The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform
Mohamed G. Gouda - One of the best experts on this subject based on the ideXlab platform.
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Stabilization of max-min fair networks without per-flow state
Theoretical Computer Science, 2011Co-Authors: Jorge A. Cobb, Mohamed G. GoudaAbstract:Let a flow be a sequence of packets that are sent from a source Computer to a Destination Computer. In this paper, we consider the fair allocation of bandwidth to each flow in a Computer network. We focus on max?min fairness, which assigns to each flow the largest possible bandwidth that avoids affecting other flows. What distinguishes our approach is that routers only maintain a constant amount of state, i.e., no per-flow state is maintained. This is consistent with trends in the Internet (such as the proposed Differentiated Services Internet architecture). In addition, to provide a high degree of fault-tolerance, we ensure our approach is self-stabilizing, that is, it returns to a normal operating state after a finite sequence of faults.
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SSS - Stabilization of Max-Min Fair Networks without Per-flow State
Lecture Notes in Computer Science, 2008Co-Authors: Jorge A. Cobb, Mohamed G. GoudaAbstract:Let a flow be a sequence of packets sent from a source Computer to a Destination Computer. Routers at the core of the Internet do not maintain any information about the flows that traverse them. This has allowed for great speeds at the routers, at the expense of providing only best-effort service. In this paper, we consider the problem of fairly allocating bandwidth to each flow. We assume some flows request a constant amount of bandwidth from the network. The bandwidth that remains is distributed fairly among the rest of the flows. The fairness sought after is max-min fairness, which assigns to each flow the largest possible bandwidth that avoids affecting other flows. The distinguishing factor to other approaches is that routers only maintain a constant amount of state, which is consistent with trends in the Internet (such as the proposed Differentiated Services Internet architecture). In addition, due to the need for high fault-tolerance in the Internet, we ensure our protocol is self-stabilizing, that is, it tolerates a wide variety of transient faults.
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ICCCN - An anti-replay window protocol with controlled shift
Proceedings Tenth International Conference on Computer Communications and Networks (Cat. No.01EX495), 1Co-Authors: Chin-tser Huang, Mohamed G. GoudaAbstract:The anti-replay window protocol is used to secure IP against an adversary that can insert (possibly replayed) messages in the message stream from a source Computer to a Destination Computer in the Internet. We discuss this important protocol and point out a potential problem faced by the protocol, in which severe reordering of messages can cause the protocol to discard a lot of good messages. We then introduce a controlled shift mechanism that can reduce the number of discarded good messages by sacrificing a relatively small number of messages. We use simulation to show that the modified protocol is more effective than the original protocol when a severe reordering of messages occurs. In particular, we show that the modified protocol reduces the number of discarded good messages by up to 70%.
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ICCCN - Anti-replay window protocols for secure IP
Proceedings Ninth International Conference on Computer Communications and Networks (Cat.No.00EX440), 1Co-Authors: Mohamed G. Gouda, Chin-tser HuangAbstract:The anti-replay window protocol is used to secure IP against an adversary that can insert (possibly replayed) messages in the message stream from a source Computer to a Destination Computer in the Internet. In this paper, we verify the correctness of this important protocol using standard methods (i.e. auxiliary variables, annotation, and invariants). We show that despite the adversary, the protocol delivers each message at most once, and discards a message only if another copy of this message has already been delivered, or the message has suffered a reorder of degree w or more, where w is the window size. We then develop another variation of this protocol that uses two windows of size w/2 each. This protocol delivers every message at most once, and discards a message only if another copy of this message has already been delivered, or the message has suffered a reorder of degree w+d or more, where d is the sum of current distances between successive windows in the protocol. We argue that the double-window protocol is more effective than the original single-window protocol.
Jorge A. Cobb - One of the best experts on this subject based on the ideXlab platform.
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Stabilization of max-min fair networks without per-flow state
Theoretical Computer Science, 2011Co-Authors: Jorge A. Cobb, Mohamed G. GoudaAbstract:Let a flow be a sequence of packets that are sent from a source Computer to a Destination Computer. In this paper, we consider the fair allocation of bandwidth to each flow in a Computer network. We focus on max?min fairness, which assigns to each flow the largest possible bandwidth that avoids affecting other flows. What distinguishes our approach is that routers only maintain a constant amount of state, i.e., no per-flow state is maintained. This is consistent with trends in the Internet (such as the proposed Differentiated Services Internet architecture). In addition, to provide a high degree of fault-tolerance, we ensure our approach is self-stabilizing, that is, it returns to a normal operating state after a finite sequence of faults.
