The paper is devoted to designing of the Fast ReRoute QoS protection scheme for bandwidth and probability of packet loss in Software-Defined WAN. The solution represented by a nonlinear flow-based model of fast rerouting with the protection of such two network performance indicators as bandwidth and probability of packet loss is proposed. This model at the level of the flow conservation conditions takes into account the buffer limitedness of queues on the routers interfaces, which allowed controlling the probable overload of the link resource. The numerical example confirmed the adequacy of the offered model and the efficiency of the decisions made in relation to the fast rerouting of data traffic with the realization of the protection scheme for bandwidth and probability of packet loss.

IP Fast Reroute (IPFRR) is resiliency technology to provide fast traffic recovery upon link or node failure for mission critical services. This technology is able to recover impacted traffic in 50 ms upon any single link or node failure. The key aspect of IP Fast Reroute technology is fast failure detection and pre-calculation of alternative path in advance, before the link or node failure occurs. If specific failure within the network occurs, IP Fast Reroute mechanism uses this pre-calculated alternative path to bypass failure and restores communication. In this paper, we bring survey of advanced Fast Reroute solutions for IP-based intra-domain networks. There have been several approaches proposed such as Directed LFA, Topology Independent LFA, BIER-TE FRR and others.

The sprawling nature of Internet of Things (IoT) sensors require the comprehensive management and reliability of the entire network. Modern Internet Protocol (IP) networks demand specific qualitative and quantitative parameters that need to be met. One of these requirements is the minimal packet loss in the network. After a node or link failure within the network, the process of network convergence will begin. This process may take an unpredictable time, mostly depending on the size and the structure of the affected network segment and the routing protocol used within the network. The categories of proposed solutions for these problems are known as Fast ReRoute (FRR) mechanisms. The majority of current Fast ReRoute mechanisms use precomputation of alternative backup paths in advance. This paper presents an Enhanced Multicast Repair (EM-REP) FRR mechanism that uses multicast technology to create an alternate backup path and does not require pre-calculation. This principle creates a unique reactive behavior in the Fast ReRoute area. The enhanced M-REP FRR mechanism can find an alternative path in the event of multiple links or nodes failing at different times and places in the network. This unique behavior can be applied in the IoT sensors area, especially in network architecture that guarantees reliability of data transfer.

In the article, we present the research and development of an improved delay-sensitive routing tensor model for the core of the IoT network. The flow-based tensor model is considered within the coordinate system of interpolar paths and internal node pairs. The advantage of the presented model is the application for IoT architectures to ensure the Quality of Service under the parameters of bandwidth, average end-to-end delay, and the probability of packet loss. Hence, the technical task of delay-sensitive routing is formulated as the optimization problem together with constraints and conditions imposed on the corresponding routing variables. The system of optimality criteria is chosen for an investigation. Each selected criterion concerning the specifics of the demanded routing problem solution aims at the optimal use of available network resources and the improvement of QoS indicators, namely, average end-to-end delay. The analysis of the obtained routing solutions under different criteria is performed. Numerical research of the improved delay-sensitive routing tensor model allowed us to discover its features and proved the adequacy of the results for the multipath order of routing.

At the beginning, this paper describes basic overview of Cloud Computing (CC) and its usage among companies. Second part describes how is Cloud Computing being taught on another schools and companies around the world. Next, there is description of our physical and logical topology, used during experiments. In the next part, there are descriptions of experiments we made during semester while teaching cloud related subjects. This is followed by results of measurements of used resources in our CC system.