A Mobile Ad Hoc Network Manet

Chapter 1

Introduction and Statement of Problem

1.1 Introduction

A mobile ad-hoc network (MANET) is a set of mobile strategies that used wireless communications ability without any central network power. The mobile devices can effortlessly communicate with another device by forwarding packets over themselves. The network nodes in a MANET not only pretend as the normal network nodes but also as the routers for other stared devices.

The various security threats are rising in the meadow of MANET. One of these security threats is black hole attack which drops all customary data packets proposed for forwarding. A mobile ad-hoc network (MANET) is a set of mobile strategies that used wireless communications ability without any central network power. The mobile devices can effortlessly communicate with another device by forwarding packets over themselves. The network nodes in a MANET not only pretend as the normal network nodes but also as the routers for other stared devices. Lack of a fixed infrastructure, dynamic topology and the wireless character make MANETs vulnerable to the security attacks. Wireless ad hoc networks are swiftly gaining fame as an approach of communication, particularly among highly mobile sectors of society. Fig 1.1 shows an overview of Mobile Ad hoc Network. A Mobile Ad hoc Network (MANET) is shaped with wireless mobile devices without the necessity for existing network infrastructure. As a outcome, such networks are comparatively simple to deploy and use for a very small time. In addition to providing a suitable mode of communication for business purposes, wireless ad hoc networks are very pleasing for use in emergency situations in disaster-stricken areas. In such cases, where no network infrastructure exists, it provides a decisive mode of communication. A high level of cooperation is necessary for applications that need real-time data transmission. Though, the partial energy supply of mobile devices raises queries about the skill of every node to be entirely cooperative. As an outcome, packet delivery cannot be assured even when malicious nodes are not present, and redirecting data packets does not provide a superior solution.

If malicious nodes are present in a mobile ad-hoc network, they may try to reduce the network connectivity by pretending to be cooperative but as a conclusion dropping any data they are meant to pass on. These actions may result in defragmented networks, inaccessible nodes, and radically reduced network performance. MANET protocols are usually evaluated by means of simulation: a network of nodes is made and then run for a set of scenarios in a précised simulation background. MANET having discrete types of routing protocol which working process of different protocols may gives different result on the different types of circumstances. AODV is perhaps the most renowned routing protocol for MANET, which is a hop-by-hop reactive (On demand) source routing protocol [16], AODV only wishes to maintain the routing information about the active paths of the different nodes. Dynamic Source Routing (DSR) is a routing protocol for wireless mesh networks [7].

Figure 1.1: Mobile Ad hoc Network

One of the main objectives of this study is to find out the comparative performance virtues of the existing routing protocols in the different pictures of MANET with different simulation outcomes. The routing protocol used in this research is AODV (Ad Hoc On-Demand Distance Vector).

1.2 Statement of Problem

As we know, protocols are the set of rules. As such, the Routing protocols are mainly used to transport the data cogently and for RD and discover the network topology. The basic job of routing protocols in the ad-hoc network is to give groundwork of optimal paths between source and destination with the least overhead so that packets are delivered in an appropriate succession with the least obstructions. These protocols are vital because of the mobility of the nodes. A MANET protocol should function lucidly over a wide range of networking context from small ad-hoc group to larger mobile Multihop networks.

Routing is also one of the key challenges in designing and operating large scale Mobile Ad hoc Networks’ (MANET). The lack of central point’s makes the detection process of attacks hard as it is harder to monitor the traffic in a dynamic and large scaled network. All these characteristics of MANETs allow the attackers to easily target the network and ruin its resources by troubling and overcrowding the communication between genuine nodes. Malicious nodes can perform unpleasant attacks that can spoil the basic aspects of safety, such as integrity, confidentiality and privacy. In order to guarantee the effective operation as the total number of nodes in the MANET becomes bulky, the overhead of the employed routing algorithms should be small and self-governing of the total number of nodes in MANET. There are copious of and unalike routing protocols in MANET and kinds of investigations have been done in recent decades. In previous research, I have studied the different types of MANET protocol; many variations are shown while analyzing the outcomes but were not focused on other simulation factors. In this paper, I am simulating and analyzing the impact of black hole attack on Ad Hoc On-Demand Distance Vector (AODV) protocol as the outcomes varies. The simulation is carried on NS-3 and the simulation results are analyzed on various network performance metrics such as data rates, different connection like UDP and TCP.

Nodes help each other in fleeting the information about the topology of set of connections and share the obligations of managing the network. The structural design of MANET consists of many layers, they are- Applications & middleware layer, Networking layer, enabling technology layer and consist of cross layer issues. Generally, there are two types of attacks in MANETs, one is Passive attack and other is Active Attack. In the Passive attack, the intruder quietly hears the communication channel without altering or breaking the data packets. On the other hand, In Active attack, intruder can amend or break the real data. Therefore, the active attacks like Black hole attack, Rushing attack, Wormhole attack have great bang on the presentation of the network. The Black hole attack is one of many doable attacks in MANET. This is a special type of attack that usually takes place in the Reactive protocols

MANET has many matchless qualities like movement of host frequently, no cellular infrastructure etc. It is patchily used in disaster area, military purpose, and personal area network and so on. In the following, we first examine the throughout by increasing the nodes on the viewpoint of UDP and TCP Connections. In MANET where the network state varies oftenly, the prestated normal state may not accurately replicate the present network state. Therefore, employing this normal state may reduce the detection truthfulness.

Chapter 2

Mobile Ad hoc Network

2.1 General

Mobile ad hoc network (MANET) is a collection of mobile hosts without the required participation of any accessible infrastructure or federal access point such as a base station. A mobile ad-hoc network (MANET) is a self-configuring infrastructure less [5] [14] network of mobile devices such as PDA, laptop connected by wireless links. Nodes in the network should be able to intellectual and come across with the nearby nodes .Due to the limited broadcasting range of wireless network interfaces, multiple network “hops” may be required for one node to swap over the data with another across the network.

An even more tremendous case is one in which the routers with their own are movable. in the midst of such, some possibilities are:

1. Military vehicles on a combat zone with no obtainable infrastructure.

2. Emergency employees at an earthquake that shattered the infrastructure. Etc.

In all these cases, and others, each and every node consists of a router and a host, more oftenly on the same computer. Networks of nodes that just occur to be near each other are thus referred as ad hoc networks or MANET (Mobile Ad hoc Networks).

Each device in a MANET is free to shift by own in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unconnected to its own use, and thus be a router. The primary task in building a MANET is quipping each device to endlessly maintain the information required to properly route traffic. Such networks may operate by themselves or may be linked to the bigger internet. They may contain one or multiple and different transceivers among the nodes. This results in an extremely dynamic, autonomous topology.

The set-up of MANET is shown in figure 2.1. In each situation, the set of events generated by the nodes are précised. The simulation atmosphere may take into account the physical area in which nodes are positioned, the time period of simulation, the physical uniqueness of nodes, and a node mobility model [18], which defines the speed and direction of a node’s movement over time and also simulation outcome the vigorness of protocol.

These protocols can be classified according to the “routing strategy” that they go after to get a path “route” to the destination.

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Figure 2.1 Mobile Ad hoc Network

MANETs are a sort of wireless ad hoc network that generally has a routable networking surroundings on top of a Link Layer ad hoc network. MANET consists of a peer-to-peer, self-forming, self-curative network. MANET circa 2000-2015 in general communicates at radio frequencies 930 MHz-5 GHz). Different protocols are evaluated based on actions such as the packet drop rate, the overhead introduced by the routing protocol, network throughput, end-to-end packet delays, ability to scale etc. There are different types of Ad hoc Networks, they are:

1. Vehicular Ad hoc Networks.

2. Smart Phone Ad hoc Networks

3. Internet based Mobile Ad hoc Network

There are several ways to study MANETs. One solution is the use of simulation tools like OPNET, NetSim and NS-3.

2.2 Infrastructure Base Model

A Mobile Ad Hoc Network is a type of ad hoc network that can amend locations and arrange itself on the fly. Because MANETs are portable, they use wireless connections to connect to a variety of networks. This can be a usual Wi-Fi connection, or another medium, such as a cellular or satellite transmission.

Some MANETs are limited to a local area of wireless devices ( such as a group of laptop computers), while others may be linked to the internet. For example VANET (Vehicle Ad Hoc Network), is a type of MANET that allows vehicles to communicate with roadside tools. While the vehicles may not have a direct internet connection, the wireless equipment may be connected to the internet, permitting data from the vehicles to be sent over the internet. The vehicle data may be used to compute the traffic conditions. Because of the active environment of MANETs, they are usually not very secure, so it is significant to be vigilant what data is sent over a MANET.