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SSS - Stabilization of Max-Min Fair Networks without Per-flow State
Lecture Notes in Computer Science, 2008Co-Authors: Jorge A. Cobb, Mohamed G. GoudaAbstract:Let a flow be a sequence of packets sent from a source Computer to a Destination Computer. Routers at the core of the Internet do not maintain any information about the flows that traverse them. This has allowed for great speeds at the routers, at the expense of providing only best-effort service. In this paper, we consider the problem of fairly allocating bandwidth to each flow. We assume some flows request a constant amount of bandwidth from the network. The bandwidth that remains is distributed fairly among the rest of the flows. The fairness sought after is max-min fairness, which assigns to each flow the largest possible bandwidth that avoids affecting other flows. The distinguishing factor to other approaches is that routers only maintain a constant amount of state, which is consistent with trends in the Internet (such as the proposed Differentiated Services Internet architecture). In addition, due to the need for high fault-tolerance in the Internet, we ensure our protocol is self-stabilizing, that is, it tolerates a wide variety of transient faults.
Azuma Ohuchi - One of the best experts on this subject based on the ideXlab platform.
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distributed visitors coordination system in theme park problem
Lecture Notes in Computer Science, 2005Co-Authors: Takashi Kataoka, Hidenori Kawamura, Koichi Kurumatani, Azuma OhuchiAbstract:A distributed visitors coordination system is proposed as an application of a massively multi-agent system. In the system, some agents register their next Destination using an information device such as a cellular phone, and this information is used to reduce the effect of the time delay between decision-making and effect-emergence. This delay causes queue lengths to oscillate. However, it is troublesome for agents to continuously register their next Destination. To compensate them, exclusive queues are made available to agents registering their next Destination. Computer simulation of the theme park problem, showed that when all agents avoid the congestion by registering their next Destination, the total waiting time is minimized and queue length oscillation is reduced.
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MMAS - Distributed visitors coordination system in theme park problem
Massively Multi-Agent Systems I, 2005Co-Authors: Takashi Kataoka, Hidenori Kawamura, Koichi Kurumatani, Azuma OhuchiAbstract:A distributed visitors coordination system is proposed as an application of a massively multi-agent system. In the system, some agents register their next Destination using an information device such as a cellular phone, and this information is used to reduce the effect of the time delay between decision-making and effect-emergence. This delay causes queue lengths to oscillate. However, it is troublesome for agents to continuously register their next Destination. To compensate them, exclusive queues are made available to agents registering their next Destination. Computer simulation of the theme park problem, showed that when all agents avoid the congestion by registering their next Destination, the total waiting time is minimized and queue length oscillation is reduced.
Takashi Kataoka - One of the best experts on this subject based on the ideXlab platform.
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distributed visitors coordination system in theme park problem
Lecture Notes in Computer Science, 2005Co-Authors: Takashi Kataoka, Hidenori Kawamura, Koichi Kurumatani, Azuma OhuchiAbstract:A distributed visitors coordination system is proposed as an application of a massively multi-agent system. In the system, some agents register their next Destination using an information device such as a cellular phone, and this information is used to reduce the effect of the time delay between decision-making and effect-emergence. This delay causes queue lengths to oscillate. However, it is troublesome for agents to continuously register their next Destination. To compensate them, exclusive queues are made available to agents registering their next Destination. Computer simulation of the theme park problem, showed that when all agents avoid the congestion by registering their next Destination, the total waiting time is minimized and queue length oscillation is reduced.
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MMAS - Distributed visitors coordination system in theme park problem
Massively Multi-Agent Systems I, 2005Co-Authors: Takashi Kataoka, Hidenori Kawamura, Koichi Kurumatani, Azuma OhuchiAbstract:A distributed visitors coordination system is proposed as an application of a massively multi-agent system. In the system, some agents register their next Destination using an information device such as a cellular phone, and this information is used to reduce the effect of the time delay between decision-making and effect-emergence. This delay causes queue lengths to oscillate. However, it is troublesome for agents to continuously register their next Destination. To compensate them, exclusive queues are made available to agents registering their next Destination. Computer simulation of the theme park problem, showed that when all agents avoid the congestion by registering their next Destination, the total waiting time is minimized and queue length oscillation is reduced.
