How to Implement Ring Topology in NS2

 

To implement a Ring Topology in NS2 (Network Simulator 2) has a series of steps to follow and the nodes must be connected in a circular fashion, in which each node has a direct link to two other nodes, that creating a closed loop. In this topology, data is transferred in a unidirectional or bidirectional method, with nodes moving the packets till they reach their destination. The below is the detailed approach to implement the ring topology in ns2:

Steps to Implement a Ring Topology in NS2:

  1. Set Up the Ring Topology:
    • Describe multiple nodes in the network, and connect each node to its two neighbours, forming a circular (ring) connection.
  2. Simulate Traffic Flow:
    • Traffic can be delivering from one node to another, and packets will traverse via intermediate nodes if they are not directly connected.
  3. Choose a Direction for the Traffic:
    • We can decide whether the traffic flows in a unidirectional (one way around the ring) or bidirectional (both ways) manner.

Example of Ring Topology Implementation in NS2:

# Create a new simulator

set ns [new Simulator]

# Open trace file for output

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Define nodes in the ring (4 nodes for simplicity)

set n0 [$ns node]  ;# Node 0

set n1 [$ns node]  ;# Node 1

set n2 [$ns node]  ;# Node 2

set n3 [$ns node]  ;# Node 3

# Create duplex links between nodes to form a ring topology

$ns duplex-link $n0 $n1 1Mb 10ms DropTail  ;# Link between node 0 and node 1

$ns duplex-link $n1 $n2 1Mb 10ms DropTail  ;# Link between node 1 and node 2

$ns duplex-link $n2 $n3 1Mb 10ms DropTail  ;# Link between node 2 and node 3

$ns duplex-link $n3 $n0 1Mb 10ms DropTail  ;# Link between node 3 and node 0 (closing the ring)

# Define TCP agents and sinks for communication between nodes

set tcp0 [new Agent/TCP]

set sink0 [new Agent/TCPSink]

$ns attach-agent $n0 $tcp0

$ns attach-agent $n2 $sink0

$ns connect $tcp0 $sink0

# Simulate traffic from node 0 to node 2

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ns at 1.0 “$ftp0 start”

# Set up another TCP connection from node 1 to node 3

set tcp1 [new Agent/TCP]

set sink1 [new Agent/TCPSink]

$ns attach-agent $n1 $tcp1

$ns attach-agent $n3 $sink1

$ns connect $tcp1 $sink1

# Simulate traffic from node 1 to node 3

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ns at 2.0 “$ftp1 start”

# End the simulation after 10 seconds

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

Explanation of the Script:

  1. Nodes:
    • n0, n1, n2, and n3 signify the nodes in the ring topology.
  2. Links:
    • The links are generated among adjacent nodes to form a ring. For instance, node n0 is associated to node n1, and node n3 is connected back to node n0 to complete the ring.
  3. Traffic Simulation:
    • TCP agents are used to mimic interaction among nodes. For instance, traffic flows from n0 to n2 and from n1 to n3.
    • FTP applications create file transfer traffic among the nodes.
  4. End of Simulation:
    • The simulation executes for 10 seconds, permits to monitor the interaction among nodes in the ring topology.

Post-Simulation Analysis:

  1. Trace File Analysis:
    • Open the trace file (out.tr) to monitor the packet flow in the ring topology. We need to evaluate the routes taken by packets as they travel from the source node to the destination, passing via the intermediate nodes if necessary.
  2. NAM Visualization:
    • Use NAM (Network Animator) to visualize the ring topology. We will see the circular connections among the nodes and how traffic flows around the ring.
  3. Performance Metrics:
    • We need to evaluate the network performance metrics like delay, throughput, and packet loss to evaluate the effectiveness of the ring topology.

Enhancing the Simulation:

  1. Unidirectional vs Bidirectional Ring:
    • In this sample, traffic can flow in both directions. We can mimic a unidirectional ring by checking traffic to one direction around the ring like always forwarding packets in the clockwise direction.
  2. Fault Tolerance:
    • Mimic node or link failures in the ring and monitor on how the network continues to function. In a ring topology, the failure of one node or link can disturb communication, specifically in unidirectional rings.
  3. Different Traffic Patterns:
    • Test with diverse traffic types like UDP traffic, or mimic more complex application-level traffic to assess on how the ring topology manages numerous workloads.
  4. Increasing Node Count:
    • Attach more nodes to the ring to mimic a larger network and monitor on how the network performance scales with the number of nodes.

In the above procedures will demonstrate how to complete the implementation process for ring topology using the ns2 tool. We will intend to provide the more information about the ring topology.

Ring Topology in NS2 implementation are worked by us we guide you. you can approach ns2project.com for customized ideas and topics. Get best simulation assistance from us. We work unidirectional or bidirectional method, with nodes   drop us all your requirements we will guide you with best project results.