts provide insights into the challenges involved with using these technologies, and suggests the viability of mixed device environments despite the limitations of early OpenFlow implementations

/pdf/cardigan-sdn-distributed-routing-fabric-going-live-at-an-2pexjgp5ek.pdf

Cardigan: SDN distributed routing fabric going live at an Internet exchange

SDN is an active area for network research, with many organisations exploring the opportunities provided by the de-coupling of network control from packet forwarding. Previous work has suggested that a hybrid networking model will pave the way for migration towards SDN, through interoperability with legacy devices. However, questions remain over the operation of such systems in production environments. In order to build operational confidence, we built a simple distributed router using OpenFlow and deployed it at a public Internet exchange. This implementation provides insights into the challenges involved with using these technologies, and suggests the viability of mixed device environments despite the limitations of early OpenFlow implementations.

/pdf/cardigan-deploying-a-distributed-routing-fabric-4nros8crc2.pdf

Cardigan: deploying a distributed routing fabric

Mobile Ipv6 protocols are retrofit of mobility onto the next generation Internet (IPv6) protocols. Many of the original IPv6 protocols have inbuilt timing mechanisms which aim at ensuring fairness of access to media and signaling efficiency. The effects of these timers on mobile IPv6 traffic has been found to significantly affect application traffic on these networks. One proposal to remove unnecessary timers in neighbor discovery is called fast router advertisement (FastRA). This paper presents performance comparisons of FastRA with unmodified neighbor discovery in mobile IPv6 environments.

Richard Nelson

Papers

Application flow control in YouTube video streams

Libtrace: a packet capture and analysis library

Cardigan: SDN distributed routing fabric going live at an Internet exchange

Cardigan: deploying a distributed routing fabric

Effects of fast routers advertisement on mobile IPv6 handovers