Self-Stabilization, Byzantine Containment, and Maximizable Metrics: Necessary Conditions

Self-stabilization is a versatile approach to fault-tolerance since it permits a distributed system to recover from any transient fault that arbitrarily corrupts the contents of all memories in the system. Byzantine tolerance is an attractive feature of distributed systems that permits to cope with arbitrary malicious behaviors. We consider the well known problem of constructing a maximum metric tree in this context. Combining these two properties leads to some impossibility results. In this paper, we provide two necessary conditions to construct maximum metric tree in presence of transients and (permanent) Byzantine faults

Load balancing of communication channels with the use of routing protocols

In the article the authors propose a method for load-balancing of network resources forthe case which uses a routing protocols. In the first part of the article the authors present currentlyused algorithms for load balancing and possibilities of their modification. Through the introductionof additional hardware components for each node: the agent and the probe; it is possible to monitorand control the current system performance. The whole analyzed network is treated as a complexsystem. This allows to eliminate overloading of route nodes (through ongoing analysis of the optimaloperating point for a given node). Load balancing can be achieved using a modified mechanism ofECMP. The proposed approach allows for dynamic adjustment of load to network resources and thuseffectively to balance network traffic

A hybrid objective function with empirical stability aware to improve RPL for IoT applications

The diverse applications of the internet of things (IoT) require adaptable routing protocol able to cope with several constraints. Thus, RPL protocol was designed to meet the needs for IoT networks categorized as low power and lossy networks (LLN). RPL uses an objective function based on specific metrics for preferred parents selection through these packets are sent to root. The single routing metric issue generally doesn’t satisfy all routing performance requirements, whereas some are improved others are degraded. In that purpose, we propose a hybrid objective function with empirical stability aware (HOFESA), implemented in the network layer of the embedded operating system CONTIKI, which combines linearly three weighty metrics namely hop count, RSSI and node energy consumption. Also, To remedy to frequent preferred parents changes problems caused by taking into account more than one metric, our proposal relies on static and empirical thresholds. The designed HOFESA, evaluated under COOJA emulator against Standard-RPL and EC-OF, showed a packet delivery ratio improvement, a decrease in the power consumption, the convergence time and DIO control messages as well as it gives network stability through an adequate churn

МЕТОД ФОРМУВАННЯ АНТИВІРУСНОГО ЗАХИСТУ ДАНИХ З ВИКОРИСТАННЯМ БЕЗПЕЧНОЇ МАРШРУТИЗАЦІЇ МЕТАДАНИХ

У даній статті розроблено метод антивірусного захисту даних у ТКС за рахунок безпечної маршрутизації метаданих у хмарні антивірусні системи. Він призначений для рішення проблематики, яка полягає в тому, що з метою підвищення ефективності використання засобів антивірусного захисту даних і мінімізації наслідків подібних кіберзлочинів, своєчасне виявлення і локалізація комп'ютерних вірусів є вкрай важливим і разом з тим складним завданням. Основними складовими методу, що пропонується в даній роботі, є: алгоритми формування множини маршрутів передачі метаданих, метод контролю ліній зв'язку ТКС, моделі системи нейромережних експертів безпечної маршрутизації. Відмінною рисою алгоритмів формування множини маршрутів передачі метаданих є показники оптимізації і обмеження, що вводяться, для безпечної маршрутизації. Новизна методу контролю ліній зв'язку ТКС полягає в обліку «скомпрометованих» біт даних спеціальних сигнатур, що передаються у хмарні антивірусні системи. Це дозволить знизити ймовірність маніпуляцій метаданими, які передаються в вузли програмного сервера. Особливістю розробленої системи нейромережних експертів є комплексність використання нейронних мереж типу АРТ і багатошарового персептрону для рішення завдання безпечної маршрутизації, що дозволить підвищити точність ухвалення правильного рішення про несанкціонований доступ до волоконно-оптичних ліній зв'язку

Обзор технологических и теоретических решений в области маршрутизации на основе качества обслуживания

Проведен обзор решений задач маршру-тизации на основе качества обслуживания, включаю-щий как протокольные варианты, так и теоретиче-ские решения, которые еще не получили технологиче-ской реализации. Обзор охватывает комбинаторные методы маршрутизации, а также потоковые модели и методы формализации и решения маршрутных задач.Under rising requirements for telecommunication network role of routing increases, because routing is an ef-fective tool to ensure the specified end-to end quality of service (QoS). Nowadays the routing is transformed into QoS-based rout-ing which focuses on the searching one or more paths for delivering packets where all described in the SLA requirements for quali-ty of service must be satisfied. A set of technological and theoretical solutions is developed for solving QoS-based routing problem. About it several concepts deserves attention among which source routing, precomputed routing, route server concept. From theo-retical point of view QoS-based routing problem can be solved by using graph theory approach or flow-based mathematical model of network. The graph theory approach is based on structure only and doesn’t take into account flow properties of transmitted traffic. As a result it doesn’t allow allocating network resources between different traffics and concordance between routing, accesses, queuing, and reservation. As a rule a flow-based approach solves QoS-based routing problem as mathematical programming prob-lem with QoS-constrains. For example, it can be tensor constrains. The article contains possible lines of development of QoS-based routing that include conversion to dynamical metrics and dynamical models with QoS-constrains, not only load balancing but quality balancing, concordance between routing and another traffic control tasks

