How to Calculate Network Redundancy in NS2

To calculate the Network redundancy using NS2, which refers to the presence of additional or backup paths, nodes, or resources within the network to make sure that high availability, reliability, and fault tolerance. Redundancy make certain that even if part of the network fails, then the system can be continued functioning without important performance of the degradation.

In network simulations using NS2, redundancy can calculate according to the various features:

Path Redundancy: The number of another paths are obtainable among the origin and end.

Node Redundancy: The presence of backup nodes, which can take over the roles of failed nodes.
Link Redundancy: The obtainability of backup links in case a primary link fails.

Steps to Calculate Network Redundancy in NS2:

Set Up the Network Topology: Make a network including several links and nodes where redundant paths and links are obtainable among the source and destination nodes.
Identify Redundant Paths: Replicate traffic and verify how many different paths are obtainable among the source and destination nodes. It can be done using routing protocols such as AODV, DSR, or OSPF that maintain route tables, which can examine for numerous ways.
Measure Node and Link Redundancy: Determine if the network contains backup nodes and links, which can take over when a primary node or link fails. It can be replicated by disabling particular nodes or links and verifying if still traffic can be routed via another nodes or links.
Calculate Network Redundancy: We can be computed the network redundancy rely on the number of obtainable backup paths, nodes, or links. The redundancy factor can describe as the ratio of the number of backup paths or resources to the total amount of paths or resources.

General Approach to Calculate Redundancy:

Path Redundancy Calculation: Path redundancy is the number of another paths are obtainable among a source and destination node. If numerous paths exist among the nodes then the network is deliberated more redundant.
Link Redundancy Calculation: Link redundancy refers to the number of another links are obtainable among the nodes. It make sure that if one link fails, data can be routed via another link.
Node Redundancy Calculation: Node redundancy refers to the obtainability of backup nodes, which can take over if a primary node fails.

Example Tcl Script to Simulate Redundancy in NS2:

Given below is an instance Tcl script, which replicates a basic network with numerous ways among the origin and end that permitting to estimate the redundancy.

# 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]

set node5 [$ns node]

# Define links between nodes to create redundancy (multiple paths)

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

$ns duplex-link $node1 $node3 1Mb 10ms DropTail

$ns duplex-link $node0 $node2 1Mb 10ms DropTail

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

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

$ns duplex-link $node3 $node5 1Mb 10ms DropTail

$ns duplex-link $node5 $node4 1Mb 10ms DropTail

# Attach UDP agents and connect traffic between node0 and node4

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 a CBR traffic source

set cbr0 [new Application/Traffic/CBR]

$cbr0 attach-agent $udp0

$cbr0 set packetSize_ 512

$cbr0 set rate_ 1Mb

# Start and stop traffic

$ns at 1.0 “$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 the trace file and stop the simulation

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# End simulation at 6 seconds

$ns at 6.0 “finish”

$ns run

Explanation of the Script:

Network Topology: A network with several paths among the nodes is made. For instance, there are two paths from the nodes node0 to node4 through node1 -> node3 and node2 -> node3. Likewise, two paths exist from node3 to node4 through node3 -> node4 and node3 -> node5 -> node4.
Traffic Generation: Traffic is made from node0 to node4 using a UDP agent and a CBR traffic source.
Redundant Links and Paths: The network is created with redundant links and paths, permitting numerous another routes among the origin and end nodes.

Path Redundancy Calculation:

To estimate the path redundancy, we can count the number of different paths among the source and destination nodes using the routing table or trace file.

Bash Script to Count Path Redundancy:

# Extract routing information from the trace file for packets between node0 and node4

grep “^r” trace.tr | grep “_4_” | awk ‘{print $10}’ | sort | uniq -c

This script:

Extorts the routing paths used by packets from node0 to node4.
Counts how many times each distinct path was used that showing the obtainability of alternate paths.

Node and Link Redundancy Calculation:

To replicate the node or link redundancy, we can be disabled particular links or nodes during the simulation and verify whether alternate nodes or links can take over.

Example Tcl Command to Disable a Link:

# Disable the link between node0 and node1 at time 2.5s

$ns at 2.5 “$ns unlink $node0 $node1”

After disabling a link, we can be observed the trace file to verify if packets are still being routed through an alternate paths that showing redundancy.

Network Redundancy Factor:

The redundancy factor can be computed as the ratio of the number of obtainable backup paths, nodes, or links to the total number of paths, nodes, or links in the network. For sample:

Redundancy Factor (Path)=Number of Backup PathsTotal Number of Paths\text{Redundancy Factor (Path)} = \frac{\text{Number of Backup Paths}}{\text{Total Number of Paths}}Redundancy Factor (Path)=Total Number of PathsNumber of Backup Paths

Example:

If there are 3 paths among the source and destination and 1 path is the primary one used under normal conditions then the redundancy factor would be:

Redundancy Factor=23=0.67\text{Redundancy Factor} = \frac{2}{3} = 0.67Redundancy Factor=32=0.67

It shows that 67% of the network has redundant paths are available.

Summary:

Set up the Network: Make a network topology within NS2 including numerous links and paths among the source and destination nodes.
Measure Path Redundancy: Count the number of different paths are obtainable among the nodes by examining the routing table or trace file.
Simulate Node and Link Redundancy: Disable particular nodes or links to verify if the network can still function using alternative routes.
Calculate Redundancy Factor: Estimate the redundancy factor according to the number of backup paths, nodes, or links are obtainable in the network.

We had indicated the computation procedure with some instance to calculate the network redundancy according to the various features like path redundancy, link redundancy, and node redundancy in NS2. Furthermore, we will be delivered more concepts based on your requirements.

We focus on the availability of supplementary or backup pathways, nodes, or resources for your projects. Please provide us with all relevant project details, and we will assist you. Our team is equipped to help you assess Network Redundancy using the NS2 tool in relation to your project concepts and topics, ensuring that you receive expert guidance.