A MANET have an extraordinary property that is likely to be of bigger size than the radio range of the wireless antennas, since due to this fact it could be essential to route the traffic through a multi-hop path to give two nodes the skill to communicate [1]. In this route neither fixed routers nor fixed locations for the routers as in cellular networks. This network is classified as infrastructure networks. Infrastructure mode act as a wireless networking bridges to connect a wireless network to a wired Ethernet network. Infrastructure mode wireless also helps in central connection points for WLAN clients.An Infrastructure mode network needs the use of an Access Point. The Access Point (AP) controls wireless communication and suggests numerous important advantages over an Ad-hoc network shown in figure 2.2. For example, an Infrastructure based network ropes increased levels of security, potentially faster data transmission speeds and integration with a wired network [22].

To connect the WLAN, the AP and all wireless clients must be configured to use the same SSID. The AP is then wired to the wired network to allow wireless clients access to, for example, Internet connections or printers.

Figure 2.2 Infrastructure Base Wireless Model

In any significant scenarios such as natural disasters, military conflicts etc, ad-hoc network provides improved performance due to the lowest configuration and rapid operations [18][24]. The disadvantage of infrastructure wireless networks is the additional cost to purchase AP hardware [21].

2.3 Mobile Ad hoc Network Model

A MANET is an independent collection of mobile users that communicate over comparatively bandwidth constrained wireless links. Since the nodes are mobile, the network topology may change quickly and randomly over time. The network is decentralized, where the entire network’s activity including discovering the topology and delivering messages must be executed by the nodes themselves, i.e., routing functionality will be integrated into mobile nodes.

The design of network protocols for these networks is a difficult matter. In spite of the application, MANETs requires competent distributed algorithms to find out the network organization, link scheduling, and routing. However, shaping feasible routing paths and delivering messages in a decentralized atmosphere where network topology fluctuates is not a well-defined problem. While the shortest path (based on a given cost function) from a source to a destination in a static network is usually the optimal route, this scheme is not easily extended to MANETs.

The distinctive architecture of Mobile Ad hoc Network model is shown in figure 2.2. All the routing services are being facilitated by routing protocol of MANET to nodes. Each mobile node works not merely as a host but furthermore as a router [2]. Since nodes have a restricted range and are capable of sending the message to another host, but if sender’s host exists not in the transmission range, data packets must be forwarded through the network using other hosts which will be operated as routers for delivering the message over the network [6].

Figure 2.3 Mobile Ad hoc Network Model

MANETs have dynamic nature of topology of such network rapidly changed because each network node can freely move anywhere. Due to the limited wireless transmission range of each node, data packets then may be forwarded along hop by hop.

2.3.1 Characteristics of MANET

Factors such as variable wireless link quality propagation path loss, fading, multiuser interference, power expended, and topological changes, become related issues. The network ought to be proficient to adaptively change the routing paths to improve any of these effects. Furthermore, in a military atmosphere, protection of security, latency, dependability, international overcrowding, and healing from malfunction are major concerns. Military network are intended to sustain a little probability of intercept and/or a low probability of recognition. Thus, nodes desire to radiate as slight power as required and broadcast as infrequently as possible, thus decreasing the probability of detection or interception. The set of applications for MANETs is diverse, ranging from small ,static network that are controlled by power source, to large-scale, mobile, highly dynamic network. A fall in any of these requirements may degrade the performance and dependability of the network. Since, Mobile ad-hoc network (MANET) is a collection of wireless devices like laptop and PDA therefore, these devices can simply be connect on a wireless medium and appears as an arbitrary and dynamic network with wireless associations and are capable to relocate and getting the data by help of Mobile Ad hoc Network protocols. Though the ad hoc networks are widely used but still it has some vulnerability in it. Therefore, there is a need of security to defend such problems. An intruder utilizes this vulnerability to know about the network processes and then attack the network. Following are some nearby vulnerability in ad hoc networks.

• Mobility- Each node in ad hoc network is movable. It can link or depart a network at any instant of time without indicating any node.

• Open Wireless Medium- The entire communication between nodes is taking place through the medium of air instead of wires.

• Resource Constraint- All the nodes in mobile ad hoc network has limited resources like battery, computational power, bandwidth etc

• Broadcast Channel- In ad hoc network, the communication among nodes is broadcast in nature than point to point communication. It means whenever a node transmits a request, it broadcast it to every surrounding node.

• Dynamic Network Topology- As the nodes are highly movable in nature, so the topology changes every time the communication takes place. The packets from source to destination may take different path for communication.

• Scalability- Ad hoc network may consist of number of nodes. This number is not fixed.

• Reliability- All the wireless communication is limited to a range of 100 meter which puts a constraint on nodes to be in range for establishing communication. Due to this limited range, some data errors are also generated.

2.3.2 Application Area

MANET’s node carries wireless transmitters and receivers using antennas which are: highly directional, Omni-directional or a combination of both [18]. To facilitate communication within a MANET, a routing protocol is necessary to set up routes among the participating nodes. Since, due to the limited transmission range, multiple network hops may be desired to permit data communication among the two nodes in the network. In MANET, mobile nodes share the similar frequency channel as such restricting the network capacity. Hence one of the vastly pleasing properties of a routing protocol for MANET is that it should be bandwidth proficiently. While MANET is an infrastructure-less network, every mobile node operates not only as a host but also as a router, forwarding packets for additional mobile nodes in the network [14]. Some applications include:

Military battlefield: – The modern digital battlefield demands robust and reliable communication in many forms. Most communication devices are installed in mobile vehicles, tanks, trucks etc. Also soldiers could carry telecomm devices that could talk to a wireless base station or directly to other telecom devices if they are within the radio range. However these forms of communication are considered to be primitive. At times when wireless base station is destroyed by enemy, a soldier will be prohibited from communicating with other soldiers if the called party is not within the radio range. This is the scenario where mobile ad hoc networks come into play. Through multi-hop communication [25], soldiers can communicate to remote soldiers via data hoping and data forwarding from one radio device to another.

Satellite transmission: – MANET combined with satellite-based information delivery, provides an extremely flexible method for establishing communications for fire/safety/rescue operations [24].

Sensor Networks: – Another application of MANET is sensor networks. This technology is a network composed of a very large number of small sensors. These can be used to detect any number of properties of an area. Examples include temperature, pressure, toxins, pollutions, etc. Applications are the measurement of ground humidity for agriculture, forecast of earthquakes. The capabilities of each sensor are very limited, and each must rely on others in order to forward data to a central computer. Individual sensors are limited in their computing capability and are prone to failure and loss. Mobile ad hoc sensor networks [25] could be the key to future homeland security.

Automotive Applications: – Automotive networks are widely discussed currently. Cars should be enabled to talk to the road, to traffic lights, and to each other, forming ad-hoc networks of various sizes. The network will provide the drivers with information about road conditions, congestions, and accident-ahead warnings [25], helping to optimize traffic flow.

Commercial sector: – Cooperative and mobile data exchange in case of industrial and commercial applications. Ad hoc can be used in emergency/rescue operations for disaster relief efforts, e.g. in fire, flood, or earthquake. Emergency rescue operations must take place where none existing or damaged communications infrastructure and rapid deployment of a communication network is needed. Information is relayed from one rescue team member to another over a small handheld [25]. Other commercial scenarios include e.g. ship-to-ship ad hoc mobile communication, law enforcement, etc.

Education: – MANET can also be used by students to participate in an interactive lecture using their laptop computers.

Personal Area Network: – Personal Area Networks (PANs) are formed between various mobile (and immobile) devices mainly in an ad-hoc manner, e.g. for creating a home network. They can remain an autonomous network, interconnecting various devices, at home, for example, but PANs will become more meaningful when connected to a larger network. In this case PANs can be seen as an extension of the telecom network or Internet. Closely related to this is the concept of ubiquitous / pervasive computing [25] where people, noticeable or transparently will be in close and dynamic interaction with devices in their surroundings..

2.3.3 Advantages of MANET

1) They grant access to information and services in spite of geographic position.

2) These networks can be located at any place and time.

3) Setting up a wireless system is simple plus fast and it eliminates the need for pulling out the cables through walls and ceilings.

4) Network can be extended to places which cannot be wired.

5) Wireless networks offer more elasticity and get familiar easily to changes in the configuration of the network.

2.3.4 Disadvantages of MANET

1) Limited resources and physical security.

2) Volatile network topology makes it hard to sense malicious nodes.

3) Interference due to weather, other radio frequency devices, or obstructions like walls.

4) Security protocols for wired networks cannot be occupied for ad hoc networks.

5) The entire Throughput is affected when multiple connections exists.