Обзор технологических и теоретических решений в области маршрутизации на основе качества обслуживания

Проведен обзор решений задач маршру-тизации на основе качества обслуживания, включаю-щий как протокольные варианты, так и теоретиче-ские решения, которые еще не получили технологиче-ской реализации. Обзор охватывает комбинаторные методы маршрутизации, а также потоковые модели и методы формализации и решения маршрутных задач.Under rising requirements for telecommunication network role of routing increases, because routing is an ef-fective tool to ensure the specified end-to end quality of service (QoS). Nowadays the routing is transformed into QoS-based rout-ing which focuses on the searching one or more paths for delivering packets where all described in the SLA requirements for quali-ty of service must be satisfied. A set of technological and theoretical solutions is developed for solving QoS-based routing problem. About it several concepts deserves attention among which source routing, precomputed routing, route server concept. From theo-retical point of view QoS-based routing problem can be solved by using graph theory approach or flow-based mathematical model of network. The graph theory approach is based on structure only and doesn’t take into account flow properties of transmitted traffic. As a result it doesn’t allow allocating network resources between different traffics and concordance between routing, accesses, queuing, and reservation. As a rule a flow-based approach solves QoS-based routing problem as mathematical programming prob-lem with QoS-constrains. For example, it can be tensor constrains. The article contains possible lines of development of QoS-based routing that include conversion to dynamical metrics and dynamical models with QoS-constrains, not only load balancing but quality balancing, concordance between routing and another traffic control tasks

Energy efficiency considerations in software‐defined wireless body area networks

Wireless body area networks (WBAN) provide remote services for patient monitoring which allows healthcare practitioners to diagnose, monitor, and prescribe them without their physical presence. To address the shortcomings of WBAN, software-defined networking (SDN) is regarded as an effective approach in this prototype. However, integrating SDN into WBAN presents several challenges in terms of safe data exchange, architectural framework, and resource efficiency. Because energy expenses account for a considerable portion of network expenditures, energy efficiency has to turn out to be a crucial design criterion for modern networking methods. However, creating energy-efficient systems is difficult because they must balance energy efficiency with network performance. In this article, the energy efficiency features are discussed that can widely be used in the software-defined wireless body area network (SDWBAN). A comprehensive survey has been carried out for various modern energy efficiency models based on routing algorithms, optimization models, secure data delivery, and traffic management. A comparative assessment of all the models has also been carried out for various parameters. Furthermore, we explore important concerns and future work in SDWBAN energy efficiency

Study, evaluation and contributions to new algorithms for the embedding problem in a network virtualization environment

Network virtualization is recognized as an enabling technology for the future Internet. It aims to overcome the resistance of the current Internet to architectural change and to enable a new business model decoupling the network services from the underlying infrastructure. The problem of embedding virtual networks in a substrate network is the main resource allocation challenge in network virtualization and is usually referred to as the Virtual Network Embedding (VNE) problem. VNE deals with the allocation of virtual resources both in nodes and links. Therefore, it can be divided into two sub-problems: Virtual Node Mapping where virtual nodes have to be allocated in physical nodes and Virtual Link Mapping where virtual links connecting these virtual nodes have to be mapped to paths connecting the corresponding nodes in the substrate network. Application of network virtualization relies on algorithms that can instantiate virtualized networks on a substrate infrastructure, optimizing the layout for service-relevant metrics. This class of algorithms is commonly known as VNE algorithms. This thesis proposes a set of contributions to solve the research challenges of the VNE that have not been tackled by the research community. To do that, it performs a deep and comprehensive survey of virtual network embedding. The first research challenge identified is the lack of proposals to solve the virtual link mapping stage of VNE using single path in the physical network. As this problem is NP-hard, existing proposals solve it using well known shortest path algorithms that limit the mapping considering just one constraint. This thesis proposes the use of a mathematical multi-constraint routing framework called paths algebra to solve the virtual link mapping stage. Besides, the thesis introduces a new demand caused by virtual link demands into physical nodes acting as intermediate (hidden) hops in a path of the physical network. Most of the current VNE approaches are centralized. They suffer of scalability issues and provide a single point of failure. In addition, they are not able to embed virtual network requests arriving at the same time in parallel. To solve this challenge, this thesis proposes a distributed, parallel and universal virtual network embedding framework. The proposed framework can be used to run any existing embedding algorithm in a distributed way. Thereby, computational load for embedding multiple virtual networks is spread across the substrate network Energy efficiency is one of the main challenges in future networking environments. Network virtualization can be used to tackle this problem by sharing hardware, instead of requiring dedicated hardware for each instance. Until now, VNE algorithms do not consider energy as a factor for the mapping. This thesis introduces the energy aware VNE where the main objective is to switch off as many network nodes and interfaces as possible by allocating the virtual demands to a consolidated subset of active physical networking equipment. To evaluate and validate the aforementioned VNE proposals, this thesis helped in the development of a software framework called ALgorithms for Embedding VIrtual Networks (ALEVIN). ALEVIN allows to easily implement, evaluate and compare different VNE algorithms according to a set of metrics, which evaluate the algorithms and compute their results on a given scenario for arbitrary parameters