How to Start Blockchain Networks Projects Using NS2

To start a Blockchain Network simulation using NS2 (Network Simulator 2), we will want to make the network model for replicating blockchain-specific modules like nodes (miners, validators), consensus mechanisms like Proof of Work, Proof of Stake, and transaction propagation. While NS2 is a robust network simulator but it doesn’t directly support for blockchain networks. Then, we need to generate a custom simulation by means of designing network nodes, blockchain transactions, and consensus protocols.

Following is a complete instruction on how to start a Blockchain Network project in NS2.

Steps to Start Blockchain Network Projects in NS2

  1. Install NS2

Initially, we should install NS2 on the system. NS2 is an open-source network simulator which is frequently utilised to replicate the network protocols, and it can be downloaded and installed using official website or repositories:

  • Download NS2 from: NS2 Website
  • Adhere to the installation instruction based on the operating system.

For scripting and simulation management, we require Tcl (Tool Command Language) and OTcl.

  1. Understand the Basic Blockchain Concepts

Followings are key components of Blockchain network:

  • Blockchain Nodes: These nodes can be “miners” or “validators” according to the consensus protocols.
  • Transactions: Data packages, which are propagate over the network.
  • Blocks: Sets of transactions.
  • Consensus Mechanism: Approaches for attaining the agreement over nodes such as Proof of Work or Proof of Stake.
  • Blockchain Chain: A series of blocks, which are cryptographically connected together.

We will design these modules and its communications like how transactions are broadcasted, how blocks are made, and how consensus is attained for replicating a blockchain network.

  1. Create the Network Topology

In NS2, we make a network topology in Tcl scripts. We can replicate the blockchain nodes’ network in which every single node denotes the member of blockchain network (either a miner or validator).

Example: Basic Blockchain Network Topology

# Define the simulator

set ns [new Simulator]

# Create nodes (representing blockchain nodes)

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

set node4 [$ns node]

# Create links between nodes (with different delay/bandwidth)

$ns duplex-link $node1 $node2 10Mb 10ms DropTail

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

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

# Create a queue for managing packet size

$ns queue-limit $node1 $node2 50

$ns queue-limit $node2 $node3 50

$ns queue-limit $node3 $node4 50

# Create an agent (this can be a custom agent for blockchain transactions)

set agent1 [new Agent/TCP]

$ns attach-agent $node1 $agent1

set agent2 [new Agent/TCP]

$ns attach-agent $node2 $agent2

# Start traffic between the nodes

$ns connect $agent1 $agent2

# Set up routing and other configurations

$ns run

Key points:

  • Nodes denote the blockchain network participants.
  • Links replicate the interaction channels among nodes including defined bandwidth and latency.
  • Agents can be denoted the blockchain messages transmission like transactions, blocks, and so on.
  • Queues are configured for replicating congestion and packet handling among the nodes.
  1. Model Blockchain Components (Transactions, Blocks)

We can make custom protocols or agents for denoting blockchain-specific modules such as transactions, blocks, and consensus mechanisms within NS2.

Example: Create a Transaction Agent

We will need to describe a Transaction Agent for replicating the blockchain transactions transmitting among nodes.

# Define a new Transaction agent

namespace eval Transaction {

variable transaction_counter 0

proc sendTransaction {src dst data} {

# Create a new packet for the transaction

set transaction_id [incr transaction_counter]

set packet [new Packet]

$packet set timestamp [timestamp]

$packet set data $data

$packet set transaction_id $transaction_id

# Send the transaction packet

$src send $packet $dst

}

}

  • This Transaction Agent is in response to build and transmit the blockchain transactions through the network.
  • Every single transaction contains an ID, timestamp, and data field that we need to change depends on the requirements of blockchain simulation.
  1. Simulate Consensus Mechanisms

Blockchain networks according to the consensus protocols such as Proof of Work, Proof of Stake, and so on for authenticating the transactions and integrating blocks to the blockchain.

