Opnet

The rapidly growing Internet is driving the demand for higher transmission capacity and high-speed networks. Designing an efficient network to achieve desirable performance is a challenging task, requiring designers to balance user performance expectations with costs and capacities. The study is based on the OPNET simulation tool focusing on the question of whether faster connections are worth higher prices for the Small Office/Home Office network. The paper simulated 3 different scenarios comparing application performance with different connection speeds between a SOHO LAN and the ISP, to evaluate application performance and server capacity planning for web browsing, E-mail, video conferencing, database and FTP. It also examined how response times, throughput, utilization on the WAN link and other network performance measured. Use numbers to justify our recommendation. The investigation results reveal that upgrading a link data rate will not necessarily be economically feasible with the performance improvement that it gives, and solve them cost-effectively by understanding the impact of changes.

A VLAN is a logical connection that allows hosts to be grouped together in the same broadcast domain, so that packets are delivered only to ports that are combined to the same VLAN. We can improve wireless network performance and save bandwidth through the characteristic VLAN network. In addition, the implementation of VLAN greatly improves wireless network security by reducing the number of hosts receiving copies of frames broadcast by switches, thus keeping hosts holding critical data on a separate VLAN. In this paper we compare wireless network with VLAN via wireless network. The proposed network is evaluated within terms of delay and average throughput using web browsing applications and file transfer in heavy traffic. The simulation was carried out using OPNET 14.5 modeler and the results show that the use of VLAN via wireless network improved performance by reducing traffic resulting in a minimized delay time. Furthermore, VLAN implementation reduces network throughput because...

A VLAN is a logical rather than physical connection that allows grouping hosts together in the same broadcast domain, so that packets are only delivered to ports that are combined to the same VLAN. By characteristic VLAN network, we can improve efficiency of wireless network and save bandwidth. Furthermore, implementing VLAN greatly improves wireless network security by decreasing the number of hosts that receive copies of frames broadcasted by switches, so hosts holding critical data are kept on a separate VLAN. This paper compares wireless network with wireless network having VLAN deployment. The proposed Network is evaluated in terms of average throughput and delay using file transfer in heavy traffic and web browsing applications. The simulation was carried out by employing OPNET 14.5 modeler simulation and the results show that the use of VLAN via wireless network had improved the performance by decreasing the traffic resulting in minimizing delay time. In addition, implementing VLAN reduces the network throughput because the traffic that is received and forwarded has a positive relationship with throughput. Furthermore, we investigated to improve the throughput in a wireless VLAN network by using adhoc routing protocols. Evaluation, comparison of broad adhoc routing protocols like AODV, DSR, OLSR, TORA and GPR are conducted in order to show the effect of the proposed VLAN on the performance results, like throughput and delay.

"In recent years, a lot of progress has been made in
the field of networks and communications; and also in design
of simulators. In this paper, we survey and review prominent
fields where OPNET has been applied and compare it
with other existing simulators. Our work helps beginners
and researchers alike in estimating the useful features
and limitations of OPNET and the state-of-art in network
simulations, modeling and curriculum design. We cover a
wide variety of areas of application, to highlight the versatility
of applications of simulation tool. The conclusions from the
study give valuable directions for further employment of
OPNET and also for its extension."

For the past ten years, heterogeneous networks wired and wireless had tended to integrate seamlessly, offering
effective and reliable service for medical operations. One of the problems encountered by network practitioners is the seamless integration of network components into healthcare delivery. As a multiplexing hospital model, the implementation certainly presents some challenges. The major technical and performance issues involve are as following. The operating parameters should keep aligned to the Quality of Service (QoS) requirement throughout simulation. Bandwidth utilisation of wireless networking is a challenging issue for real-time multimedia transmission. IEEE 802.11 provides relatively lower data rate than wired networks, thus the developer tends to adopt a more compromised solution: either reduce the file size or compress the image packets. Communication performance that varies constantly with the impact of signal strength, traffic load and interference. As stated radio signal senses as a curve and attenuates greatly while metallic object and
microwave exist within the active range. To ensure devices do not interfere with other electronic equipments (e.g. heart monitors), assert wireless spectrum has to be managed appropriately. This research paper aims to develop a generic hospital network scenarios using Wireless Local Area Network (WLAN) over OPNET Simulation, to evaluate the performance of the integrated network scenario for Intensive Care Units (ICU).  This research makes use of computer simulation and discusses various aspects of the network design, so as to discover the performance behaviour pertaining to effect of traffic type, traffic load and network size. In the ICU scenario, the performance of video conference degrades with network size, thus, a QoS-enabled device is recommended to reduce the packet delay and data loss. IEEE 802.11a suits in hospital environment because it mitigates interference on the 2.4GHz band where most wireless devices operate. Experiment examines the effect of signal strength in WLAN. It is convinced that -88dBm is the best signal strength threshold. Although 802.11a generates slightly lower throughput than 802.11g, this issues can be addressed by placing more APs in the service area. It is convinced that 802.11a suits the hospital environments, because it mitigates interference on the popular 2.4GHz band where most wireless devices operate. It is important for medical devices which require future upgrade and Bluetooth deployment.