2.4 Problem in Mobile Ad hoc Network

Asymmetric links: – Most of the wired networks rely on the symmetric links [8] which are always fixed. But this is not a case with ad-hoc networks as the nodes are mobile and constantly changing their position within network.

Routing Overhead: – In mobile ad hoc networks, nodes often change their location within network. So, some stale routes are generated in the routing table which leads to unnecessary routing overhead.

Interference: – This is the major problem with mobile ad-hoc networks as links come and go depending on the transmission characteristics [8], one transmission might and can corrupt the total transmission.

Dynamic Topology: – This is also the major problem with ad-hoc routing since the topology is not constant. The mobile node might move or medium characteristics might change. In ad-hoc networks, routing tables must somehow reflect these changes in topology and routing algorithms have to be adapted. For example in a fixed network routing table updating takes place for every 30sec [8][25]. This updating frequency might be very low for ad-hoc networks.

Chapter 3

Literature Review and Proposed Work

3.1 Literature Review

The process is carried under the Ad hoc On- Demand Distance Vector routing (AODV) and various simulation parameters are evaluated in the presence of UDP and TCP connection with varying the number of nodes in the network. In this scenario, all simulation result has done with 4, 6 and 16 source of nodes. All simulation has done in Network Simulator 3.23.

After simulation it analyze that the throughputs are increased while increasing the nodes with the different date rates and on the other hand the throughput is decreased while increasing the nodes on different connections like UDP and TCP. The packet delivery of AODV is almost independent of the number of sources. AODV suffers from end to end delays. The AODV protocol is the ideal choice for communication when the communication has to happen under the UDP protocol as the base. Ad hoc networking can be applied somewhere where there is little or no communication infrastructure or the present infrastructure is expensive or inconvenient to employ. Ad hoc networking facilitates the devices to maintain connections to the network as well as easily accumulating and removing devices to and from the network. With the increase of portable devices as well as evolution in wireless communication, ad hoc networking is gaining importance with the increasing number of widespread applications.

3.1.1 Existing System

In the existing system the work was carried under NS-2 which was totally based on C++, but in our work we had used the NS-3 simulator. And had analyzed the various parameters by varying the nodes under different circumstances. In existing system having number of simulator parameters used that is node movement model is Random waypoint, speed of node is 0.25 m/s, bandwidth of the channel is 2Mb/s and transmission range of the network is 250m.

3.2 Proposed Work

The set of applications for MANET is diverse, ranging from large-scale, mobile, highly dynamic networks, to small, static networks that are constrained by power sources. It has a figure of routing protocols having unlike properties which works in different size of the network due to dynamic nature. The objective of our work is to compare the performance and finding simulation result by increasing the nodes in different conditions on AODV Routing Protocol.

For mobile ad hoc networks based on the performance, and comparison has been made on the basis of their property like throughput between two different scenarios i.e – one by varying the number of nodes in TCP and UDP connection, and second by varying the same nodes in different Data Rates.

In proposed work, I have created an analytical scenario that shows an analysis structure of different types of Simulation properties. In this scenario, we first simulate the results by varying the nodes at different instant of time by using ns-3. Second, we evaluate the performance of the protocol which is based on two different connections which are TCP and UDP connections. Finally, we examine the performance of different properties of simulation across their throughputs and discuss the resultant outcome.

The main objective of our study is to analyze the working of AODV in different scenarios. In the study we would perform the following:

Analysis of the protocol which is AODV under different data rates.

Analysis of the traffic pattern: The traffic pattern can be TCP or UDP according to the form of packets transmitted.

Chapter 4

Description of Routing Protocols

4.1 Routing in MANET

An ad hoc routing protocol is a convention, or customary, that controls how nodes choose which way to route packets between computing devices in a mobile ad hoc network. In ad hoc networks, nodes are not recognizable with the topology of their networks. As an alternative, they have to discover it: usually, a new node announces its existence and listens for announcements transmitted by its neighbors. Every node learns about others close by and how to contact them, and may announce that it too can reach them. Some of the challenges for routing protocols are:

No centralized entity.

Host is no longer just an end system.

Acting as an intermediate system.

Changing network topology over time.

Each node can be mobile.

The routing thought mainly involves, two activities: firstly, determining optimal routing paths and secondly, transferring the information groups (called packets) through a network. The later concept is called as packet switching which is straight forward, and the path determination could be very intricate (Cisco, 2002). Routing is the operation of moving information from a source to a destination in a network. During this course, at least one intermediate node within the network is encountered.

In ad hoc networks, nodes do not start out commonly with the topology of their networks: instead, they have to discover it. The routing process generally directs forwarding on the basis of routing tables which maintain a record of the routes to various network destinations. Therefore, constructing routing tables, which are held in the router's memory, is very essential for efficient routing. Nodes in the network oblige in multi-hop [2] forwarding and operate the same random access wireless channel. A node forwards and receives packets to and from other nodes, and thus acts both as client or a server. Since the nodes are movable, a dynamic routing protocol is required.

4.2 Classification of Routing Protocol in MANET

The absence of fixed infrastructure in a MANET poses numerous types of challenges. The major challenge among them is routing. Routing is the process of choosing paths in a network along which to send data packets. An ad hoc routing protocol is a convention, or standard, that controls how nodes decide which way to route packets between computing devices in a mobile ad-hoc network. Routing protocols uses numerous metrics to estimate the finest path for routing the packets to its destination. These metrics are a standard measurement that could be number of hops, which is used by the routing algorithm to decide the optimal path for the packet to its destination. The procedure of path determination is that, routing algorithms initialize and maintain routing tables, which hold the total route information for the packet. An amount of MANET routing protocols were expected in the last decade. The classification of MANET protocols are shown in figure 4.1. These protocols can be distinguished according to their “routing strategy” because they follow to find a path “route” from source to destination and vice versa [10]. The existing routing protocols in MANET can be classified into three types. Proactive routing protocols [11] such as Destination-Sequenced Distance Vector (DSDV) routing maintain routing information all the time in routing table and constantly update the route information by broadcasting update message. Due to the information exchange overhead, especially in volatile environment, proactive routing protocols are not appropriate for Ad hoc network [7].

Fig 4.1 Classifications of MANET Protocols

However, reactive routing [10] [11] is started only if source node needs to deliver the data to destination node such as AODV and DSR. Hybrid Protocols [15] are the combinations of reactive and proactive protocols and takes advantages of these two protocols and as a result, routes are found quickly in the routing zone such as Zone Routing Protocol (ZRP) and Temporally Ordered Routing Algorithm (TORA).

4.2.1 Flat Routing Protocol

In a flat structure, every node in a network are at the similar level and have the same routing functionality. Flat routing is easy and efficient for little network. The problem is that when a network becomes large, the volume of routing information will be large and it will take a long time for routing information to reach at remote node. A lot of proactive routing protocols stem from conventional link state routing. Reactive routing is a more new rising routing philosophy in the ad hoc area than proactive.

Some different types of On Demand driven protocols are:

Ad hoc On Demand Distance Vector (AODV).

Ad hoc On Demand Multipath Distance Vector (AOMDV).

Dynamic Source routing protocol (DSR).

Associatively Based routing (ABR).

Signal Stability-Based Adaptive Routing (SSA).

Location-Aided Routing Protocol (LAR).

Relative Distance Micro-discovery Ad hoc Routing (RDMAR).

Cluster Based Routing Protocol (CBRP).

Caching and Multipath Routing (CHAMP).

Ant-based Routing Algorithm (ARA).

4.2.2 Hybrid Routing Protocol

Hybrid routing protocols [15] is the restrictive the set of forwarding nodes and using the proactive routing algorithm for nearby placed nodes which usually forward data to faraway placed nodes. While route to nearly placed nodes is available instantly, there is no waste of bandwidth due to propagation of the local information to the distant placed nodes. It is used to find stability between both protocols. Also with the flexibility and correctness of the reactive routing, the overhead is greatly decreased caused by restrictions of number of forwarding nodes [11]. Hybrid routing algorithm does not focus on the route maintenance beside mobility. Protocol in this group is:

Zone Resolution Protocol (ZRP)

Temporally Ordered Routing Algorithm (TORA)

The main disadvantages of such algorithms are:

Advantage depends on number of other nodes activated.

Reaction to traffic demand depends on gradient of traffic volume.

Examples are: ZRP (Zone Routing Protocol), ZHLS (Zone based Hierarchical Link State Routing protocol)

4.2.3 Hierarchical Routing Protocol

With this type of protocol the option of proactive and of reactive routing resides on the hierarchic level in which a node depends. Classically, when wireless network size are raised (beyond certain thresholds), current “flat” routing schemes turn into infeasible due to link and processing overhead. One way to resolve this problem and to create scalable and efficient solutions is hierarchical routing [24]. An instance of hierarchical routing is the Internet hierarchy, which has been skillful in wired network for a long time. Both routing table size and update packet size are reduced by including in them only an element of the network (instead of the whole), thus control overhead is reduced.

