List of subject articles Network Management


    • Open Access Article

      1 - A Stochastic Lyapunov Theorem with Application to Stability Analysis of Networked Control Systems
      Babak Tavassoli Parviz Jabehdar Maralani
      The source of randomness in stochastic systems is an input with stochastic behavior as treated in the existing literature. Special types of stochastic processes such as the Wiener process or the Brownian motion have served as an adequate model of such an input for years Full Text
      The source of randomness in stochastic systems is an input with stochastic behavior as treated in the existing literature. Special types of stochastic processes such as the Wiener process or the Brownian motion have served as an adequate model of such an input for years. The body of stochastic systems theory is elegantly shaped around such input models. An example is the Itô’s formula. With development of new applications, we are faced with various phenomena that are more demanding from a stochastic modeling approach. To cope with this problem we restate the stochastic Lyapunov theorem such that it can be applied to a wider class of stochastic systems. In this paper stochastic systems are considered without imposing assumptions on the nature of the stochastic input and the way it affects the sample trajectories. Lyapunov stability theorem is represented for this type of systems in terms of a stability notion that generalizes the notion of stability in moments. As a result, the new theorem finds a larger domain of applications while it can be reduced to some known versions of the stochastic Lyapunov theorem. As an application, an existing deterministic result for nonlinear networked control systems is extended to a more practical probabilistic setting which extends the available analysis tools for checking the stability of continuous-time nonlinear networked control systems in the stochastic setting. The results are applied to a two-channel magnetic levitation system which is controlled over a local communication network to obtain a bound on the rate of transmission failures due to the presence of noise in the industrial environment. Manuscript Document
    • Open Access Article

      2 - An Ultra-Wideband Common Gate LNA With Gm-Boosted And Noise Canceling Techniques
      Amin Jamalkhah Ahmad Hakimi
      In this paper, an ultra-wideband (UWB) common gate low-noise amplifier (LNA) with gm-boosted and noise-cancelling techniques is presented. In this scheme we utilize gm-boosted stage for cancelling the noise of matching device. The bandwidth extension and flat gain are a Full Text
      In this paper, an ultra-wideband (UWB) common gate low-noise amplifier (LNA) with gm-boosted and noise-cancelling techniques is presented. In this scheme we utilize gm-boosted stage for cancelling the noise of matching device. The bandwidth extension and flat gain are achieved by using of series and shunt peaking techniques. Simulated in .13 um Cmos technology, the proposed LNA achieved 2.38-3.4dB NF and S11 less than -11dB in the 3.1-10.6 GHz band. Maximum power gain (S21) is 11dB and -3dB bandwidth is 1 .25-11.33 GHz. The power consumption of LNA is 5.8mW. Manuscript Document
    • Open Access Article

      3 - A Model for Mobile Code Computing Paradigms in Computer Networks
      hojatallah hamidi Maryam Parvini
      This paper presents a reliable model for mobile codes in distributed networks, which represents reliable mobile agent execution. The model ensures non-blocking mobile agent execution and forces the once property without relying on correct fault detection. A mobile agent Full Text
      This paper presents a reliable model for mobile codes in distributed networks, which represents reliable mobile agent execution. The model ensures non-blocking mobile agent execution and forces the once property without relying on correct fault detection. A mobile agent execution is blocking if a fault of agent prevents the agent from continuing in its execution. The once problem is related to non-blocking in the sense that solutions to the latter may lead to multiple executions of the mobile agent. A solution to reliable mobile agent execution needs to ensure both the non-blocking and once properties. The analytical results show new theoretical perceptions into the statistical behaviors of mobile agents and provide useful tools for executing mobile agents in networks. The results show that agents' behavior is influenced by places' characteristics and the agents' behavior can be managed to network. In this paper, we analyzed the average time consuming of mobile agents between two places. The approach, Fault-Tolerant approach for mobile codes offers a user-transparent fault tolerance which can be selected by the user for every single application given to the environment. Thereby, the user can decide for every application weather it has to be treated fault-tolerant or not. We proposed a reliable execution model of mobile codes and analyzed the life expectancy, including the average time consuming of mobile agents between two places, the average number of places agents will visit, and the agents' life expectancy. Manuscript Document
    • Open Access Article

