OPNET IT Research Articles

QoS Enhancement of Wireless Campus Network Using Throughput Parameter

In recent years, broadband wireless systems developed themselves as one of the fastest growing and emerging sector in the field of telecommunications. It is a network of multiple interconnected local area networks in a limited geographical area. Quality of Service (QoS) is considered as one of the key issue in Wireless Campus Network due to the bottleneck and the competition among different kinds of traffic flow on the network. In this paper a Short-Term and Long-Term models are developed to enhancements QoS performance for Wireless Campus Network using throughput parameter. The models were designed and simulated using Optimized Network Engineering Tool, OPNET IT GURU Academic Edition with linkages between wireless workstations suitable for implementation to determine the performance of the network throughput. The two versions contain the same number of wireless workstations, but with some additional access points and multiple processors in the long-term model, a point-to - point protocol (PPP) was used to link the access points to the routers and the cloud while using 100BaseT cable to connect. In each case, the wireless network throughput was obtained. The findings obtained from these models showed that, relative to the short-term model, the Long-Term model achieves higher wireless network performance. That may be due to the fact that while in both models the total number of wireless workstations is the same, the long-term model topology includes additional access points and double processors resulting in the observed minimum throughput.

The Effect of Decreased Voice Quality in a VoIP Network

Voice over Internet Protocol (VOIP) is a telephone system telecommunication technology that uses an IP (Internet Protocol) network. VoIP offers numerous advantages for customers and communication, including cost savings, phone and service portability, mobility, and integration with other applications. Because voice is sensitive to delay and jitter, bandwidth must be guaranteed while it is being transported. There are some issues with Quality of Service (QoS), the most significant of which is latency in VOIP. The purpose of this paper is to investigate the effect of delay on speech quality in Voice Over Internet Protocol (VOIP). One source of delay is the buffer that already exists in the original multiplexing'-multicast node. There will be no buffering to store packets in the proposed multiplexing'-multicast algorithm, so any packet received will be sent immediately unless the packet arrives after a specific time or in a different order, where OPNET IT Guru Academic Edition simulation was used to analyze network performance.

Fragmentation Analysis For Scalable Wireless Local Area Networks

Wireless networks are being deployed widely to provide network connectivity without requiring the web of physical wires. A collection of a small number of workstations connected using a wireless network forms a wireless local area network (WLAN) that follows the IEEE 802.11 standard. In a WLAN, the communication takes place using packets whose sizes may vary and have a significant impact on the delay incurred during transmission. In this regard, fragmentation may play a vital role in reducing the delay for efficient transmission across the network. This paper analyzes the performance of WLANs with respect to the packet fragmentation. We simulate three network scenarios having 4, 8 and 12 wireless workstations respectively. The scenarios are simulated using OPNET IT Guru Academic Edition v 9.1 while incorporating a peer-to-peer (P2P) based communication model for each scenario. We compare the performance of non-fragmented and fragmented communication in terms of network delay and throughput. Our results show that the fragmentation minimizes the delay and increases the throughput, however its impact is highly dependent on the size of the underlying network.

An Effective Aggregate Signature Scheme Suitable for VANETs and Its Implementation Using OPNET IT Guru

An Effective Aggregate Signature Scheme Suitable for VANETs and Its Implementation Using OPNET IT Guru

Performane Analysis of IEEE 802.11 WLAN by Varying PCF, DCF and EDCF to Enhance Quality of Service

With the improvement of wireless network, quality of service has become a major research area. Researchers have proposed many co-ordination functions for improvement of service quality. In our study, we have compared the different characteristics and properties of PCF, DCF and Enhanced DCF to evaluate the performance of wireless network .We used OPNET IT GURU Academic Edition simulator for perform simulations. Protocols are tested under the realistic conditions to perform evaluation of the coordination functions. Various parameters such as Delay, Data Dropped, Throughput, Load, Retransmission Attempts Traffic Sent and Traffic Received in wireless network are tested to study the quality in various environments using OPNET network simulator. Different parameters are considered to study the impact of various co-ordination functions for wireless networks. In this paper we have studied the results obtained, and recommend the best possible protocol that can provide high QoS under respective network traffic conditions.

Performance Analysis for Channel Utilization in Wireless LAN

Wireless network plays an important role in field of communication. Now a days people are always eager to access the data at any time of moment. The wireless network allows to access the Internet from anywhere at any time. The connectivity can be easily established via devices such as smartphones, laptops, etc. this paper simulates a campus WLAN using OPNET IT GURU EDUCATIONAL VERSION 14.5. Depending on certain justified scenarios the evaluation has been done onto stations participating in the network. Also, performance of the network is measured on parameters such as congestion, delay, throughput, Traffic, Load in wireless environment. The paper discusses about how to handle the channel performance issues using different access mechanisms.

