How to Calculate Network Resource Utilization in NS2

To calculate network resource utilization in NS2, we need to follow a series of steps which includes configuring the simulation, capturing relevant parameters, and then processing the information to estimate the resource utilization. Here’s a general guide to get you started:

Step-by-Step Implementation:

  1. Define Resource Utilization Metrics

Network resource utilization can defined to numerous aspects based on what resources we are concentrating on, such as:

  • Bandwidth utilization (data rate usage)
  • CPU utilization (processing power)
  • Memory utilization
  • Network node or link utilization
  • Packet delivery ratio (PDR), latency, etc.

For NS2, bandwidth and node/link utilization are common resources to measure.

  1. Set Up the Simulation in NS2

Generate the network topology and traffic flow in NS2 simulation script (a .tcl file). Here’s a simple sample of a simulation script setup:

# Create simulator instance

set ns [new Simulator]

# Open trace file for output

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Define nodes

set n0 [$ns node]

set n1 [$ns node]

# Create link between nodes

$ns duplex-link $n0 $n1 1Mb 10ms DropTail

# Set up traffic (CBR)

set udp [new Agent/UDP]

$ns attach-agent $n0 $udp

set null [new Agent/Null]

$ns attach-agent $n1 $null

$ns connect $udp $null

set cbr [new Application/Traffic/CBR]

$cbr set packetSize_ 500

$cbr set interval_ 0.005

$cbr attach-agent $udp

# Schedule events

$ns at 0.5 “$cbr start”

$ns at 4.5 “$cbr stop”

$ns at 5.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

  1. Collect Trace Data

NS2 creates a trace file like out.tr in the course of the simulation. This file will contain numerous data, like packet send and receive events, link utilization, packet drops, and delays.

Each line in the trace file usually looks something like this:

r 0.123456 0 1 cbr 1000 ——- 1 0.0 0.0 1.0

+ 0.123789 0 1 tcp 1040 ——- 1 0.0 0.0 1.0

The trace file contains the following data:

  • Event (receives r, send +, drop d, etc.)
  • Time
  • Source node
  • Destination node
  • Packet size
  • Flow ID, etc.
  1. Analyse Trace Data to Calculate Resource Utilization

Use a script (in AWK, Python, or Perl) to process the trace file and extract data related to resource utilization.

Example 1: Bandwidth Utilization

Bandwidth utilization is the ratio of used bandwidth to the available bandwidth. We can estimate it by dividing the total bytes sent over a link by the simulation time and the link capacity.

awk ‘$1 == “+” && $4 == “tcp” { total_bytes += $6 } END { print “Total Bytes: “, total_bytes }’ out.tr

To calculate bandwidth utilization, use:

Bandwidth Utilization = (Total Bytes Sent) / (Link Bandwidth * Simulation Time)

Example 2: Node or Link Utilization

We can estimate link utilization by evaluating the traffic via each link. Summing up the number of packets sent over a link and related it with the maximum capacity of that link:

awk ‘$1 == “+” { count++ } END { print “Packets Sent: “, count }’ out.tr

Example 3: CPU or Memory Utilization

CPU and memory utilization cannot be directly evaluated from NS2. But, if you are executing particular applications such as TCP or CBR flows, we can estimate utilization by summing the processing tasks like the number of packets processed or events managed.

  1. Visualize or Post-process Data

Once we have extracted the relevant parameters, we can:

  • Utilize a spreadsheet like Excel to calculate ratios, percentages, and envision resource utilization.
  • Utilize a plotting tool such as gnuplot, matplotlib to generate graphs that display utilization over time.

Here’s a instance Python script to estimate bandwidth utilization from the trace file:

# Python script to calculate bandwidth utilization from a trace file

total_bytes = 0

simulation_time = 5.0  # Set this to your simulation time in seconds

link_bandwidth = 1 * 10**6  # 1 Mbps

with open(‘out.tr’, ‘r’) as f:

for line in f:

data = line.split()

if data[0] == ‘+’ and data[4] == ‘tcp’:

total_bytes += int(data[5])

# Bandwidth utilization in percentage

bandwidth_utilization = (total_bytes * 8) / (link_bandwidth * simulation_time) * 100

print(f”Bandwidth Utilization: {bandwidth_utilization:.2f}%”)

  1. Interpret the Results
  • High utilization: Designates the network is being heavily used, and congestion might happen.
  • Low utilization: it signifies underutilization of resources that can impact network efficiency.

By following these procedures, we can estimate network resource utilization in terms of particular network scenario in NS2.

We had aggregated the important information on how to compute the network resource utilization in NS2 simulator that has to generate the network topology then accumulated trace Data and evaluated the results. We plan to deliver more information regarding the resource utilization in further manual. Contact ns2prject.com for information on your Network Resource Utilization in the NS2 tool. We can assist you with innovative project ideas and topics. Share your parameter details with us to receive help in measuring network performance levels. We will guide you in configuring the simulation and capturing the necessary parameters for your projects.