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Abstract: We investigate the relation between the (ideal) time and space complexities for the gathering problem with anonymous agents in asynchronous anonymous tree networks. The gathering problem requires that all the agents in the network have to meet at a single node within a finite time. Although an asymptotically space-optimal algorithm is known, its time complexity is quite large. In this paper, we consider asymptotically (ideal-)time-optimal algorithms and investigate the minimum memory requirement per agent for asymptotically time-optimal algorithms. First, we show that there exists a tree with nodes in which bits of memory per agent is required to solve the gathering problem in time (asymptotically time-optimal). Then, we present an asymptotically time-optimal gathering algorithm. This algorithm can be executed if each agent has bits of memory. From this lower/upper bound, this algorithm is asymptotically space-optimal on the condition that the time complexity is asymptotically optimal. [Copyright &y& Elsevier]

Abstract: With the evolution in the computer networks, many companies are trying to come up with efficient products which can make life easier for network administrators. Silent automated installation is one category among such products. In this paper, we have proposed silent network installer and tester (SNIT) which provides silent, automated and intelligent installation of software(s) over the network. SNIT will intelligently install any kind of software on request of the network administrator. SNIT not only provides installation services, it also enables network administrators to verify the installation of software over the network. SNIT uses an efficient algorithm to transfer the software installation setup on the network nodes. The system is fully autonomous and does not require any kind of user interaction or intervention. Network administrator is responsible for assigning the task(s) to SNIT and once assigned it performs the task(s) over the network autonomously with the help of intelligent mobile agents. SNIT has been deployed for evaluation purpose at the University Campus Lab equipped with 200 machines and some of the popular softwares were tested in the lab, results were very promising and support the implementation of the solution. [Copyright &y& Elsevier]

Abstract: We consider a fixed, undirected, known network and a number of “mobile agents” which can traverse the network in synchronised steps. Some nodes in the network may be faulty and the agents are to find the faults and repair them. The agents could be software agents, if the underlying network represents a computer network, or robots, if the underlying network represents some potentially hazardous physical terrain. Assuming that the first agent encountering a faulty node can immediately repair it, it is easy to see that the number of steps necessary and sufficient to complete this task is , where is the number of nodes in the network, is the diameter of the network, and is the number of agents. We consider the case where one agent can repair only one faulty node. After repairing the fault, the agent dies. We show that a simple deterministic algorithm for this problem terminates within steps, where , assuming that the number of faulty nodes is at most . We also demonstrate the worst-case asymptotic optimality of this algorithm by showing a network such that for any deterministic algorithm, there is a placement of faults forcing the algorithm to work for steps. [Copyright &y& Elsevier]

Abstract: Mobile agent-based distributed job workflow execution requires the use of execution coordination techniques to ensure that an agent executing a subjob can locate its predecessors’ execution results. This paper describes the classification, implementation, and evaluation of execution coordination techniques in the mobile agent-based distributed job workflow execution system. First, a classification of the existing execution coordination techniques is developed for mobile agent systems. Second, to put the discussion into perspective, our framework for mobile agent-based distributed job workflow execution over the Grid (that is, MCCF: Mobile Code Collaboration Framework) is described. How the existing coordination techniques can be applied in the MCCF is also discussed. Finally, a performance study has been conducted to evaluate three coordination techniques using real and simulated job workflows. The results are presented and discussed in the paper. [Copyright &y& Elsevier]

This paper presents a framework for reusable mobile agents for network management in the sense that they are independent of either particular networks or applications. The framework enables a mobile agent to be composed from two layered components, which are mobile agents. The former is a carrier of the latter over particular networks independent of any management tasks and the latter defines management tasks performed at each host independently of any networks. The framework also oilers a mechanism for matchmaking the two components. Since the mechanism is formulated on a process algebra approach, it can accurately select the appropriate itinerary component to perform management tasks at hosts that the tasks want to visit over networks. The framework provides a methodology for easily developing and operating mobile agents for traveling among multiple sub-networks to perform their management tasks at all of the nodes that they visit. This paper also describes the framework, its prototype implementation, and a practical application. [ABSTRACT FROM AUTHOR]

Modern Intrusion Detection Systems (IDSs) are distributed real-time systems that detect unauthorized use or attacks upon an organization's network and/or hosts. The components of most distributed IDSs are arranged in a hierarchical tree structure, where the sensor nodes pass information to the analyzer nodes. Optimal placement of the analyzer nodes results in an improved response time for the IDS, and isolation of attacks within the IDS network. Since the network topology and workload are constantly changing, we are able to maintain near-optimal placement of the analyzer nodes by instantiating them as mobile agents. The analyzer nodes may then relocate, reproduce or be deleted as necessary. Such flexibility improves the response times and the stability of an IDS. The movement of the analyzer nodes also offers some protection against denial-of service attacks, since secure analyzer nodes will be relocated to take over some of the functionality of the host under attack. [ABSTRACT FROM AUTHOR]

The Internet is a wide area distributed network emphasizing the importance of interoperability and scalability and takes a bottom-up approach by stacking local schemata. It is considered a dynamic network environment including nondeterministic and nonformatted characteristics. In this paper we propose a platform involving user adaptive agent with a mechanism to realize deliberative responses in order to carry out predictive learning of the environmental variations, not just reactive responses. Further, the present platform is applied to a network QoS control system. It is now possible to provide for graceful degradation while the trade-off point between the user and the network is found autonomously. © 2000 Scripta Technica, Electron Comm Jpn Pt 2, 83(4): 1–12, 2000 [ABSTRACT FROM AUTHOR]