      4 - Towards Accelerating IP Lookups on Commodity PC Routers using Bloom Filter: Proposal of Bloom-Bird
      Bahram Bahrambeigy Mahmood Ahmadi mahmood Fazlali
      Nowadays, routers are the main backbone of computer networks specifically the Internet. Moreover, the need for high-performance and high-speed routers has become a fundamental issue due to significant growth of information exchange through the Internet and intranets. On Full Text
      Nowadays, routers are the main backbone of computer networks specifically the Internet. Moreover, the need for high-performance and high-speed routers has become a fundamental issue due to significant growth of information exchange through the Internet and intranets. On the other hand, flexibility and configurability behind the open-source routers has extended their usage via the networks. Furthermore, after assigning the last remaining IPv4 address block in 2011, development and improvement of IPv6-enabled routers especially the open-sources has become one of the first priorities for network programmers and researchers. In IPv6 because of its 128-bits address space compared to 32-bits in IPv4, much more space and time are required to be stored and searched that might cause a speed bottleneck in lookup of routing tables. Therefore, in this paper, Bird as an example of existing open source router which supports both IPv4 and IPv6 addresses is selected and Bloom-Bird (our improved version of Bird) is proposed which uses an extra stage for its IP lookups using Bloom filter to accelerate IP lookup mechanism. Based on the best of our knowledge this is the first application of Bloom filter on Bird software router. Moreover, false positive errors are handled in an acceptable rate because Bloom-Bird scales its Bloom filter capacity. The Bloom-Bird using real-world IP prefixes and huge number of inserted prefixes into its internal FIB (Forwarding Information Base), shows up to 61% and 56% speedup for IPv4 and IPv6 lookups over standard Bird, respectively. Moreover, using manually generated prefix sets in the best case, up to 93% speedup is gained. Manuscript Document
    • Open Access Article

      5 - Toward Energy-Aware Traffic Engineering in Intra-Domain IP Networks Using Heuristic and Meta-Heuristics Approaches
      Muharram Mansoorizadeh
      Because of various ecological, environmental, and economic issues, energy efficient networking has been a subject of interest in recent years. In a typical backbone network, all the routers and their ports are always active and consume energy. Average link utilization i Full Text
      Because of various ecological, environmental, and economic issues, energy efficient networking has been a subject of interest in recent years. In a typical backbone network, all the routers and their ports are always active and consume energy. Average link utilization in internet service providers is about 30-40%. Energy-aware traffic engineering aims to change routing algorithms so that low utilized links would be deactivated and their load would be distributed over other routes. As a consequence, by turning off these links and their respective devices and ports, network energy consumption is significantly decreased. In this paper, we propose four algorithms for energy-aware traffic engineering in intra-domain networks. Sequential Link Elimination (SLE) removes links based on their role in maximum network utilization. As a heuristic method, Extended Minimum Spanning Tree (EMST) uses minimum spanning trees to eliminate redundant links and nodes. Energy-aware DAMOTE (EAD) is another heuristic method that turns off links with low utilization. The fourth approach is based on genetic algorithms that randomly search for feasible network architectures in a potentially huge solution space. Evaluation results on Abilene network with real traffic matrix indicate that about 35% saving can be obtained by turning off underutilized links and routers on off-peak hours with respect to QoS. Furthermore, experiments with GA confirm that a subset of links and core nodes with respect to QoS can be switched off when traffic is in its off-peak periods, and hence energy can be saved up to 37%. Manuscript Document
    • Open Access Article

      6 - A New Set Covering Controller Placement Problem Model for Large Scale SDNs
      احمد جلیلی رضا اکبری منیژه  کشتگری
      Software Defined Network (SDN) is an emerging architecture that can overcome the challenges facing traditional networks. SDN enables administrator/operator to build a simpler and manageable network. New SDN paradigms are encouraged to deploy multiple (rather than centra Full Text
      Software Defined Network (SDN) is an emerging architecture that can overcome the challenges facing traditional networks. SDN enables administrator/operator to build a simpler and manageable network. New SDN paradigms are encouraged to deploy multiple (rather than centralized) controllers to monitor the entire system. The Controller Placement Problem (CPP) is one of the key issues in SDN that affects every aspect of it such as scalability, convergence time, fault tolerance and node to controller latency. This problem has been investigated in diverse papers with their major attention paid on optimizing the location of an arbitrary number of controllers. The related works in this area get less attention to two following important issues. i) Bidirectional end-to-end latency between switch and its controller instead of propagation latency, ii) finding the minimal number of controllers that even is a prerequisite for locating them. In this paper, a Set Covering Controller Placement Problem Model (SCCPPM) to find the least number of required controllers with regard to carrier grade latency requirement is proposed. The new model is carried out on a set of 124 graphs from the Internet Topology Zoo and solve them with IBM ILOG CPLEX Optimization package. As expected, our results indicate that the number of required controllers for high resiliency is dependent on topology and network size. As well, in order to achieve carrier grade requirement, 86 percent of topologies must have more than one controller. Manuscript Document
    • Open Access Article

