How to Calculate Network Packet Analysis in NS2
To calculate Packet analysis in NS2 has needs to inspect numerous contexts of packet transmission, reception, and loss to evaluate network performance. The performance metric for packet analysis usually contain Packet Delivery Ratio (PDR), Packet Loss, Throughput, End-to-End Delay, and Jitter. Each of these parameters delivers insights into diverse features of the network. The following are the step-by-implementation to compute the network packet analysis in ns2:
Steps for Network Packet Analysis in NS2:
- Set Up NS2 Simulation: set up a simulation with nodes and traffic among them.
- Run the Simulation: Perform the NS2 simulation to create a trace file.
- Analyze the Trace File: Utilize an AWK script or other tools to parse the trace file and extract key parameters.
Example TCL Script for Data Transmission:
Here’s a basic sample to mimic packet transmission among two nodes using UDP and CBR traffic:
# Create the simulator
set ns [new Simulator]
# Define the topology with two nodes: source and destination
set node_(0) [$ns node]
set node_(1) [$ns node]
# Create a duplex link between the nodes (1 Mbps bandwidth, 10ms delay)
$ns duplex-link $node_(0) $node_(1) 1Mb 10ms DropTail
# Attach UDP agents to nodes for sending and receiving data
set udp0 [new Agent/UDP]
set sink [new Agent/Null]
$ns attach-agent $node_(0) $udp0
$ns attach-agent $node_(1) $sink
$ns connect $udp0 $sink
# Set up Constant Bit Rate (CBR) traffic on the UDP agent
set cbr0 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp0
$cbr0 set packetSize_ 512 ;# Packet size in bytes
$cbr0 set rate_ 1Mb ;# Transmission rate
# Start and stop the traffic
$ns at 1.0 “$cbr0 start”
$ns at 10.0 “$cbr0 stop”
# Set up the simulation to end and generate trace files
$ns at 12.0 “finish”
proc finish {} {
global ns
$ns flush-trace
exit 0
}
# Run the simulation
$ns run
Key Metrics for Packet Analysis:
- Packet Delivery Ratio (PDR):
PDR=Total Packets ReceivedTotal Packets Sent×100\text{PDR} = \frac{\text{Total Packets Received}}{\text{Total Packets Sent}} \times 100PDR=Total Packets SentTotal Packets Received×100
AWK Script for PDR:
BEGIN {
sent_packets = 0;
received_packets = 0;
}
# Count sent packets from the source node (_0_)
$1 == “s” && $4 == “_0_” && $7 == “cbr” {
sent_packets++;
}
# Count received packets at the destination node (_1_)
$1 == “r” && $4 == “_1_” && $7 == “cbr” {
received_packets++;
}
END {
if (sent_packets > 0) {
pdr = (received_packets / sent_packets) * 100;
print “Packet Delivery Ratio (PDR): ” pdr “%”;
print “Total Packets Sent: ” sent_packets;
print “Total Packets Received: ” received_packets;
} else {
print “No packets were sent!”;
}
}
- Packet Loss:
Packet Loss=Total Packets Sent−Total Packets Received\text{Packet Loss} = \text{Total Packets Sent} – \text{Total Packets Received}Packet Loss=Total Packets Sent−Total Packets Received
AWK Script for Packet Loss:
This script is alike to the PDR script; nevertheless it estimates the number of lost packets.
