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wormhole
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An Intrusion Detection System for Wormhole Attack Detection in MANETs
, M.Sc. Thesis Sharif University of Technology ; Movaghar, Ali (Supervisor)
Abstract
Mobile ad hoc networks (MANETs) have been attracting the attention of the researchers in the duration of last years. Because of lack of infrastructure in such networks, all network operations such as routing are done by the nodes themselves. On the other hand, standard MANETs' routing protocols suppose that all nodes are trusted. Thus, these protocols are prone to serious security attack. Wormhole attack is one of the attacks which abuse distributed routing in MANETs. This attack is held between two malicious nodes which are far away from each other. Mentioned nodes introduce themselves as one-hop neighbor of each other. Therefore, they deceive normal nodes and disturb the routing mechanism....
Experimental and Modeling Study of Scale and Flow Geometry Effects on Carbonate Matrix Acidizing Efficiency
, Ph.D. Dissertation Sharif University of Technology ; Ayatollahi, Shahaboddin (Supervisor)
Abstract
Acidizing is one of the common methods of stimulating the well to remove formation damage and Skin factor. In carbonate reservoirs, hydrochloric acid creates permeable channels called wormholes due to the reaction with the porous medium. Previous researches have studied the effect of the main rock and fluid parameters (temperature, pressure, type and concentration of acid and rock lithology) at the core scale. However, wellbore scale will different from core scale due to the difference in the wormhole density, the flow geometry, the amount of acid leakage from wormhole wall and competition. Very limited models predict these effects for large scales. In this research, the geometry of linear...
Analytical performance modelling of partially adaptive routing in wormhole hypercubes
, Article 20th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2006, 25 April 2006 through 29 April 2006 ; Volume 2006 , 2006 ; 1424400546 (ISBN); 9781424400546 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
IEEE Computer Society
2006
Abstract
Although several analytical models have been proposed in the literature for different interconnection networks with different routing algorithms, there is only one work dealing with partially adaptive routing algorithms. This paper proposes an accurate analytical model to predict message latency in wormhole-routed hypercube based networks using the partially adaptive routing algorithm. The results obtained from simulation experiments confirm that the proposed model exhibits a good accuracy for various network sizes and under different operating conditions. © 2006 IEEE
Analytical performance comparison of deterministic, partially- And fully-adaptive routing algorithms in binary n-cubes
, Article 12th International Conference on Parallel and Distributed Systems, ICPADS 2006, Minneapolis, MN, 12 July 2006 through 15 July 2006 ; Volume 2 , 2006 , Pages 21-28 ; 15219097 (ISSN); 0769526128 (ISBN); 9780769526126 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
2006
Abstract
In this paper, we study the effect of adaptivity of routing algorithm on the overall performance in a hypercube multicomputer using wormhole switching. To this end, we use three accurate analytical models proposed for deterministic, fully-adaptive, and partially-adaptive routing algorithms in hypercube. Surprisingly, our analysis shows that under uniform traffic load, the partially-adaptive routing exhibits a lower performance compared to the deterministic routing with less adaptivity. ©2006 IEEE
Constraint-based performance comparison of multi-dimensional interconnection networks with deterministic and adaptive routing strategies
, Article Computers and Electrical Engineering ; Volume 30, Issue 3 , 2004 , Pages 167-182 ; 00457906 (ISSN) ; Sharif University of Technology
2004
Abstract
Several studies have examined the relative performance merits of the torus and hypercube taking into account the channel bandwidth constraints imposed by implementation technology. While the torus has been shown to outperform the hypercube under the constant wiring density constraint, the opposite conclusion has been reached when the constant pin-out constraint is considered. However, all these studies have assumed deterministic routing and have not taken into account the internal hardware cost of routers. This paper re-examines the performance merits of the torus and hypercube using both fully-adaptive and deterministic routing strategies. Moreover, it uses a new cost model which takes into...