Many corporations are seriously concerned about security of networks and therefore, their network supervisors are still reluctant to install WLANs. In this regards, the IEEE802.11i standard was developed to address the security problems, even though the mistrust of the wireless LAN technology is still existing. The thought was that the best security solutions could be found in open standards based technologies that can be delivered by Virtual Private Networking (VPN) being used for long time without addressing any security holes for the past few years. This work, addresses this issue and presents a simulated wireless LAN of IEEE802.11g protocol, and analyzes impact of integrating Virtual Private Network technology to secure the flow of traffic between the client and the server within the LAN, using OPNET WLAN utility. Two Wireless LAN scenarios have been introduced and simulated. These are based on normal extension to a wired network and VPN over extension to a wired network. The re...

Wikipedia describes network simulation as " a technique where a program models the behavior of a network by calculating the interaction between the different network entities (hosts/routers, data links, packets, etc.) using mathematical formulas. " But beyond the basic description, how can you use network simulation to predict and check your network systems? Network simulation is designed for characterizing, creating and validating the communication solutions, computer networks and distributed or parallel systems. It enables predicting network behavior and network performance. One can create, run and analyze any desired communication scenario. Generally, a simulation is the only method that allows continuous testing and debugging of network comprised of hundreds and thousands of communication elements (devices, hosts, routers, switches, servers, so on), since a standard lab won't do, and field tests are expensive, difficult to operate and non-deterministic. Simulation Platforms There is a variety of simulation platforms available, some of them open source and some of them commercial: OPNET, QualNet, OMNET++, NS-3 …

In the network area, to establish a network in real time for any experiment is very difficult. To test a simple problem takes a large amount of time and cost. So it is not quite possible to implement the whole network scenario in a real time. There are many tools which helps network developer to test their network scenarios virtually whether the network is able to work in real time environment. The network simulators are used for performance analysis in the field of communication. With the help of these simulation tools both the time and cost of testing the functionality of network have been reduced and implementations are made easy. In this paper, we briefly discuss the main features of different simulators, new developments and also discuss their advantages and disadvantages in the field of network simulation. We hope that the people who face difficulty in selecting a proper suitable network simulation tool in their research this paper is helpful for them.

In Adhoc Network group communication is more important, in which routing protocols play a vital role for data transmission. With/Without using central server or access point, the Wireless network form a temporary network with collection of wireless nodes in which, each node changes randomly at different times. In order to establish data transmission between nodes, multiple hops are needed because of limited range i.e. transmission rate. In this paper, we have analyzed and simulated a proposed Wireless Local Area Network (WLAN) using different routing protocols. The performances of different protocols are compared and analyzed using Optimum Network Performance (OPNET) simulator tool in which metrics like delay, throughput, packet delivery, load, Ethernet delay, are measured.

Network simulation is used to evaluate the performance of different wired and wireless networks and their topologies without real world implementation. Network simulators are widely used by the research community to evaluate new theories and hypotheses. There are a number of network simulators, to name a few, ns-2, ns-3, OMNET++, NetSim, QualNet, OPNET, SSFNET, J-Sim, and GloMoSiM etc. Therefore, the selection of a network simulator for evaluating research work is a crucial task for researchers. According to the previous researches on the performance of OPNET, it has been proved that OPNET is comparatively more reliable, easy to understand and implement network simulation tool than its other counterparts. The main focus of this paper is to study the Wimax performance when implemented with OPNET.

