How to Start Next Hop Protocol Project Using NS2

To create a Next Hop Protocol projects using NS2 (Network Simulator 2), follow this step-by-step procedure. The Next Hop idea has concentrate for select the immediate next node for sending the packets according to their routing table or metric. It’s often used in different routing algorithms, such as Shortest Path First or Distance Vector protocols.

Steps to Start a Next Hop Protocol Project in NS2

  1. Set up the NS2 Environment

NS2 which assure is installed and ready for use.

  • Install NS2 on Ubuntu/Linux:

sudo apt-get update

sudo apt-get install ns2 nam xgraph

  • Verify installation:

ns

If successful, you’ll see the % prompt.

  1. Understand the Next Hop Concept
  • Definition: In the routing process for the next hop is the immediate node that a packet should be transfer the reach for final destination.
  • Use Case: It executes the unicast routing protocols such as DSDV, AODV, or RIP.
  • Decision Criteria:
    • Shortest path
    • Lowest latency
    • Minimum hop count
  1. Design the Network Topology

Define:

  • Number of nodes
  • Connectivity for sample links among nodes
  • Traffic sources and destinations
  • Next Hop Selection Logic for instance based on hop count or predefined paths.
  1. Create a TCL Script

Below is an example TCL script implementing Next Hop Routing:

NS2 Script for Next Hop Protocol

# Initialize the Simulator

set ns [new Simulator]

set tracefile [open nexthop_trace.tr w]

$ns trace-all $tracefile

set namfile [open nexthop_nam.nam w]

$ns namtrace-all $namfile

# Define Colors for Visualization

$ns color 1 Blue

$ns color 2 Red

# Create Nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

set n4 [$ns node]

# Create Links (Topology)

$ns duplex-link $n0 $n1 2Mb 5ms DropTail

$ns duplex-link $n1 $n2 2Mb 5ms DropTail

$ns duplex-link $n2 $n3 2Mb 5ms DropTail

$ns duplex-link $n3 $n4 2Mb 5ms DropTail

$ns duplex-link $n0 $n2 2Mb 10ms DropTail

# Define Next Hop Behavior (Routing Logic)

# Setting predefined routes from source to destination

$n0 label “Source”

$n4 label “Destination”

$ns rtproto Static   ;# Use static routing for simplicity

# Define Static Routes (Next Hop Routing Table)

$n0 add-route $n1 1

$n1 add-route $n2 1

$n2 add-route $n3 1

$n3 add-route $n4 1

 

# Define Traffic Source (UDP/CBR)

set udp [new Agent/UDP]

set null [new Agent/Null]

$ns attach-agent $n0 $udp

$ns attach-agent $n4 $null

$ns connect $udp $null

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp

$cbr set packetSize_ 512

$cbr set rate_ 1Mb

# Schedule Traffic

$ns at 1.0 “$cbr start”

$ns at 4.0 “$cbr stop”

# Finish Procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam nexthop_nam.nam &

exit 0

}

# Run the Simulation

$ns at 5.0 “finish”

$ns run

  1. Run the Simulation
  1. Store the script as nexthop_simulation.tcl.
  2. Process for the replication in NS2:

ns nexthop_simulation.tcl

  1. Outputs:
    • Trace file: nexthop_trace.tr
    • NAM file: nexthop_nam.nam for sample visualize the packet flow.
  1. Analyze Results

Key Metrics to Analyze:

  1. Packet Delivery Ratio: Use the tools like AWK for study the tranmsit and received packets:

awk ‘BEGIN {sent=0; received=0}

{if ($1==”s”) sent++; if ($1==”r”) received++}

END {print “PDR:”, received/sent*100 “%”}’ nexthop_trace.tr

  1. End-to-End Delay: Extract the latency for timestamps in forwarding and receiveing packets.
  2. Throughput: Sum up the number of data received per unit time through throughput.
  1. Extend the Project
  1. Dynamic Routing: Alter the script for integrates the dynamic next-hop selection using AODV or DSDV.
  2. Failure Handling: Replicate the connection/node failures and execute the recovery mechanisms.
  3. Mobility Models: Use the mobility models for validate the Random Waypoint Mobility next-hop choose the dynamic networks.
  4. Performance Comparison:
    • Assoicate the fixed next-hop routing through protocols such as AODV, DSR, or OSPF.
  1. Document the Results

Include the following:

  • Network Topology: Define the node and connection setting.
  • Routing Logic: State on how the selected is next-hop .
  • Performance Metrics:
    • Packet Delivery Ratio (PDR)
    • End-to-End Delay
    • Routing Overhead
    • Throughput
  • Comparative Analysis:
    • Associate through other protocols for sample Static vs Dynamic Next Hop.

Finally, we had successfully delivered the significant procedures to simulate the Next Hop Routing in ns2 tool and we will issue an additional document for enquiries related to this project.