Comparative Analysis of Packet Loss in Extended Wired LAN Environment

Computer network allows the sharing of data and resources in timely and an efficient manner. The devices used in computer network may be wired or wireless. Although wireless network provide more flexibility than wired network, but still to achieve fast data transfer speed most of the offices and colleges labs are still functioning on fixed infrastructure i.e. wired LANs. Wired LAN provides better results in terms of packet-loss and handover latency than wireless LANs. This paper simulates an office LAN using OPNET IT GURU EDUCATIONAL VERSION 14.5. Evaluation has been done onto different devices in different extended topologies, measuring performance metrics like traffic sent, traffic received, delay, packet loss that has occurred at lower levels of packet loss and collision in the Ethernet environment on different extended topologies. In addition, simulation shows the performance of extended LAN with respect to the utilization of hub and switch on mentioned parameters.

Performance Study of Star Topology in Small Internetworks

This paper studies the performance of star topology in a Small Internetworks. In this network model, general LANs models are used and a simulated environment is formed where many applications are in used at a time and their mutual effects thereof. I was performed simulations using OPNET IT GURU Academic Edition simulator. Several simulation graphs were obtained and used to analyze the network performance. The results being obtained represent the optimum possible improvements in terms of number of node, Ethernet delay (second), load (bits/sec). The result was found that when the number of nods and simulation time were varied the server loads also was changed but the delay was almost same. The only limitation of this program is that we can not save translated text i.e it can only work with predetermined application. It can apply as a University network which covers most of its departments and colleges, many industries and garments, etc. A detailed simulation study helped to find out the best solution of research questions.

Performance Analysis of LAN and VLAN Using Soft Computing Techniques

The aim of this paper is to evaluate the performance of LAN and VLAN networks in different scenarios, measuring performance metrics like traffic sent, traffic received, delay and collision count in the Ethernet environment. The simulation was carried out using OPNET IT GURU ACADEMIC EDITION 9.1. To observe the performance of LAN and VLAN networks three different scenarios were presented. In the first scenario, the network consists of one hub and 16 workstations; the second scenario was connected with two hubs and a switch while the third scenario VLAN is explained and detailed, the simulation results displayed that more traffic exists in the network without VLANs, since any communication between departments is allowed, when using VLANs; it is no more possible to send traffic or access the network resources of other departments, VLANs improve the bandwidth utilization, security and the administration by supporting a virtual organization.

Performance Analysis of Ethernet LAN Network Connection under Different Network Devices

This paper studies the performance of different network devices in an Ethernet based network environment. That is the performance of Hub, Switch and Bridge in local area networks (LANs) in order to know which among these three networks devices mentioned above performs best in terms of packet transfer, collision count and delay. The simulation was carried out using OPNET IT Guru Academic Edition 9.1. To observe the performance of these devices, three scenarios were presented. In the first scenario, the network was connected with one hub and 16 nodes; the second scenario was connected with two hubs and a switch while the third scenario was connected with two hubs and a bridge. These entire scenarios were observed under different Packet sizes 1500 bytes, 1024 bytes and 512 bytes. But it was observed that the higher the packet size the higher the value of some of the performance metrics such as traffic received and delay on the other hand some performance such as collision count was improving as the packet size reduces from 1500 bytes, 1024 bytes e.t.c. but in some situation the packet size has no significant impact on some performance metric such as traffic sent. The simulation results displayed the level of data traffic observed in the three scenarios

Mobility in Ad Hoc-Based Network with Active High Traffic

This paper used OPNET IT Guru academic edition to simulate four scenarios of ad ho based mobile local area networks in the existence of active high traffic applications: FTP and Database. In order to study the effect of hidden node problem due to mobility, the first and the third scenarios did not use the request to send (RTS) / clear to send (CTS) mechanism and the second and the fourth scenarios used the mechanism. The effect of mobility on TCP and applications performance is also shown. The paper showed how mobility affected the congestion window size, WLAN load, Throughput, Media Access Delay, received traffic for FTP and Database, response time for database and the retransmission parameters in case of using and not using RTS/CTS mechanism in the existence of FTP and Database traffic. The results revealed that with respect to the mobile client and the FTP application, when the RTS/CTS mechanism is used, the congestion window size is reduced, and the mobile servers have higher data load than fixed ones although stopped transmission earlier. With respect to the fixed client, however, the mobile servers have lower load and congestion window size. As for the database application and the mobile client, using the RTS/CTS mechanism and having the servers stayed mobile causes the congestion window size be low, with the fixed client, however, there was no difference whether the servers are mobile or fixed. The WLAN and throughput for the fixed servers are lower than the mobile ones and higher with the RTS/CTS scenarios. Also, there was no effect on the status of the server (mobile or fixed) on the media access delay but employing the RTS/CTS mechanism reduced the value. The highest received client traffic with respect to the mobile client is reported in the server is fixed and the RTS/CTS mechanism is employed with database application and in the mobile server with no RTS/CTS for FTP application. The minimum DB Query response time as a global value was reported when the RTS/CTS mechanism was used while the server was fixed and had a highly noticeable value when the server was fixed and no RTS/CTS mechanism was used.

