Modeling and Simulation of a University LAN in OPNET Modeller Environment

Academia has peculiar networking needs that must be satisfied for effective dissemination of knowledge. The main purpose of a campus network is efficient resource sharing and access to information among its users. A key issue with designing and implementing such Local Area Networks (LAN) is its performance under ever increasing network traffic, and how this is affected by various network metrics such as latency and end-to-end delay. Implementation of network systems is a complex and expensive task; hence network simulation has become essential and has proven to be cost effective and highly useful for modeling the desired characteristics and analyzing performance under different scenarios. As well as providing useful prognosis of future network performance based on current expansion dynamics. We present in this paper the simulation and analysis of the Covenant University campus LAN in the OPNET Modeler environment

Flexpop: A popularity-based caching strategy for multimedia applications in information-centric networking

Information-Centric Networking (ICN) is the dominant architecture for the future Internet. In ICN, the content items are stored temporarily in network nodes such as routers. When the memory of routers becomes full and there is no room for a new arriving content, the stored contents are evicted to cope with the limited cache size of the routers. Therefore, it is crucial to develop an effective caching strategy for keeping popular contents for a longer period of time. This study proposes a new caching strategy, named Flexible Popularity-based Caching (FlexPop) for storing popular contents. The FlexPop comprises two mechanisms, i.e., Content Placement Mechanism (CPM), which is responsible for content caching, and Content Eviction Mechanism (CEM) that deals with content eviction when the router cache is full and there is no space for the new incoming content. Both mechanisms are validated using Fuzzy Set Theory, following the Design Research Methodology (DRM) to manifest that the research is rigorous and repeatable under comparable conditions. The performance of FlexPop is evaluated through simulations and the results are compared with those of the Leave Copy Everywhere (LCE), ProbCache, and Most Popular Content (MPC) strategies. The results show that the FlexPop strategy outperforms LCE, ProbCache, and MPC with respect to cache hit rate, redundancy, content retrieval delay, memory utilization, and stretch ratio, which are regarded as extremely important metrics (in various studies) for the evaluation of ICN caching. The outcomes exhibited in this study are noteworthy in terms of making FlexPop acceptable to users as they can verify the performance of ICN before selecting the right caching strategy. Thus FlexPop has potential in the use of ICN for the future Internet such as in deployment of the IoT technology

On the Use of Hybrid Heuristics for Providing Service to Select the Return Channel in an Interactive Digital TV Environment

The technologies used to link the end-user to a telecommunication infrastructure, has been changing over time due to the consolidation of new access technologies. Moreover, the emergence of new tools for information dissemination, such as interactive digital TV, makes the selection of access technology, factor of fundamental importance. One of the greatest advantages of using digital TV as means to disseminate information is the installation of applications. In this chapter, a load characterization of a typical application embedded in a digital TV is performed to determine its behavior. However, it is important to note that applications send information through an access technology. Therefore, this chapter, based on the study on load characterization, developed a methodology combining Bayesian networks and technique for order preference by similarity to ideal solution (TOPSIS) analytical approach to provide support to service providers to opt for a technology (power line communication, PLC, wireless, wired, etc.) for the return channel

