Bandwidth utilization in a campus network if not properly managed,may leads to the congestion of the network bandwidth. This research work presents bandwidth control system implemented at the access layer of a campus network which is aimed at reducing the processing time at the core of the network. Ibrahim BadamasiBabangidaUniversity Lapai (IBBUL) campus network was monitored and data were collected on daily basis between 12am to 11pm over a period of 60 days (from 1st September, 2014 to 30th October, 2014). Analyses of these data were carried out which include: (i) peer-to-peer (p2p) activities, (ii) user traffic analysis and,(iii) web analysis. The analyses revealed the highest and lowest p2p activities of the users across the monitored nodes, as well as the time-of-day they occurred. It also revealed the nodes with the highest traffic and the time-of-day it usually occurred. Based on these results, IBBUL network scenario was modelled and simulated using Graphical Network Simulator 3 (GNS3). A star network topology with a Juniper EX4200 core was modelled. Juniper EX2200 series switches were modelled as the access layers. A number of host computers with various specifications were also attached to these switches and all the devices were configured appropriately. Traffic shaping technique was employed to implement bandwidth regulation on the access layer switches. The results obtained were validated by comparing it with the monitored data collected. From the results it was noticed that the developed model performed better by reducing the average processing time of the core to 6.00ms when bandwidth management was implemented at the access layer as compared to the average processing time of 9.950ms when bandwidth management was implemented at the core. This represents about 40% reduction in processing time. The average rate of download and upload speeds of the network users increased by 203.76Kb/s and 110.07Kb/s respectively. This represents about 95% improvement in the download and upload speeds.
TABLE OF CONTENTS
TITLE PAGE ii
TABLE OF CONTENTS
LIST OF FIGURES xii
LIST OF TABLES xiv
LIST OF ABBREVIATIONS xv
CHAPTER ONE: INTRODUCTION
1.1 Background 1
1.1.1 IBBUL Network Structure 1
1.2 Aim and Objectives 4
1.3 Statement of Problem 5
1.4 Methodology 5
1.5 Significant Contributions 6
1.6 Dissertation Organization 6
CHAPTER TWO: LITERATURE REVIEW
2.1 Introduction 7
2.2 Review of Fundamental Concepts 7
2.2.1 Bandwidth and its Management 7
2.2.2 Bandwidth Management Categorization 8
2.2.3 Types of Bandwidth Management Techniques and Policies 10
2.2.4 Comparative analysis of Network Simulators 12
2.2.5 Hierarchical Network Structure 13
2.3 Review of Similar Works 14
CHAPTER THREE: MATERIALS AND METHODS
3.1 Introduction 21
3.2 Method of Data Collection 22
3.3 Data Monitoring 23
3.4 Installations and Configurations 23
3.5 Simulation 23
3.5.1 Simulation Parameters 24
3.5.2 Traffic Filtering (Web Filtering) 25
3.5.3 Steps for Traffic Filtering 26
3.6 Traffic Shaping Technique 32
3.6.1 Application of Traffic Shaping Technique on Access Layer Switches 32
CHAPTER FOUR: RESULTS AND DISCUSSIONS
4.1 Introduction 36
4.2 Results 36
4.2.1 Peer-to-peer (p2p) Analysis 36
4.2.2 Traffic Analysis 39
4.2.3 User Behavioural Pattern 41
4.2.4 Web Analysis 44
4.2.5 Bandwidth Utilization Rate across Nodes 45
4.2.6 Relationship between Number of User, P2P Intensity and Overall Traffic 48
4.2.7 Bandwidth Management 48
4.3 Evaluation of the Processing Time of the Core 49
4.4 Evaluation of Bandwidth Utilization Rate with Increase in Network Users 52
4.5 Evaluation of Downloading and Uploading Speed among Users 53
4.6 Evaluation of the Network Traffic per Node 54
4.7 Validation 54
4.8 Life Network Scenario of Bandwidth Management Implementation 57
4.9 Network Scenario Setup 57
4.10 Evaluation of the Processing Time of the Life Network Scenario 58
4.11 Proposing an Acceptable Use Policy (AUP) on Bandwidth Utilization for IBBUL Network 59
CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS
5.1 Conclusions 60
5.3 Recommendations for Further Works 60
APPENDIX A: A Snap Shot of the Juniper Junos Pulse Access Control Software 64
APPENDIX B: A Snap Shot of User Session Details 65
APPENDIX C: Domain Hits per Second 66
APPENDIX D: Ping Test I& II 67
This chapter discusses the network structure of IBBUL, the type of devices use in the network, as well as the challenges facing the network with respect to bandwidth management.
