Ayodeji Oludola Oluwatope

A User Identity Management Protocol for Cloud Computing Paradigm

Cloud computing paradigm is a service oriented system that delivers services to the customer at low cost. Cloud computing needs to address three main security issues: confidentiality, integrity and availability. In this paper, we propose user identity management protocol for cloud computing customers and cloud service providers. This protocol will authenticate and authorize customers/providers in other to achieve global security networks. The protocol will be developed to achieve the set global security objectives in cloud computing environments. Confidentiality, integrity and availability are the key challenges of web services’ or utility providers. A layered protocol design is proposed for cloud computing systems, the physical, networks and application layer. However, each layer will integrate existing security features such as firewalls, NIDS, NIPS, Anti-DDOS and others to prevent security threats and attacks. System vulnerability is critical to the cloud computing facilities; the proposed protocol will address this as part of measures to secure data at all levels. The protocol will protect customers/cloud service providers’ infrastructure by preventing unauthorized users to gain access to the service/facility.

Architectural model for Wireless Peer-to-Peer (WP2P) file sharing for ubiquitous mobile devices

This paper presents an architectural model for Wireless Peer-to-Peer (WP2P) file sharing system for ubiquitos mobile devices. File sharing is one of the rationales for computer networks with increasing demand for file sharing applications and technologies in small and large enterprise networks and on the Internet. With the popularity of mobile phones in day-to-day activities, P2P file sharing in mobile phones is highly desirable, especially in 2/2.5G mobile networks. The proposed model is based on a hybrid or semi centralized architecture with the central database server acting as an interface between the mobile devices. The P2P communication model employs the Short Messaging Service (SMS) and Multimedia Messaging Service (MMS) as the messaging medium. The mobile phone initiates a search for a particular file on the mobile P2P network using a General Packet Radio Service (GPRS) connection. The database replies the “searcher” mobile phone with a list of all the available files and the details of the mobile phones that have them. Using this information, the requesting mobile phone makes a SMS connection to any of the phones provided by the database server. The mobile phone with the file then sends it to the requesting mobile phone using the MMS. We present an architectural model using mobile proxy, SMS and MMS, for a mobile P2P network for 2/2.5G networks despite operator constraints.

End-to-End Performance Evaluation of Selected TCP Variants across a Hybrid Wireless Network

Reliable transport protocols such as TCP are tuned to perform well in traditional networks where packet losses occur mostly because of congestion. TCP is intended for use as a highly reliable end-to-end transport protocol for transporting applications such as World-Wide Web (WWW) between hosts in packet-switched computer communication networks. TCP was originally designed for wired links where the error rate is really low and actually assumed that packet losses are due to congestion in the network. However, the increasing popularity of wireless networks indicates that wireless links will play more important role in future internetworks but TCP performance in such networks suffers from significant throughput degradation and very high interactive delays. TCP responds to all losses by invoking congestion control and avoidance algorithms, resulting in degraded end-to-end performance in wireless and lossy systems. Thus, in a bid to show and determine the possibility of adapting TCP protocol for optimal performance on the wireless link, this paper reviews and models the behaviors of TCP variants with a view to evaluate the end-to-end performance analysis of TCP versions: TCP Reno, TCP SACK and TCP Westwood (TCPW), which are designed to improve the performance of TCP in lossy networks. A wireless network model was developed using NS-2 network simulator which and the model was simulated. The results were analyzed in MATLAB 6.5 using throughput as a metric for comparison. The overall results indicate that TCP Westwood (TCPW) demonstrates better performance indices over other versions in a hybrid wireless network environment.

A Load Balancing Policy for Distributed Web Service

The proliferation of web services; and users appeal for high scalability, availability and reliability of web servers to provide rapid response and high throughput for the Clients’ requests occurring at anytime. Distributed Web Servers (DWSs) provide an effective solution for improving the quality of web services. This paper addresses un-regulated jobs/tasks migration among the servers. Considering distributed web services with several servers running, a lot of bandwidth is wasted due to unnecessary job migration. Having considered bandwidth optimization, it is important to develop a policy that will address the bandwidth consumption while loads/tasks are being transferred among the servers. The goal of this work is to regulate this movement to minimize bandwidth consumption. From literatures, little or no attention was given to this problem, making it difficult to implement some of these policies/schemes in bandwidth scarce environment. Our policy “Cooperative Adaptive Symmetrical Initiated Dynamic/Diffusion (CASID)” was developed using Java Development Environment (JADE) a middle ware service oriented environment which is agent-based. The software was used to simulate events (jobs distribution) on the servers. With no job transfer allowed when all servers are busy, any over loaded server process jobs internally to completion. We achieved this by having two different agents; static cognitive agents and dynamic cognitive agents. The results were compared with the existing schemes. CASID policy outperforms PLB scheme in terms of response time and system throughput.

