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.

Network function virtualization (NFV) has drawn significant attention from both industry and academia as an important shift in telecommunication service provisioning. By decoupling network functions (NFs) from the physical devices on which they run, NFV has the potential to lead to significant reductions in operating expenses (OPEX) and capital expenses (CAPEX) and facilitate the deployment of new services with increased agility and faster time-to-value. The NFV paradigm is still in its infancy and there is a large spectrum of opportunities for the research community to develop new architectures, systems and applications, and to evaluate alternatives and trade-offs in developing technologies for its successful deployment. In this paper, after discussing NFV and its relationship with complementary fields of software defined networking (SDN) and cloud computing, we survey the state-of-the-art in NFV, and identify promising research directions in this area. We also overview key NFV projects, standardization efforts, early implementations, use cases, and commercial products.

/pdf/network-function-virtualization-state-of-the-art-and-29gg3feprt.pdf

Network Function Virtualization: State-of-the-Art and Research Challenges

/pdf/introduction-to-the-modern-theory-of-dynamical-systems-1eced70mum.pdf

Introduction to the Modern Theory of Dynamical Systems

Here we present Singularity, software developed to bring containers and reproducibility to scientific computing. Using Singularity containers, developers can work in reproducible environments of their choosing and design, and these complete environments can easily be copied and executed on other platforms. Singularity is an open source initiative that harnesses the expertise of system and software engineers and researchers alike, and integrates seamlessly into common workflows for both of these groups. As its primary use case, Singularity brings mobility of computing to both users and HPC centers, providing a secure means to capture and distribute software and compute environments. This ability to create and deploy reproducible environments across these centers, a previously unmet need, makes Singularity a game changing development for computational science.

/pdf/singularity-scientific-containers-for-mobility-of-compute-1cc0ze5ylx.pdf

Singularity: Scientific containers for mobility of compute.

Software-Defined Networking (SDN) refers to a new approach for network
programmability, that is, the capacity to initialize, control, change,
and manage network behavior dynamically via open interfaces. SDN
emphasizes the role of software in running networks through the
introduction of an abstraction for the data forwarding plane and, by
doing so, separates it from the control plane. This separation allows
faster innovation cycles at both planes as experience has already
shown. However, there is increasing confusion as to what exactly SDN
is, what the layer structure is in an SDN architecture, and how layers
interface with each other. This document, a product of the IRTF
Software-Defined Networking Research Group (SDNRG), addresses these
questions and provides a concise reference for the SDN research
community based on relevant peer-reviewed literature, the RFC series,
and relevant documents by other standards organizations.

/pdf/software-defined-networking-sdn-layers-and-architecture-1m0vviv871.pdf

Software-Defined Networking (SDN): Layers and Architecture Terminology

In this paper an accurate, analytical model for the evaluation of the CMOS inverter transient response and propagation delay for short-channel devices is presented. An exhaustive analysis of the inverter operation is provided which results in accurate expressions of the output response to an input ramp. Most of the factors which influence the inverter operation are taken into account. The /spl alpha/-power law MOS model, which considers the carriers' velocity saturation effects of short-channel devices, is used. The final results are in excellent agreement with SPICE simulations.

Analytical transient response and propagation delay evaluation of the CMOS inverter for short-channel devices

Two architectures and VLSI implementations of the AES Proposal, Rijndael, are presented in this paper. These alternative architectures are operated both for encryption and decryption process. They reduce the required hardware resources and achieve high-speed performance. Their design philosophy is completely different. The first uses feedback logic and reaches a throughput value equal to 259 Mbit/sec. It performs efficiently in applications with low covered area resources. The second architecture is optimized for high-speed performance using pipelined technique. Its throughput can reach 3.65 Gbit/sec.

Architectures and VLSI implementations of the AES-Proposal Rijndael

The continued growth of both wired and wireless communications has triggered the revolution for the generation of new cryptographic algorithms. SHA-2 hash family is a new standard in the widely used hash functions category. An architecture and the VLSI implementation of this standard are proposed in this work. The proposed architecture supports a multi-mode operation in the sense that it performs all the three hash functions (256, 384 and 512) of the SHA-2 standard. The proposed system is compared with the implementation of each hash function in a separate FPGA device. Comparing with previous designs, the introduced system can work in higher operation frequency and needs less silicon area resources. The achieved performance in the term of throughput of the proposed system/architecture is much higher (in a range from 277 to 417%) than the other hardware implementations. The introduced architecture also performs much better than the implementations of the existing standard SHA-1, and also offers a higher security level strength. The proposed system could be used for the implementation of integrity units, and in many other sensitive cryptographic applications, such as, digital signatures, message authentication codes and random number generators.

Implementation of the SHA-2 Hash Family Standard Using FPGAs

Couple to the communications wired and unwired networks growth, is the increasing demand for strong secure data transmission. New cryptographic standards are developed, and new encryption algorithms are designed, in order to satisfy the special needs for security. SHA-2 is the newest powerful standard in the hash functions families. In this paper, a VLSI architecture for the SHA-2 family is proposed. For every hash function SHA-2 (256, 384, and 512) of this standard, a hardware implementation is presented. All the implementations are examined and compared in the supported security level and in the performance by using hardware terms. This work can substitute efficiently the previous SHA-1 standard implementations, in every integrity security scheme, with higher offered security level, and better performance. In addition, the proposed implementations could be applied alternatively in the integrations of digital signature algorithms, keyed-hash message authentication codes and in random numbers generators architectures.

Odysseas Koufopavlou

Papers

Software-Defined Networking (SDN): Layers and Architecture Terminology

Analytical transient response and propagation delay evaluation of the CMOS inverter for short-channel devices

Architectures and VLSI implementations of the AES-Proposal Rijndael

Implementation of the SHA-2 Hash Family Standard Using FPGAs

On the hardware implementations of the SHA-2 (256, 384, 512) hash functions