Distributed Denial of service (DDoS) attacks affect millions of users and businesses across the globe every year. With the ever-increasing sophistication and complexity of these attacks services and resources are at the mercy of the attacker, with very little in the way of prevention against these kinds of attacks. Voice over internet protocol (VoIP) and Video Conferencing are most affected by these attacks because they rely on real-time packet delivery whereas applications such as Web browsing can be resent. For the client to be satisfied by application performance, Quality of Service (QoS) needs to be measured. This is usually defined in a service level agreement and is the overall quality of an application. For instance, if the QoS of VoIP is not maintained, then the call quality is severely degraded, and thus the call session is lost.

In this project study of the LTE and its architecture is considered and understand the mechanism of QoS deployment in LTE which introduce the main concept of traffic classification.
A simulation based study is performed in OPNET by deploying a WiMAX network model that performs the same mechanism of QoS in LTE. The simulation considers a simple network topology with three traffic source and destination each of them uses different application the QoS configuration is applied by defining three different classes that are Gold, Silver, Bronze. And the applications used is the HTTP, VoIP, and Video conference. And then the evaluation is performed by comparing the result with QoS and without. And from the simulation result it's obvious that QoS mechanism represent the solution of future needs of networking and communication.

L’informatisation de la profession de traducteur a entraîné la mise en ligne gratuite de nombreuses ressources professionnelles de qualité, comme des articles sur les principes et les règles de traduction, générale ou spécialisée, des répertoires lexicographiques et terminologiques et des outils pédagogiques sur la langue, qui constituent un imposant référentiel de connaissances. Toute formation à la traduction, qu’elle soit en ligne ou traditionnelle, ne peut plus aujourd’hui faire l’économie de ces ressources documentaires. Notre communication vise à montrer comment on peut utiliser ce matériel, accessible à tous, pour concevoir des activités d’apprentissage reposant sur des règles de raisonnement et d’inférence et l’application de celles-ci à des énoncés ou à des extraits choisis que les étudiants doivent analyser ou traduire, en tout ou en partie. Ce type d’activité pédagogique convient à l’acquisition de connaissances et de compétences propres à la formation initiale en traduction générale, et même à l’initiation à la traduction spécialisée. Des exemples d’utilisation du matériel et de questions d’apprentissage formulées à partir de celui-ci seront fournis pour illustrer la démarche.

Deployment Video on Demand (VoD) over the next generation (WiMAX) has become one of the intense interest subjects in the research these days, and is expected to be the main revenue generators in the near future and the efficiency of video streaming over next generation 4G is the key to enabling this. We are considering video streaming for real time video was coded by different H.264.x codes (H.264/AVC, and SVC), and we consider an IP-Unicast to deliver this streaming video over WiMAX. Our approach investigates the performance evaluation of IPTV (VoD) over WiMAX networks. OPNET is used to investigate the performance of VoD over WiMAX. Results obtained from simulation indicate that SVC video codec is an appropriate video codec for video streaming over WiMAX.

Voice over internet protocol (VOIP) was been important technology for service providers because it has real time services. VOIP is a gigantism technology .its facility dispatch of voice data over Internet Protocol .This paper is study the performance of VoIP traffic over WiMAX networks. The vestige of various voice codec and statistical distribution for VoIP over WiMAX has been studied in detail [2] .there is a Parameters that beckon the Quality of Service such as throughput, delay, jitter and loss with obeisance to Silence Detection (SD) or Voice Activity Detection (VAD) in voice codec G.729.[2] The simulation result beckon that the pareto distribution in inter arrival time has a important vestige on the performance of VoIP in WiMAX network.[1]

Network traffics management and congestion control are becoming complex and critical issue due to the emergence of modern multimedia internet applications. Industries and universities are facing critical challenges of providing the required internet services demanded by the users. Global and rapid internet accesses by the users slow down the network performance and lower the quality of service. Efficient scheduling mechanism plays a significant role in the sharing of network resources effectively during the period of congestion.  As part of the resource allocation scheme, each router must implement certain scheduling algorithm that governs the order of packets transmission in a network. In this paper a class-based weighted fair queue (CBWFQ) algorithm is proposed and simulated along side with first-in-first-out (FIFO) and custom queue (CQ) scheduling algorithms on an IP router using OPNET simulation software. The arrivals and service rate of the applications traffics classes considered follows the poisons and exponential distribution based on Markov-Chain queuing model. The HTTP, FTP, video and voice application traffics are configured in the network environment using the applications and profiles configuration objects. Additionally, discrete event simulations statistics are collected and recorded. Simulations graphs of various scenarios are generated and analyzed critically. Results revealed an efficient performance improvement of the class-based weighted fair queue algorithm compared with the custom queue and first-in-first-out queuing scheduling algorithms. In terms of packets loss and queuing delay, CBWFQ algorithm demonstrated an excellent performance with a very low probability of dropping packets and minimal queuing delay. Overall, the study contributed in the use of scheduling algorithm on network routers and switches for proper traffic control and management during congestion.