In NS2, it can be designed by means of making custom modules or agents for replicating the consensus mechanisms. For instance:

  • Proof of Work (PoW): Nodes will find the computational puzzles and participate to make new blocks.
  • Proof of Stake (PoS): Nodes including higher stakes are more probable for making new blocks.

Below is a basic conceptual model for Proof of Work:

Example: Proof of Work Model

namespace eval PoW {

variable current_difficulty 4

proc mineBlock {node data} {

# Simulate mining by trying to find a hash with required difficulty

set hash [md5sum $data]

if {[string length $hash] < $::current_difficulty} {

# Successfully mined the block, broadcast it

$node sendBlock $data

} else {

# Retry mining after some delay

after 1000 [PoW mineBlock $node $data]

}

}

}

  • mineBlock extracting a block by dint of hashing the transaction information.
  • If the hash converges the difficulty that is block is valid then it transmits the network block.

We need to extend it for managing block propagation through network, block verification, and blockchain chain updating.

  1. Transaction and Block Propagation

Blockchain networks broadcast the transactions and blocks through network. In NS2, we will want to replicate it by means of describing how messages (blocks/transactions) are transmitted from one node to another node.

Example: Propagate Transaction

# Define how a transaction is propagated across nodes

proc propagateTransaction {src dst data} {

# Transaction packet is created and sent to the destination node

Transaction::sendTransaction $src $dst $data

}

We can expand it further for replicating delays, retransmissions, and validation processes if required.

  1. Handle Blockchain State

Every single node would sustain their individual blockchain state for a more realistic simulation. It encompasses to monitor the new block, confirm the chain, and integrating the latest blocks when they are authenticated.

In Node agent, we may integrate a basic blockchain structure:

namespace eval Node {

variable blockchain [list]

proc addBlock {block} {

lappend blockchain $block

}

proc getBlockchain { } {

return $blockchain

}

}

This is a basic method for sustaining a blockchain within every node. We need to change it for managing advanced blockchain rules and operations like block verification, forks, and chain synchronization.

  1. Configure Simulation Parameters

We modify diverse simulation metrics using Tcl script configuration:

  • Transaction generation rate: Estimate how frequently nodes build the new transactions.
  • Block size: Measure the volume of transactions for each block.
  • Network conditions: Compute the network performance metrics like delay, bandwidth, and packet loss among the nodes.
  • Consensus timing: Evaluate how long nodes take time to attain the consensus.

# Set parameters for transaction generation

set transaction_interval 1 # 1 second per transaction

set block_size 10 # 10 transactions per block

# Configure simulation time and other parameters

set ns [new Simulator]

set node1 [$ns node]

$ns at 0.0 “Transaction::sendTransaction $node1 $node2 data”

$ns run

  1. Run the Simulation

When everything is configured then we can execute the simulation to utilise the ns command:

ns blockchain_network.tcl

It will execute the simulation and make output in record files that we need to examine the behavior of blockchain network in diverse conditions.

  1. Analyze Results

We need to examine the simulation by:

  • Examining logs: Monitor how transactions and blocks broadcast once nodes authenticate blocks, and when consensus is attained.
  • Visualizing Network Activity: Make use of tools such as NS2 Trace Files for examining network behavior and performance.
  • Evaluating Performance: Estimate the performance parameters like throughput, transaction delays, block creation time, and consensus effectiveness.

Conclusion

Replicating a Blockchain Network to utilise NS2, we can:

  1. Create the network topology of blockchain nodes to utilise Tcl scripts.
  2. Make custom agents for replicating transactions, blocks, and the consensus protocols like Proof of Work or Proof of Stake.
  3. Estimate the transaction propagation, block verification, and blockchain state maintenance within every node.
  4. Set and execute the simulation for examining blockchain performance in a replicated environment.

Since NS2 doesn’t directly support blockchain networks including custom scripting and modeling then we can replicate the core blockchain modules and its communication for estimating the performance, scalability, and consensus approaches within a controlled environment.

In this manual, you can clearly understand the simulation process of Blockchain Networks Projects that were simulated and analysed using NS2 environment. If you want to know more about this topic, we will also provide it.