How to Implement Partial Mesh Topology in NS2

To implement a Partial Mesh Topology that contains some nodes are associated to every other nodes such as in a fully connected topology, however others are only connected to a subset of the nodes. It equalises the redundancy and the fault tolerance of a full mesh including the minimised cost and difficulty of less connections. Given below is a stepwise approach on how to implement it in the NS2:

Steps to Implement Partial Mesh Topology in NS2:

  1. Set Up the Partial Mesh Network Topology:
    • Describe numerous nodes.
    • Make a links among the nodes like some nodes are fully associated to others, whereas some have less connections that forming a partial mesh.
  2. Simulate Traffic Flow:
    • Create a traffic among any pair of nodes that permitting the data to navigate directly among the connected nodes or via intermediate nodes while not directly connected.

Example of Partial Mesh Topology Implementation in NS2:

Given below is an example script that establishes how to configure a partial mesh topology with 5 nodes and mimic traffic among them:

# 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 for the partial mesh topology (5 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

set n4 [$ns node]  ;# Node 4

# Create duplex links to form the partial mesh

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

$ns duplex-link $n0 $n2 1Mb 10ms DropTail  ;# Link between node 0 and node 2

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

$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 $n4 1Mb 10ms DropTail  ;# Link between node 3 and node 4

# ======= TRAFFIC SIMULATION =======

# Define TCP agents for communication between nodes

# Traffic from node 0 to node 3 (direct link)

set tcp0 [new Agent/TCP]

set sink0 [new Agent/TCPSink]

$ns attach-agent $n0 $tcp0

$ns attach-agent $n3 $sink0

$ns connect $tcp0 $sink0

# Simulate FTP traffic from node 0 to node 3

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ns at 1.0 “$ftp0 start”   ;# Start traffic at 1 second

# Traffic from node 1 to node 4 (no direct link, via intermediate nodes)

set tcp1 [new Agent/TCP]

set sink1 [new Agent/TCPSink]

$ns attach-agent $n1 $tcp1

$ns attach-agent $n4 $sink1

$ns connect $tcp1 $sink1

# Simulate FTP traffic from node 1 to node 4

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ns at 2.0 “$ftp1 start”   ;# Start traffic at 2 seconds

# 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:
    • Nodes n0, n1, n2, n3, and n4 are signify the five nodes within the partial mesh topology.
  2. Links:
    • Duplex links are made among a subset of nodes. Some nodes, such as n0, are associated to numerous other nodes, whereas others, like n4, are connected to less nodes that forming a partial mesh.
    • For instance, the node n0 is connected to n1, n2, and n3 whereas n4 is only associated to n3.
  3. Traffic Simulation:
    • TCP agents are used to replicate the communication among nodes.
    • FTP (File Transfer Protocol) is used to produce file transfer traffic among the nodes.
    • In this setup, traffic flows directly from the node n0 to n3 whereas traffic from n1 to n4 must go via intermediate nodes since they are not directly associated.
  4. Simulation Duration:
    • For 10 seconds, the simulation runs while that traffic flows via the partial mesh network.

Post-Simulation Analysis:

  1. Trace File Analysis:
    • Open the trace file (out.tr) to examine how packets are sent among the nodes, especially how packets are routed via intermediate nodes in the partial mesh.
  2. NAM Visualization:
    • We can use the NAM (Network Animator) to envision the partial mesh topology. We will observe some nodes fully associated to others and some with fewer connections, and also we can monitor how traffic flows among directly and indirectly connected nodes.
  3. Performance Metrics:
    • We can evaluate the network performance metrics like delay, throughput, and packet loss to evaluate how effectively the partial mesh topology manages the traffic.

Enhancing the Simulation:

  1. Adding More Nodes and Links:
    • Append more nodes and links to the partial mesh topology to replicate a larger and more difficult network.
  2. Simulating Traffic in Both Directions:
    • Configure traffic in both directions such as from n4 to n1 that to mimic the bidirectional communication over the partial mesh network.
  3. Changing Traffic Type:
    • Swap the TCP with UDP or use CBR (Constant Bit Rate) rather than FTP to replicate various kinds of traffic and estimate how the network behaves.
  4. Varying Link Parameters:
    • Test with various link parameters like bandwidth, delay, and queue type such as DropTail or RED to learn how the network performance alters under several conditions.

We methodically followed a staged protocol, carrying out and analysing the Partial Mesh Topology via the simulation platform NS2. Extra specific details regarding this topic will also be shared, if needed.

To achieve successful implementation of Partial Mesh Topology in NS2, don’t hesitate to contact us for the best results. Additionally, you can check out project ideas at ns2project.com, where we offer assistance to ensure you complete your research efficiently, including support for comparison analysis.