scholarly journals CALCULATION OF THE EFFEC TION OF THE EFFECTIVENESS OF THE FUNC TIVENESS OF THE FUNCTIONING TIONING OF MULTISERVICE COMMUNICA VICE COMMUNICATION NE TION NETWORKS T WORKS TAKING IN AKING INTO ACCOUNT DROPPED P T DROPPED PACKETS

2020 ◽  
Vol 4 (6) ◽  
pp. 21-32
Author(s):  
Gulrukh Bakhtiyorovna Sherboboyeva ◽  

Background. The article discusses the formalization of performance indicators of a multiservice network management system based on the use of hybrid neural-fuzzy technology that combines the advantages of fuzzy logic and neural networks. A developed fuzzy neural model was subsequently used to make a decision about the transfer of real time streams through the channel of the multi-servo network. Methods for assessing the effectiveness of multiservice communication networks can be conditionally divided into three large groups: technical, economic and technical and economic. As the technical characteristics of the efficiency of the computer network, various indicators of network performance and reliability are used. Estimates of the costs of designing, installing and maintaining the network are used as economic characteristics. Technical and economic indicators are used for a comprehensive assessment of the project, and include various combinations of technical and economic characteristics. The response time is an integral performance characteristic, the most important for the network subscriber.

the computer network area has grown very fast from previous years, as a result of which the control of traffic load in the network is at a higher priority. In network, congestion occurs if numbers of coming packets exceed, like bandwidth allocation along with buffer space. This might be due to poor network performance in terms of throughput, packet loss rate, and average packet queuing delay. For enhancing the overall performance when this network will become congested, numerous exclusive aqm (active queue management) techniques were proposed and few are discussed in this research paper. Particularly, aqm strategies are analyzed in detail as well as their obstacles along with strengths are emphasized. There are several algorithms which are under the aqm like ared, fred, choke, red (random early detection), blue, stochastic fair blue (sfb), random exponential marking (rem), svb, raq, etc.


2016 ◽  
Vol 6 (2) ◽  
pp. 1-10
Author(s):  
Chaima Bensaid ◽  
Sofiane Boukli Hacene ◽  
Kamel Mohamed Faraoun

Vehicular networks or VANET announce as the communication networks of the future, where the mobility is the main idea. These networks should be able to interconnect vehicles. The optimal goal is that these networks will contribute to safer roads and more effective in the future by providing timely information to drivers and concerned authorities. They are therefore vulnerable to many types of attacks among them the black hole attack. In this attack, a malicious node disseminates spurious replies for any route discovery in order to monopolize all data communication and deteriorate network performance. Many studies have focused on detecting and isolating malicious nodes in VANET. In this paper, the authors present two mechanisms to detect this attack. The main goal is detecting as well as bypass cooperative black hole attack. The authors' approaches have been evaluated by the detailed simulation study with NS2 and the simulation results shows an improvement of protocol performance.


Author(s):  
Oleksandr Romanov ◽  
Ivan Saychenko ◽  
Anton Marinov ◽  
Serhii Skolets

Background. The implementation of the new modern services on existing networks requires replacement or modernization of the old equipment. This negatively affects the efficiency of providing users with new types of services and their cost. Therefore, the issues/tasks of implementing SDN technology in the construction of networks are in the center of attention of representatives of science-research organizations and telecom operators. SDN networks have the advantages of flexible scaling of the system without replacing existing server and network equipment, eliminating operator dependence on specific vendor solutions, and rapid implementation of the new network technologies and services. To determine the numerical values of indicators of the functioning of SDN networks and check their compliance with the requirements, it is proposed to use in working process simulation modelling. For these goals, the Open Networking Foundation consortium developed the Mininet network emulator, the elements of that are published publicly. The formation of the simulation model and the procedure for determining the performance indicators of the SDN network that uses Mininet has a number of features that are considered in the work. Objective. The purpose of the article is to build a simulation model based on the Mininet network emulator and to determine the performance indicators of SDN networks of various structures/topologies. Methods. Creation of a SDN network segment for testing process of its functioning in the overload mode of various communication routes. Results. The Mininet network emulator allows simulating SDN networks of a rather complex structure, change the performance of network branches and the amount of load in communication routes, to create a network-wide overload mode. During the simulation, it is possible to determine a number of indicators of network performance, such as the RTT (Round Trip Time) parameter for each route of communication, the bandwidth of branches and routes of communication, the amount of delay on network elements, loading of OpenFlow Switch ports/interfaces, network elements with the highest delay, the number of served and lost packets. Conclusions. Use of the Mininet network emulator is a fairly convenient tool for determining the performance indicators of SDN networks. However, there are also some problems. First of all, setting up the system's operability requires writing programs to ensure the interaction among standard elements from the Mininet library. Secondone, is when congestion occurs in the communication routes, the Floodlight Controller does not automatically balance traffic along the work-around route. This task has to be solved manually by making changes to the OpenFlow Switch routing tables. Keywords: Software Defined Networking; SDN; Mininet; OpenFlow; Floodlight Controller; OpenFlowSwitch; NFV; virtualization.


Author(s):  
S. Yuness ◽  
E.S. Lobusov

The use of communication networks in control systems has several important advantages, such as the ability of information transfer and remote control of various objects, the possibility of modifications and maintenance. On the other hand, the time between reading measurements from the sensor and sending a control signal to the actuator depends on the network characteristics (topology and routing scheme), and such a time delay can greatly affect the overall network performance. Delays, distortions and loss of transmitted data not only degrade the performance of the network management system, but also destabilize it. The paper considers the use of Petri nets as a method for modeling networked control systems (NCS) on the example of designing an active suspension control system for a car. When modeling, the star and common bus topologies were used, the comparison of which revealed that control systems with the common bus topology function 40% faster than systems with the star topology.


Author(s):  
A. Danladi ◽  
G. P. Vasira

Fractal dimension is mathematically defined as a ratio of statistical complexity of network traffic; its significant manifestation can affect the network performance. In this work, two models of corporate computer networks have been developed using optimized network engineering tool (OPNET) technology. Raw packet generator (RPG) traffic was imposed on the corporate networks and modeled using H = 0.7 and D = 1.3, under the influence of Pareto distribution. Autocorrelation function and power law were used to confirm the presence of fractal traffic on the networks. Average Hurst index (H) of 50 and 100 workstations were estimated using aggregate of variance, absolute moment, periodogram and R/S methods as 0.627, 0.608 and its corresponding fractal dimensions (D) were obtained as 1.371 and 1.391 respectively. These results obtained mean, there is a manifestation of fractal traffic and delay is minimised on the network.  


2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Mairi C. Meehan ◽  
Natalie C. Ban ◽  
Rodolphe Devillers ◽  
Gerald G. Singh ◽  
Joachim Claudet

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