A Quantitative Analysis of Firewall Impact on Critical Data Communication

Multimedia communication is considered to engulf the entire transmission taking place through internet. Most of the applications running on clients communicating through internet incorporate video or audio data transmission. Such transmission may however hinder the performance of other critical applications running on the network. For instance, the clients connecting to a database may suffer large delays if the network bandwidth is being utilized for multimedia communication. In this regards, a firewall may be used to block the non-critical and unnecessary communication.In this paper, we perform a quantitative analysis to record the impact of a firewall deployed in a network. We develop various network scenarios with voice and video data being transmitted in parallel with queries from a database client. As the database application is critical for its clients, the unnecessary communication causing the wastage of bandwidth is blocked through a firewall. We record the improvement in the performance of the database application due to the usage of firewall. We simulate all the scenarios using OPNET IT Guru v 9.1. Our results show that due to the blocking of video transmission, there is a significant improvement in performance of the database application. We also find that the use of a firewall has an overhead that depends mainly on the amount of communication taking place simultaneously and can also impact the performance of the critical application.

Analysis of Link Utilization in MPLS Enabled Network using OPNET IT Guru

This paper presents comparison study based on link utilization in the networks running over RIP (Routing information Protocol), OSPF (Open Shortest Path First) and MultiProtocol Label Switching (MPLS). Poor link utilization in case of RIP and OSPF is identified. A detailed simulation study is performed over MPLS network where we have shown MPLS network has utilized most of links resulting in congestion avoidance, low queuing delays. General Terms Computer Science, Network Technology, Network Simulation

Performance Analysis of Various Codecs using RSVP on VoIP Quality of Service over Variable Bandwidth

With the rapid growth of the Internet, customers are demanding multimedia applications such as telephony and video on demand, to be available on the internet. Voice over Internet Protocol (VoIP) is a rapidly emerging technology for voice communication that uses the ubiquity of IP-based networks. The greatest challenge is the provisioning of Quality of Service (QoS) over limited bandwidth. Multimedia applications need a lot more bandwidth and have different QoS requirements than the applications that were used in early years of the internet. The purpose of this paper is to check the performance of VoIP application under different Codec’s such as G.711, G.729 and G.723.1 over variable bandwidth. This paper proposes RSVP protocol for providing end to end QoS for real time applications over diverse networks. The performance is checked under RSVP and Non RSVP. Packet end to end delay and packet delay variation are evaluated through simulation. The result shows that under any bandwidth G.723.1 gives better result as compared to G.711 and G.729. Simulation is done using OPNET IT Guru Academic edition.

Performance Evaluation of audio codecs using VoIP traffic in Wireless LAN using RSVP

has become an interesting topic of research in both the internet and the telecommunication industry. The tremendous increase in popularity of VoIP services is a result of huge growth in broadband access. In wired as well as in wireless communication, VoIP is expected to completely replace the traditional telephony approaches. To provide a good quality speech through VoIP applications, certain QoS parameters must be analyzed. These QoS parameters help us to evaluate the performance of various networking protocols, voice encoding schemes, etc. Numbers of QoS techniques like IntServ, DiffServ and RSVP are adopted to ensure good quality in IP based networks. In this paper, our main contribution is to analyze and evaluate the performance of various voice encoding schemes using RSVP, in a VoIP based wireless LAN. The network model designed in this paper is based on OPNET IT GURU Academic Edition. Various scenarios for different voice encoding schemes using RSVP are setup in the OPNET simulation environment. Different parameters that indicate the QoS like throughput, end to end delay, delay variations, traffic send, traffic received, etc. are calculated and analyzed in WLAN. KeywordsWLANs, QoS, IntServ, DiffServ, RSVP.

Throughput Analysis of Ieee802.11b Wireless Lan With One Access Point Using Opnet Simulator

This paper analyzes the throughput performance of IEEE 802.11b Wireless Local Area Network (WLAN) with one access point. The IEEE 802.11b is a wireless protocol standard. In this paper, a wireless network was established which has one access point. OPNET IT Guru Simulator (Academic edition) was used to simulate the entire network. Thus the effects of varying some network parameters such as the data-rate, buffer-sizes, and fragmentation threshold were observed on the throughput performance metric. Several simulation graphs were obtained and used to analyze the network performance.

Introduction: Basics of OPNET IT Guru Academic Edition

Introduction: Basics of OPNET IT Guru Academic Edition

Performance Evaluation of Wlan by Varying Pcf, Dcf and Enhanced Dcf Slots To Improve Quality of Service

Researchers have proposed a number of co-ordination functions in literature for improving quality of service. Each one is based on different characteristics and properties. In this paper, we evaluate the performance of wireless network using PCF, DCF & EDCF. We perform simulations using OPNET IT GURU Academic Edition simulator. In the performance evaluation of the co-ordination function, the protocols are tested under the realistic conditions. Tests are performed for various parameters (Delay, Data Dropped, Throughput) in wireless Networks. This OPNET simulation shows the impact of co-ordination function for wireless networks for different parameters.

Review of the OPNET IT GURU Software

Review of the OPNET IT GURU Software