How to Start Ring Mesh Hybrid Topology Projects Using NS2

To start a Ring-Mesh Hybrid Topology project using NS2 (Network Simulator 2), it has integrating the both Ring Topology and Mesh Topology’s aspects. Nodes are associated within a ring-like structure, and a few nodes may have links to other nodes, creating a mesh structure to offer redundancy and numerous interaction paths within this hybrid topology.

Below is a structured mechanism on how to start a Ring-Mesh Hybrid Topology project in NS2:

Steps to Start Ring-Mesh Hybrid Topology Projects in NS2

Understand Ring-Mesh Hybrid Topology

Ring-Mesh Hybrid Topology:
- The network makes a ring in which each node is associated to two other nodes such as in a ring topology.
- The nodes can contain more links to other nodes for making a mesh-like structure in the ring. It offers fault tolerance and several paths for data transmission.
Applications:
- Fault-tolerant communication networks.
- Internet backbones.
- Large-scale enterprise networks.
Advantages:
- Redundancy: Numerous paths for interaction.
- Scalability: It is simply scalable by inserting additional mesh links.
- Fault Tolerance: Data can flow even if a link drops.

Set Up NS2

Install NS2:
- We can set up and confirm NS2 functionality by executing an example script:

ns example.tcl

Tools for Analysis:
- NAM (Network Animator) is designed for envisioning the topology.
- Trace Analysis Tools supports to compute the metrics like throughput, latency, and packet delivery ratio (PDR).

Plan the Ring-Mesh Hybrid Topology

Network Design:
- Make a logical ring in which nodes are associated within a circular manner.
- Integrate the mesh connections to some nodes are permitting numerous communication paths.
Metrics to Analyze:
- Throughput.
- Latency.
- Packet Delivery Ratio (PDR).

Write the Simulation Script

Step 4.1: Create the TCL Script

We can store the tcl script like ring_mesh_hybrid_topology.tcl in NS2.

Step 4.2: Initialize the Simulator

Configure the simulator and tracing the file:

# Initialize the simulator

set ns [new Simulator]

set tracefile [open trace.tr w]

$ns trace-all $tracefile

set namfile [open ring_mesh_hybrid_topology.nam w]

$ns namtrace-all $namfile

Step 4.3: Create Nodes

In the topology, we need to specify the nodes:

# Create nodes in the ring

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

set node4 [$ns node]

set node5 [$ns node]

# Add extra mesh links between selected nodes

set node6 [$ns node]

set node7 [$ns node]

Step 4.4: Configure Links

Ring Connections:
- Attack the nodes within a ring topology.
Mesh Connections:
- Integrate additional connections to make mesh structure.

# Ring links

$ns duplex-link $node1 $node2 1Mb 10ms DropTail

$ns duplex-link $node2 $node3 1Mb 10ms DropTail

$ns duplex-link $node3 $node4 1Mb 10ms DropTail

$ns duplex-link $node4 $node5 1Mb 10ms DropTail

$ns duplex-link $node5 $node1 1Mb 10ms DropTail

# Mesh links (extra links to form mesh)

$ns duplex-link $node1 $node6 1Mb 10ms DropTail

$ns duplex-link $node3 $node7 1Mb 10ms DropTail

$ns duplex-link $node4 $node6 1Mb 10ms DropTail

$ns duplex-link $node2 $node7 1Mb 10ms DropTail

Step 4.5: Configure Traffic

Configure traffic flows among the nodes:

# Traffic from node1 to node4

set udp1 [new Agent/UDP]

$ns attach-agent $node1 $udp1

set null1 [new Agent/Null]

$ns attach-agent $node4 $null1

$ns connect $udp1 $null1

set cbr1 [new Application/Traffic/CBR]

$cbr1 attach-agent $udp1

$cbr1 set packetSize_ 512

$cbr1 set rate_ 50kb

$ns at 1.0 “$cbr1 start”

# Traffic from node6 to node2

set udp2 [new Agent/UDP]

$ns attach-agent $node6 $udp2

set null2 [new Agent/Null]

$ns attach-agent $node2 $null2

$ns connect $udp2 $null2

set cbr2 [new Application/Traffic/CBR]

$cbr2 attach-agent $udp2

$cbr2 set packetSize_ 512

$cbr2 set rate_ 50kb

$ns at 2.0 “$cbr2 start”

Step 4.6: Enable Routing Protocol

Make use of a routing protocol which is appropriate for mesh networks like AODV:

$ns rtproto AODV

Step 4.7: Finalize the Script

Integrate the simulation end conditions to finish the script:

# End simulation

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam ring_mesh_hybrid_topology.nam &

exit 0

}

$ns run

Run the Simulation

We must store the simulation tcl script for instance ring_mesh_hybrid_topology.tcl.
Then, run the simulation in NS2:

ns ring_mesh_hybrid_topology.tcl

Go to NAM for envisioning the topology:

nam ring_mesh_hybrid_topology.nam

Analyze Results

Trace File Analysis:
- Measure throughput, latency, and PDR with the support of trace.tr.
- Example AWK script for throughput:

awk ‘{if ($1 == “r” && $4 == “udp”) sum += $8} END {print “Throughput: “, sum}’

Key Metrics:
- Packet Delivery Ratio (PDR): Estimate the reliability within distributing packets.
- Latency: Assess delay in interaction.
- Throughput: Measure the effectiveness of data transfer.

Expand the Simulation

Increase Network Size:
- Integrate additional nodes and mesh connections to measure the network.
Simulate Link Failures:
- In the mesh or ring topology, launch failures and then monitor the behaviour of the network:

$ns at 5.0 “$ns link-fail $node3 $node4”

Experiment with Traffic Patterns:
- Set up more advanced traffic models with unicast, multicast, or broadcast.
Test Different Routing Protocols:
- We will equate the performance of diverse routing protocols like AODV, DSDV, or other protocols.

Document the Project

Objective: Define the project’s goals of replicating a ring-mesh hybrid topology.
Setup: It offers specifics regarding node placement, traffic models, and routing protocols.
Results: Offer performance parameters such as throughput, latency, and PDR.
Conclusions: Sum up observations and recommend enhancements for the network.

In conclusion, Ring Mesh Hybrid Topology projects has been effectively replicated and examined using NS2 platform, employing an innovative approach, with a comprehensive explanation to follow in the upcoming manual.