1.1.1 IBBUL Network Structure
With the use of wired or wireless connectivity, instant access to email, the Internet and other IT services has dramatically changed the way people live, work and study. To this end, students, staff and visitors always expect easy access to most information and services of an institution.
While academic institutions are characterized by high rate of electronic file sharing and Internet surfing, Ibrahim BadamasiBabangida University, Lapai (IBBUL) as a fast growing institution is not exempted from such demand. These demands can only be met effectively with a robust bandwidth management policy.
The current population of IBBUL comprising both students and staff is about ten thousand, nine hundred and seventy five (12,975) (Ibrahim, 2015). In the year 2006, IBBUL network bandwidth was 1Mbps/1Mbps (1Mbps uplink and 1Mbps downlink) used for its online academic activities. This was gradually increased to its present size of 45Mbps uplink and 45Mbps downlink in order to provide adequate resource sharing among its academia (Ibrahim, 2015)
Figure 1.1 shows the current network structure of IBBUL (Ibrahim, 2014). From Figure 1.1 it can be seen that the Information and Communications Technology (ICT) Center houses the data centre that provides all the Internet connectivity and Intranet services through optic fiber backbone network to other buildings on the campus. This fiber optic backbone is single-mode with 10Gbps capability and covers a distance of 10km. A star topology is used for the network where every network device is connected to a central point. IBBUL network infrastructure comprises of the following devices: Juniper Networks products (45%), Cisco Systems, Inc (35%), Ubiquitous Networks (15%) and D-Link (5%).
Figure 1.1: Network Structure of IBBUL (Topology)(ICT Center, IBBUL)
As shown in Figure 1.1, each Department in a Faculty such as Faculty of Arts, Management and Social Science, as well as other buildings such as: the Central Laboratory, the Security Office, Senate Building, Library, School Clinic and twin theatre have Ethernet Local Area Network (LAN) structure. Multi-Layer switches (Juniper EX 2200 series) are used to connect the LANs in these buildings. Optical fibre cables (i.e B-Z) are used to connect other devices to the Virtual Chassis Switch (Core).
The IBBUL network is interfaced with the Internet through a secure and reliable Juniper SRX 650 Firewall device. This firewall is capable of accommodating up to four (4) different Internet Service Providers (ISPs) into a single network depending on the internal distribution of the service. Also connected to the Virtual Chassis Switch is the Juniper Network System Monitor Express (NSMExpress). This NSMExpress has Orion Network Performance Monitoring software installed on it for network monitoring. The Wireless Local Controller (WLC) which controls all the wireless devices in IBBUL network is directly connected to the Virtual Chassis Switch.
Figure 1.2 (ICT Center, IBBUL) shows the hot spot devices in the IBBUL environment. One hot spot is located between Faculty of Sciences and the Faculty of Management, the hostel
and staff quarters have one hotspot each. Hotspots typically provide Internet access through wireless access points for laptops, smart phone, etc. These hotspots have about 30m coverage range. In addition to the LAN in some of these buildings, hotspots are provided to increase the number of connected users. These buildings include: ICT Centre, Library and Senate building. These hotspots are connected to the Virtual Chassis Switch using an interface called the Media Converter. Figure 1.2: Network Structure of IBBUL (Buildings and Hotspots)(ICT Center, IBBUL)
The VSAT in Figure 1.2 connects IBBUL network to its Internet Service Provider (ISP).