An investigation into internetworking education

Computer network technology and the Internet grew rapidly in recent years. Their growth created a large demand from industry for the development of IT and internetworking professionals. These professionals need to be equipped with both technical hands-on skills and non-technical or soft skills. In order to supply new professionals to the industry, educational institutions need to address these skills training in their curricula. Technical hands-on skills in internetworking education can be emphasised through the practical use of equipment in classrooms. The provision of the networking equipment to the internetworking students is a challenge. Particularly, university students in developing countries may find that this equipment is ineffectively provided by their teaching institutions, because of the expense. Modern online learning tools, such as remote access laboratories, may be used to address this need. However, the provision of such tools will also need to concentrate upon the pedagogical values. In addition, traditional remote access laboratories provide only text-based access, which was originally designed for highly professional use. Novice students may struggle with learning in these virtual environments, especially when the physical equipment is not available locally. Furthermore, non-technical skills or soft skills are social skills that should not be neglected in graduates’ future workplaces. A traditional model of developing soft skills that was used in face-to-face classroom may not be as effective when applied in an online classroom. Research on students’ opinions about their soft skills development during attending internetworking courses is needed to be conducted. In order to address both research needs, this study was focused on two research aspects related to online learning in internetworking education. The first focus was on research into providing a suitable technical learning environment to distance internetworking students. The second focus was on the students’ opinions about their non-technical skills development. To provide a close equivalent of a face-to-face internetworking learning environment to remote students in Thailand, a transformation of a local internetworking laboratory was conducted. A new multimedia online learning environment integrated pedagogically-rich tools such as state model diagrams (SMDs), a real-time video streaming of equipment and a voice communication tool. Mixed research data were gathered from remote online and local student participants. The remote online participants were invited to use the new learning environment developed in this study. Qualitative research data were collected from twelve remote online students after their trial usage. Concurrently, another set of research data were collected from local students asking their opinion about the development of soft skills in the internetworking course. There were sixty six participants in this second set of research data. Although the research data was limited, restricting the researcher’s ability to generalise, it can be concluded that the provision of multimedia tools in an online internetworking learning environment was beneficial to distant students. The superiority of the traditional physical internetworking laboratory cannot be overlooked; however, the remote laboratory could be used as a supplementary self-practice tool. A concrete learning element such as a real-time video stream and diagrams simplified students learning processes in the virtual environment. Faster communication with the remote instructors and the equipment are also critical factors for a remote access network to be successful. However, unlike the face-to-face laboratory, the future challenge of the online laboratory will creating materials which will encourage students to build soft skills in their laboratory sessions

Performance Evaluation of Network Security Protocols on Open Source and Microsoft Windows Platforms

Internet is increasingly being used to support collaborative applications such as voice and video-conferencing, replicated servers and databases of different types. Since most communication over the Internet involves the traversal of insecure open networks, basic security services such as data privacy, integrity and authentication are necessary. One of the levels of computer security is operating system security. This paper analyzes the limitations and behavioral patterns of security protocols across different platform. It compared the performance of security protocols in terms of authentication, encryption algorithm, cryptographic methods etc.; in order to determine which platform provides better support for security protocols. Network simulator tool was used to simulate different scenarios to show the performance of security protocols across two Operating System Platforms (Linux and Windows). Analysis of the simulation values of selected performance metrics of the security protocols, across both platforms, were evaluated. Results obtained showed comparable differences in the values of the performance parameters considered. For instance, IP processing delay of the Windows Client node was initially high (about 0.0125 milliseconds), but later decreases to about 0.0115 milliseconds, while the Linux Client node is constant at about 0.0115 milliseconds. Variations in the values of the performance parameters for both platforms, in both network scenarios are not significant enough to reflect a noticeable difference in the impacts of the network security protocols on the performance of the operating system platforms. Keywords: Open Source, IP Security, SSL, OPNET, Security Protocol, Operating System

A Hybrid Communications Network Simulation-Independent Toolkit

Net-centric warfare requires information superiority to enable decision superiority, culminating in insurmountable combat power against our enemies on the battlefield. Information superiority must be attained and retained for success in today’s joint/coalition battlespace. To accomplish this goal, our combat networks must reliably, expediently and completely deliver over a wide range of mobile and fixed assets. Furthermore, each asset must be given special consideration for the sensitivity, priority and volume of information required by the mission. Evolving a grand design of the enabling network will require a flexible evaluation platform to try and select the right combination of network strategies and protocols in the realms of topology control and routing. This research will result in a toolkit for ns2 that will enable rapid interfacing and evaluation of new networking algorithms and/or protocols. The toolkit will be the springboard for development of an optimal, multi-dimensional and flexible network for linking combat entities in the battlespace

Enhanced Forwarding Strategies in Information Centric Networking

Content Centric Networking (CCN), a Clean Slate architecture to Information Centric Networking (ICN) , uses new approaches to routing named content, achieving scalability, security and performance. This thesis proposes a design of an effective multi-path forwarding strategy and performs an evaluation of this strategy in a set of scenarios that consider large scale deployments. The evaluations show improved performance in terms of user application throughput, delays, adoptability and scalability against adverse conditions (such as differing background loads and mobility) compared to the originally proposed forwarding strategies. Secondly, this thesis proposes an analytical model based on Markov Modulated Rate Process (MMRP) to characterize multi-path data transfers in CCN. The results show a close resemblance in performance between the analytical model and the simulation model

