scholarly journals Software-defined networks: A walkthrough guide from occurrence To data plane fault tolerance

Author(s):  
Ali Malik ◽  
Benjamin Aziz ◽  
Ali Al-Haj ◽  
Mo Adda

In recent years, the emerging paradigm of software-defined networking has become a hot and thriving topic that grabbed the attention of industry sector as well as the academic research community. The decoupling between the network control and data planes means that software-defined networking architecture is programmable, adjustable and dynamically re-configurable. As a result, a large number of leading companies across the world have latterly launched software-defined solutions in their data centers and it is expected that most of the service providers will do so in the near future due to the new opportunities enabled by software-defined architectures. Nonetheless, each emerging technology is accompanied by new issues and concerns, and fault tolerance and recovery is one such issue that faces software-defined networking. Although there have been numerous studies that have discussed this issue, gaps still exist and need to be highlighted. In this paper, we start by tracing the evolution of networking systems from the mid 1990's until the emergence of programmable networks and software-defined networking, and then define a taxonomy for software-defined networking dependability by means of fault tolerance of data plane to cover all aspects, challenges and factors that need to be considered in future solutions. We discuss in a detailed manner current state-of-the-art literature in this area. Finally, we analyse the current gaps in current research and propose possible directions for future work.

Author(s):  
Ali Malik ◽  
Benjamin Aziz ◽  
Ali Al-Haj ◽  
Mo Adda

In recent years, the emerging paradigm of software-defined networking has become a hot and thriving topic that grabbed the attention of industry sector as well as the academic research community. The decoupling between the network control and data planes means that software-defined networking architecture is programmable, adjustable and dynamically re-configurable. As a result, a large number of leading companies across the world have latterly launched software-defined solutions in their data centers and it is expected that most of the service providers will do so in the near future due to the new opportunities enabled by software-defined architectures. Nonetheless, each emerging technology is accompanied by new issues and concerns, and fault tolerance and recovery is one such issue that faces software-defined networking. Although there have been numerous studies that have discussed this issue, gaps still exist and need to be highlighted. In this paper, we start by tracing the evolution of networking systems from the mid 1990's until the emergence of programmable networks and software-defined networking, and then define a taxonomy for software-defined networking dependability by means of fault tolerance of data plane to cover all aspects, challenges and factors that need to be considered in future solutions. We discuss in a detailed manner current state-of-the-art literature in this area. Finally, we analyse the current gaps in current research and propose possible directions for future work.


Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1543
Author(s):  
Pilar Manzanares-Lopez ◽  
Juan Pedro Muñoz-Gea ◽  
Josemaria Malgosa-Sanahuja

Software-defined networking (SDN) architecture has provided well-known advantages in terms of network programmability, initially offering a standard, open, and vendor-agnostic interface (e.g., OpenFlow) to instruct the forwarding behavior of network devices from different vendors. However, in the last few years, data plane programmability has emerged as a promising approach to extend the network management allowing the definition and programming of customized and non-standardized protocols, as well as specific packet processing pipelines. In this paper, we propose an in-network key-based routing protocol called P4-KBR, in which end-points (hosts, contents or services) are identified by virtual identifiers (keys) instead of IP addresses, and where P4 network elements are programmed to be able to route the packets adequately. The proposal was implemented and evaluated using bmv2 P4 switches, verifying how data plane programmability offers a powerful tool to overcome continuing challenges that appear in SDN networks.


Author(s):  
Doan Hoang

Software-Defined Networking (SDN) has emerged as a networking paradigm that can remove the limitations of current network infrastructures by separating the control plane from the data forwarding plane. As an immediate result, networks can be managed cost effectively and autonomously through centralising the decision-making capability at the control plane and the programmability of network devices on the data plane. This allows the two planes to evolve independently and open up separate horizontal markets on simplified network devices and programmable controllers.  More importantly, it opens up markets for infrastructure providers to provision and offer network resources on-demand to multiple tenants and for service providers to develop and deploy their services on shared infrastructure resources cost-effectively. This paper provides an essential understanding of the SDN concept and architecture. It discusses the important implications of the control/data plane separation on network devices, management and applications beyond the scope of the original SDN. It also discusses two major issues that may help to bring the disruptive technology forward: the intent northbound interface and the cost-effective SDN approaches for the industry.


2020 ◽  
Vol 10 ◽  
pp. 7 ◽  
Author(s):  
Eoin P. Carley ◽  
Carla Baldovin ◽  
Pieter Benthem ◽  
Mario M. Bisi ◽  
Richard A. Fallows ◽  
...  

The low frequency array (LOFAR) is a phased array interferometer currently consisting of 13 international stations across Europe and 38 stations surrounding a central hub in the Netherlands. The instrument operates in the frequency range of ~10–240 MHz and is used for a variety of astrophysical science cases. While it is not heliophysics or space weather dedicated, a new project entitled “LOFAR for Space Weather” (LOFAR4SW) aims at designing a system upgrade to allow the entire array to observe the Sun, heliosphere, Earth’s ionosphere, and Jupiter throughout its observing window. This will allow the instrument to operate as a space weather observing platform, facilitating both space weather science and operations. Part of this design study aims to survey the existing space weather infrastructure operating at radio frequencies and show how LOFAR4SW can advance the current state-of-the-art in this field. In this paper, we survey radio instrumentation and facilities that currently operate in space weather science and/or operations, including instruments involved in solar, heliospheric, and ionospheric studies. We furthermore include an overview of the major space weather service providers in operation today and the current state-of-the-art in the radio data they use and provide routinely. The aim is to compare LOFAR4SW to the existing radio research infrastructure in space weather and show how it may advance both space weather science and operations in the radio domain in the near future.