Each and every cluster has a foremost node (cluster head) to communicate to other nodes on behalf of the cluster. Another way is to have implicit hierarchy. In this way, each node has a local scope. Dissimilar routing strategies are used inside and outside the scope. Communications pass across overlapping scopes. The main disadvantages of such algorithms are:

Advantage depends on depth of nesting and addressing scheme.

Reaction to traffic demand depends on meshing parameters.

Examples are: CBRP (Cluster Based Routing Protocol), FSR (Fisheys State Routing Protocol), and ZHLS (Zone-based Hierarchical Link State Routing Protocol)

4.2.4 Geographical Routing Protocol

The advances in the development of Global Positioning System (GPS) [24] nowadays make it possible to provide location information with a exactness in the order of a few meters. They also provide universal timing. While location information can be used for directional routing in distributed ad hoc systems, the universal clock can provide global synchronizing among GPS equipped nodes. Research has shown that geographical location information can improve routing performance in ad hoc networks. Additional concern must be taken into account in a mobile environment.

4.3 Ad hoc On Demand Distance Vector (AODV)

Ad hoc On-Demand Distance Vector (AODV) Routing is a routing protocol for mobile ad hoc networks (MANETs) and other wireless ad-hoc networks. AODV is capable of both unicast and multicast routing. It is a reactive routing protocol, meaning that it establishes a route to a destination only on demand. As such, the most common routing protocols of the Internet are proactive, meaning they find routing paths independently of the usage of the paths. AODV is, as the name indicates, a distance-vector routing protocol. AODV avoids the counting-to-infinity problem of other distance vector protocols by using sequence numbers on route updates, a technique explored by DSDV.

Much of the complexity of the protocol is to lesser the number of messages to protect the capacity of the network. For example, every request for a route has a sequence number. Nodes use this sequence number so that they do not repeat route requests that they have previously passed on. Another such characteristic is that the route requests have a "time to live" number that limits how many times they can be retransmitted. The third characteristic is that if a route request fails, another route request may not be sent until twice as much time has passed as the timeout of the previous route request.

AODV is a very simple, efficient, and effective routing protocol for Mobile Ad-hoc Networks which do not have any permanent topology. AODV is competent for both unicast and multicast routing [13]. It is an on demand algorithm, which means that it builds routes between nodes only as desired by source nodes. It borrows most of the advantageous concepts from DSR and DSDV algorithms. The on demand RD and route maintenance from DSR and hop-by-hop routing, usage of node sequence numbers from DSDV make the algorithm cope up with topology and routing information.

4.3.1 Introduction

In AODV, the network is noiseless until a connection is needed. At that point the network node that requires a connection broadcasts a request for connection. Other AODV nodes forward this message, and trace the node that they heard it from, creating an explosion of temporary routes back to the needy node. When a node receives such a message and already has a route to the desired node, it sends a message backwards through a temporary route to the requesting node. The needy node then starts using the route that has the least number of hops through other nodes. Unemployed entries in the routing tables are recycled after a time. When a link fails, a routing error is passed back to a transmitting node, and the process repeats.

4.3.2 Technical Description

The AODV Routing protocol uses an on-demand approach for searching routes, that is, a route is established only when it is required by a source node for transmitting data packets. It employs destination sequence numbers to classify the most recent path. The key dissimilarity between AODV and Dynamic Source Routing (DSR) is that DSR uses source routing in which a data packet carries the complete path to be traversed; however, in AODV, the source node and the intermediate nodes preserve the next-hop information corresponding to each flow for data packet transmission. In an on-demand routing protocol, the source node floods the RouteRequest packet in the network when a route is not obtainable for the desired destination. It may obtain numerous routes to different destinations from a single RouteRequest. The major difference between AODV and other on-demand routing protocols is that it uses a destination sequence number (DestSeqNum) to find out an up-to-date path to the destination. A node updates its path information only if the DestSeqNum of the current packet received is greater than the last DestSeqNum stored at the node. A RouteRequest carries the source identifier (SrcID), the Destination Identifier (DestID), the source sequence number (SrcSeqNum), the destination sequence number (DestSeqNum), the broadcast identifier (BcastID), and the time to live (TTL) field. DestSeqNum indicates the newness of the route that is acknowledged by the source. When an intermediate node receives a RouteRequest, it either forwards it or prepares a RouteReply if it has a valid route to the destination. The validity of a route at the intermediate node is determined by comparing the sequence number at the intermediate node with the destination sequence number in the RouteRequest packet. If a RouteRequest is received several times, which is indicated by the BcastID-SrcID pair, the duplicate copies are discarded. All intermediate nodes having valid routes to the destination, or the destination node itself, are permitted to send RouteReply packets to the source. Every intermediate node, while forwarding a RouteRequest, enters the previous node address and it’s BcastID. A timer is used to erase this entry in case a RouteReply is not received before the timer expires. This helps in storing an active path at the intermediate node as AODV does not utilize source routing of data packets. When a node receives a RouteReply packet, information about the previous node from which the packet was received is also stored in order to forward the data packet to this next node as the next hop in the direction of the destination.

4.3.3 Routing in AODV

Prior to transmit the data packet by source node, AODV create a link from source node to destination node by the help of routing table which is maintained by every intermediate node there in the network and its inform dynamically because of broadcasting of the HELLO message [5][13]. Initially, the node broadcast the Route Request message to all nodes into the network. By help of this HELLO message every node update own routing information in the routing table like sequence number, IP address etc. AODV defines three types of control messages for route maintenance (RD), they are:

4.3.3.1 Route Request (RREQ)

In fig: 4.2, source node1 initiates a path-finding procedure by originating a RouteRequest to be flooded in the network for destination node, assuming that the RouteRequest contains the destination sequence number as 3 and the source sequence number as 1. A route request message is transmitted by a node requiring a route to a node. RD begins with broadcasting a route request (RREQ) packet [3] by the source node to its neighbors. RREQ packet contains broadcast ID, two sequence numbers, and Addresses of source and destination and hop count [9].

Figure 4.2 Route Request in AODV

4.3.3.2 Route Reply (RREP)

A route reply message is unicasted back to the inventor of a RREQ if the receiver is either the node using the requested address, or it has an applicable route to the requested address. AODV transmit on routing table entries to propagate an RREP back to the source and, RREP propagates back to the source, nodes set up forward pointers to the destination. Once the source node receives the RREP, it may start to forward data packets to the destination. If the source later receives a RREP containing a bigger sequence number or contains the same sequence number with a lesser hop count, it may update its routing information for that destination and initiate using the better route [7].

Figure 4.3 Route Reply in AODV

4.3.3.3 Route Request & Reply (RERR)

When a bond breakage in an active route is detected, a RERR message [9] is used to notify other nodes of the loss of the link. The node may discover of a lost link from its neighbors through route error control messages “RERR”.

At the time of link breakage the host must invalidate the existing route in the routing table entry. The host must list the affected destinations and determine which neighbors can be affected with this breakage. Lastly the host ought to send the route error (RERR) message to the corresponding neighbors. The RERR message can be broadcasted if there are many neighbors which need that information or unicasted if there is only one neighbor. The hosts can also iteratively unicast the message to needed neighbors if the broadcast is not possible. However, iterative unicasting must be considered as a single broadcast RRER message, so the RERR messages per second limit, is essential.

Figure 4.4 Route Request & Reply in AODV

If the host detects the link breakage of the active route, then the host makes a list of unreachable destinations based on the routing table entries where the unreachable neighbor acts as a next hop address. If host gets RERR messages, then the unreachable destinations is consisted from the routing table which has same addresses as in RERR message and routing table next hop address entries. The destination sequence numbers for the entries in the routing table for the unreachable destinations must be incremented or if the host received RERR message, then simply copied from it. After this the entry for the unreachable hosts must be set to invalid lifetime. Lifetime is set to the current time plus specific deletion time, so that the entry is not deleted from the routing table before the lifetime expires. Then the RERR message with the unreachable destinations should be unicasted for one neighbor or broadcasted to the many neighbors with TTL value set to 1.

4.3.3.4 Sequence Numbers

Sequence numbers serve as time stamps. They allow nodes to judge against how “fresh” their information on other nodes is. Each time a node sends out any type of message it increases its own Sequence number. Every node records the Sequence number of all the other nodes it talks to. A higher Sequence numbers signifies a fresher route. This it is possible for other nodes to figure out which one has more accurate information.

