Convergence of Probability Measures. By P. Billingsley. Chichester, Sussex, Wiley, 1968. xii, 253 p. 9 1/4“. 117s.

Convergence of Probability Measures

Social Network Analysis

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

Infectious Diseases Society of America.

The structure and dynamics of multilayer networks

Today’s end-user devices have multiple access networks available and can achieve better application performance by distributing traffic across access networks. However, matching application traffic to the most suitable access network or bundling them is non-trivial, given varying application needs and network performance characteristics. Therefore, we propose an application-informed approach for access network selection (IANS). Based on the size of a Web resource, we select the better access network in terms of latency and available downstream capacity. We implement IANS within our Socket Intents prototype and evaluate its benefits for Web page loads under a variety of network conditions and for various Web pages. IANS provides the highest speedups for scenarios with asymmetric network conditions and for scenarios with low downstream capacity. Here, IANS improves relevant Web metrics by between 500 and 1000 ms in the median, compared to using the better of the two access networks, and may also outperform MPTCP. This confirms that IANS improves application performance over using a single network and, in several scenarios, even using MPTCP.

Informed Access Network Selection: The Benefits of Socket Intents for Web Performance

/pdf/improving-network-troubleshooting-using-virtualization-r7s40y8e7y.pdf

Improving Network Troubleshooting using Virtualization

Knowing customer's interests, e.g. which Video-On-Demand (VoD) or Social Network services they are using, helps telecommunication companies with better network planning to enhance the performance exactly where the customer's interests lie, and also offer the customers relevant commercial packages. However, with the increasing deployment of CDNs by different services, identification, and attribution of the traffic on network-layer information alone becomes a challenge: If multiple services are using the same CDN provider, they cannot be easily distinguished based on IP prefixes alone. Therefore, it is crucial to go beyond pure network-layer information for traffic attribution. 

FlowDNS

The virtualization trend in today's Internet decouples services from the constraints of the underlying physical infrastructure. This decoupling facilitates more flexible and efficient resource allocations: the service can be realized at any place in the substrate network which fulfills the service specification requirements.

https://www.net.t-labs.tu-berlin.de/~stefan/itc13slides.pdf

Anja Feldmann

Papers

Informed Access Network Selection: The Benefits of Socket Intents for Web Performance

Improving Network Troubleshooting using Virtualization

FlowDNS

Specificity vs. flexibility: On the embedding cost of a virtual network

CloudNets: Combining Clouds with Networking