Author(s):  
Doan Hoang

Software-Defined Networking (SDN) has emerged as a networking paradigm that can remove the limitations of current network infrastructures by separating the control plane from the data forwarding plane. As an immediate result, networks can be managed cost effectively and autonomously through centralising the decision-making capability at the control plane and the programmability of network devices on the data plane. This allows the two planes to evolve independently and open up separate horizontal markets on simplified network devices and programmable controllers.  More importantly, it opens up markets for infrastructure providers to provision and offer network resources on-demand to multiple tenants and for service providers to develop and deploy their services on shared infrastructure resources cost-effectively. This paper provides an essential understanding of the SDN concept and architecture. It discusses the important implications of the control/data plane separation on network devices, management and applications beyond the scope of the original SDN. It also discusses two major issues that may help to bring the disruptive technology forward: the intent northbound interface and the cost-effective SDN approaches for the industry.


2020 ◽  
Vol 14 (4) ◽  
pp. 324-369 ◽  
Author(s):  
Rafał Rusiecki ◽  
Jakub Witkowski ◽  
Joanna Jaszczewska-Adamczak

Background: Mouse Double Minute 2 protein (MDM2) is a cellular regulator of p53 tumor suppressor (p53). Inhibition of the interaction between MDM2 and p53 proteins is a promising anticancer therapy. Objective: This updated patent review is an attempt to compile the research and achievements of the various researchers working on small molecule MDM2 inhibitors from 2010 to date. We provide an outlook into the future for therapy based on MDM2 inhibition by presenting an overview of the most relevant patents which have recently appeared in the literature. Methods: Literature and recent patents focusing on the anticancer potential of MDM2-p53 interaction inhibitors and its applications have been analyzed. We put the main emphasis on the most perspective compounds which are or were examined in clinical trials. Results: Literature data indicated that MDM2 inhibitors are therapeutically effective in specific types of cancer or non-cancer diseases. A great number of patents and research work around new MDM2- p53 interaction inhibitors, possible combinations, new indications, clinical regimens in previous years prove that this targeted therapy is in the scope of interest for many business and academic research groups. Conclusion: Novel MDM2 inhibitors thanks to higher potency and better ADME properties have shown effectiveness in preclinical and clinical development however the final improvement of therapeutic potential for MDM2 inhibitors might depend on the useful combination therapy and exploring new cancer and non-cancer indications.


Author(s):  
Paul B. Miller

This chapter charts new frontiers of scholarly inquiry in fiduciary law. The chapter first orients the reader by taking stock of the current state of play in fiduciary scholarship. It then identifies a range of important questions that should inspire future work in the field. More specifically, it identifies pressing questions of legal theory (conceptual and normative analysis), economic and empirical legal studies (including classical and behavioral economic analysis), and historical and sociological inquiry. The chapter also raises questions of interest to private law theorists and scholars interested in exploring the significance of fiduciary principles within various subfields, from trust and corporate law to health law and legal ethics.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Niclas Hoffmann ◽  
Robert Stahlbock ◽  
Stefan Voß

Abstract The use of shipping containers for the transport of goods has become indispensable and a crucial factor for globalization by providing inexpensive and safe transport opportunities. It is expected that the number of globally operating containers will increase in the near future. Despite a high technical modernisation of the logistic chain, the container still faces a risk of damage at any time and any place within the transport chain. In principle, a container is taken out of service, when a damage is recognized. Different causes of damage exist and various types of damage could occur to the container, ranging from minor to substantial major ones that do not permit the continued proper use of the container. Thus, an individual decision on repair and maintenance (R&M) for each damaged container is necessary. Aside from technical aspects, it has to be decided from an economical perspective whether a repair should be performed. A profound decision should consider various criteria like, e.g., repair costs, lifespan of the container, future yields and possible sales price. Based on a regulatory, practical, and scientific view, this paper proposes a multi-criteria decision model for the economic decision on the R&M of a damaged container. Implemented in Microsoft Excel, this decision model is easily applicable. The user can deduce a first (limited) guidance for dealing with a respective damaged container based on its current state and general market conditions.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2169
Author(s):  
Pauline Macharia ◽  
Nzula Kitaka ◽  
Paul Yillia ◽  
Norbert Kreuzinger

This study examined the current state of water demand and associated energy input for water supply against a projected increase in water demand in sub-Saharan Africa. Three plausible scenarios, namely, Current State Extends (CSE), Current State Improves (CSI) and Current State Deteriorates (CSD) were developed and applied using nine quantifiable indicators for water demand projections and the associated impact on energy input for water supply for five Water Service Providers (WSPs) in Kenya to demonstrate the feasibility of the approach based on real data in sub-Saharan Africa. Currently, the daily per capita water-use in the service area of four of the five WSPs was below minimum daily requirement of 50 L/p/d. Further, non-revenue water losses were up to three times higher than the regulated benchmark (range 26–63%). Calculations showed a leakage reduction potential of up to 70% and energy savings of up to 12 MWh/a. The projected water demand is expected to increase by at least twelve times the current demand to achieve universal coverage and an average daily per capita consumption of 120 L/p/d for the urban population by 2030. Consequently, the energy input could increase almost twelve-folds with the CSI scenario or up to fifty-folds with the CSE scenario for WSPs where desalination or additional groundwater abstraction is proposed. The approach used can be applied for other WSPs which are experiencing a similar evolution of their water supply and demand drivers in sub-Saharan Africa. WSPs in the sub-region should explore aggressive strategies to jointly address persistent water losses and associated energy input. This would reduce the current water supply-demand gap and minimize the energy input that will be associated with exploring additional water sources that are typically energy intensive.


Sign in / Sign up

Export Citation Format

Share Document