Towards a more realistic comparative analysis of multicomputer networks
, Article Concurrency and Computation: Practice and Experience ; Volume 16, Issue 13 , 2004 , Pages 1271-1289 ; 15320626 (ISSN) ; Ould Khaoua, M ; Mackenzie, L. M ; Sharif University of Technology
John Wiley and Sons Ltd
2004
Abstract
Several studies have examined the relative performance merits of the torus and hypercube taking into account the channel bandwidth constraints imposed by implementation technology. While the torus has been shown to outperform the hypercube under the constant wiring density constraint, the opposite conclusion has been reached when the constant pin-out constraint is considered. However, these studies have assumed a pure uniform traffic pattern and deterministic routing. The 'uniform traffic' assumption is not always justifiable in practice as there are many real-world parallel applications that exhibit non-uniform traffic patterns, which can create unbalanced traffic such as hotspots in the...
Analytical modelling of wormhole-routed k-ary n-cubes in the presence of matrix-transpose traffic
, Article Journal of Parallel and Distributed Computing ; Volume 63, Issue 4 , 2003 , Pages 396-409 ; 07437315 (ISSN) ; Ould-Khaoua, M ; Mackenzie, L. M ; Sharif University of Technology
Academic Press Inc
2003
Abstract
Several analytical models of fully adaptive routing in wormhole-routed k-ary n-cubes under the uniform traffic pattern have recently been proposed in the literature. Although the uniform reference model has been widely used in the past, it is not always true in practice as there are many applications that exhibit non-uniform traffic patterns. There has not been so far any study that describes an analytical model of fully adaptive routing under non-uniform traffic conditions. This paper describes a new analytical model of fully adaptive routing in k-ary n-cubes in the presence of non-uniform traffic generated by matrix-transpose permutations, which is an important communication operation...
Mathematical performance modelling of stretched hypercubes
, Article 9th International Conference on Distributed Computing and Networking, ICDCN 2008, Kolkata, 5 January 2008 through 8 January 2008 ; Volume 4904 LNCS , 2008 , Pages 375-386 ; 03029743 (ISSN); 3540774432 (ISBN); 9783540774433 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
Springer Verlag
2008
Abstract
The stretched hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties, VLSI and algorithmic aspects of this network. Several analytical models have been proposed in the literature for different interconnection networks, as the most cost-effective tools to evaluate the performance merits of such systems. This paper proposes an analytical performance model to predict message latency in wormhole-switched stretched hypercube interconnection networks with fully adaptive routing. The analysis focuses on a fully adaptive routing algorithm which has been shown to be the...
Performance modeling of wormhole hypermeshes under hotspot traffic
, Article 2nd International Symposium on Computer Science in Russia, CSR 2007, Ekaterinburg, 3 September 2007 through 7 September 2007 ; Volume 4649 LNCS , 2007 , Pages 290-302 ; 03029743 (ISSN); 9783540745099 (ISBN) ; Sarbazi Azad, H ; Nayebi, A ; Navi, K ; Sharif University of Technology
Springer Verlag
2007
Abstract
Traffic pattern is a point of concern in today's modeling approach of network-based computing systems including NoCs and Clusters. Hypermesh is a promising network topology suitable for a range of networks. Although there are few models reported for hypermeshes with uniform traffic pattern, no analytical model has been reported yet that deal with hotspot traffic load. Since uniform traffic assumption is not always justifiable in practice as there are many parallel applications that exhibit non-uniform traffic patterns, which can produce hotspots in the network, in this study we propose a novel analytical model to analyze the mean message latency in wormhole-switched hypermesh in the presence...
Computing accurate performance bounds for best effort networks-on-chip
, Article IEEE Transactions on Computers ; Vol. 62, issue. 3, Article number 6109240 , 2013 , pp. 452-467 ; ISSN: 00189340 ; Murali, S ; Benini, L ; Angiolini, F ; De Micheli, G ; Sarbazi-Azad, H ; Sharif University of Technology
Abstract
Real-time (RT) communication support is a critical requirement for many complex embedded applications which are currently targeted to Network-on-chip (NoC) platforms. In this paper, we present novel methods to efficiently calculate worst case bandwidth and latency bounds for RT traffic streams on wormhole-switched NoCs with arbitrary topology. The proposed methods apply to best-effort NoC architectures, with no extra hardware dedicated to RT traffic support. By applying our methods to several realistic NoC designs, we show substantial improvements (more than 30 percent in bandwidth and 50 percent in latency, on average) in bound tightness with respect to existing approaches
Performance modeling of n-dimensional mesh networks
, Article Performance Evaluation ; Vol. 67, issue. 12 , 2010 , p. 1304-1323 ; ISSN: 01665316 ; Sarbazi-Azad, H ; Zarandi, H.-R ; Khodaie, E ; Hashemi-Najafabadi, H ; Ould-Khaoua, M ; Sharif University of Technology
Abstract
Mesh-based interconnection networks are the most popular inter-processor communication infrastructures used in current parallel supercomputers. Although many analytical models of n-D torus interconnection networks have been reported in the literature over the last decade, few analytical models have been proposed for the 2-D mesh case (and not for the general n-D mesh network) using inaccurate approximations as they have not fully incorporated the asymmetry effects of the mesh topology, in order to reduce the model complexity. There has not been reported, to the best of our knowledge, a performance model that can deal with the n-D mesh network. To fill this gap, in this paper, we propose the...
