How to Calculate Network Connection Loss in NS2

To calculate the network connection using NS2 simulation environment, which refers to the scenarios in which packets are dropped or lost in the course of the transmission and leading to a breakdown in communication among the nodes. It is particularly significant in wireless networks in which the link instability, interference, and congestion can outcome in packet drops and connection failures. The network connection loss can assess by estimating the packet loss rate that is the ratio of packets that are transferred but never received at the end. The followings are key metrics and simple technique to approach the Network Connection Loss in NS2:

Key Metrics for Connection Loss:

Packet Loss Ratio (PLR): The percentage of packets, which were lost during transmission.
Packet Drop Events: Examples in which the packets are explicitly dropped because of the network congestion, link failures, or other reasons.
Lost Packets: Packets, which were transmitted but never attained the end.

Steps to Calculate Network Connection Loss in NS2

Set Up NS2 Simulation:

Primarily, we require to configure the simulation in which packets are transmitted from one node (source) to other node (destination). Then we can be estimated the trace file generated by NS2 to compute the number of lost packets and the packet loss ratio.

Example TCL Script for Data Transmission:

# Create the simulator

set ns [new Simulator]

# Create 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 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”

# Enable tracing to capture packet transmission, reception, and drop events

set tracefile [open out.tr w]

$ns trace-all $tracefile

# End the simulation after 12 seconds

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# End simulation at 12 seconds

$ns at 12.0 “finish”

Trace File Overview:

When the simulation finishes then the simulation platform NS2 generates a trace file (out.tr), which records the events like packet transmission, reception, and drop. We will be used these events to assess the connection loss by examining the number of dropped packets and total packets are transmitted.

Example Trace File Entries:

plaintext

Copy code

s 1.000000000 _0_ AGT — 512 cbr 0 0.0 1.0 1.0

r 1.010000000 _1_ AGT — 512 cbr 0 0.0 1.0 1.0

d 1.500000000 _0_ AGT — 512 cbr 1 0.0 1.0 1.0

s 2.000000000 _0_ AGT — 512 cbr 1 0.0 1.0 1.0

d 2.010000000 _0_ AGT — 512 cbr 2 0.0 1.0 1.0

In the trace file:

s: Packet sent event.
r: Packet received event.
d: Packet dropped event, which indicates the packet was lost.
0 and 1: Node IDs (source node _0_, destination node _1_).
512: Packet size in bytes.

Calculate Packet Loss Ratio (PLR):

To estimate the Packet Loss Ratio (PLR), we can be used the below formula:

PLR=Number of Dropped PacketsNumber of Sent Packets×100\text{PLR} = \frac{\text{Number of Dropped Packets}}{\text{Number of Sent Packets}} \times 100PLR=Number of Sent PacketsNumber of Dropped Packets×100

We require to count the number of sent packets and dropped packets then calculate the ratio among them.

AWK Script to Calculate PLR:

BEGIN {

sent_packets = 0;

dropped_packets = 0;

}

# Count sent packets from the source node (_0_)

$1 == “s” && $4 == “_0_” && $7 == “cbr” {

sent_packets++;

}

# Count dropped packets at the source node (_0_)

$1 == “d” && $4 == “_0_” && $7 == “cbr” {

dropped_packets++;

}

END {

if (sent_packets > 0) {

plr = (dropped_packets / sent_packets) * 100;

print “Packet Loss Ratio (PLR): ” plr “%”;

print “Total Sent Packets: ” sent_packets;

print “Total Dropped Packets: ” dropped_packets;

} else {

print “No packets were sent!”;

}

This script:

Traces the number of sent packets and dropped packets.
Calculate the Packet Loss Ratio (PLR) as the ratio of dropped packets to sent packets.

Calculate Connection Loss as Dropped Packets:

As well as the Packet Loss Ratio (PLR), we can directly assess the connection loss by counting the total number of dropped packets. It provides an idea of how frequently the connection experiences packet loss that can lead to communication breakdowns.

AWK Script to Calculate Dropped Packets:

BEGIN {

dropped_packets = 0;

}

# Count dropped packets at the source node (_0_)

$1 == “d” && $4 == “_0_” && $7 == “cbr” {

dropped_packets++;

}

END {

print “Total Dropped Packets: ” dropped_packets;

}

Above simple script counts the total amount of dropped packets that directly shows how many packets were lost in the course of transmission.

Running the AWK Script:

We can be saved the AWK scripts (for PLR or dropped packets) as isolated files then run them on the trace file generated by NS2.

For example, to calculate PLR:

awk -f plr.awk out.tr

To calculate dropped packets:

awk -f dropped_packets.awk out.tr

Interpreting the Results:

The outcome will be delivered with:

Packet Loss Ratio (PLR) that is the percentage of packets are lost during transmission.
Total Dropped Packets that shows how many packets were lost because of network issues like congestion or link failures.

Example output for PLR:

Packet Loss Ratio (PLR): 20.0%

Total Sent Packets: 10

Total Dropped Packets: 2

Example output for dropped packets:

Total Dropped Packets: 2

Conclusion:

To compute the network connection loss in NS2:

Configure a simulation that packets are sent among the nodes.
Allow tracing to capture packet transmission, reception, and drop events.
Estimate the trace file using AWK scripts to count the total number of dropped packets also compute the Packet Loss Ratio (PLR).
We can be used the outcomes to calculate the connection stability and packet loss in the network that is significant for estimating the reliability of communication in the network.

To conclude, we had expressed the computation process including some examples using TCL and AWK scripts to calculate and analyse the Network Connection Loss within NS2 simulation tool. More informations will be provided rely on your needs. Please provide us with all relevant parameter details, and we assure you that we will deliver optimal comparison project outcomes. It can be quite challenging, so we encourage you to maintain communication with us; we are here to guide you toward achieving the best results. Our focus includes addressing issues related to link instability, interference, and congestion, so share your information with us to attain the most favourable results.