Nevertheless, with the current bandwidth size of 45Mbps as compared to the current staff and student population of about 12,975 in IBBUL and the trend in Bring Your Own Device (BYOD) technology (such as smart phones, notepads, etc.) among students as well as University staff, the institution network is being congested. Thus, the need for effective bandwidth management policy. This policy is intended to facilitate effective and enhanced learning within and outside the classroom(s); and support a broad range of multidisciplinary
research activities that would deliver innovative academic and business solutions and serve as a source of revenue for the IBBUL University.
The major challenges experienced by IBBUL are: (i) students’ overuse of undesired applications; (ii) lack of prioritization of traffic or applications; (iii) use of multiple devices to access the network by students` and staff; (iv) long connectivity durations by users; (v) automation of connectivity by users` devices such as laptops, smart phones, tablets, etc; (vi) poor application performance such as Windows updater, etc;
Apart from the limited bandwidth, the improper use of existing connectivity is a major challenge. Inappropriate use of existing bandwidth, due to absence of bandwidth management strategies promotes bandwidth wastage on unwanted traffic such as viruses; music and movie download by some users. The largely unrestricted access exposes the University Internet connectivity to bandwidth-hogging applications such as media streaming. No matter how much more bandwidth is bought, it will quickly get exhausted if no bandwidth management policy is in place.Hence, the need for an effective and efficientbandwidth management policy.
1.2 Aim And Objectives
The aim of this dissertation is thedevelopment of decentralized bandwidth utilization management model for access layer in order to improve the performance of IBBUL campus network that will meet the demands of IBBUL community as a multidisciplinary institution.
This will be achieved through the following objectives:
(i) To reduce the work load and processing time at the core of the network in order to achieve improvement in the network performance.
(ii) Development of a traffic classification based bandwidth management system which will aid in effective utilization of the bandwidth.
(iii) To improve the network performance of IBBUL in order to have reliable access by all users.
1.3 Problem Statement
Regardless of the type of network (wired or wireless) being accessed by users, bandwidth is a scarce resource that needs to be controlled among its users. In IBBUL, the use of multiple devices by users to access the network, their long connectivity durations and the current lack of bandwidth management policy have led to the congestion of the University network especially at peak hours. It is therefore important that the University network has an accountable bandwidth management policy. This research is therefore aimed at developing an acceptable use bandwidth management policy for IBBUL network.
The following methodology was adopted in carrying out this research work:
I. Monitoring and collection of data traffic flowing through the network. The data traffic was collected from the monitoring server between 12am to 11pm daily for a period of 60 days (from 1st September, 2014 to 30th October, 2014). A packet capturing software (Juniper Network Monitor) was used for the collection of the data;
II. Analysis of the collected traffic for traffic classifications; using PRTG software;
III. Bandwidth regulations (or resizing), traffic filtering and traffic priority setting usingtraffic shaping as a bandwidth management technique was used;
IV. Implementation of step III at Access Layer levels;
V. Modelling and simulation of network scenario;
VI. Validation of results by comparing the simulation results and that of the data collected before simulation;
VII. Proposing an acceptable bandwidth utilization policy based on results obtained for optimization of IBBUL network.
1.5 Significant Contributions
Quite a number of research work have been carried out in the direction of bandwidth management, however, to the best of my knowledge, these works have focused on managing bandwidth at the core layer of the networks. While this approach is common, this research has chosen to implement bandwidth management on the access layer of the network. This is aimed at reducing the data processing time of the core. The significant contributions of this work include: (i) reduction of the processing time at the core of the network, (ii) improvement of the browsing experience by users of the network, and (iii) development of an acceptable use policy.
1.6 Dissertation Organization
Chapter one of this dissertation presents the general introduction. The review of similar works as well as relevant fundamental concepts about bandwidth and its management, bandwidth categorization, types of bandwidth management techniques and hierarchical network structure are presented in chapter two. Chapter three presents the materials and methods used in carrying out the research such as network monitoring and data collection, modelling and simulation. The results obtained from the monitored network areanalysed, simulated and discussedin chapter four. Chapter five presents the conclusions and recommendations of the dissertation. References lists and appendices are also presented at the end of this dissertation.
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