Hidden and Uncontrolled - On the Emergence of Network Steganographic Threats

Network steganography is the art of hiding secret information within innocent network transmissions. Recent findings indicate that novel malware is increasingly using network steganography. Similarly, other malicious activities can profit from network steganography, such as data leakage or the exchange of pedophile data. This paper provides an introduction to network steganography and highlights its potential application for harmful purposes. We discuss the issues related to countering network steganography in practice and provide an outlook on further research directions and problems.Comment: 11 page

Implementação de redes 5G baseadas em código aberto

Recently, a growth of mobile networks, from a huge connection of only a few devices, to the need for constant maintenance with support even with different technological needs. This requires increasing the capacity of networks to respond to user needs, increasing connection speeds and decreasing latencies. In many cases, the demand for the capabilities offered by the new generation of mobile networks, 5G, remains unanswered with conventional structures, especially in urban areas. As a viable option for these needs, the use of small cells emerged. The use of this equipment is facilitated due to the flexibility offered by the architecture of 5G mobile networks that facilitate the division of the same into functional units with a virtual implementation, thus helping to spread the coverage area. The growing interest in 5G mobile networks and the immense possibilities they offer have given rise to projects focused on the development of 5G mobile networks that are made available for consultation and use by the interested community. These networks are mostly implemented in a virtual way, with the exception of the component responsible for the emission of the radio signal, where some options will be presented for this purpose during the course of the dissertation. As a target of study and evaluation of the state of development and usefulness throughout this dissertation, OpenAirInterface was chosen from among these open-source projects. The complete implementation of the same is presented and described, as well as the tests carried out in order to determine which are the functional bandwidths and which are the options for optimizing its operation. To conclude the work carried out, the results and balance of these tests are presented in the form of speed and latency tests in various bandwidths, verification of occupancy of the same, flexibility in modifying the emission frequency, as well as the result of a test of connecting elements of mobile networks developed by different open-source projects as a way of evaluating the flexibility of these networks.Recentemente temos assistido a um crescimento enorme de redes móveis, desde a conexão de apenas alguns dispositivos, até à necessidade de manter ligação constante com múltiplos equipamentos com necessidades tecnológicas diferentes. Isto requer o aumento da capacidade das redes para dar resposta às necessidades dos utilizadores, aumentar velocidades de conexão e diminuir latências. Em muitos casos, a procura pelas capacidades oferecidas pela nova geração de redes móveis, o 5G, continua sem resposta com as estruturas convencionais, especialmente em áreas urbanas. Como opção viável para essas necessidades, surgiu o uso de small cells. O uso desse equipamento é facilitado devido à flexibilidade oferecida pela arquitetura de redes móveis 5G que facilitam a divisão da mesma em unidades funcionais com uma implementação virtual ajudando assim à propagação da área de cobertura. O interesse crescente de redes móveis 5G e as imensas possibilidades que as mesmas oferecem, fizeram surgir projetos focados no desenvolvimento de redes móveis 5G que são colocados disponíveis para consulta e uso da comunidade interessada. Estes redes são maioritariamente implementadas de forma virtual à exceção do componente responsável pela emissão do sinal rádio, onde serão apresentadas algumas opções para o efeito no decorrer da dissertação. Como alvo de estudo e avaliação do estado de desenvolvimento e utilidade ao longo desta dissertação, foi escolhida a OpenAirInterface de entre esses projetos open-source. É apresentada e descrita a implementação completa da mesma, assim como os testes efetuados no sentido de apurar quais as larguras de banda funcionais e quais as opções de otimização de funcionamento da mesma. Para concluir o trabalho realizado, é apresentado o resultado e balanço desses testes na forma de testes de velocidade e latência em várias larguras de banda, verificação de ocupação da mesma, flexibilidade em modificar a frequência de emissão, assim como o resultado de um teste de conexão de elementos de redes móveis desenvolvidos por projetos open-source diferentes como forma de avaliar a flexibilidade destas redes.Mestrado em Engenharia Eletrónica e Telecomunicaçõe

Reliable Server Pooling - Evaluierung, Optimierung und Erweiterung einer neuen IETF-Architektur

The Reliable Server Pooling (RSerPool) architecture currently under standardization by the IETF RSerPool Working Group is an overlay network framework to provide server replication and session failover capabilities to applications using it. These functionalities as such are not new, but their combination into one generic, application-independent framework is. Initial goal of this thesis is to gain insight into the complex RSerPool mechanisms by performing experimental and simulative proof-of-concept tests. The further goals are to systematically validate the RSerPool architecture and its protocols, provide improvements and optimizations where necessary and propose extensions if useful. Based on these evaluations, recommendations to implementers and users of RSerPool should be provided, giving guidelines for the tuning of system parameters and the appropriate configuration of application scenarios. In particular, it is also a goal to transfer insights, optimizations and extensions of the RSerPool protocols from simulation to reality and also to bring the achievements from research into application by supporting and contributing relevant results to the IETF's ongoing RSerPool standardization process. To achieve the described goals, a prototype implementation as well as a simulation model are designed and realized at first. Using a generic application model and appropriate performance metrics, the performance of RSerPool systems in failure-free and server failure scenarios is systematically evaluated in order to identify critical parameter ranges and problematic protocol behaviour. Improvements developed as result of these performance analyses are evaluated and finally contributed into the standardization process of RSerPool