4.3.4 Advanced uses of AODV

The key benefit of this protocol is that routes are established on demand and destination sequence numbers are used to find the newest route to the destination. The connection setup delay is lower. It creates no additional traffic for communication along existing links. Also, distance vector routing is easy, and doesn't involve much memory or calculation. Some key points are listed below:

Due to its reactive nature, AODV can grip highly dynamic behavior of Vehicle Ad-hoc networks.

It is worn for both unicasts and multicasts using the J (Join multicast group) flag in the packets (Ramachandran, 2006).

4.3.5 Advantages

AODV is capable of doing broadcast and multicast routing.

Routes are established on demand and destination sequence numbers are used to find the latest route to the destination.

The connection setup delay is less.

AODV reduce the control traffic messages overhead at the cost of increased latency in finding new routes.

Use of Sequence numbers to track accuracy of information

AODV always makes sure that the overhead of the messages remains small.

It has large benefit in overhead over simple protocols which need to keep the whole route from the source host to the destination host in their messages.

AODV reacts relatively faster to the topological changes in the network and updating only the hosts that may be affected by the change, using the RRER message.

Only keeps track of next hop for a route instead of the whole route.

4.3.6 Disadvantages of AODV

This routing protocol requires more time to set up a connection, and the primary communication to establish a route is heavier than some other approaches.

Intermediate nodes can direct to inconsistent routes if the source sequence number is very old and the intermediate nodes have a superior but not the newest destination sequence number, thereby having old entries.

Multiple RouteReply packets in response to a single RouteRequest packet can lead to serious control overhead.

The periodic beaconing leads to unnecessary bandwidth consumption.

4.3.7 Limitations of AODV

The algorithm wishes that the nodes in the broadcast medium can observe each other’s broadcasts. The routing information is always obtained on demand, including for common cause traffic. The messages can be mishandled for insider attacks including route disruption, route invasion, node isolation, and resource consumption (Ning & Sun, 2003). AODV is designed to support the shortest hop count metric. This metric provides long, low bandwidth links over short, high-bandwidth links (Ramachandran, 2006). AODV is a reactive routing protocol, which means that AODV does not find out a route until a stream is initiated. This RD latency outcome can be high in large-scale mesh networks.

4.4 Black hole Attack

Black hole attack is that kind of attack which occurs in Mobile Ad-Hoc networks (MANET). AODV is a reactive protocol and it discovers routes only when a node wishes to deliver data over the network. It maintains these routes as long as they are required by the sources. Moreover, AODV forms trees which bonds multicast group members. AODV uses sequence numbers to ensure the freshness of routes. It is loop-free, self-starting, and scales to large numbers of mobile nodes [10]. Black hole attack [4][5][2] is a type of Denial of Service (DoS) attacks [7] in MANET. In this Black hole attack, a malicious node pretends that it has the best path to the destination node during the RD procedure. Whenever it receives the RREQ message, it immediately sends out a forged RREP to the source node. The source node firstly receives the RREP from the malicious node ahead of other RREPs. However, when the source node starts sending the data packet to the destination by using this route, the malicious node drops all packets instead of forwarding. In this way attacker node will always have the availability in replying to the route request and so intercept the data packet and keep it [21]. In protocol based on flooding, the malicious node reply will be received by the requesting node before the greeting of reply from actual node; hence a malicious and fake route is created. When this route is created, so now it’s up to the node whether to drop all the packets or forward it to the unidentified address [22]. The method how malicious node fits in the data routes varies. Fig. 4.5 illustrates how black hole problem arises, here node “S” is desire to send data packets to node “D” and begin the RD procedure. Thus if node “4” is a malicious node then it will assert that it has active route to the specified destination as soon as it receives RREQ packets. It will next send the response to node “S” before any other node. In this way node “S” will think that this is the active route and thus active RD is complete. Node “S” will ignore all other replies and will start seeding data packets to node “4”. In this way all the data packet will be lost consumed or lost.

Figure. 4.5 Black Hole Problem

Since wireless ad-hoc networks lack an infrastructure, they are exposed to a lot of attacks [2] [3]. A malicious node dropping all the traffic in the network makes use of the vulnerabilities of the RD (Route Discovery) packets of the on demand protocols, such as AODV. Black Hole attack may happen due to a malicious node which is deliberately misbehaving, as well as a damaged node interface. In any situation, nodes in the network will constantly try to find a route for the destination, which makes the node utilize its battery in addition to losing packets.

A. Internal Black hole Attack: – In this type of black hole attack an internal malicious node fits in between the routes of given source and destination. As soon as it gets the chance this malicious node make itself an active data route element. At this stage it is now able of conducting attack with the start of data transmission. This is an internal attack because node itself lies to the data.

B. External Black hole Attack: – External attacks physically resides outside of the network and refuse access to network traffic or creating overcrowding in network or by distracting the whole network. External attack can turn out to be a kind of internal attack when it take control of internal malicious node and manage it to attack other nodes in MANET. External black hole attack can be mashed up in following points:

1. Malicious node finds out the active route and remarks the destination address.

2. Malicious node sends a route reply packet (RREP) counting the destination address field spoofed to an unknown destination address.

3. Malicious node send RREP to the nearby available node which resides to the active route. This can also be send straight to the data source node if route is available.

4. The latest information received in the route reply will permit the source node to update its routing table.

5. The malicious node will drop now all the data to which it fits in the route.

4.5 Internet Protocol Suite

The Internet Protocol Suite is the computer networking model and set of communications protocols used on the Internet and similar computer networks. Mobile Ad Hoc Network (MANET) [1] is an immense novelty of up to date technology. In such type of network each mobile node operates not only as a host but also as a router and does not depend on any pre-established infrastructure. There are two types transport layer protocols: i.e. UDP (User Datagram Protocol) and TCP (Transport Layer Protocol). Both of these are accountable for hooking up the programs that are communicating with each other, whereas the underlying IP is simply responsible for receiving the packets from machine to machine. Because nodes in mobile ad hoc networks (MANETs) are forwarding packets for each other, some short of routing protocols is necessary to make the routing decisions. Although a number of studies have been conducted, improving and analyzing UDP performance in MANETs is still an active area of research and also a challenging task. If traffic performance is analyzed on MANET then it can be determined that which type of application can be used in the MANET.As it is known that TCP is transmission control protocol and UDP is used datagram protocol, both of them are compared on the basis of various traffic parameters like HTTP, Email, FTP etc, in manet.

4.5.1 TCP

Communications among computers on a network is made through protocol suits. The most broadly used and most commonly available protocol suite is TCP/IP protocol suite. A protocol suit consists of a layered architecture where each layer grants some functionality which can be carried out by a protocol. Each layer generally has more than one protocol options to carry out the responsibility that the layer adheres to. TCP/IP is generally considered to be a 4 layer system. The 4 layers are as follows:

Application layer

Transport layer

Network layer

Data link layer

Figure.4.6 TCP Model

Application layer

Application Layer is the topmost layer of TCP/IP protocol suite as shown in fig. This layer includes applications or processes that use transport layer protocols to deliver the data to destination computers. At each layer there are certain protocol options to bring out the task designated to that particular layer. So, application layer also has various protocols that applications employ to communicate with the second layer, which is the transport layer. Some of the popular application layer protocols are listed below:

HTTP (Hypertext transfer protocol)

FTP (File transfer protocol)

SMTP (Simple mail transfer protocol)

SNMP (Simple network management protocol) etc.

Transport Layer

This layer provides the backbone to data flow among the two hosts. This layer receives data from the application layer over it. There are many protocols that work at this layer but the two most commonly used protocols at transport layer are TCP and UDP. TCP is used where a reliable connection is required while on the other hand UDP is used in case of unreliable connections. TCP divides the data (approaching from the application layer) into proper sized chunks and then passes these chunks onto the network. It acknowledges received packets, waits for the acknowledgments of the packets it sent and sets timeout to resend the packets if acks are not received in time. The term ‘reliable connection’ is used where it is not desired to lose any information that is being transferred over the network through this connection. So, the protocol used for this type of connection must afford the mechanism to achieve this desired characteristic. For example, while downloading a file, it is not preferred to lose any information (bytes) as it may direct to corruption of downloaded content.

UDP provides a comparatively easier but unreliable service by sending packets from one host to another. UDP does not take any extra measures to ensure that the data sent is received by the target host or not. The term ‘unreliable connection’ is used where failure of some information does not hinder the task being fulfilled through this connection. For example while streaming a video; loss of few bytes of information due to some reason is acceptable as this does not damage the user knowledge much.

