Andrzej Paszkiewicz

The Use of Statistical Signatures to Detect Anomalies in Computer Network

This article presents a new approach for detecting anomalies in the computer network. The approach is based on the determination of the network traffic statistical parameters in case of normal condition. When network anomaly happens, usually more than one statistical parameter is change. A set of parameters that have changed can be used to identify threats. Currently, anomaly detection mechanisms used in the network traffic are computationally complex and cannot be used in case of high speed connection. The presented method does not guarantee the anomaly identification but can be used as one of the indicators used for the isolation of suspicious flows (through ongoing modifications the routing or switching rules). Separated flow is subjected to further analysis with use of classical methods for anomaly detection. With this approach it is possible to make a rough anomaly identification in the core of high speed computer network.

Wireless Networks Environment and Complex Networks

Models describing the wireless network environment in most cases are based on the assumption that they are simple systems. However, the parameters describing this type of networks are particularly sensitive to the volatility of the operating conditions. Simple systems take only two operating states into account apart from an overload state, i.e. underload state and a state of equilibrium at the limit of the system. However, the overload state is normal and acceptable by actual natural systems. Wireless networks often operate on the border of a balance between available resources and expectations for the implementation of communication tasks. Therefore, the paper will introduce wireless network especially WLAN in terms of complex systems moving away from the current reductionist paradigm. In addition, there will be presented the method of the dynamic allocation of resources (bandwidth) that is based on properties of complex systems.

Use of Ising Model for Analysis of Changes in the Structure of the IT Network

The paper presents the potential of using the Ising model to analyze changes in IT networks. These systems belong to the group of complex systems, like other natural systems, therefore, the processes occurring in them can be modeled using similar algorithms. The authors presented a modification of Ising algorithm based on the sensitivity factor. It allowed to take into account the individual susceptibility of separate nodes in the network structure to occurring changes. Due to the wide range of possibilities of using Ising model and, above all, its modifications, only a certain area of application has been presented in individual algorithms. Additionally, the use of the order parameter enabled presentation of phase transitions in the network structure.

Software Development for Modeling and Simulation of Computer Networks: Complex Systems Approach

The process of creating software for modeling and simulation of phenomena taking place in computer networks should take into account many aspects of their functioning. However, until now, the creation of such software was based on a reductionist approach. This approach is typical for simple or most complicated systems. In contrast, software for modeling and simulation of computer networks should be treated as a complex system. Therefore, the process of its creation should take into account such properties of complex systems as: feedback loop, non-extensivity, indeterminacy, self-similarity, non-additivity, etc. The authors use computer simulators in their work on everyday basis. However, they have generally an outdated, static architecture that prevents their easy and continuous development. Therefore, the authors started working on developing their own model of creating such software and this paper is an introduction to this issue. The authors focused on the selected features of complex systems in the context of the software development process. Based on the feedback loop, a new spiral of software development and modeling for computer networks is presented. The paper also defines the notion of process and functional non-additivity and its importance in the software development process. The presented approach allows for flexible development of the software under consideration in terms of their functionality. The authors also presented examples of application of complex system properties when creating selected functional modules of software for modeling and simulation of computer networks.

A set of connection network synthesis based on the linear Diophantine constraints solution in area {0,1}

In the paper we present a method for synthesis of a set of connection networks, which fulfill the designer’s assumption. In order to do that, the designed network is presented as a system of Diophantine constraints in a special form. A method to resolve those systems is proposed, which is characterized by lower computational complexity, especially in the case of rare topologies design.

Interconnection distributed systems designed with hierarchical organization

In this paper an origin approach to distributed systems design is shown. It allows to include complete costs of their life circuit. In order to simplify complexity of a design procedure we assume that a created system will have a regional hierarchical structure. A model based on the equivalence relation can describe that problem. In this way, it is possible to describe hierarchical regionalization simply for n-levels.

Designing of improvement efficiency of multi-channel optical communication system criteria optimization

The computer program controlling MALDI system and a time of flight mass spectrometer is described. This program allows to reduce a number of necessary activities for operation of used machines as well as to raise an operational safety of this equipment. Additionally, an advantage of the computer control is possibility of quick changing of any measurement parameters that is impossible to do manually.