Browsing by Author "Nagesh, H.R."

Now showing 1 - 7 of 7

Design and development of proactive solutions for mitigating denial-of-service attacks
(2006) Nagesh, H.R.; Sekaran, K.C.
Denial of Service attacks, orchestrated by a single host or multiple hosts in a coordinated manner, has become an increasingly frequent disturbance in today's Internet. Generally, attackers launch DDoS attacks by directing a massive number of attack sources to send useless traffic to the victim. The victim's services are disrupted when its host or network resources are occupied by the attack traffic. The threat of DDoS attacks has become even more severe as attackers can compromise a huge number of computers using vulnerabilities in popular operating systems [4].This paper deals with Denial of service (DoS) and Distributed DoS (DDoS) attacks. In the first part, we categorize existing defense mechanisms, and analyze their strengths and weaknesses. In the second part of our investigation, we develop and evaluate two defense models for DoS attacks: the Secure Overlay Services (SOS) Model and the Server Hopping Model using distributed firewalls. Each of these models provide defense in a different part of the network, and has different resource requirements. In the third part of our investigation, we assess the effectiveness of our defense models for different types of DoS attack. � 2006 IEEE.
Design and development of proactive solutions for mitigating denial-of-service attacks
(2006) Nagesh, H.R.; Chandra Sekaran, K.C.
Denial of Service attacks, orchestrated by a single host or multiple hosts in a coordinated manner, has become an increasingly frequent disturbance in today's Internet. Generally, attackers launch DDoS attacks by directing a massive number of attack sources to send useless traffic to the victim. The victim's services are disrupted when its host or network resources are occupied by the attack traffic. The threat of DDoS attacks has become even more severe as attackers can compromise a huge number of computers using vulnerabilities in popular operating systems [4].This paper deals with Denial of service (DoS) and Distributed DoS (DDoS) attacks. In the first part, we categorize existing defense mechanisms, and analyze their strengths and weaknesses. In the second part of our investigation, we develop and evaluate two defense models for DoS attacks: the Secure Overlay Services (SOS) Model and the Server Hopping Model using distributed firewalls. Each of these models provide defense in a different part of the network, and has different resource requirements. In the third part of our investigation, we assess the effectiveness of our defense models for different types of DoS attack. Â© 2006 IEEE.
Implementation of an adaptive buffering algorithm to improve QoS in VoIP
(2005) Nagesh, H.R.; Sekaran, K.C.; Kordcal, A.R.
The Internet has evolved into a worldwide communication infrastructure and it now provides various services including Voice over IP (VoIP) or Internet Telephony [7]. VoIP involves transmission of voice packets across the IP network known as IP telephony. Internet Protocol (IP) Telephony has many issues that have to be overcome before it can be considered a rival to the existing telephony infrastructure. One such issue is the Quality of service (QoS). The use of play-out buffering at the receiver helps to improve the quality of Voice over IP (VoIP). There exists a buffering algorithm, which uses a dynamic adaptive approach. In this algorithm the playout times of voice packets are calculated using adaptive estimation of the network delays. In contrast to previous solutions, weighting factor that controls the estimation process is dynamically adjusted according to the observed delay variations. This results in higher quality estimates of network delay. The contribution of this paper is to analyze, implement and incorporate one such adaptive buffering algorithm into the Session Initiation Protocol (SIP) through which one can achieve better delay/loss trade-off and thus better call quality.
Implementation of an adaptive buffering algorithm to improve QoS in VoIP
(2005) Nagesh, H.R.; Chandra Sekaran, K.C.; Kordcal, A.R.
The Internet has evolved into a worldwide communication infrastructure and it now provides various services including Voice over IP (VoIP) or Internet Telephony [7]. VoIP involves transmission of voice packets across the IP network known as IP telephony. Internet Protocol (IP) Telephony has many issues that have to be overcome before it can be considered a rival to the existing telephony infrastructure. One such issue is the Quality of service (QoS). The use of play-out buffering at the receiver helps to improve the quality of Voice over IP (VoIP). There exists a buffering algorithm, which uses a dynamic adaptive approach. In this algorithm the playout times of voice packets are calculated using adaptive estimation of the network delays. In contrast to previous solutions, weighting factor that controls the estimation process is dynamically adjusted according to the observed delay variations. This results in higher quality estimates of network delay. The contribution of this paper is to analyze, implement and incorporate one such adaptive buffering algorithm into the Session Initiation Protocol (SIP) through which one can achieve better delay/loss trade-off and thus better call quality.
Proactive model for mitigating Internet denial-of-service attacks
(2007) Nagesh, H.R.; Chandra, Sekaran, K.; Kordcal, A.R.
Denial-of-Service is one of the most frequent, costly and rapidly growing attacks on the Internet. In a denial of service attack, a malicious user exploits the connectivity of the Internet to cripple the services offered by a victim site, often simply by flooding a victim with many requests. In this paper we have compared the three main architectures already proposed for mitigating the DoS attacks. The comparison is with respect to incremental deployment, traffic analysis, and the attacks on the infrastructure itself. Finally, we combine the strengths of the different proposals to propose a new model for denial of service. Our model uses the concept of active networks to mitigate DoS attacks. � 2007 IEEE.
Proactive model for mitigating Internet denial-of-service attacks
(2007) Nagesh, H.R.; Chandra Sekaran, K.; Kordcal, A.R.
Denial-of-Service is one of the most frequent, costly and rapidly growing attacks on the Internet. In a denial of service attack, a malicious user exploits the connectivity of the Internet to cripple the services offered by a victim site, often simply by flooding a victim with many requests. In this paper we have compared the three main architectures already proposed for mitigating the DoS attacks. The comparison is with respect to incremental deployment, traffic analysis, and the attacks on the infrastructure itself. Finally, we combine the strengths of the different proposals to propose a new model for denial of service. Our model uses the concept of active networks to mitigate DoS attacks. Â© 2007 IEEE.
Proactive models for mitigating internet denial-of-service/distributed denial-of-service attacks
(World Scientific Publishing Co., 2010) Nagesh, H.R.; Chandra Sekaran, K.C.
The enormous growth of the Internet has had a huge impact on users' daily lives, providing us with a wealth of information easily and conveniently.At the same time, this accessibility has made the Internet an easy target for users who wish to disrupt the flow of information or exploit the Web for personal gain. Those who compromise the flow of information or access information in an unauthorized manner are called attackers.Many tools are now available for attackers to test the vulnerability of Internet. © 2010 by World Scientific Publishing Co. Pte. Ltd. All Rights Reserved.