Network Layer

This layer is also termed as Internet layer. The main intention of this layer is to systematize or handle the movement of data on network. By movement of data, we commonly suggest routing of data over the network. The key protocol used at this layer is IP. While ICMP (used by popular ‘ping’ command) and IGMP are also used at this layer.

Data Link Layer

Data Link Layer is also identified as Network Interface Layer. This layer usually consists of device drivers in the OS and the network interface card attached to the system. Both the device drivers and the network interface card take care of the communication details with the media being used to move the data over the network. In most of the cases, this media is in the form of cables. Some of the well-known protocols which are used at this layer include ARP (Address resolution protocol), PPP (Point to point protocol) etc.

4.5.2 UDP

The UDP (User Datagram Protocol) is one of the main members of the Internet protocol suite. The protocol was designed by David P. Reed in 1980 and officially defined in RFC 768. It uses an easy connectionless transmission model with a minimum of protocol mechanism, which is the key point. UDP has no handshaking dialogues, and thus exploits the user's program to any unreliability of the underlying network protocol. In this, there is no guarantee of delivery, ordering, or duplicate protection. It provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol (IP) network with no previous communications to set up unique transmission channels or data paths. UDP is appropriate for purposes where error checking and correction is either not required or is performed in the application, avoiding the overhead of such processing at the network interface level. Time-sensitive applications often use UDP because dropping packets is preferable to waiting for delayed packets, which may not be a choice in a real-time system. A numeral of UDP's attributes make it mainly suited for certain applications, which are listed below:

It is transaction-oriented, suitable for simple query-response protocols such as the Domain Name System or the Network Time Protocol.

It grants datagrams, suitable for modeling other protocols such as in IP tunneling or Remote Procedure Call and the Network File System.

It is easy, suitable for bootstrapping or other purposes without a full protocol stack, such as the DHCP and Trivial File Transfer Protocol.

It is stateless, suitable for very large numbers of clients, such as in streaming media applications.

Applications utilize datagram sockets to establish host-to-host communications. An application binds a socket to its endpoint of data transmission, which is a combination of an IP address and a service port. A port is a software structure that is identified by the port number, a 16 bit integer value, allowing for port numbers between 0 and 65535. Port 0 is reserved, but is a permissible source port value if the sending process does not expect messages in response. The Internet Assigned Numbers Authority (IANA) has separated port numbers into three ranges. Port numbers 0 through 1023 are used for common, well-known services. Port numbers 1024 through 49151 are the registered ports used for IANA-registered services. Ports 49152 through 65535 are dynamic ports that are not officially designated for any specific service, and may be used for any purpose. They also are used as ephemeral ports, from which software running on the host may randomly choose a port in order to define itself. In effect, they are used as temporary ports primarily by clients when communicating with servers. Fig shows an overview.

Figure.4.7 UDP

Applications of UDP

Many important Internet applications use UDP, including: the Domain Name System (DNS), where queries must be fast and only consist of a single request followed by a single reply packet, the Simple Network Management Protocol (SNMP), the Routing Information Protocol (RIP)[1] and the Dynamic Host Configuration Protocol (DHCP). Voice and video traffic is usually transmitted using UDP. Real-time video and audio streaming protocols are designed to handle occasional lost packets, so only slight degradation in superiority occurs, rather than large delays if lost packets were retransmitted. Few VPN systems such as OpenVPN may use UDP while implementing reliable connections and error checking at the application level.

4.5.3 Comparison of UDP and TCP

UDP provides two services not provided by the IP layer. It provides port numbers which helps distinguish different user requests and, optionally, a checksum capability to verify that the data arrived intact.

TCP has emerged as the dominant protocol used for the bulk of Internet connectivity due to services for breaking large data sets into individual packets, checking for and resending lost packets and reassembling packets into the correct sequence. But these additional services come at a cost in terms of additional data overhead, and delays called latency.

UDP (User Datagram Protocol) is an alternative communications protocol to Transmission Control Protocol (TCP) used primarily for establishing low-latency and loss tolerating connections between applications on the Internet. Both UDP and TCP run on top of the Internet Protocol (IP) and are sometimes referred to as UDP/IP or TCP/IP. Both protocols send short packets of data, called datagrams.

UDP can also be used in applications that need lossless data transmission when the application is configured to manage the process of retransmitting lost packets and properly arranging received packets. This approach can help to improve the data transfer rate of large files compared with TCP.

In the Open Systems Interconnection (OSI) communication model, UDP, like TCP, is in layer 4, the Transport Layer. UDP works in combination with higher level protocols to help data transmission services including Trivial File Transfer Protocol (TFTP), Real Time Streaming Protocol (RTSP), Simple Network Protocol (SNP) and Domain Name System (DNS) lookups.

The service provided by UDP is an unreliable service that provides no guarantees for delivery and no protection from. The simplicity of UDP reduces the overhead from using the protocol and the services may be adequate in many cases.

UDP provides a minimal, unreliable, best-effort, message-passing transport to applications and upper-layer protocols. UDP communication consequently does not incur connection establishment and teardown overheads and there is minimal associated end system state. Because of this uniqueness, UDP can offer a very proficient communication transport to some applications, but has no inherent congestion control or reliability. A second unique characteristic of UDP is that it provides no inherent On many platforms, applications can send UDP datagrams at the line rate of the link interface, which is often much greater than the available path capacity, and doing so would contribute to congestion along the path, applications therefore need to be designed responsibly.

UDP does not provide any communications security. Applications that wishes to protect their communications against eavesdropping, tampering, or message forgery therefore need to separately provide security services using additional protocol mechanisms.

4.5.4 Using UDP

Application designers are usually aware that UDP does not provide any reliability, e.g., it does not retransmit any lost packets. Often, this is a main reason to consider UDP as a transport. Applications that do need reliable message delivery therefore need to implement appropriate protocol mechanisms in their applications (e.g. tftp).

UDP's finest effort service does not protect against datagram duplication, i.e., an application may get multiple copies of the same UDP datagram. Application designers therefore need to authenticate that their application kindly handles datagram duplication and may need to implement mechanisms to detect duplicates.

The Internet may also significantly delay some packets with respect to others, e.g., due to routing transients, intermittent connectivity, or mobility. This can cause reordering, where UDP datagrams arrive at the receiver in a away different from the transmission order. Applications that require ordered delivery must restore datagram ordering them.

Chapter 5

Experimental Setup and Result

5.1 Operating System

Ubuntu is a Debian-based Linux operating system and distribution for personal computers, smartphones and network servers. It uses Unity as its default desktop environment. It is based on free software and named after the Southern African philosophy of ubuntu (literally, "human-ness"), which often is translated as "humanity towards others" or "the belief in a universal bond of sharing that connects all humanity".[15]

Development of Ubuntu is led by UK-based Canonical Ltd.,[16] a company owned by South African entrepreneur Mark Shuttleworth. Canonical generates revenue through the sale of technical support and other services related to Ubuntu.[17]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-Morgan-18"[18]. Ubuntu project is publicly committed to the principles of open-source software development; people are encouraged to use free software, study how it works, improve upon it, and distribute it.

Ubuntu is an open-source software platform that runs everywhere from the smartphones, tablets etc. It is used by 26.15 of all the Linux websites. Fig 5.1 dipicts the scenario of an Ubuntu platform. It is very easy to work in such an Operating system.

Figure 5.1: Ubuntu Platform

5.1.1 Features

A default installation of Ubuntu includes a wide range of software that contains LibreOffice, Firefox, Thunderbird, Transmission, and several lightweight games such as Sudoku and chess.[21]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-22"[22]. Many additional software packages, including titles no longer in the default installation such as Evolution, GIMP, Pidgin, and Synaptic, are accessible from the built in Ubuntu Software Center as well as any other APT-based package management tool. Execution of Microsoft Office and other Microsoft Windows applications can be facilitated via the Wine compatibility package or through the use of a virtual machine such as VirtualBox or VMware Workstation.