Data-Driven resource orchestration in sliced 5G Networks

En los últimos años la quinta generación de comunicaciones móviles ha comenzado a desarrollarse. El 5G supone un gran cambio si se compara con las anteriores generaciones de comunicaciones móviles, puesto que no se centra meramente en aumentar el ancho de banda, reducir la latencia o mejorar la eficiencia espectral, sino en ofrecer un amplio rango de servicios y aplicaciones, con requisitos muy dispares entre sí, a una gran variedad de tipos de usuario. Estos objetivos pretenden ser alcanzados empleando nuevas tecnologías: Network Function Virtualization, Software Defined Networks, Network Slicing, Mobile Edge Computing, etc. El objetivo de este Trabajo de Fin de Máster es analizar el soporte actual de end-to-end Network Slicing en un entorno 5G Open Source y desarrollar una maqueta 5G con software que admita Network-slicing.In the past few years the fifth generation in mobile communications started to arise. 5G supposes a great change compared with the past mobile communication generations, it doesn’t aim merely at improving bandwidth, reducing delay or upgrading spectral efficiency but at offering a wide range of services and applications, with huge differentrequirements, to a vast variety of users. These objectives are to be accomplished using new technologies such as: Network Function Virtualization, Software Defined Networks, Network Slicing, Mobile Edge Computing, etc. The objective of this Master Thesisis to analyze the current support for end-to-end Network Slicing in a 5G Open Source environment and to developan open source5GTestbedwith recent Software contributions in Network Slicing.Máster Universitario en Ingeniería de Telecomunicación (M125

Cooperative resource pooling in multihomed mobile networks

The ubiquity of multihoming amongst mobile devices presents a unique opportunity for users to co-operate, sharing their available Internet connectivity, forming multihomed mobile networks on demand. This model provides users with vast potential to increase the quality of service they receive. Despite this, such mobile networks are typically underutilized and overly restrictive, as additional Internet connectivity options are predominantly ignored and selected gateways are both immutable and incapable of meeting the demand of the mobile network. This presents a number of research challenges, as users look to maximize their quality of experience, while balancing both the financial cost and power consumption associated with utilizing a diverse set of heterogeneous Internet connectivity options. In this thesis we present a novel architecture for mobile networks, the contribution of which is threefold. Firstly, we ensure the available Internet connectivity is appropriately advertised, building a routing overlay which allows mobile devices to access any available network resource. Secondly, we leverage the benefits of multipath communications, providing the mobile device with increased throughput, additional resilience and seamless mobility. Finally, we provide a multihomed framework, enabling policy driven network resource management and path selection on a per application basis. Policy driven resource management provides a rich and descriptive approach, allowing the context of the network and the device to be taken into account when making routing decisions at the edge of the Internet. The aim of this framework, is to provide an efficient and flexible approach to the allocation of applications to the optimal network resource, no matter where it resides in a mobile network. Furthermore, we investigate the benefits of path selection, facilitating the policy framework to choose the optimal network resource for specific applications. Through our evaluation, we prove that our approach to advertising Internet connectivity in a mobile network is both efficient and capable of increasing the utilization of the available network capacity. We then demonstrate that our policy driven approach to resource management and path selection can further improve the user’s quality of experience, by tailoring network resource usage to meet their specific needs

Understanding O-RAN: Architecture, Interfaces, Algorithms, Security, and Research Challenges

The Open Radio Access Network (RAN) and its embodiment through the O-RAN Alliance specifications are poised to revolutionize the telecom ecosystem. O-RAN promotes virtualized RANs where disaggregated components are connected via open interfaces and optimized by intelligent controllers. The result is a new paradigm for the RAN design, deployment, and operations: O-RAN networks can be built with multi-vendor, interoperable components, and can be programmatically optimized through a centralized abstraction layer and data-driven closed-loop control. Therefore, understanding O-RAN, its architecture, its interfaces, and workflows is key for researchers and practitioners in the wireless community. In this article, we present the first detailed tutorial on O-RAN. We also discuss the main research challenges and review early research results. We provide a deep dive of the O-RAN specifications, describing its architecture, design principles, and the O-RAN interfaces. We then describe how the O-RAN RAN Intelligent Controllers (RICs) can be used to effectively control and manage 3GPP-defined RANs. Based on this, we discuss innovations and challenges of O-RAN networks, including the Artificial Intelligence (AI) and Machine Learning (ML) workflows that the architecture and interfaces enable, security and standardization issues. Finally, we review experimental research platforms that can be used to design and test O-RAN networks, along with recent research results, and we outline future directions for O-RAN development.Comment: 33 pages, 16 figures, 3 tables. Submitted for publication to the IEE