Converged IP-over-standard ethernet progress control networks for hydrocarbon process automation applications controllers

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The maturity level of Internet Protocol (IP) and the emergence of standard Ethernet interfaces of Hydrocarbon Process Automation Application (HPAA) present a real opportunity to combine independent industrial applications onto an integrated IP based network platform. Quality of Service (QoS) for IP over Ethernet has the strength to regulate traffic mix and support timely delivery. The combinations of these technologies lend themselves to provide a platform to support HPAA applications across Local Area Network (LAN) and Wide Area Network (WAN) networks. HPAA systems are composed of sensors, actuators, and logic solvers networked together to form independent control system network platforms. They support hydrocarbon plants operating under critical conditions that — if not controlled — could become dangerous to people, assets and the environment. This demands high speed networking which is triggered by the need to capture data with higher frequency rate at a finer granularity. Nevertheless, existing HPAA network infrastructure is based on unique autonomous systems, which has resulted in multiple, parallel and separate networks with limited interconnectivity supporting different functions. This created increased complexity in integrating various applications and resulted higher costs in the technology life cycle total ownership. To date, the concept of consolidating HPAA into a converged IP network over standard Ethernet has not yet been explored. This research aims to explore and develop the HPAA Process Control Systems (PCS) in a Converged Internet Protocol (CIP) using experimental and simulated networks case studies. Results from experimental and simulation work showed encouraging outcomes and provided a good argument for supporting the co-existence of HPAA and non-HPAA applications taking into consideration timeliness and reliability requirements. This was achieved by invoking priority based scheduling with the highest priority being awarded to PCS among other supported services such as voice, multimedia streams and other applications. HPAA can benefit from utilizing CIP over Ethernet by reducing the number of interdependent HPAA PCS networks to a single uniform and standard network. In addition, this integrated infrastructure offers a platform for additional support services such as multimedia streaming, voice, and data. This network‐based model manifests itself to be integrated with remote control system platform capabilities at the end user's desktop independent of space and time resulting in the concept of plant virtualization

Simulations of Networks in OPNET and Implementation of OFDM in ADS

The OPNET software was used to simulate the different scenarios of the networks which clearly explain the way the data is transmitted and received. We also find a lot about different topologies and how subnets can be used to effectively connect nodes in a network. The easy-to-use and drag-and-drop nature of OPNET helped a lot in simulating networks in star topology, creating different types of servers for each department of a campus network. The papers on wireless networks were very enlightening, awakening us to different standards presently in use, like, 802.11, 802.16, etc. The second half of the project included simulating ofdm in ADS. It is a case in point of the use of communication systems in present day technologies. We came to know of the use of ofdm in present wireless technologies. The advantages and disadvantages of ofdm also came to the fore. The ADS software’s user-friendly interface was very helpful in simulating the transmitter and receiver

H-NAMe: a hidden-node avoidance mechanism for wireless sensor networks

The hidden-node problem has been shown to be a major source of Quality-of-Service (QoS) degradation in Wireless Sensor Networks (WSNs) due to factors such as the limited communication range of sensor nodes, link asymmetry and the characteristics of the physical environment. In wireless contention-based Medium Access Control protocols, if two nodes that are not visible to each other transmit to a third node that is visible to the formers, there will be a collision – usually called hidden-node or blind collision. This problem greatly affects network throughput, energy-efficiency and message transfer delays, which might be particularly dramatic in large-scale WSNs. This paper tackles the hiddennode problem in WSNs and proposes H-NAMe, a simple yet efficient distributed mechanism to overcome it. H-NAMe relies on a grouping strategy that splits each cluster of a WSN into disjoint groups of non-hidden nodes and then scales to multiple clusters via a cluster grouping strategy that guarantees no transmission interference between overlapping clusters. We also show that the H-NAMe mechanism can be easily applied to the IEEE 802.15.4/ZigBee protocols with only minor add-ons and ensuring backward compatibility with the standard specifications. We demonstrate the feasibility of H-NAMe via an experimental test-bed, showing that it increases network throughput and transmission success probability up to twice the values obtained without H-NAMe. We believe that the results in this paper will be quite useful in efficiently enabling IEEE 802.15.4/ZigBee as a WSN protoco