Mobile Ad-hoc Network (MANET) is a collection of wireless mobile nodes dynamically forming a temporary network without the aid of any established infrastructure or centralized administration. The mobility of nodes in MANETs results in frequent changes of network topology making routing in MANETs a challenging task. Routing protocols in MANET helps node to send and receive packets. Some studies have been
reported in the literature to evaluate the performance of the proposed routing algorithms. This paper evaluates the performance of reactive (DSR) routing protocols in MANETs based on Average end-to-end delay, Throughput using OPNET 14.5. The performance DSR routing protocols is evaluated with respect to throughput and end-to-end delay under different traffic load using OPNET simulator.

The simulation of large-scale networks is a challenging task especially if the network to simulate is the Dynamic Multipoint Virtual Private Network, it requires expert knowledge to properly configure its component technologies. The study of these network architectures in a real environment is almost impossible because it requires a very large number of equipment, however, this task is feasible in a simulation environment like OPNET Modeler, provided to master both the tool and the different architectures of the Dynamic Multipoint Virtual Private Network.
Several research studies have been conducted to automate the generation and simulation of complex networks under various simulators, according to our research no work has dealt with the Dynamic Multipoint Virtual Private Network. In this paper we present a simulation model of the Dynamic and Multipoint Virtual Private network in OPNET Modeler, and a WEB-based tool for project management on the same network.

Forest Fires are one of the most important and prevalent type of disasters and they can create a great deal of Environmental Impacts due to which their early detection is very vital. The main need for choosing this particular application for the detection of forest fires is to overcome the demerits present in the existing technologies of MODIS and Basic Wireless Sensor Network-based Forest Fire Detection Systems and an advanced system is developed for the detection of forest fires. The two main modules present in the project are the Monitoring Area Module and the Forest Area Module. All these together are split into five sub-modules for step-by-step development and implementation. Those include Sensors' Module, Serial Communication Module using Zigbee, Optimized Solar Energy Harvester using Maximum Power Point Tracking (MPPT), PC-based Web Server and Mechanical Modeling. The first three sub-modules belong to the Forest Area Module. They are integrated together and mechanical modeling is done to place it in the forest, whereas, the PC-based Web Server is developed for the Monitoring Area. The outcome of the above implementations reveal that various sensors used in addition to the temperature sensor improves security level for areas located near the forests. It also shows that the Optimized Solar Energy Harvester increases the efficiency to about 85 % and the use of PC-based Web Server reduces the bulkiness and cost of the entire system.

This paper presents a performance evaluation study of dual stack, 6to4 tunnelling, and Network Address Translation transition schemes on simulative method in IPv4/IPv6 networks. This research aims to find out what IPv4/IPv6 transition scheme performs better in terms of performance parameters packet losses, delays, segment delays, query response times, packet delay variations, packet end-to-end delays, jitters, mean opinion score value, and traffic sent and received for data, voice and video traffic. An equal capacity of network load in terms of probes for the three scenarios is considered and benchmarked to ascertain the impact on the performance parameters on IPv4/IPv6 networks. The scenarios are basically network models configured and simulated using Optimized Network Engineering Tool modeler. The core model designed represents an Internet Service Provider network deployed to form an ideal choice of IP domain corresponded to a realistic network topology running both IPv4 and IPv6 ...

