How to Implement Network Bootstrapping in NS2

To implement the Network Bootstrapping with in NS2, that refers to the protocol of the initializing a network in which the nodes are discover each other, set up themselves, and ascertain the communication. It is specifically vital within ad hoc networks, sensor networks, or peer-to-peer systems in which nodes are actively enter the network without the prior configuration. It is normally encompasses discovery mechanisms, address allocation, and configure the initial communication or routing tables.

Key Concepts for Network Bootstrapping in NS2:

  1. Node Initialization: These nodes are initialized and start the broadcasting their presence or listening for others.
  2. Discovery Process: This nodes are find each other, either via broadcasting or routing protocols such as AODV, DSR, etc.
  3. Address or Role Assignment: Nodes may allocate the roles or addresses actively if required, mimicking the allocation of IP addresses or network responsibilities.
  4. Communication Setup: When a nodes are discovered, they ascertain the communication via TCP/UDP agents.

Steps to Implement Network Bootstrapping in NS2

  1. Node Initialization: Describe the nodes in the simulation and set their primary configuration like routing protocol, agents.
  2. Node Discovery: These nodes can find each other using a routing protocol or a custom discovery mechanism such as beaconing.
  3. Address/Role Assignment (Optional): If required, replicate the IP address assignment or role set up dynamically.
  4. Communication Setup: Nodes are establish the communication after bootstrapping such as setting up TCP/UDP connections.

Example: Simulating Network Bootstrapping in NS2

In this instance,  we will replicate a simple bootstrapping procedure in which nodes are discover each other using the AODV routing protocol, and also after discovery, they configure the communication using TCP. This simulates the initialization of an ad hoc network.

Step 1: Define Nodes and Set Up the Routing Protocol

# Define the simulator object

set ns [new Simulator]

# Define trace and nam files for output

set tracefile [open out.tr w]

set namfile [open out.nam w]

$ns trace-all $tracefile

$ns namtrace-all $namfile

# Define a ‘finish’ procedure to end the simulation and visualize in NAM

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam out.nam &

exit 0

}

# Set up the topography for the simulation area

set topo [new Topography]

$topo load_flatgrid 1000 1000

# Define the wireless channel

set chan [new Channel/WirelessChannel]

# Configure wireless nodes using AODV for the bootstrapping process

$ns node-config -adhocRouting AODV \

-llType LL \

-macType Mac/802_11 \

-ifqType Queue/DropTail/PriQueue \

-ifqLen 50 \

-antType Antenna/OmniAntenna \

-propType Propagation/TwoRayGround \

-phyType Phy/WirelessPhy \

-channel $chan

# Create three nodes for the bootstrapping process

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set node positions for NAM visualization

$node1 set X_ 100; $node1 set Y_ 100; $node1 set Z_ 0

$node2 set X_ 500; $node2 set Y_ 500; $node2 set Z_ 0

$node3 set X_ 900; $node3 set Y_ 100; $node3 set Z_ 0

Step 2: Configure Node Discovery Using the Routing Protocol (AODV)

# Define bootstrapping through node discovery using AODV

# Node1 will act as a TCP source

set tcp0 [new Agent/TCP]

set sink0 [new Agent/TCPSink]

$ns attach-agent $node1 $tcp0

$ns attach-agent $node2 $sink0

$ns connect $tcp0 $sink0

# Node3 will act as a source for a second communication path

set tcp1 [new Agent/TCP]

set sink1 [new Agent/TCPSink]

$ns attach-agent $node3 $tcp1

$ns attach-agent $node2 $sink1

$ns connect $tcp1 $sink1

# Start FTP traffic after bootstrapping (node discovery is done)

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ftp0 start 2.0  ;# Start communication at 2 seconds

$ftp0 stop 6.0   ;# Stop communication at 6 seconds

# Start FTP traffic for second communication path

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ftp1 start 3.0  ;# Start communication at 3 seconds

$ftp1 stop 7.0   ;# Stop communication at 7 seconds

Step 3: Optional: Simulate Node Mobility or Dynamic Address Assignment

To replicate the dynamic performance, like a node mobility or dynamic address assignment, we can launch the movement or IP address changes dynamically while the bootstrapping process.

# Simulate node mobility to trigger dynamic network configuration

$ns at 1.0 “$node1 setdest 200 200 10.0”

$ns at 1.0 “$node3 setdest 800 800 5.0”

# Optional: Simulate IP address assignment or role configuration (abstract)

proc assign_address {node id} {

puts “Node $node assigned address $id”

}

# Assign addresses to nodes after bootstrapping

$ns at 2.0 “assign_address $node1 192.168.1.1”

$ns at 2.0 “assign_address $node2 192.168.1.2”

$ns at 2.0 “assign_address $node3 192.168.1.3”

Step 4: Schedule the End of the Simulation

# Schedule the end of the simulation

$ns at 10.0 “finish”

# Run the simulation

$ns run

Explanation of the Script

  1. Node Initialization: These three nodes are initialized that each with the AODV routing protocol for the node discovery. It permits nodes to dynamically discover each other while the bootstrapping process.
  2. Discovery and Routing: When nodes are discovered using AODV, TCP agents are connected to mimic communication among the nodes. Node1 communicates with Node2, and Node3 communicates with Node2, both across the distinct FTP sessions.
  3. Optional Dynamic Behaviour: Mobility and IP address assignment are replicated for more dynamic bootstrapping, in which nodes are move and allocate roles or addresses while the bootstrapping process.
  4. Traffic Generation: FTP traffic is used to replicate the data transfer when the nodes have finished the bootstrapping process and discovered each other.

Run the Simulation

We can save the script as network_bootstrapping.tcl then run it using:

ns network_bootstrapping.tcl

It will produce a trace file (out.tr) and a NAM file (out.nam). The trace file records the packet transmissions, and the NAM file permits to envision the bootstrapping and communication among the nodes.

Visualize the Simulation in NAM

To visualize the simulation in NAM, use the below command:

nam out.nam

In NAM, we will monitor the nodes are discovering each other using AODV, and communication being established among them.

Advanced Features for Bootstrapping

  1. Dynamic Topology Changes: Launch more difficult mobility patterns that nodes are dynamically enter and leave the network, forcing continuous bootstrapping and reconfiguration.

Example:

$ns at 3.0 “$node1 setdest 300 300 5.0”

$ns at 4.0 “$node2 setdest 400 400 10.0”

  1. Hierarchical Bootstrapping: Replicate a hierarchical bootstrapping process in which particular nodes are take on special roles such as leader or gateway to help other nodes in joining the network.
  2. Energy-Aware Bootstrapping: Append the energy constraints to the nodes in which nodes are only execute discovery or communication according to their energy levels.
  3. Security in Bootstrapping: Mimic secure bootstrapping by launching authentication mechanisms while the discovery process.

In brief, we explained the stepwise approach that execute and replicate the Network Bootstrapping in the simulation tool NS2. Furthermore we will deliver in depth information regarding this topic in various manual.

Keep connected with ns2project.com for top-notch guidance. We will provide you with a thorough performance analysis to help you implement Network Bootstrapping in NS2 tool.