Biblio

In this article, authors present the results of testing the modified HTB traffic control algorithm in an experimental setup. The algorithm is implemented as a Linux kernel module. An analysis of the experimental results revealed the effect of uneven packet loss in priority classes. In the second part of the article, the authors propose a solution to this problem by applying a distribution scheme for the excess of tokens, according to which excess class tokens are given to the leaf with the highest priority. The new modification of the algorithm was simulated in the AnyLogic environment. The results of an experimental study demonstrated that dividing the excess tokens of the parent class between daughter classes is less effective in terms of network performance than allocating the excess tokens to a high-priority class during the competition for tokens between classes. In general, a modification of the HTB algorithm that implements the proposed token surplus distribution scheme yields more consistent delay times for the high-priority class.

Vehicular Adhoc Network (VANET), a specialized form of MANET in which safety is the major concern as critical information related to driver's safety and assistance need to be disseminated between the vehicle nodes. The security of the nodes can be increased, if the network availability is increased. The availability of the network is decreased, if there is Denial of Service Attacks (DoS) in the network. In this paper, a packet detection algorithm for the prevention of DoS attacks is proposed. This algorithm will be able to detect the multiple malicious nodes in the network which are sending irrelevant packets to jam the network and that will eventually stop the network to send the safety messages. The proposed algorithm was simulated in NS-2 and the quantitative values of packet delivery ratio, packet loss ratio, network throughput proves that the proposed algorithm enhance the security of the network by detecting the DoS attack well in time.

This article discusses existing approaches to building regional scale networks. Authors offer a mathematical model of network growth process, on the basis of which simulation is performed. The availability characteristic is used as criterion for measuring optimality. This report describes the mechanism for measuring network availability and contains propositions to make changes to the procedure for designing of regional networks, which can improve its qualitative characteristics. The efficiency of changes is confirmed by simulation.