Computing accurate performance bounds for best effort networks-on-chip
, Article IEEE Transactions on Computers ; Volume 62, Issue 3 , 2013 , Pages 452-467 ; 00189340 (ISSN) ; Murali, S ; Benini, L ; Angiolini, F ; De Micheli, G ; Sarbazi Azad, H ; Sharif University of Technology
2013
Abstract
Real-time (RT) communication support is a critical requirement for many complex embedded applications which are currently targeted to Network-on-chip (NoC) platforms. In this paper, we present novel methods to efficiently calculate worst case bandwidth and latency bounds for RT traffic streams on wormhole-switched NoCs with arbitrary topology. The proposed methods apply to best-effort NoC architectures, with no extra hardware dedicated to RT traffic support. By applying our methods to several realistic NoC designs, we show substantial improvements (more than 30 percent in bandwidth and 50 percent in latency, on average) in bound tightness with respect to existing approaches
Performance modeling of n-dimensional mesh networks
, Article Performance Evaluation ; Volume 67, Issue 12 , December , 2010 , Pages 1304-1323 ; 01665316 (ISSN) ; Sarbazi Azad, H ; Zarandi, H. R ; Khodaie, E ; Hashemi Najafabadi, H ; Ould Khaoua, M ; Sharif University of Technology
2010
Abstract
Mesh-based interconnection networks are the most popular inter-processor communication infrastructures used in current parallel supercomputers. Although many analytical models of n-D torus interconnection networks have been reported in the literature over the last decade, few analytical models have been proposed for the 2-D mesh case (and not for the general n-D mesh network) using inaccurate approximations as they have not fully incorporated the asymmetry effects of the mesh topology, in order to reduce the model complexity. There has not been reported, to the best of our knowledge, a performance model that can deal with the n-D mesh network. To fill this gap, in this paper, we propose the...
An accurate mathematical performance model of partially adaptive routing in binary n-cube multiprocessors
, Article Mathematical and Computer Modelling ; Volume 48, Issue 1-2 , 2008 , Pages 34-45 ; 08957177 (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
2008
Abstract
Although several analytical models have been proposed in the literature for different interconnection networks with different routing algorithms, there is only one work [M. Ould-Khaoua, An approximate performance model for partially adaptive routing algorithm in hypercubes, Microprocessors and Microsystems 23 (1999) 185-190] dealing with partially adaptive routing. It is not accurate enough especially in heavy traffic regions due to the rough approximation of assuming equal traffic rate over network channels. We show, however, such an approximation can greatly affect the accuracy of the model. This paper proposes an accurate analytical model to predict the average message latency in wormhole...
An accurate mathematical performance model of adaptive routing in the star graph
, Article Future Generation Computer Systems ; Volume 24, Issue 6 , 2008 , Pages 461-474 ; 0167739X (ISSN) ; Sarbazi Azad, H ; Ould Khaoua, M ; Sharif University of Technology
2008
Abstract
Analytical modelling is indeed the most cost-effective method to evaluate the performance of a system. Several analytical models have been proposed in the literature for different interconnection network systems. This paper proposes an accurate analytical model to predict message latency in wormhole-switched star graphs with fully adaptive routing. Although the focus of this research is on the star graph but the approach used for modelling can be, however, used for modelling some other regular and irregular interconnection networks. The results obtained from simulation experiments confirm that the proposed model exhibits a good accuracy for various network sizes and under different operating...
