Edyta Biernacka

Software-Defined Networking, as a relatively recent networking paradigm, offers centralized infrastructure management, flexibility and high programmability. However, it also creates particular security risks due to being exposed to external threats. To address these challenges, numerous methods have been developed and applied over the past few years. This study proposes a hybrid Intrusion Detection System that combines signature-based analysis with deep learning-based anomaly detection. In this architecture, a signature module quickly filters known attack patterns, while remaining traffic is analyzed by an autoencoder and a supervised deep neural network classifier. The final decision is based on rule-based prioritization of the outputs from both models, improving the reliability and robustness of detection.

This paper focuses on handling traffic demands dynamically in a multi-layer IP-over-elastic optical network (IP-over-EON). We propose a mechanism that uses two types of optical resources. Some resources are visible for the network layer to serve IP traffic. Another part is hidden and reserved for handling congestions solely in the optical layer when resources in the network layer are insufficient. In such a case, the proposed algorithm tries to establish a new lightpath, allocating hidden optical resources. Extensive discrete-event computer simulations were conducted under various network conditions to evaluate the performance of the proposed solution, using two network topologies, the NSF15 and UBN24 networks. The results obtained confirm that the new solution allows for a significant decrease in the bandwidth blocking probability with better utilization of resources compared to the reference scenario (only IP).

The Software-Defined Networking concept plays an important role in network management. The central controller, which is the main element of SDN, allows the provision of traffic engineering and security solutions in single- and multiple-layer networks based on optical transmission. In this work, we compare selected open-source implementations of SDN controllers. Throughput and latency measurements were analyzed using the CBench program. The simulation of a link failure and a controller failure were conducted using the API provided by the Mininet network simulator. To detect security vulnerabilities, a dedicated program, called sdnpwn, was used. This work provides an overview of the selected controllers, indicating their strengths and weaknesses. Moreover, some implemention suggestions and recommendations are presented.

As a consequence of increased complexity, technical requirements of services and expectations of end-users, telecommunication networks and systems must still increase their efficiency. Research currently focuses on introducing automation and intelligence into network control and management. Neural Networks form a class of Machine Learning techniques utilizing the supervised learning paradigm. The class is mature and comprises a significant number of algorithms. As a result, Neural Networks-based solutions are widely applicable, also in the context of communications and networking. The aim of this tutorial is twofold. Firstly, to provide fundamentals regarding the Neural Network (NN) method. Secondly, to comprehensively study the examples of applying NN-based solutions to solve problems in different aspects of communications and networking. Studies are supplemented with additional explanations, figures and critical considerations, including pros and cons of using selected methods for particular purposes. This part uniquely complements the tutorial one and facilitates in-depth understanding of NN. Based on the conducted studies, we draw a comparative analysis, summaries and expected future research topics and challenges of using NN in communications and networking.

The Software-Defined Networking concept plays an important role in network management. The central controller, which is the main element of SDN, allows to provide traffic engineering and security solutions in single and multiple-layer networks based on optical transmission. In this work, we compare selected open-source implementations of SDN controllers. Throughput and latency measurements were analyzed using the CBench program. The simulation of a link failure and a controller failure were conducted using the API provided by the Mininet network simulator. For detecting security vulnerabilities, a dedicated program, called sdnpwn, was used. The work provides an overview of the selected controllers, indicating their strengths and weaknesses. Moreover, some implemention suggestions and recommendations are presented.

The problem of resource provisioning in multi-layer networks is an important issue. We discuss and analyze resource provisioning in terms of the visibility of optical resources for the virtual layer in a network. In this context, we propose the diversification of the optical spectrum in such a way that some resources are hidden for the virtual layer and used when needed. We introduce and investigate automatic hidden lightpaths to improve resource utilization in multi-layer networks. Our solution uses a software-defined networking concept to automatically set up and release hidden lightpaths, which are not visible at the network layer. We evaluate and analyze two main approaches to resource provisioning in terms of the blocking probability. Future research should focus on resource diversification and the usage of the hidden elastic optical spectrum in modern networks as a promising solution.

In this paper, we propose a novel priority-aware solution named bypass to handle high- and low-priority traffic in multi-layer networks. Our approach assumes diversification of elastic optical spectrum to ensure additional resources reserved for emergency situations. When congestion occurs, the solution dynamically provides new paths, allocating a hidden spectrum to offload traffic from the congested links in the IP layer. Resources for a bypass are selected based on traffic priority. High-priority traffic always gets the shortest bypasses in terms of physical distance, which minimizes delay. Bypasses for low-priority traffic can be established if the utilization of the spectrum along the path is below the assumed threshold. The software-defined networking controller ensures the global view of the network and cooperation between IP and elastic optical layers. Simulation results show that the solution successfully reduces the amount of rejected high-priority traffic when compared to regular bypasses and when no bypasses are used. Also, overall bandwidth blocking probability is lower when our priority-aware bypasses are used.

We demonstrate tests of a flow-based router enhanced with the additional mechanisms: Emergency Connections, Efficient Congestion Control, Global Protected Flow List and Per-User Fairness. The tests were conducted in the Click environment. The analyzed mechanisms allow for immediate acceptance of high priority traffic, protection of streaming flows in congestion, and ensure high reliability and fairness. In this paper, we show that these mechanisms work successfully in a laboratory network. Moreover, they all work at the same time providing high-level coordinated performance. Test results show significant advantages of the cross-protect router architecture over standard IP routers in several areas.

In this paper, we concentrate on solving the dynamic routing problem with traffic classification using the Software Defined Elastic Optical Networks framework. We first define three categories of traffic based on the CISCO Traffic Reports. Then, we propose two algorithms to solve the Routing, Modulation and Spectrum Assignment problem with the support of traffic class recognition - the Split Spectrum and the Buffer. We evaluate our approach using representative network topologies and a wide range of simulations. The results clearly show that the Butter algorithm provisions efficiently the incoming traffic in the network. In addition, we show the reduction of request blocking for the highest priority traffic that cannot be interrupted.