5.1.2 Security

Ubuntu's goal is to be secure "out-of-the box". By default, the user's programs run with low privileges and cannot corrupt the operating system or other user's files. For increased security, the sudo tool is used to assign temporary privileges for performing administrative tasks, which allows the root account to remain locked and helps prevent inexperienced users from inadvertently making catastrophic system changes or opening security holes.[23] PolicyKit is also being widely implemented into the desktop to further harden the system. Most network ports are closed by default to prevent hacking.[24] A built-in firewall allows end-users who install network servers to control access. A GUI (GUI for Uncomplicated Firewall) is available to configure it.[25] Ubuntu compiles its packages using GCC features such as PIE and buffer overflow protection to harden its software.[26] These extra features greatly increase security at the performance expense of 1% in 32 bit and 0.01% in 64 bit.[27]

5.1.3 Installation of Ubuntu

Ubuntu running on the Nexus S, a smartphone that ran Android prior to Ubuntu. The system requirements vary among Ubuntu products. For the Ubuntu desktop release 14.04, a PC with at least 768 MB of RAM and 5 GB of disk space is recommended.[43] For less powerful computers, there are other Ubuntu distributions such as Lubuntu and Xubuntu. As of version 12.04, Ubuntu supports the ARM architecture.[3]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-the_inquirer_ubuntu_arm-4"[4]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-ars_technica_ubuntu_1204-5"[5]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-phoronix_ubuntu_arm-6"[6] Ubuntu is also available on PowerPC,[3]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-44"[44]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-45"[45] and SPARC platforms,[citation needed] although these platforms are not officially supported.[46]

Live images are the typical way for users to assess and subsequently install Ubuntu. These can be downloaded as a disk image (.iso) and subsequently burnt to a DVD and booted, or run via UNetbootin directly from a USB drive (making, respectively, a live DVD or live USB medium). Running Ubuntu in this way is typically slower than running it from a hard drive, but does not alter the computer unless specifically instructed by the user. If the user chooses to boot the live image rather than execute an installer at boot time, there is still the option to then use an installer called Ubiquity to install Ubuntu once booted into the live environment.[47] Disk images of all current and past versions are available for download at the Ubuntu web site.[48] Various third-party programs such as remastersys and Reconstructor are available to create customized copies of the Ubuntu Live DVDs (or CDs). "Minimal CDs" are available (for server use) that fit on a CD.

Additionally, USB flash drive installations can be used to boot Ubuntu and Kubuntu in a way that allows permanent saving of user settings and portability of the USB-installed system between physical machines (however, the computers' BIOS must support booting from USB).[49] In newer versions of Ubuntu, the Ubuntu Live USB creator can be used to install Ubuntu on a USB drive (with or without a live CD or DVD). Creating a bootable USB drive with persistence is as simple as dragging a slider to determine how much space to reserve for persistence; for this, Ubuntu employs casper.[50]HYPERLINK "https://en.wikipedia.org/wiki/Ubuntu_(operating_system)#cite_note-51"[51]

The desktop edition can also be installed using the Netboot image (a.k.a. netbook tarball) which uses the debian-installer and allows certain specialist installations of Ubuntu: setting up automated deployments, upgrading from older installations without network access, LVM and/or RAID partitioning, installs on systems with less than about 256 MB of RAM (although low-memory systems may not be able to run a full desktop environment reasonably).

5.2 Network Simulator

A Network Simulator is software which predicts the performance of a computer network. Since communication network have turn out to be too complex for traditional analytical methods to grant an accurate understanding of system behavior network simulator are used. In simulators, the computer network is classically modeled with devices, links etc and the performance is analyzed. Simulators usually come with support for the most popular technologies and networks in use nowadays. There are both free/open-source and proprietary network simulators are available. Examples of prominent network simulator/emulator include:

Ns (open source)

OPNET

NetSim

Most of the commercial simulators are GUI driven, while some network simulators are CLI driven. A network simulator is a software program that imitates the working of a computer network. In simulators, the computer network is typically modeled with devices, traffic etc. and the performance is analyzed. A network simulator is a sort of software or hardware that predicts the behavior of a network, without an actual network being present. Typically, users can then customize the simulator to fulfill their specific analysis needs.

NS-3 is selected as the simulation tool amongst the others simulation tools because NS-3 permits networking research and education. Ns-3 is very much proper for designing new protocols, comparing different protocols and traffic evaluations. NS-3 is developed as a joint environment. It is distributed freely and open source. A large amount of institutes and people in development and research use, maintain and develop NS-3. Versions are available for FreeBDS, Linux, Solaris, Windows and Mac OS X. NS-2 also provides substantial support for simulation of TCP, UDP, routing and multicast protocols over wired and wireless networks.

Most network simulators use discrete event simulation, in which a list of pending “events” is stored, and those events are processed in order, with some events triggering future events. Uses of network simulators are:

Network simulator provide a cost effective method for

a. Network design validation for data centers, sensor networks etc.

b. Defense applications and network centric warfare.

There are a wide variety of network simulators, ranging from the easiest to the complex. Simply, a network simulator must enable a user to model the network topology specifying the nodes on the network and the links between those nodes, application flow amongst the nodes.

5.3 Types of Network Simulator

Different types of network simulators can be categorized and explained based on some criteria such as if they are commercial or free, or if they are simple ones or complex ones.

5.3.1. Commercial and open source simulators

Some of the network simulators are commercial which means that they would not provide the source code of its software or the affiliated packages to the general users for free. The entire user’s had to pay to get the license to use their software or pay to order specific packages for their own specific usage requirements. One typical example is the OPNET. The advantage of Commercial simulator is that it generally has complete and up-to-date documentations and they can be consistently maintained by some specialized staff in that company [26]. However, the open source network simulator is disadvantageous in this aspect, and generally there are not enough specialized people working on the documentation.

On the contrary, the open source network simulator has the advantage that everything is very open and everyone or organization can contribute to it and find bugs in it. It can also be very flexible and reflect the most new recent developments of new technologies in a faster way than commercial network simulators. Open source network simulators include NS2, NS3. We will introduce and analyze them in great detail in the following sections.

Table 5.1 Types of Network simulators

5.3.2 Simple vs. complex

Currently there are a great variety of network simulators, ranging from the simple ones to the complex ones. Minimally, a network simulator should enable users to represent a network topology, defining the scenarios, specifying the nodes on the network, the links between those nodes and the traffic between the nodes. Graphical applications also allow users to easily visualize the workings of their simulated environment. Some of them may be text-based and can provide a less visual or intuitive interface, but may allow more advanced forms of customization [26]. Others may be programming-oriented and can provide a programming framework that allows the users to customize to create an application that simulates the networking environment for testing.

5.3.3 Simulation in NS-3

A team led by Tom Henderson, George Riley, Sally Floyd, and Sumit Roy, applied for and received funding from the U.S. National Science Foundation (NSF) to build a replacement for ns-2, called ns-3. This team collaborated with the Planete project of INRIA at Sophia Antipolis, with Mathieu Lacage as the software lead, and formed a new open source project. NS (from network simulator) is a name for series of discrete event network simulators, specifically ns-1, ns-2 and ns-3. Each of them are discrete-event computer network simulators, primarily used in research and teaching. NS-3 is free software, publicly available under the GNU GPLv2 license for research, development, and use. The major aim of the ns-3 project is to create an open simulation environment for computer networking research that will be preferred inside the research community:

It should be aligned with the simulation needs of modern networking research.

It should encourage community contribution, peer review, and validation of the software.

Since the process of creation of a network simulator that contains a sufficient number of high-quality validated, tested and actively maintained models needs a lot of work, ns-3 project spreads this work load over a big community of users and developers. In the procedure of developing ns-3, it was decided to completely abandon backward-compatibility with ns-2. The upcoming simulator would be written from scratch, using the C++ programming language. Development of ns-3 began in July 2006. A framework for generating Python bindings (pybindgen) and use of the Waf build system were contributed by Gustavo Carneiro. The first release, ns-3.1 was made in June 2008, and afterwards the project continued making quarterly software releases, and more recently has moved to three releases per year. ns-3 made its twenty first release (ns-3.21) in September 2014. Present status of the three versions is:

ns-1 is no longer developed nor maintained,

ns-2 is not actively maintained,

ns-3 is actively developed (but not compatible for work done on ns-2)

NS-3 is split over couple dozen modules containing one or more models for real-world network devices and protocols. NS-3 has more recently integrated with related projects: the Direct Code Execution extensions allowing the use of C or C++-based applications and Linux kernel code in the simulations.

The general process of creating a simulation can be divided into several steps:

Topology definition: to ease the creation of basic facilities and define their interrelationships, ns-3 has a system of containers and helpers that facilitates this process.

Model development: models are added to simulation (for example, UDP, IPv4, point-to-point devices and links, applications); most of the time this is done using helpers.

Node and link configuration: models set their default values (for example, the size of packets sent by an application or MTU of a point-to-point link); most of the time this is done using the attribute system.

Execution: simulation facilities generate events, data requested by the user is logged.

Performance analysis: after the simulation is finished and data is available as a time-stamped event trace. This data can then be statistically analysed with tools like R to draw conclusions.

Graphical Visualization: raw or processed data collected in a simulation can be graphed using tools like Gnuplot, matplotlib or XGRAPH. 5.3.4 Uses of network simulator

5.3.4 Installation

NS-3 can be installed on common platforms

-Desktop & servers- 32 bit & 64 bit ,windows.