Black hole and Grey hole attack is most happening attacks in Mesh networks. Mesh networks means nonstatic networks with making loops of networks with the help of active hotspots. In Wireless networks all the communication between the nodes is happening wirelessly and the nodes are so much resource constraint that it is difficult to employ any security solutions of other ad hoc networks. So they are attacked by malicious nodes. In black hole attack the attacker windup all the information and dropped it. In black hole attack, the series of RREQ (route request) and RREP (route reply) follows the smallest way of networking communication. The fault node always transmit RREP message as it receives RREQ, while managing the receivers sequence number. By the help of fault node packets are dropped. Sometimes fault node is authorised and otherwise it is unauthorised. Black hole attack is type of routing attack and can bring harm to whole network. Grey hole attack is the kind of denial of service attack. In this attack, the router which is mesh behave just not well and a subset of packets are forward and handle by receiver but leave by others. The presences of these attackers are hard to detect in wireless networks because over the wireless link the packets are lost due to bad channel quality. This paper deals with the study of analysis of delay occurs by these attack in Wireless Mesh networks and its types and also discuss about previous study by which we get idea about attack occurs in networks and also study various techniques to detect and prevent network from black hole and grey hole attack. Then we discuss about their result by using simulator OPNET.

Voice over Internet Protocol (VoIP) service is growing very fast and supported by many applications. Its interactive nature makes it very attractive service. VoIP requires a precise level of quality to be utilized. Quality of Service (QoS) is determined by factors like jitter, traffic sent, traffic received and end-to-end delay. In this paper, we study the performance of different scheduling schemes, like: FIFO, PQ, and WFQ for different codec formats. The implementation of the schemes was carried out using OPNET. VoIP service is deployed using the internet implementing the Resource Reservation Protocol (RSVP). The paper discusses the results through a number of figures for the jitter, end-to-end delay and the traffic sent and received. Figures show the different scheduling schemes PQ, WFQ and FIFO with different codec formats, G.711, G.729A and G.723.15 codec formats. I. INTRODUCTION Nowadays, very huge amounts of voice traffic are transferred between millions of people across the world using different social media applications. Using VoIP over the Internet connection, we should be aware about the quality of the VoIP service. VoIP service requires a precise level of quality to be utilized. The end user perception of the quality is determined by subjective testing as a function of the network impairments such as delay, jitter, packet loss, and blocking probability. The amount of impairment introduced by a packet network depends on the particular QoS mechanism implemented [1] Quality of Service (QoS) is determined by factors like the delay the packet delay variation (jitter), and the data loss rate [2]. The greatest technical problem in supporting multimedia services over IP is that real-time traffic must reach its destination within a preset time interval (delay) and with some tolerance of the delay variation (jitter). This is difficult because the original UDP/IP operates on a best-effort basis and permits dropping of packets on the way to a destination [3]. The simulation model was done using OPNET Modeler [4] [5]. OPNET has gained considerable popularity in academia as it is being offered free of charge to academic institutions. That has given OPNET an edge over DES NS2 in both market place and academia [6]. In this paper, we studied the performance of the most popular scheduling schemes, like: First-In First-Out (FIFO), priority Queuing (PQ), and Weighted Fair Queuing (WFQ). A comparison is carried out between different codecs (G.711, G.729A and G.723.15) which are the most appropriate to improve QoS for VoIP. The rest of the paper is organized as follows. Section II presents a typical WAN network topology that uses RSVP protocol to be used as a case study for deploying VoIP service. Section III describes the VoIP service and its parameters. Section IV presents the OPNET-based simulation approach for deploying VoIP service. Section V describes the results and analysis of the simulation study. Then section VI conclusion.

Voice over Internet Protocol (VoIP) service is growing very fast. Service providers offer VoIP service along with traditional data services using the same IP infrastructure. That is why today it is one of the most dominant technologies for communication. In this paper, simulative investigations have been done for VoIP service in WiFi campus network. Step by step, increasing the number of calls, investigations have been done in terms of important Quality of Service parameters like jitter, packet end-to-end delay, wireless LAN load and wireless LAN throughput.

Moving services to the Cloud is a trend that has steadily gained popularity over recent years, with a constant increase in sophistication and complexity of such services. Today, critical infrastructure operators are considering moving their services and data to the Cloud. Infrastructure vendors will inevitably take advantage of the benefits Cloud Computing has to offer. As Cloud Computing grows in popularity, new models are deployed to exploit even further its full capacity, one of which is the deployment of Cloud federations. A Cloud federation is an association among different Cloud Service Providers (CSPs) with the goal of sharing resources and data. In providing a larger-scale and higher performance infrastructure, federation enables on-demand provisioning of complex services. In this paper we convey our contribution to this area by outlining our proposed methodology that develops a robust collaborative intrusion detection methodology in a federated Cloud environment. For collaborative intrusion detection we use the Dempster-Shafer theory of evidence to fuse the beliefs provided by the monitoring entities, taking the final decision regarding a possible attack. Protecting the federated Cloud against cyber attacks is a vital concern, due to the potential for significant economic consequences.