      7 - Modeling the Inter-arrival Time of Packets in Network Traffic and Anomaly Detection Using the Zipf’s Law
      علی نقاش اسدی Mohammad  Abdollahi Azgomi
      In this paper, a new method based on the Zipf’s law for modeling the features of the network traffic is proposed. The Zipf's law is an empirical law that provides the relationship between the frequency and rank of each category in the data set. Some data sets may follow Full Text
      In this paper, a new method based on the Zipf’s law for modeling the features of the network traffic is proposed. The Zipf's law is an empirical law that provides the relationship between the frequency and rank of each category in the data set. Some data sets may follow from the Zipf’s law, but we show that each data set can be converted to the data set following from the Zipf’s law by changing the definition of categories. We use this law to model the inter-arrival time of packets in the normal network traffic and then we show that this model can be used to simulate the inter-arrival time of packets. The advantage of this law is that it can provide high similarity using less information. Furthermore, the Zipf’s law can model different features of the network traffic that may not follow from the mathematical distributions. The simple approach of this law can provide accuracy and lower limitations in comparison to existing methods. The Zipf's law can be also used as a criterion for anomaly detection. For this purpose, the TCP_Flood and UDP_Flood attacks are added to the inter-arrival time of packets and they are detected with high detection rate. We show that the Zipf’s law can create an accurate model of the feature to classify the feature values and obtain the rank of its categories, and this model can be used to simulate the feature values and detect anomalies. The evaluation results of the proposed method on MAWI and NUST traffic collections are presented in this paper. Manuscript Document
    • Open Access Article

      8 - Investigate Network Simulation Tools in Designing and Managing Intelligent Systems
      fatemeh fakhar
      Network simulation is a technique that models network behavior by performing transaction calculations between different network entities and using mathematical formulas and taking observations of network products. A network simulator is a software program have been appl Full Text
      Network simulation is a technique that models network behavior by performing transaction calculations between different network entities and using mathematical formulas and taking observations of network products. A network simulator is a software program have been applied to analyze the performance of a computer network without the presence of a real network. Hardware equipment, equipment configuration, communication, and routing protocols and network traffic modeled in simulation software and the behavior of the network and its components examined from different dimensions. The user can also customize the simulation software according to their needs. Simulation software has different uses, and the user can use these tools to model their network by recognizing this software. In terms of research, it is difficult to create a network, especially large networks, in a real-time scenario, and it is not easily possible to carry out it in the real world, and it is very costly. So, simulators help network developers to control whether the network can work in real-time or not, or whether it is efficient enough. This reduces the time and cost of network application testing.Today, simulation technology is successfully used to model, design and manage a variety of intelligent systems. Numerous tools have been created in this regard. In this article, we review and compare important network simulators such as CloudSim, GloMoSim, GNS3, NS-2, Opnet, OMNet ++, NetSim, NS-3, AVRORA, Packet Tracer, QualNet, J-Sim, REAL and OptSim and their results. These comparisons express from several perspectives in the tables. Manuscript Document
    • Open Access Article

      9 - An Autonomic Software Defined Network (SDN) Architecture With Performance Improvement Considering
      Alireza  shirmarz Ali Ghaffari
      SDN makes the network programmable, agile, and flexible with data and control traffic separating. This architecture consists of three layers which are application, control and data. The aim of our research is concentrated on the control layer to improve the performance Full Text
      SDN makes the network programmable, agile, and flexible with data and control traffic separating. This architecture consists of three layers which are application, control and data. The aim of our research is concentrated on the control layer to improve the performance of the network in an autonomic manner. In the first step, we have categorized the performance improvement researches based on network performance improvement solutions proposed in the recent papers. This performance improvement solution clustering is one of our contributions to our paper. The significant contribution in this paper is a novel autonomic SDN-based architecture to ameliorate the performance metrics including blocking probability (BP), delay, jitter, packet loss rate (PLR), and path utilization. Our SDN-based autonomic system consists of three layers (data, autonomic control, and Route learning) to separate the traffics based on deep neural networks (DNN) and to route the flows with the greedy algorithm. The autonomic SDN-based architecture which has proposed in this paper makes better network performance metrics dynamically. Our proposed autonomic architecture will be developed in the POX controller which has developed by python. Mininet is used for simulation and the results are compared with the commonly used SDN named pure SDN in this article. The simulation results show that our structure works better in a full-mesh topology and improves the performance metrics simultaneously. The average performance is improved by about %2.5 in comparison with pure SDN architecture based on the Area Under Curve (AUC) of network performance. Manuscript Document