-any major OS: Linux, Mas OS, Windows, Ubuntu.

Installation includes following steps:

-download

-build

-validation

Download NS-3 package, unzip and untar it.

-http://www.nsnam.org/release/

-tar –jxf ns-3.x.tar.bz2

Check the system for prerequisites and build

-change directory to ns-3.x

-./waf –d debug configure

-./waf

Validation build by running tests

-./test.py –c core

5.3.5 Usage Overview

Decide what we want to simulate

Define topology

Create nodes, channel, network interfaces

Configure Internet Stack and applications

Set attributes

Build the simulation script using a text editor

Execute the .cc program via waf

Analyze output

5.3.6 Features

It a discrete event simulator

Modular design / Open source

Actively developed (Contrast NS-2)

Developed in C++. Python binding available.

Live visualize

Logging facility for debugging

Tracing facility fo getting output

Can be connected to a real network

Direct Code Execution (DCE)

5.3.7 Requirement of Simulation

Network simulation is a method where a program models the performance of a network either by estimating the interaction between the different network entities (hosts/routers, data links, packets, etc.) using mathematical formulas, or actually capturing and playing back observations from a production network. The behavior of the network and the various applications and services it supports can then be observed in a test lab; various attributes of the surroundings can also be modified in a controlled way to assess how the network would perform under different conditions. When a simulation program is worned in conjunction with live applications and services in order to observe end-to-end performance to the user desktop, this technique is also referred to as network emulation. For simulation, we need to write a simulation script which is a C++ program. To this program the ns-3 library is linked to build our simulation executible. API calls are used in the program to do the necessary simulation. The waf build system is used to build the simulation.

5.4 Performance Metric

The following essential performance metrics can be evaluated:-

Throughput (messages/second): – The ratio of the number of data packets sent and the number of data packets received. Throughput of the protocol shows number of messages delivered per one second.

Node Mobility: As the name suggests, it indicates the mobility speed of nodes.

5.5 Scenario of Simulation Setup

All extensive simulations were conducted using NS-3.23. The simulated network consisted of 4, 6 and 16 nodes randomly scattered in 800x800m area at the starting time of the simulation. All simulation parameter are described in below table 1:

In this picture, I had varied the nodes, keeping the malicious node constant and on that I have examined the behavior of throughputs under different simulation factors.

Table 5.2. Simulation Parameter

5.6 Results and Discussion

5.6.1 Scenario 1

In this scenario, the performance of protocol compare with respect to their throughputs, and the number of nodes connected in a network as varying with simulation time with AODV Routing protocol, through which the comparison graphs of TCP and UDP connection is obtained. Observation graphs are shown as below:

Figure 5.2 Variation of throughput in UDP Connection

The figure 5.2 shows that simulation result for 4, 6 and 16 nodes with AODV Routing Protocol. It is clearly observed that the throughput is decreased while increasing the nodes in UDP (User Data gram Protocol) connection. As TCP uses the occurrence of losses to detect congestion, In MANETs, random wireless errors and mobility serves as primary contributor to losses as well as congestion. More than 80% of the losses in the network are due to link failures. Essentially, most losses in ad-hoc networks occur as a result of route failures. If TCP enters congestion control state because of packet losses caused by random wireless errors and mobility, then the throughput of TCP can be degraded significantly. Expected throughput does not take into account the performance overhead of determining new routes after route failures. It serves as a upper bound of throughput in mobile network.

Figure 5.3 Variation of throughput in TCP connection

In the fig 5.3, it is clearly viewed that, the collision of the Black hole attack to the Networks throughput. The throughput is again been decreased when the nodes are varied randomly in TCP (Transmission Control Protocol) connection. In this, AODV routing protocol were randomly distributed, and one malicious node performs the black-hole attack. The Throughput deals with the average rate of successful message delivery over a networking channel. Congestion window can become quite small for successive packet losses. Throughput falls dramatically as a result. Packets are Lost due to high BER (Bit Error Rate).

5.6.2 Scenario 2

On the other hand, In this scenario, the performance of simulation factors compares between different types of data rates, which varies along with the variation of traffic nodes. The comparison graphs between varing data rates i.e 100kbps, 250kbps and 600kbps are shown in below.

Figure 5.4 Variation of throughput with 4 nodes

It is observed from the above fig.5.4 that, the throughput of the network increases with the increase in data rate. However it shows the same variations in two other scenario.

Figure 5.5 Variation of throughput with 6 nodes

The figure 5.5 shows the comparison graph of 4, 6 and 16 nodes as we increase the data rates and nodes in AODV routing protocol the throughput increases slowly with the increase in data rates. A black hole attack happens when a malicious node intercepts the data traffic from the source node to the destination node. When the attack exists in the network and the routing recovery protocol is disabled, the traffic which delivers to the attacker and which delivers to the destination is almost the same . The performance metrics chosen for the evaluation of black hole attack is network throughput.

Figure 5.6 Variation of throughput with 16 nodes

At last, the figure 5.6 shows that initially for 4 node the throughput is less with the data rate of 100kbps. But there is not much difference between the other two nodes with the data rate of 250kbps and 600kbps.

The comparison of above three graphs shows that when the number of nodes increasing with different data rates, the values of AODV increases. It means that the black holes deals with the places in the network where incoming or outgoing traffic is silently discarded (or "dropped"), without informing the source that the data did not arrive at its projected recipient.

5.7 NAM Output of different protocols

In this, the output scenario is been shown and the 3 dimensional view is analyzed with different simulation parameters under varing number of nodes.

Figure 5.7 Output of 16nodes under UDP connection with AODV in ns3

The above fig 5.7 shows the output of 16nodes under UDP (User Data gram Protocol) connection in AODV Routing Protocol using NS-3. From the fig we can examine that received bytes is less than the transmitted bytes, therefore the throughput is 0.027145Mbps. Thus the outcome is estimated with the number of packets dropped during the process

Figure 5.8 AODV simulation result at 16 nodes running up to 20.016sec

Figure 5.9 AODV simulation result at 16 nodes running up to 36.063sec

Figure 5.10 AODV simulation result at 16 nodes running up to 46.061sec

Figure 5.11 AODV simulation result at 16 nodes running up to 57.084sec

Figure 5.12 AODV simulation result at 16 nodes running up to 67.084sec

The above figures show that the network animation (NAM) output of AODV protocol with presence of 16 nodes in the network and transmitting the data from 0 to 150 seconds. Circle shows the range of a node in the network and red dots indicates the position of each node ranging from 1 to 16.

Throughput deals with the effectiveness of a routing protocol in the network. When comparing the routing throughput by each of the simulation factor, the throughput value of AODV increases when the number of nodes and simulation time increases with different data rates. All nodes in this network maintain a routing bench, which contains information on the subject of the route to a particular destination. The routing messages do not hold information about the entire route path, but only about the source and the destination. Therefore, routing messages do not have an increasing volume. It uses destination sequence numbers to denote how fresh a route is.

As the NAM works with 16nodes, in the same way it works with 4nodes and for 6nodes in different traffic overheads,i.e in TCP and UDP connections with different data rates.

Chapter 6

Conclusion and Suggestions for Future Work

6.1 Conclusion

In this thesis, I have analyzed the throughputs in the presence of different scenario in network. The outcomes is examined with simulation using NS-3.23 simulator scenario available at 4, 6 and 16 nodes and the simulation time has varied on the basis of their throughput. We simulated the Black Hole Attack and investigated its result with different parameters. In this research, we conclude that while using the AODV protocol in NS-3 the throughputs is increased while increasing the nodes with the different date rates and on the other hand the throughput is decreased while increasing the nodes on different connections like UDP and TCP.

6.2 Suggestions for Future Work

With the increase in computing environments, the services based on ad hoc networks have been enlarged as a result different kinds of attacks might take place. All the routing protocols are expected to present different outcomes. Therefore, the best routing protocol for minimizing the Black Hole Attack may be resolute. Many of the routing protocol provide different kinds of services to nodes in the presence of different situation of the network. All protocol shows different uniqueness in the environment of mobile ad hoc network. The simulation cram can be extended to any future MANET routing protocols to assist comparison of the new protocol to the existing ones.

In the future work nodes can be extended and the outcomes can be estimated. In MANET applications where affirmation is not essential, there is still a need for mechanisms whereby nodes can be assured that packets will be delivered to their proposed target. Furthermore, the protocol used does not address security issues; it would be appealing to observe the effects of security additions to the performance of these protocols. In our study, we used the AODV routing protocol. But the other routing protocols could be simulated as well. All routing protocols are expected to present different results. Therefore, the best routing protocol for minimizing the Black Hole Attack may be determined.