The Wireless local area networks WLAN performance is a key factor in spreading and usage of such technologies. The WLAN are more bandwidth limited as compared to the wired networks because they depend on an inexpensive, but prone to errors, physical medium (air).Hence it is important to improve their performance. Fibre-optic media will do better transmitting high frequency radio signals over a longer distance because fibre-optic cables are immune to EMI and noise, provide excessive bandwidth in the region of THz. Application response times are greatly improved irrespective of the nature of the application.

A VLAN is a logical connection that allows hosts to be grouped together in the same broadcast domain, so that packets are delivered only to ports that are combined to the same VLAN. We can improve wireless network performance and save bandwidth through the characteristic VLAN network. In addition, the implementation of VLAN greatly improves wireless network security by reducing the number of hosts receiving copies of frames broadcast by switches, thus keeping hosts holding critical data on a separate VLAN. In this paper we compare wireless network with VLAN via wireless network. The proposed network is evaluated within terms of delay and average throughput using web browsing applications and file transfer in heavy traffic. The simulation was carried out using OPNET 14.5 modeler and the results show that the use of VLAN via wireless network improved performance by reducing traffic resulting in a minimized delay time. Furthermore, VLAN implementation reduces network throughput because the traffic received and transmitted has a positive relationship with throughput. Eventually, we investigated the use of adhoc routing protocols such as AODV, DSR, OLSR, TORA and GPR to improve the performance of wireless VLAN networks.

Mobile Ad-hoc networks are made up of nodes which are mobile in nature, Their network topology is not fixed and change over time, so need to support dynamic routing protocol .The bandwidth is limited in case of Ad-hoc networks. Routing is a prominent operation of MANET because it decides how many nodes will transfer the packets to the intended destination via different nodes. MANET is rapidly deployable self configuring network. It can be standalone network or can be connected to internet also. Routing protocol in MANET classified into three broad categories namely proactive, reactive and hybrid. Proactive routing also termed as table driven protocols, maintains routing table at all the time, Each and every node in a network maintains routing table regarding all nodes under communication. Nodes collects routing information through network updates that can be changed over time .Reactive protocols that consists of nodes that build routing table whenever commutation needed. Hybrid routing protocol combines the features of both Reactive and Proactive routing protocols. The applications of MANET include Military scenarios, Sensor networks, Rescue operations, Students on campus, Free Internet connection sharing, Conferences etc.

New services like Video on demand, Television (IPTV), high speed Internet access and Voice over IP on top the same link are called Triple Play services. These services demand very high bandwidth to customers. ADSL and ADLS2+ aren't enough for supporting the new bandwidth requirement. One suitable solution for high bandwidth demand with a long reach is to use optical cable to customers (FTTX). Nowadays there are two technologies GPON (Gigabit passive optical network) and EP2P (Ethernet point-to-point) fighting for to be implemented in network access. This paper makes an evaluation between both solutions and it tries to answer the next question: What is the best solution for supporting requirement of Triple Play applications?

Wireless networks have become a tremendous network solution for home and enterprise users, without worrying about wire, and mobility.  With IEEE 802.11e Wireless Local Area Networks (WLAN) we have implemented Quality of Service (QoS) to our wireless network that provides significant improvements for high-priority QoS traffic [1]. However, these improvements have a negative performance impact to lower-level traffic, such as HTTP, FTP etc.  In this paper we will examine two of the IEEE 802.11e Quality of Service (QoS)  factors which are Point Coordination Function (PCF), and Hybrid Coordination Function (HCF). We will also examine their negative effects on performance for lower-level traffic on two different Wireless Local Area Network (WLAN) infrastructures which are Basic Service Set (BSS) and Extended Service Set (ESS), using OPNET Modeler software

Simulation has been an important resource for functional and performance analyses of computer networks. Although the number of widely adopted network simulators is small, new ones continue to be created to address gaps in the functionality of existing tools. It can be argued, however, that the greatest need of the scientific community is to raise the credibility of published simulation studies. In this paper, we show that this need can be addressed by enabling network simulators to provide fool-proof automation of the experimental process. Ideally, the simulator's interface would provide users with an environment to minimize set up time for experiments and to guarantee their reproducibility, and to safeguard the statistical rigor of data analysis. We demonstrate that advances toward this goal have been made by three different tools. Our contributions in this paper culminate with the derivation of requirements for automation tools from recent literature and from our own experience in tool construction. Once these requirements are fulfilled, network simulation tools can have a stronger impact in education, in carrying out large simulation studies, and in enhancing the credibility of simulation results.

