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.

When selecting a television program for recording, a user may configure the delivery of the selected television program and associated data and interactive applications to different user equipment devices in a home network, which may have different capabilities. Because the user equipment devices in the home network may have different capabilities, the user may wish to deliver different types and amount of content, different amounts of data, and different versions of interactive applications to the user equipment devices in the home network.

Interactive media guidance system having multiple devices

Data centers are critical, energy-hungry infrastructures that run large-scale Internet-based services. Energy consumption models are pivotal in designing and optimizing energy-efficient operations to curb excessive energy consumption in data centers. In this paper, we survey the state-of-the-art techniques used for energy consumption modeling and prediction for data centers and their components. We conduct an in-depth study of the existing literature on data center power modeling, covering more than 200 models. We organize these models in a hierarchical structure with two main branches focusing on hardware-centric and software-centric power models. Under hardware-centric approaches we start from the digital circuit level and move on to describe higher-level energy consumption models at the hardware component level, server level, data center level, and finally systems of systems level. Under the software-centric approaches we investigate power models developed for operating systems, virtual machines and software applications. This systematic approach allows us to identify multiple issues prevalent in power modeling of different levels of data center systems, including: i) few modeling efforts targeted at power consumption of the entire data center ii) many state-of-the-art power models are based on a few CPU or server metrics, and iii) the effectiveness and accuracy of these power models remain open questions. Based on these observations, we conclude the survey by describing key challenges for future research on constructing effective and accurate data center power models.

Data Center Energy Consumption Modeling: A Survey

Methods and apparatus for delivery of packetized content (e.g., video, audio, data, etc.) over a content delivery network. In one embodiment, the content is packetized using an Internet Protocol (IP), and delivered by a service provider over both managed and unmanaged networks to subscribers of the provider, so as to provide delivery at any time, at any location, and via any designated user device. The delivered content may originate from the service provider, third-party content sources (e.g., networks or studios), the subscriber(s) themselves, or other sources including the Internet. Use of a common control and service functions within the network afford the ability to integrate or blend services together, thereby affording the service provider and subscriber new service and economic opportunities. Content delivery sessions may also be migrated from one device to another. A network-based user interface infrastructure, and gateway-based client-side architecture, are also disclosed.

Methods and apparatus for packetized content delivery over a content delivery network

http://bnrg.cs.berkeley.edu/~randy/Courses/CS294.S13/1.3.pdf

Data center evolution

Embodiments of the present invention relate to a network of peer-to-peer communication devices controlled by a central controller. Using respective peer-to-peer communication devices, users can submit customized program schedules to the central controller, for media broadcasts that the users wish to record and view at a later time. The central controller maintains a global schedule of individual user-entered program schedules, and directs the peer-to-peer communication devices to record and re-play the content as requested in the schedules. The requested content may be recorded locally by any peer-to-peer communication device and transmitted upon request to a different peer-to-peer communication device of the network.

Method and system for customized television viewing using a peer-to-peer network

Many personal computers and workstations have two or four cores (that is, CPUs) that enable multiple threads to be executed simultaneously. Computers in the near future are expected to have significantly more cores. To take advantage of the hardware of today and tomorrow, you can parallelize your code to distribute work across multiple processors. In the past, parallelization required low-level manipulation of threads and locks. Visual Studio 2010 and the .NET Framework 4 enhance support for parallel programming by providing a new runtime, new class library types, and new diagnostic tools. These features simplify parallel development so that you can write efficient, fine-grained, and scalable parallel code in a natural idiom without having to work directly with threads or the thread pool. The following illustration provides a high-level overview of the parallel programming architecture in the .NET Framework 4.

NSF/IEEE-TCPP curriculum initiative on parallel and distributed computing: core topics for undergraduates

Secure socket layer (SSL) is the most popular protocol used in the Internet for facilitating secure communications. In this paper, we analyze the performance and architectural impact of SSL on the servers in terms of various parameters such as throughput, utilization, cache sizes, cache miss ratios, number of processors, control dependencies, file access sizes, bus transactions, network load, etc. The major conclusions from this study are as follows: The use of SSL increases computational cost of the transactions by a factor of 5-7. SSL transactions do not benefit much from a larger L2 cache, but a larger L1 cache would be helpful. A complex logic for handling control dependencies is not useful for SSL transaction as the frequency of branches is very low. Because SSL workload is highly CPU bound, it may be possible to enhance SSL performance by using a number of other architectural features as well.

Architectural impact of secure socket layer on Internet servers

Popularized by Napster and Gnutella file sharing solutions, peer-to-peer (P2P) computing has suddenly emerged at the forefront of Internet computing. The basic notion of cooperative computing and resource sharing has been around for quite some time, although these new applications have opened up possibilities of very flexible web-based information sharing. This article provides a frame-work for classifying current and future P2P technologies. The main motivation for the classification is to identify basic characteristics of P2P applications so that the infrastructure to support P2P computing can concentrate on these basic characteristics.

/pdf/a-framework-for-classifying-peer-to-peer-technologies-1tn6visc8n.pdf

Krishna Kant

Papers

Data center evolution

Method and system for customized television viewing using a peer-to-peer network

NSF/IEEE-TCPP curriculum initiative on parallel and distributed computing: core topics for undergraduates

Architectural impact of secure socket layer on Internet servers

A Framework for Classifying Peer-to-Peer Technologies