How to Implement Network Wireshark Analysis in NS2

To implement network Wireshark analysis in NS2 has needs to follow a series of steps that mimic a network scenario in NS2, creating a trace files, and then measuring these trace files in a tool such as Wireshark. Since NS2 doesn’t directly support Wireshark, we can follow this process to export network traffic for analysis. The below are the procedures to implement the network wireshark analysis in ns2:

Steps to Perform Wireshark Analysis for NS2 Simulations:

  1. Run a Network Simulation in NS2 and create a trace file.
  2. Convert the NS2 trace file to a setup that Wireshark can understand, like pcap.
  3. Analyze the pcap file in Wireshark.

Here’s how you can achieve this:

  1. Run a Network Simulation in NS2

We need to execute an NS2 simulation that creates traffic among nodes, like TCP or UDP flows. This will generate an NS2 trace file (.tr) that logs details about packet transmissions, receptions, drops, etc.

Example TCL Script for NS2 Simulation:

# Create a new simulator instance

set ns [new Simulator]

# Define output trace file for analysis

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Define animation file for NAM visualization (optional)

set namfile [open out.nam w]

$ns namtrace-all $namfile

# Define nodes

set n0 [$ns node]

set n1 [$ns node]

# Create a duplex link between nodes n0 and n1

$ns duplex-link $n0 $n1 10Mb 20ms DropTail

# Define TCP agent and attach it to n0

set tcp0 [new Agent/TCP]

$ns attach-agent $n0 $tcp0

# Define a TCP Sink agent and attach it to n1

set sink [new Agent/TCPSink]

$ns attach-agent $n1 $sink

# Connect the TCP agent to the sink

$ns connect $tcp0 $sink

# Define FTP traffic and attach it to the TCP agent

set ftp [new Application/FTP]

$ftp attach-agent $tcp0

# Start the FTP traffic at 1.0 seconds

$ns at 1.0 “$ftp start”

# Stop the simulation at 5.0 seconds

$ns at 5.0 “finish”

# Define finish procedure to close trace files and exit

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam out.nam &

exit 0

}

# Run the simulation

$ns run

  1. Convert NS2 Trace File to pcap Format

NS2 generates trace files in .tr format, but Wireshark requires pcap files. To convert the .tr file to a pcap file, you can use a conversion script or an external tool. Unfortunately, NS2 does not natively support the pcap format.

Option 1: Use an External Tool (Perl/Python Script)

You can write or use an existing Perl or Python script to convert .tr files to .pcap.

Here is an example approach using a Python script to convert a basic NS2 trace to pcap format:

python

Copy code

from scapy.all import *

# Open NS2 trace file

with open(“out.tr”, “r”) as tracefile:

packets = []

# Iterate through trace lines

for line in tracefile:

# Skip lines that are not packet events

if line.startswith(“r”) or line.startswith(“s”):

fields = line.split()

# Extract relevant data fields for pcap generation

event_type = fields[0]  # ‘r’ for received, ‘s’ for sent

time = float(fields[1])  # Timestamp of the event

src_ip = “10.0.0.1”  # Placeholder IP for source

dst_ip = “10.0.0.2”  # Placeholder IP for destination

protocol = fields[3]  # Protocol, e.g., TCP or UDP

packet_size = int(fields[5])  # Size of the packet

# Create a raw IP packet for the event

packet = IP(src=src_ip, dst=dst_ip) / Raw(load=”x” * packet_size)

packets.append(packet)

# Write the packets to a pcap file

wrpcap(“output.pcap”, packets)

This script:

  1. Reads the NS2 trace file (out.tr).
  2. Extracts relevant fields like packet size, source, and destination.
  3. Generates dummy packets using Scapy (a Python networking library).
  4. Compose these packets to a .pcap file.

We can adjust the script to contain more precise packet information, like protocol and source/destination IPs.

Option 2: Use Trace Format Conversion Tools

There are specific existing tools and scripts accessible that systematize the conversion process like NS2ToPCAP or customized scripts available in NS2 repositories.

  1. Analyze the pcap File in Wireshark

Once we have the output.pcap file, we can measure it using Wireshark.

Steps:

  1. Open Wireshark.
  2. Load the output.pcap file by navigating to File > Open and selecting the .pcap file.
  3. We can now examine individual packets, measure traffic patterns, monitor packet flows, and look for certain network characteristics such as TCP handshakes, packet drops, delays.

Analysing the Trace in Wireshark

Here’s what we can do with Wireshark once the .pcap file is loaded:

  • TCP Stream Analysis: Follow a TCP stream to examine how packets are sent and acknowledged.
  • Packet Loss: Aspect for rerouting or out-of-order packets to regulate in which packet loss occurs.
  • Timing Analysis: Evaluate the timing of packets, classifying delay, jitter, and latency in communication.
  • Protocol Analysis: Dive deeper into particular protocols such as TCP, UDP and examine headers and payloads.
  1. Advanced Features in Wireshark
  • Filter Packets: Wireshark enable them to filter packets according to particular condition, like IP addresses, port numbers, or protocols. we can enter filters such as:
    • tcp: Display only TCP packets.
    • udp: Display only UDP packets.
    • ip.src == 10.0.0.1: Show only packets sent by the source IP 10.0.0.1.
  • Graphing and Statistics: Wireshark can create useful graphs and statistics for further analysis. For example:
    • I/O Graph: Shows packet rate over time.
    • TCP Stream Graph: Envision the flow of packets in a TCP stream, useful for analysing throughput difficulties.

Conclusion:

Since NS2 doesn’t natively export to Wireshark’s pcap format, we can still perform network analysis by:

  1. Simulating traffic in NS2 and creating a trace file.
  2. Converting the NS2 trace file to pcap format using a script or tool.
  3. Loading the pcap file into Wireshark for comprehensive packet-level analysis.

We had understood and get a knowledge on how to setup and how to analyse the traffic that were executed using the ns2 tool. We will also provide the valuable insights on how the network Wireshark analysis will perform in other simulation tools.

ns2project.com specifies in Network Wireshark Analysis within the NS2 framework. We provide expert guidance on exporting network traffic for your project analysis. Reach out to us for swift results. Our dedicated team is also prepared to deliver an in-depth project performance analysis along with thorough explanations.