BEGIN {
sent_packets = 0;
received_packets = 0;
}
# Count sent packets from the source node (_0_)
$1 == “s” && $4 == “_0_” && $7 == “cbr” {
sent_packets++;
}
# Count received packets at the destination node (_1_)
$1 == “r” && $4 == “_1_” && $7 == “cbr” {
received_packets++;
}
END {
lost_packets = sent_packets – received_packets;
print “Packet Loss: ” lost_packets;
print “Total Packets Sent: ” sent_packets;
print “Total Packets Received: ” received_packets;
}
- Throughput:
Throughput=Total Data Received (in bits)Total Time (in seconds)\text{Throughput} = \frac{\text{Total Data Received (in bits)}}{\text{Total Time (in seconds)}}Throughput=Total Time (in seconds)Total Data Received (in bits)
AWK Script for Throughput:
BEGIN {
total_bytes = 0;
start_time = -1;
end_time = -1;
}
# Capture packet reception at the destination node (_1_)
$1 == “r” && $4 == “_1_” && $7 == “cbr” {
if (start_time == -1) {
start_time = $2; # Start time is the time of the first packet received
}
end_time = $2; # End time is the time of the last packet received
total_bytes += $8; # Add the size of the packet (field 8) to the total
}
END {
if (end_time > start_time) {
duration = end_time – start_time;
throughput = (total_bytes * 8) / duration; # Convert bytes to bits and calculate throughput
print “Throughput: ” throughput ” bps”;
} else {
print “No packets were received!”;
}
}
- End-to-End Delay:
End-to-End Delay=Sum of Delays for All PacketsNumber of Packets Received\text{End-to-End Delay} = \frac{\text{Sum of Delays for All Packets}}{\text{Number of Packets Received}}End-to-End Delay=Number of Packets ReceivedSum of Delays for All Packets
AWK Script for End-to-End Delay:
BEGIN {
total_delay = 0;
received_packets = 0;
}
# Record the time each packet was sent from the source (_0_)
$1 == “s” && $4 == “_0_” && $7 == “cbr” {
packet_time[$10] = $2; # Store the transmission time indexed by packet ID
}
# Calculate the delay for each received packet at the destination (_1_)
$1 == “r” && $4 == “_1_” && $7 == “cbr” {
delay = $2 – packet_time[$10]; # Calculate the end-to-end delay
total_delay += delay;
received_packets++;
}
END {
if (received_packets > 0) {
avg_delay = total_delay / received_packets;
print “Average End-to-End Delay: ” avg_delay ” seconds”;
} else {
print “No packets were received!”;
}
}
- Jitter: Jitter is the variation in packet delay. It is computed as the difference among the delays of consecutive packets.
AWK Script for Jitter:
BEGIN {
previous_delay = -1;
total_jitter = 0;
packet_count = 0;
}
# Record the time each packet was sent from the source (_0_)
$1 == “s” && $4 == “_0_” && $7 == “cbr” {
packet_time[$10] = $2; # Store the transmission time indexed by packet ID
}
# Calculate jitter based on differences between consecutive packet delays
$1 == “r” && $4 == “_1_” && $7 == “cbr” {
delay = $2 – packet_time[$10]; # Calculate end-to-end delay
if (previous_delay >= 0) {
jitter = delay – previous_delay;
total_jitter += (jitter >= 0 ? jitter : -jitter); # Accumulate absolute jitter
}
previous_delay = delay;
packet_count++;
}
END {
if (packet_count > 1) {
avg_jitter = total_jitter / (packet_count – 1);
print “Average Jitter: ” avg_jitter ” seconds”;
} else {
print “Not enough packets to calculate jitter!”;
}
}
- Run the AWK Scripts:
We can execute the AWK scripts on the trace file created by the NS2 simulation.
Example command to run an AWK script:
awk -f pdr.awk out.tr
Conclusion:
In NS2, packet analysis has contained parsing the trace file to calculate parameters such as Packet Delivery Ratio (PDR), Packet Loss, Throughput, End-to-End Delay, and Jitter. By utilizing AWK scripts to extract information from the trace file, we can gain insights into the performance of network simulation.
Through this approach, we understood the procedures to calculate the Packet analysis in the network that were executed using ns2 simulation. We also offer the valuable insights regarding how the Packet analysis will perform in other simulation tools.
Keep connected with ns2project.com for assistance in calculating network packet analysis in NS2, as it can be quite challenging. We are here to provide you with the best guidance and results.