Wireless Fidelity (Wi-Fi) network is created on the IEEE 802.11 standard. Connections for local devices in homes and business arenas are provided by Wi-Fi units. With the growing demand as well as penetration of wireless services, the wireless networks users now assume Quality of Service (QoS) besides performances comparable to what is accessible from secure networks. In this paper, OPNET Modeler is used as module and for the simulation of a fiber optic-based Wi-Fi network within a fixed local area network. The aim of this paper is to evaluate their Quality of service (QoS) performances in terms of Wi-Fi voice-packet delay and End-to-End for both Wi-Fi base fiber and Wi-Fi base line. Many scenarios, with same Physical and MAC parameters, have many subnet networks are implementing with fiber optics baseline in addition to Wi-Fi baseline, were created in the network OPNET simulation tool for obtaining the results. The results of simulation reveal that base line demonstrated more delay than base fiber.

A VLAN is a logical rather than physical connection that allows grouping hosts together in the same broadcast domain, so that packets are only delivered to ports that are combined to the same VLAN. By characteristic VLAN network, we can improve efficiency of wireless network and save bandwidth. Furthermore, implementing VLAN greatly improves wireless network security by decreasing the number of hosts that receive copies of frames broadcasted by switches, so hosts holding critical data are kept on a separate VLAN. This paper compares wireless network with wireless network having VLAN deployment. The proposed Network is evaluated in terms of average throughput and delay using file transfer in heavy traffic and web browsing applications. The simulation was carried out by employing OPNET 14.5 modeler simulation and the results show that the use of VLAN via wireless network had improved the performance by decreasing the traffic resulting in minimizing delay time. In addition, implementing VLAN reduces the network throughput because the traffic that is received and forwarded has a positive relationship with throughput. Furthermore, we investigated to improve the throughput in a wireless VLAN network by using adhoc routing protocols. Evaluation, comparison of broad adhoc routing protocols like AODV, DSR, OLSR, TORA and GPR are conducted in order to show the effect of the proposed VLAN on the performance results, like throughput and delay.

The objective of this work is to compare with simulating, using OPNET the performance of five Ad hoc routing protocols: DSR, AODV, OLSR ,TORA and GRP , and to examine the impact of mobility and the density of nodes on the behavior of these protocols in a Vehicular Ad hoc NETwork (VANET). The results show that there is not a protocol that is favorite for all evaluation criteria. Indeed, each protocol has different behavior in relation to performance metrics considered, including the rate of routing packets sent, delay, and the debit.

Hospital network is evolving towards a more integrated approach by interconnecting wireless technologies into backbone networks. Although various integrated network scenarios have been published in the networking literature, a generic hospital model has not yet been fully explored and it remains a challenging topic in practice. One of the problems encountered by network practitioners is the seamless integration of network components into healthcare delivery. A good understanding of the performance of integrated networks is required for efficient design and deployment of such technologies in hospital environments. This research paper discuss on the modelling and evaluation of integrated network scenarios in hospital environments. The impact of traffic types (e.g. data, voice and video), traffic load, network size and signal strength on network performance is investigated by simulation. Three piloted case studies look at client performance in radiology Accident and Emergency (A & E and Intensive Care Unit (ICU)) scenarios. Each scenario reflects the need for various traffic types that end up distinct network behaviours. In the radiology scenario, email and File Transfer Protocol (FTP) traffic is found to perform well for medium-to-large networks. In the A & E scenario, Voice over Internet Protocol (VoIP) traffic is shown to generate very limited jitter and data loss. The performance is aligned with the Quality of Service (QoS) requirements. In the ICU scenario, the performance of video conference degrades with network size, thus, a QoS-enabled device is recommended to reduce the packet delay and data loss. IEEE 802.11a suits in hospital environment because it mitigates interference on the 2.4GHz band where most wireless devices operate.

—Wireless sensor network are nowadays considered as a viable solution for medical application. A zigbee network model is more suitable for battery capacity, bandwidth, and computing limitation for WSN. This paper will present an Opnet simulation of a zigbee network performance in order to compare routing results in 3 different topologies (Star , Mesh and Tree).

