Performance Studies on Campus-Wide Focus on FTP, Video and VoIP Ethernet Network

The Advanced Network Technologies is research that investigates technology(s) behind today’s modern networks and network infrastructures. One part of this technology being Asynchronous Transfer Mode (ATM). A technology commonly in place in networks all around the world today. This paper focuses on ATM. Dubbed “Modelling and Performance Studies of ATM Networks”; this research seeks to look at and into the “impact of application segment length on the performance of an ATM network” and the “impact of traffic type data on the performance of an ATM network”. To be able to examine an ATM network, the authors need to be able to simulate a network. Thus, for this research, they have used the OPNET Modeler 14.0 Simulation software to create a network model that represents a ATM network. By actually simulating an ATM network at AUT University New Zealand, the authors can therefore change certain variables, and observe the effects the changes have on performance. As stated, one of the impacts that will be explored is the effect that application segment length has on an ATM network. Thus, one variable that will be changed in the authors’ simulation is the segment length. This is the length of each packet segment that is sent through the network for a particular traffic type. The second impact to be inspected is the impact of different traffic types on an ATM network. This network model is based on a campus network. An Application Configuration is setup with default parameters which specify 8 common applications used. Among them the ones that the authors will focus on are VOIP, Video and FTP. A Profile Configuration is setup that will define the 3 applications stated above. A fixed node model of 100BaseT will specify the profile configuration for each scenario and the number of work stations of each scenario. DOI: 10.4018/japuc.2012010106 50 International Journal of Advanced Pervasive and Ubiquitous Computing, 4(1), 49-59, January-March 2012 Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. application and transmits the voice on a RealTime Transport Protocol (RTP), User Datagram Protocol (UDP) and Internet Protocol (IP) over networks (Cai, Ling, Shen, Mark, & Cai, 2009). Each voice packet is small in size and the voice packet has the headers: RTP (12 bytes), UDP (8 bytes), and IP (20 bytes) headers. The data-link layer Medium Access Control (MAC) has a (34 bytes) header. All these headers sum up to 74 bytes of overhead in the VoIP application. The Session Initiation Protocol (SIP) was considered to handle a multimedia call setup and H.323 is considered by ITU to allocate IP-based phones on the public telephone network to talk to a PCbased phone over IP-based networks (Ehlert, Zhang, & Magedanz, 2008). It is a standard that specifies the components, protocols and procedures for multimedia communication services such as real-time audio, video and data communications over IP-based packet networks (Hasbullah, Nisar & Said, 2009; Nisar, Said, & Hasbullah, 2010). A Profile Configuration is setup that will define the 3 applications stated. A fixed node model of 100BaseT will specify the profile configuration for each scenario and the number of work stations of each scenario. Ethernet Servers and Ethernet switches have been used linked with 100BaseT Duplex links. The following scenarios have been implemented: • FTP Traffic on a network with 2 workstations • FTP Traffic on a network with 10 workstations • FTP Traffic on a network with 50 workstations • FTP Traffic on a network with 100 workstations • VOIP Traffic on a network with 2 workstations • VOIP Traffic on a network with 10 workstations • VOIP Traffic on a network with 50 workstations • VOIP Traffic on a network with 100 workstations • Video Traffic on a network with 2 workstations • Video Traffic on a network with 10 workstations • Video Traffic on a network with 50 workstations • Video Traffic on a network with 100 workstations 2. DATA TRAFFIC (FTP) 2.1. FTP Download Response Time FTP download response time is the average delay between the time a user places a request and the time when a response is received. Ethernet uses CSMA/CD (Carrier Sense Multiple Access) as means of accessing shared media. As the number of workstations in the network increase (1, 10, 50, 100) the media needs to be shared between all the workstations and thus the bandwidth of the media is also shared between the different number of workstations. As the number of workstations increase the individually allocated amount of bandwidth to each workstation is thus reduced and so the FTP download response time of each workstation is increased. As the number of workstations in a network increase the number of collisions in that network also increases. FTP Traffic also uses TCP (Transmission Control Protocol) as its underlying Transport Layer Protocol because with FTP Traffic reliability of the data is much more important than the speed of data transmission. TCP also has a congestion control mechanism in which when the network is congested each device controls its data flow and decrease the amount of data that each of them transmit in order to prevent loss and not overwhelm the receiver. This is also another factor that adds to latency as the amount of congestions increase the data will be transmitted in a controlled fashion and thus the download response time for individual workstations would increase. In the following pages I have attached graphs that will compare & display the download response time statistic with regard to a typical Ethernet LAN each with a different number of workstations. Figure 1 compares the average FTP download 9 more pages are available in the full version of this document, which may be purchased using the "Add to Cart" button on the product's webpage: www.igi-global.com/article/performance-studies-campuswide-focus/68806?camid=4v1 This title is available in InfoSci-Journals, InfoSci-Journal Disciplines Communications and Social Science. Recommend this product to your librarian: www.igi-global.com/e-resources/libraryrecommendation/?id=2