An accurate performance model of fully adaptive routing in wormhole-switched two-dimensional mesh multicomputers
, Article Microprocessors and Microsystems ; Volume 31, Issue 7 , 2007 , Pages 445-455 ; 01419331 (ISSN) ; Sarbazi Azad, H ; Rajabzadeh, P ; Sharif University of Technology
2007
Abstract
Numerous analytical performance models have been proposed for deterministic wormhole-routed mesh networks while only a single model, to our best knowledge, has been suggested for fully adaptive wormhole routing in mesh interconnection networks. This paper proposes a new and accurate analytical performance model for fully adaptive wormhole-routed mesh networks. Simulation results show that unlike the previously proposed model which is only accurate in light traffic loads, this model can be used for the performance analysis of almost all traffic loads. © 2007 Elsevier B.V. All rights reserved
The impacts of timing constraints on virtual channels multiplexing in interconnect networks
, Article 25th IEEE International Performance, Computing, and Communications Conference, 2006, IPCCC 2006, Phoenix, AZ, 10 April 2006 through 12 April 2006 ; Volume 2006 , 2006 , Pages 55-62 ; 1424401976 (ISBN); 9781424401970 (ISBN) ; Ould Khaoua, M ; Nayebi, A ; Sarbazi azad, H ; Sharif University of Technology
2006
Abstract
Interconnect networks employing wormhole-switching play a critical role in shared memory multiprocessor systems-on-chip (MPSoC) designs, Multicomputer systems and System Area Networks. Virtual channels greatly improve the performance of wormhole-switched networks because they reduce blocking by acting as "bypass" lanes for non-blocked messages. Capturing the effects of virtual channel multiplexing has always been a crucial issue for any analytical model proposed for wormhole-switched networks. Dally [8] has developed a model to investigate the behaviour of this multiplexing which have been widely employed in the subsequent analytical models of most routing algorithms suggested in the...
Modelling and evaluation of adaptive routing in high-performance n-D tori networks
, Article Simulation Modelling Practice and Theory ; Volume 14, Issue 6 , 2006 , Pages 740-751 ; 1569190X (ISSN) ; Ould-Khaoua, M ; Sharif University of Technology
2006
Abstract
Many fully-adaptive algorithms have been proposed to overcome the performance limitations of deterministic routing in networks used in high-performance multicomputers, such as the well-known regular n-D torus. This paper proposes a simple yet reasonably accurate analytical performance model to predict message communication latency in tori networks. This model requires a running time of O(1) which is the fastest model yet reported in the literature. Extensive simulations reveal that the new performance model maintains a reasonable accuracy when the network operates under different traffic conditions. The model is then used to perform an extensive investigation into the performance merits of...
A performance model of software-based deadlock recovery routing algorithm in hypercubes
, Article Parallel Processing Letters ; Volume 15, Issue 1-2 , 2005 , Pages 153-168 ; 01296264 (ISSN) ; Sarbazi Azad, H ; Ould Khaoua, M ; Sharif University of Technology
2005
Abstract
Recent studies have revealed that deadlocks are generally infrequent in the network. Thus the hardware resources, e.g. virtual channels, dedicated for deadlock avoidance are not utilised most of the time. This consideration has motivated the development of novel adaptive routing algorithms with deadlock recovery. This paper describes a new analytical model to predict message latency in hypercubes with a true fully adaptive routing algorithm with progressive deadlock recovery. One of the main features of the proposed model is the use of results from queueing systems with impatient customers to capture the effects of the timeout mechanism used in this routing algorithm for deadlock detection....
A novel approach for avoiding wormhole attacks in VANET
, Article 1st South Central Asian Himalayas Regional IEEE/IFIP International Conference on Internet, AH-ICI 2009, 3 November 2009 through 5 November 2009, Kathmundu ; 2009 ; 9781424445707 (ISBN) ; Movaghar, A ; Mohammadizadeh, M ; Sharif University of Technology
Abstract
Different attacks on routing protocols in ad hoc networks occur that one of the most dangerous types is called wormhole attack. This attack happens with the assistance of at least two or more malicious nodes. In this attack nodes create a private tunnel which if a packet comes to one of them, it will be guided to other pair of these malicious nodes by this tunnel and that node broadcasts it into network. This action provides a short connection in the network that is controlled by these malicious nodes. Hence they control all Packets that come to them and threaten the security of data within packets or delete them. Totally, what a wormhole does is an incorrect understanding of network...