Modern technology is essential for all healthy, economic, and educational sectors. Using modern technology involves high-performance networks in terms of quality of service (QoS) parameters such as delay, throughput, bandwidth, and security. A campus network involves wire and the wireless environment with and without virtual local area network (VLAN) technology has been simulated using optimized network engineering tools (OPNET). The simulation model includes four scenarios that involve heavy-loaded File transfer protocol (FTP) and web browsing applications with two logical groups of users. The simulation results show that the VLAN overcome LAN networks in terms of bandwidth and security. This has been done by reducing the throughput in both sending and receiving levels to the confidential servers. The VLAN has also reduced the broadcast domain which results in a high-power efficiency. Moreover, the VLAN network technology has been proved to have lower values of delay in transferring files and packets than LAN network technology. In addition, VLAN technology generally has been decreased values of throughput regardless of the way of connection between servers and workstations. This, in turn, allows taking advantage of wireless connection features in terms of flexibility of installation and speed of configuration.

The major purpose of this paper is to compare two important parameters of QoS between two communication technologies which are UMTS and WiMAX, the comparison based on the VoIP application as the main traffic flow of the two networks. The voice applications over IP networks are growing rapidly due to their increasing popularity. To meet the demand of providing high-quality of VoIP at anytime and from anywhere, it is imperative to design suitable QoS model. In this paper we conduct simulation study to evaluate the QoS performance of WiMAX and UMTS with support of VoIP traffic. We designed simulation  modules in OPNET  for WiMAX and UMTS each one in a separated scenario, and carried out extensive results to evaluate and analyze  several  important and common  performance metrics  such  as  end-to-end  delay and  packet  delay  variation.  Simulation results show that WiMAX outscores the UMTS with a sufficient margin, and is the better technology to support VoIP applications compared with UMTS.

IEEE802.11 have been fully understood in the networking era. Opnet with IEEE802.11 give assistance is an easily understood able simulation tool for communication researchers. However it's academic Edition have limited abilities. In this paper author have studied performance of IEEE802.11b (WLAN) using various security parameters. Author found that the throughput was decreases with respect increase in number of nodes and packet drop also increases with increase in number of nodes.

Intisari— Pada penelitian ini, dilakukan pengujian terhadap kinerja protokol RSVP pada aplikasi VoIP berbasis SIP. Keberadaan protokol RSVP ini bertujuan untuk menentukan kualitas dari sebuah layanan dengan menggunakan variasi codec. Metode yang digunakan adalah metode eksperimen, yang mana melakukan sebuah percobaan dengan melakukan simulasi jaringan menggunakan OPNET Modeler 14.5. Parameter yang diamati adalah end to end delay, jitter, packet loss dan throughput. Skenario yang digunakan sebanyak enam skenario dengan variasi penggunaan RSVP dan variasi codec G.729A dan G.723.1. Berdasarkan hasil yang telah diperoleh dapat diambil sebuah kesimpulan bahwasanya penggunaan protokol RSVP berperan dalam menurunkan delay dan jitter, karena setiap node melakukan reservasi sumber daya berupa bandwidth terlebih dahulu. Hal ini dilihat dari variasi penggunaan RSVP dengan menggunakan codec yang sama, bahwa untuk parameter delay tanpa RSVP, delay yang dihasilkan sebesar 300 ms dengan jitter sebesar 0,018 ms dan dengan penggunaan RSVP, delay yang dihasilkan sebesar 62 ms yang mana nilai jitter sebesar 0,00089 ms. Pada perbandingan pengunaan RSVP dengan menggunakan berbagai codec, dapat diambil sebuah kesimpulan bahwa codec juga turut berperan dalam menghemat penggunaan bandwidth pada sebuah jaringan. Pada parameter delay, dengan adanya RSVP dan dengan variasi codec, bahwa codec G.723.1 memperoleh nilai sebesar 245 ms dan pada codec G.729A, delay yang diperoleh sebesar 300 ms. Hal ini didasari pada bit rate yang dimiliki oleh masing-masing codec sehingga penggunaan codec juga turut berperan dalam sebuah jaringan. Sehingga, kesimpulan secara keseluruhan bahwasanya penggunaan protokol RSVP dengan penggunaan variasi codec membantu dalam menjaga kualitas dari sebuah layanan.