TCP Window Based Congestion Control Slow-Start Approach

Transmission control protocol (TCP) has undergone several transformations. Several proposals have been put forward to change the mechanisms of TCP congestion control to improve its performance. A line of research tends to reduce speed in the face of congestion thereby penalizing itself. In this group are the window based congestion control algorithms that use the size of congestion window to determine transmission speed. The two main algorithm of window based congestion control are the congestion avoidance and the slow start. The aim of this study is to survey the various modifications of window based congestion control. Much work has been done on congestion avoidance hence specific attention is placed on the slow start in order to motivate a new direction of research in network utility maximization. Mathematical modeling of the internet is discussed and proposals to improve TCP startup were reviewed. There are three lines of research on the improvement of slow start. A group uses the estimation of certain parameters to determine initial speed. The second group uses bandwidth estimation while the last group uses explicit request for network assistance to determine initial startup speed. The problems of each proposal are analyzed and a multiple startup for TCP is proposed. Multiple startups for TCP specify that startup speed is selectable from an n-arry set of algorithms. We then introduced the e-speed start which uses the prevailing network condition to determine a suitable starting speed.

A distributed intrusion detection scheme for wireless sensor networks

The task of Intrusion Detection Systems (IDS) in Wireless Sensors Networks (WSNs) is to monitor sensor network systems; detecting possible intrusions in the WSNs environment, alerting users after intrusions had been detected and reconfiguring the network if possible. In this study a Distributed IDS for WSNs was developed. Distributed IDS is implemented using TMote sky wireless sensor for testing and simulation over specified parameters. For efficient monitoring of the WSNs, the proposed system employs Mobile Agents (MAs) that can communicate with other sensors and move from one Base Station (BS) to another in order to enhance intrusion detection and prevention. Comparative analysis of the result is studied based on three major parameters: energy consumption, response time and detection accuracy. The result of the study shows better performance.

A Scalable Architecture for Network Traffic Monitoring and Analysis Using Free Open Source Software

The lack of current network dynamics studies that evaluate the effects of new application and protocol deployment or long-term studies that observe the effect of incremental changes on the Internet, and the change in the overall stability of the Internet under various conditions and threats has made network monitoring challenging. A good understanding of the nature and type of network traffic is the key to solving congestion problems. In this paper we describe the architecture and implementation of a scalable network traffic moni-toring and analysis system. The gigabit interface on the monitoring system was configured to capture network traffic and the Multi Router Traffic Grapher (MRTG) and Webalizer produces graphical and detailed traffic analysis. This system is in use at the Obafemi Awolowo University, IleIfe, Nigeria; we describe how this system can be replicated in another environment.

Double-Buffer Traffic Shaper Modelling for Multimedia Applications in Slow Speed Network

Lack of end-to-end quality-of-service support, unbounded packet-data delay, poorly adapted transport protocol and slow-speed network are factors militating against the deployment of realtime video streaming across the Internet at slow-speed. This paper presents a Double-Buffer Traffic Shaper (DBTS) for rate adaption of real-time video transmission in a slow-speed network using Transmission Control Protocol (TCP) for data transportation. The scheme was tested in Matlab and it was found to reduce variable bit rate (VBR) traffic burstiness to its barest minimum and variability to almost nil.

Computational Modeling of Collaborative Resources Sharing in Grid System

In grid computing, Grid users who submit jobs or tasks and resources providers who provide resources have different motivations when they join the Grid system. However, due to autonomy both the Grid users’ and resource providers’ objectives often conflict. This paper proposes autonomous hybrid resource management algorithm aim at optimizing the resource utilization of resources providers using “what-you-give-is-what-you-get” Service Level Agreements resource allocation policy. Utility functions are used to achieve the objectives of Grid resource and application. The algorithm was formulated as joint optimization of utilities of Grid applications and Grid resources, which combine the resource contributed, incentive score, trustworthiness and reputation score to compute resource utilization. Simulations were conducted to study the performance of the algorithm using GridSim v5.0. The simulation results revealed that the algorithm yields significantly good result because no user can consume more than what it contribute under different scenarios; hence the problem of free riding has been addressed through this algorithm.

UStream: Ultra-Metric Spanning Overlay Topology for Peer-to-Peer Streaming Systems

The last decade has seen a sharp increase in Internet traffic due to dispersion of videos. Despite this growth, users quality of experience (QoE) in peer-to-peer (P2P) streaming systems does not match the conventional television service. The deployment of P2P streaming system is affected by long delay, unplanned interruption, flash crowd, high churn situation and choice of overlay structure. The overlay structure plays significant role in ensuring that traffic are distributed to all physical links in a dynamic and fair manner, tree-based (TB) and mesh-based (MB) are the most popular. TB fails in situations where there is failure at the parent peer which can lead to total collapse of the system while MB is more vulnerable to flash crowd and high churn situation due to its unstructured pattern. This paper presents a novel P2P streaming topology (UStream), using a hybrid of TB and MB to address the disadvantages of both topologies to ensure an optimal solution. Furthermore, UStream adopts the features of ultra-metric tree to ensure that the time taken from the root peer to any of the childrens peer are equal and the spanning tree to monitor all the peers at any point in time. Ustream also employs the principle of chaos theory. The present peer determines the future, though the approximate present does not approximately determines the future. Ustream was formalized using mathematical theories. Several theorems were proposed and proved in validating this topology.