How to Implement Network Secure Shell in NS2

To implement the Network Secure Shell (SSH) in NS2, we have to concentrate on simulating network traffic and activities allied with SSH instead of SSH itself as an encryption protocol due to ns2 lacks the inherent support advanced encryption techniques. Here in the below, we delivered the essential steps to accomplish it in NS2:

Step-by-Step Implementation:

  1. Set Up a Basic Network Topology

Start by defining a simplified network topology in NS2 with two or more nodes. These nodes can be set up as client and server, where SSH communication will take place.

Example Tcl Script for Basic Topology:

# Create the simulator instance

set ns [new Simulator]

# Define nodes

set n0 [$ns node]

set n1 [$ns node]

# Create a duplex link between n0 and n1

$ns duplex-link $n0 $n1 1Mb 10ms DropTail

# Set up a queue between the nodes

$ns queue-limit $n0 $n1 50

# Define TCP as the transport agent for SSH traffic

set tcp0 [new Agent/TCP]

$ns attach-agent $n0 $tcp0

set sink [new Agent/TCPSink]

$ns attach-agent $n1 $sink

# Connect TCP agent with the sink

$ns connect $tcp0 $sink

# Generate SSH-like traffic with an Application

set ftp [new Application/FTP]

$ftp attach-agent $tcp0

$ftp set type_ FTP

$ftp set rate_ 500kb  # Set a rate to simulate SSH traffic volume

# Schedule the start and stop of the FTP traffic (acting as SSH traffic)

$ns at 0.5 “$ftp start”

$ns at 4.5 “$ftp stop”

# Simulation settings

$ns at 5.0 “finish”

proc finish {} {

global ns

$ns halt

}

# Run the simulation

$ns run

  1. Simulate SSH Traffic

In this manual, FTP traffic is used as a placeholder for SSH. You can modify the parameters (such as bandwidth, latency, and packet size) to better imitate SSH actions. The FTP/HTTP traffic replicates the file transfer or command execution that commonly happens over SSH.

  1. Simulate Encryption Overhead

To imitate the computational overhead launched by SSH encryption, you can maximize latency or present delays using NS2’s delay or error models. For instance, you could replicate encryption delays with an additional processing time at the application layer or network delays.

  1. Simulate Secure Channels

We can replicate a secure tunnel using an Application/Traffic/CBR or FTP model to denote secure traffic (TCP or SSH is the usual protocol) because ns2 doesn’t support encryption natively. So, we can imitate secure communication actions devoid of diving into encryption certainties.

  1. Log and Analyze Results

NS2 produces trace files (.tr files) that you can compute to observe how the SSH-like traffic acts under various network conditions (latency, packet loss, throughput, etc.).

To monitor the flow, you can use NS2’s animation tool, NAM, to visualize the traffic amongst nodes.

  1. Implement More Complex SSH Features (Optional)

We can attach latest mechanisms of SSH (like packet authentication, compression, etc.) by fine-tuning the traffic aspects or tailor the behavior of the agents. Launch application-level or transport-level managing of packets to include artificial packet encryption/decryption delay.

At the end of the given procedure, you have seen the brief demonstration of Network Secure Shell (SSH) and its simulating process in ns2 tool and how to include more advanced mechanisms and how to establish the encryption’s behavior into it. Also, we provide more details regarding this SSH through another manual.

For the implementation of the Network Secure Shell in the NS2 tool, you may contact us. Our team comprises leading developers who are prepared to collaborate on your project by offering customized ideas and services.