How to Simulate Mesh Topology Projects Using NS2

To simulate a Mesh Topology in NS2 has series of steps to follow and it can be completed by associating multiple nodes in such a way which the each node is linked to multiple other nodes, make sure that the redundancy and multiple paths among the nodes.phdprime.com will offer number one simulation result along with perfect topic ideas in this area.

Here’s how you can simulate a Mesh Topology in NS2:

Steps to Simulate Mesh Topology Projects in NS2

1. Set up NS2 Environment:

• Make sure that NS2 is installed and processing on the system.
• We will compose a TCL script to describe the network topology, set up nodes, and replicate traffic patterns.

2. Understanding Mesh Topology:

• In a Mesh Topology, each node is associated to multiple other nodes. This permits for multiple redundant paths for data, make sure network reliability and fault tolerance.
• A fully connected mesh topology means each node is directly associates to every other node, while a partially connected mesh topology means only some nodes have multiple connections.

3. Create a TCL Script for Mesh Topology:

Here is an instance TCL script to mimic a simple Partially Connected Mesh Topology using NS2:

# Create a new simulator instance

set ns [new Simulator]

# Open a NAM file for visualization

set nf [open out.nam w]

$ns namtrace-all $nf

# Create nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

set n4 [$ns node]

# Create duplex links to form a partially connected mesh

$ns duplex-link $n0 $n1 10Mb 10ms DropTail

$ns duplex-link $n0 $n2 10Mb 10ms DropTail

$ns duplex-link $n1 $n2 10Mb 10ms DropTail

$ns duplex-link $n1 $n3 10Mb 10ms DropTail

$ns duplex-link $n2 $n3 10Mb 10ms DropTail

$ns duplex-link $n2 $n4 10Mb 10ms DropTail

$ns duplex-link $n3 $n4 10Mb 10ms DropTail

# Create UDP agents and attach them to nodes

set udp0 [new Agent/UDP]

$ns attach-agent $n0 $udp0

set udp1 [new Agent/UDP]

$ns attach-agent $n1 $udp1

set udp2 [new Agent/UDP]

$ns attach-agent $n2 $udp2

# Null agents at receiving nodes

set null0 [new Agent/Null]

$ns attach-agent $n3 $null0

set null1 [new Agent/Null]

$ns attach-agent $n4 $null1

# Connect each UDP agent to a Null agent

$ns connect $udp0 $null0

$ns connect $udp1 $null1

$ns connect $udp2 $null0

# Define traffic sources using CBR (Constant Bit Rate)

set cbr0 [new Application/Traffic/CBR]

$cbr0 attach-agent $udp0

$cbr0 set packetSize_ 512

$cbr0 set rate_ 100Kb

set cbr1 [new Application/Traffic/CBR]

$cbr1 attach-agent $udp1

$cbr1 set packetSize_ 512

$cbr1 set rate_ 100Kb

set cbr2 [new Application/Traffic/CBR]

$cbr2 attach-agent $udp2

$cbr2 set packetSize_ 512

$cbr2 set rate_ 100Kb

# Schedule traffic

$ns at 1.0 “$cbr0 start”

$ns at 1.5 “$cbr1 start”

$ns at 2.0 “$cbr2 start”

# Stop traffic at a specific time

$ns at 5.0 “$cbr0 stop”

$ns at 5.5 “$cbr1 stop”

$ns at 6.0 “$cbr2 stop”

# Define finish procedure

$ns at 7.0 “finish”

proc finish {} {

global ns nf

$ns flush-trace

close $nf

exec nam out.nam &

exit 0

}

# Run the simulation

$ns run

4. Explanation of the Code:

• Nodes: Five nodes are generated (n0, n1, n2, n3, n4). These nodes signify devices in the mesh topology.
• Links: A partially associated mesh is designed by connecting nodes in such a way which each node is associated to multiple others. For instance, n0 is connected to n1 and n2, while n2 is connected to n1, n3, and n4.
• UDP Agents: Each node is attached to a UDP agent that creates traffic. The traffic is transmitting from one node to another through the mesh network.
• CBR Traffic: Constant Bit Rate (CBR) traffic is created and flows among the nodes at diverse times.
• Simulation: The simulation terminates after 7 seconds, and the output is saved in the out.nam file, that can be regarded in NAM.

5. Run the Simulation:

1. Save the script as mesh_topology.tcl.
2. Open a terminal and navigate to the folder containing the script.
3. Execute the simulation using:

ns mesh_topology.tcl

1. The simulation will create a .nam file (out.nam) that can be opened in Network Animator (NAM) for visualization.

6. Fully Connected Mesh Topology:

If we need to replicate a fully connected mesh topology, we would require generating links among every pair of nodes. For example:

$ns duplex-link $n0 $n1 10Mb 10ms DropTail

$ns duplex-link $n0 $n2 10Mb 10ms DropTail

$ns duplex-link $n0 $n3 10Mb 10ms DropTail

$ns duplex-link $n0 $n4 10Mb 10ms DropTail

$ns duplex-link $n1 $n2 10Mb 10ms DropTail

$ns duplex-link $n1 $n3 10Mb 10ms DropTail

$ns duplex-link $n1 $n4 10Mb 10ms DropTail

$ns duplex-link $n2 $n3 10Mb 10ms DropTail

$ns duplex-link $n2 $n4 10Mb 10ms DropTail

$ns duplex-link $n3 $n4 10Mb 10ms DropTail

This would make sure that every node is associated to every other node, forming a fully connected mesh.

7. Enhancements and Customization:

• More Nodes: Incorporate more nodes and links to extend the mesh topology.
• Traffic Types: Test with different traffic types, like TCP rather than UDP.
• Failure Scenarios: Replicate a node or link failures to validate the reliability and redundancy of the mesh topology.

In this presented manual elaborately provide the complete procedures to help you to simulate the Mesh Topology over the network using the tool of ns2. More information regarding this process is provided in further script.