Makoto Takizawa - One of the best experts on this subject based on the ideXlab platform.
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a fault tolerant transactional agent model on distributed objects
International Symposium on Object Component Service-Oriented Real-Time Distributed Computing, 2006Co-Authors: Youhei Tanaka, Naohiro Hayashibara, Tomoya Enokido, Makoto TakizawaAbstract:A transactional agent is a mobile agent to manipulate objects distributed on Computers with some type of commitment condition. For example, a transactional agent commits only if at least one object could be successfully manipulated in the at-least-one commitment condition. Computers may stop by fault while networks are assumed to be reliable. In the client-server model, servers can be fault-tolerant according to traditional replication and checkpointing technologies. However, an application program cannot be performed if a client Computer is faulty. An application program can be performed on another operational Computer even if a Computer is faulty in the transactional agent model. For example, a transactional agent can move to another operational Computer if some Destination Computer where the agent to move is faulty. There are kinds of faulty Computers for a transactional agent, current, Destination, and sibling Computers where a transactional agent now exist, will move, and has visited, respectively. We discuss how the transactional agent can be tolerant of the types of faults. We show how a program reliably manipulating objects can be realized in a mobile agent in presence of Computer faults.
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AINA (2) - A fault-tolerant transactional agent model on distributed object systems
20th International Conference on Advanced Information Networking and Applications - Volume 1 (AINA'06), 2006Co-Authors: Youhei Tanaka, Naohiro Hayashibara, Tomoya Enokido, Makoto TakizawaAbstract:A transactional agent is a mobile agent to manipulate objects distributed on Computers with some commitment condition like atomic commitment. Computers may stop by fault. In the client-server model, servers can be fault-tolerant according to replication and checkpointing technologies. However, an application program cannot be performed if a client Computer is faulty. A transactional agent can move to another operational Computer if some Destination Computer to which the agent to move is faulty. In this paper, we discuss how a program reliably manipulating objects can be realized in a mobile agent in presence of Computer faults.
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SAC - Transactional agent model for fault-tolerant object systems
Proceedings of the 2005 ACM symposium on Applied computing - SAC '05, 2005Co-Authors: Tomoaki Kaneda, Youhei Tanaka, Tomoya Enokido, Makoto TakizawaAbstract:A transactional agent is a mobile agent which manipulates objects in multiple Computers by autonomously finding a way to visit the Computers. The transactional agent commits only if its commitment condition like atomicity is satisfied in presence of faults of Computers. On leaving a Computer, an agent creates a surrogate agent which holds objects manipulated. A surrogate can recreate a new incarnation of the agent if the agent itself is faulty. If a Destination Computer is faulty, the transactional agent finds another operational Computer to visit. After visiting Computers, a transactional agent makes a Destination on commitment according to its commitment condition. We discuss design and implementation of the transactional agent which is tolerant of Computer faults.
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ISORC - A fault-tolerant transactional agent model on distributed objects
Ninth IEEE International Symposium on Object and Component-Oriented Real-Time Distributed Computing (ISORC'06), 1Co-Authors: Youhei Tanaka, Naohiro Hayashibara, Tomoya Enokido, Makoto TakizawaAbstract:A transactional agent is a mobile agent to manipulate objects distributed on Computers with some type of commitment condition. For example, a transactional agent commits only if at least one object could be successfully manipulated in the at-least-one commitment condition. Computers may stop by fault while networks are assumed to be reliable. In the client-server model, servers can be fault-tolerant according to traditional replication and checkpointing technologies. However, an application program cannot be performed if a client Computer is faulty. An application program can be performed on another operational Computer even if a Computer is faulty in the transactional agent model. For example, a transactional agent can move to another operational Computer if some Destination Computer where the agent to move is faulty. There are kinds of faulty Computers for a transactional agent, current, Destination, and sibling Computers where a transactional agent now exist, will move, and has visited, respectively. We discuss how the transactional agent can be tolerant of the types of faults. We show how a program reliably manipulating objects can be realized in a mobile agent in presence of Computer faults.