How to Calculate Network Load balance factor in NS2

To calculate the network load balance factor in NS2 (Network Simulator 2), which is a metric that computes how evenly traffic is delivered over the network. In a well-balanced network, no single node or link is overloaded, and the traffic is delivered successfully over numerous links or paths. Load balancing is a crucial for permitting the bottlenecks and make sure that efficient resource utilization in networks. The following is a simple approach on how to compute the network load balance factor in NS2:

Steps to Calculate Load Balance Factor in NS2:

  1. Simulate Network Traffic:
    Configure a network topology in NS2 in which the traffic flows among nodes. We can be used the routing protocols such as AODV, DSDV, or DSR to deliver the traffic across several paths.
  2. Measure the Traffic Load on Each Node or Link:
    Track the traffic load (in terms of the number of packets or data volume) on every node or link within the network. We can extort this data from the NS2 trace file.
  3. Calculate Load Imbalance:
    Calculate the load on each node or link and compare it including the average load across the network. A well-balanced network will have same loads on all nodes or links, whereas a poorly balanced network will have similar nodes or links with much higher loads than others.
  4. Calculate the Load Balance Factor (LBF):
    The load balance factor is normally described as the ratio of the most heavily loaded node or link to the average load over all nodes/links:

Load Balance Factor (LBF)=Maximum Load on a Node/LinkAverage Load on All Nodes/Links\text{Load Balance Factor (LBF)} = \frac{\text{Maximum Load on a Node/Link}}{\text{Average Load on All Nodes/Links}}Load Balance Factor (LBF)=Average Load on All Nodes/LinksMaximum Load on a Node/Link​

A value of 1 shows perfect load balancing (where all nodes or links have equal load), whereas higher values are show load imbalance.

Example Tcl Script to Simulate a Simple Network in NS2:

Given below is an instance NS2 Tcl script, which simulates a basic network in which traffic is distributed over numerous nodes, and later we can compute the load on each node.

# Create a new simulator instance

set ns [new Simulator]

# Define nodes

set node0 [$ns node]

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

set node4 [$ns node]

# Define network links between nodes

$ns duplex-link $node0 $node1 1Mb 10ms DropTail

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

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

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

# Attach UDP agents and connect traffic

set udp0 [new Agent/UDP]

set null0 [new Agent/Null]

$ns attach-agent $node0 $udp0

$ns attach-agent $node4 $null0

$ns connect $udp0 $null0

# Create traffic source (CBR)

set cbr0 [new Application/Traffic/CBR]

$cbr0 attach-agent $udp0

$cbr0 set packetSize_ 512

$cbr0 set rate_ 1Mb

# Start traffic at 1.0 second and stop at 5.0 seconds

$ns at 1.0 “$cbr0 start”

$ns at 5.0 “$cbr0 stop”

# Open trace file to log events

set tracefile [open trace.tr w]

$ns trace-all $tracefile

# Define finish procedure to close trace file and stop the simulation

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# End simulation at 6.0 seconds

$ns at 6.0 “finish”

$ns run

  1. Trace File Analysis for Load Calculation:

After running the simulation, the trace file (trace.tr) will be recorded events like packet transmissions and receptions among the nodes. We can be used this trace file to estimate the traffic load on each node or link.

Example Trace File Output:

s 1.0 _0_ AGT — 512 [0 0 0 0] ——- [0:0 4:0 32 0]

r 1.2 _1_ AGT — 512 [0 0 0 0] ——- [0:0 4:0 32 0]

r 1.4 _2_ AGT — 512 [0 0 0 0] ——- [0:0 4:0 32 0]

r 1.6 _3_ AGT — 512 [0 0 0 0] ——- [0:0 4:0 32 0]

r 1.8 _4_ AGT — 512 [0 0 0 0] ——- [0:0 4:0 32 0]

Here:

  • s denotes a packet sent.
  • r signifies a packet received.
  1. Calculate the Traffic Load on Each Node or Link:

To assess the traffic load on each node or link we count the number of packets sent and received by each node during the simulation.

Bash Script to Calculate Load on Each Node:

# Calculate the number of packets sent/received by each node

for node in {0..4}; do

sent=$(grep “^s” trace.tr | grep “_${node}_” | wc -l)

received=$(grep “^r” trace.tr | grep “_${node}_” | wc -l)

load=$(($sent + $received))

echo “Node $node Load: $load packets”

done

This script computes the total load (sum of sent and received packets) for each node.

  1. Calculate Load Balance Factor (LBF):

When we have the load on each node then we can compute the maximum load, average load, and the load balance factor.

Bash Script to Calculate Load Balance Factor:

# Store the loads of all nodes in an array

declare -a node_loads

total_load=0

max_load=0

# Calculate the load for each node and find the maximum load

for node in {0..4}; do

sent=$(grep “^s” trace.tr | grep “_${node}_” | wc -l)

received=$(grep “^r” trace.tr | grep “_${node}_” | wc -l)

load=$(($sent + $received))

node_loads[$node]=$load

total_load=$(($total_load + $load))

if [ $load -gt $max_load ]; then

max_load=$load

fi

done

# Calculate average load

num_nodes=5

average_load=$(echo “scale=2; $total_load / $num_nodes” | bc)

# Calculate Load Balance Factor (LBF)

lbf=$(echo “scale=2; $max_load / $average_load” | bc)

echo “Load Balance Factor: $lbf”

This script evaluates the following:

  • Total load: Sum of the loads on all nodes.
  • Maximum load: The highest load on any node.
  • Average load: The average load across all nodes.
  • Load Balance Factor (LBF): The ratio of the maximum load to the average load.
  1. Interpret the Load Balance Factor:
  • If the LBF is near to 1then it shows that the load is well-balanced over all nodes (i.e., all nodes carry a similar load).
  • If the LBF is greater than 1 then it specifies some imbalance in the network, with one or more nodes are carrying a disproportionate amount of the load compared to others.
  1. Post-Simulation Analysis:

When the simulation is finish and the load balance factor is computed then we can examine the outcomes to determine if network’s traffic distribution is optimal or if particular nodes or links are becoming bottlenecks.

Summary:

  1. Set Up the Simulation: Make a network topology in NS2 and replicate traffic flows.
  2. Measure the Traffic Load on Each Node or Link: We can use the trace file to count the number of packets sent or received by each node or link.
  3. Calculate the Maximum and Average Load: Calculate the load on each node, and discover the maximum and average load.
  4. Calculate the Load Balance Factor (LBF): We can be use the formula: LBF=Maximum LoadAverage Load\text{LBF} = \frac{\text{Maximum Load}}{\text{Average Load}}LBF=Average LoadMaximum Load​
  5. Interpret the Results: Examine the LBF to measure how successfully the network is balanced.

We had successfully calculated the network load balance factor that used some essential formula and required examples then we analysed the result within NS2 simulation platform. Moreover, we will be presented further concepts on this network as per your requirements. It is preferable to seek professional assistance in order to calculate the Network Load Balance Factor in the NS2 tool. Contact us, and we will assist you with timely delivery and optimal outcomes.