How to Start Border Gateway Protocol Projects Using NS2

To start Border Gateway Protocol (BGP) projects in NS2, we can know that NS2 doesn’t directly offers support for BGP since NS2 addresses packet-level and topology simulation whereas BGP functions like a policy-based inter-domain routing protocol at a higher deduction level.

But we will need to utilise the extensions, patches, or other mechanisms for replicating the behaviour of BGP within NS2. Below is a common simulation procedure to get started:

Steps to Start BGP Projects in NS2

  1. Set Up NS2 Environment

Make sure we have correctly installed NS2 and set up.

Install NS2

sudo apt-get update

sudo apt-get install ns2

Verify Installation

We can execute the following command:

ns

If NS2 is installed effectively then the NS2 interpreter will appear (%).

  1. Add BGP Support to NS2

While BGP isn’t portion of the build-in NS2 package then we have the following options:

  1. BGP Patch for NS2:
    • We can download a BGP patch using its repository like SourceForge or academic records. For instance: we can utilise NS-BGP patch from BGP Patch for NS2.
    • Steps to Install the Patch:

cd ns-allinone-2.35/ns-2.35

patch -p1 < /path/to/bgp_patch.diff

./configure

make

    • Confirm the BGP support within the NS2 directory by verifying BGP routing selections.
  2. Simulate BGP-Like Behavior Using Static Routing: We will need to estimate the behaviour of BGP within NS2 by way of manually setting up static routes or a set of RIP and OSPF for inter-domain communication as a patch isn’t obtainable.
  1. Write a Basic BGP Simulation Script

Here’s a TCL script to replicate the BGP-like inter-domain routing behavior applying Static Routing and numerous Autonomous Systems (AS).

BGP Simulation Script Example:

# Initialize the NS Simulator

set ns [new Simulator]

# Define trace and NAM files

set tr [open bgp-output.tr w]

$ns trace-all $tr

set nf [open bgp-output.nam w]

$ns namtrace-all $nf

# Define Nodes for Two Autonomous Systems (AS1 and AS2)

set AS1_0 [$ns node]

set AS1_1 [$ns node]

set AS2_0 [$ns node]

set AS2_1 [$ns node]

set border_router [$ns node]

# Define Links between Nodes

$ns duplex-link $AS1_0 $AS1_1 1Mb 10ms DropTail

$ns duplex-link $AS1_1 $border_router 1Mb 15ms DropTail

$ns duplex-link $border_router $AS2_0 1Mb 20ms DropTail

$ns duplex-link $AS2_0 $AS2_1 1Mb 10ms DropTail

# Static Routes for Inter-domain Communication (Simulating BGP Routing)

$AS1_0 add-route $AS2_1 0

$AS2_1 add-route $AS1_0 1

# Attach Traffic Agents

set tcp0 [new Agent/TCP]

$ns attach-agent $AS1_0 $tcp0

set sink0 [new Agent/TCPSink]

$ns attach-agent $AS2_1 $sink0

$ns connect $tcp0 $sink0

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

# Start and Stop Traffic

$ns at 0.5 “$ftp0 start”

$ns at 4.5 “$ftp0 stop”

# Finish Simulation

$ns at 5.0 “finish”

proc finish {} {

global ns tr nf

$ns flush-trace

close $tr

close $nf

exec nam bgp-output.nam &

exit 0

}

# Run Simulation

$ns run

  1. Run the BGP Simulation
  1. We want to store the simulation script like bgp_simulation.tcl using NS2.
  2. Then, execute the TCL simulation script in NS2:

ns bgp_simulation.tcl

  1. Outputs:
    • NAM File (bgp-output.nam): It helps to envision the inter-domain interaction.
    • Trace File (bgp-output.tr): Supports packet transfer events records.
  1. Analyze Results

Examine the performance parameters such as routing overhead, latency, and packet delivery ratio to utilise the trace file.

Example AWK Script for Packet Delivery Ratio:

awk ‘{if($1==”r” && $4==”tcp”) count++} END {print “PDR: “, count}’ bgp-output.tr

  1. Enhance the Project
  1. Introduce Larger Autonomous Systems:
    • Replicate numerous larger AS networks including several border routers.
  2. Dynamic Routing:
    • Make use of dynamic routing protocols like RIP or OSPF for internal routing in AS domains.
  3. Node/Link Failures:
    • We need to replicate the border routers or links failure for monitoring how traffic is redirected.

$ns rtmodel-at 2.0 down $AS1_1 $border_router

$ns rtmodel-at 3.0 up $AS1_1 $border_router

  1. QoS-Based Routing:
    • Estimate the routing to utilise Quality of Service parameters such as delay, jitter, and throughput.
  2. Performance Comparison:
    • Equate the performance of static BGP-like routing with dynamic routing protocols such as RIP or OSPF.
  1. Tools for Result Visualization
  • NAM: We need to envision the traffic flow and inter-domain routes using NAM.
  • AWK/Python Scripts: It helps to obtain the traffic information from trace files.
  • Gnuplot/Matplotlib: Graph the performance indicators such as packet delivery ratio, latency, and throughput using Gnuplot of Python’s Matplotlib.
  1. Example BGP Project Ideas
  1. Performance Analysis of BGP-Like Routing in NS2:
    • Replicate several Autonomous Systems and then examine the routing overhead using NS2 environment.
  2. BGP Route Convergence:
    • Launch link/node failures and also monitor the BGP route convergence time.
  3. Comparison of Static and Dynamic Routing:
    • Equate the performance of BGP-like static routes with dynamic routing protocols like OSPF or RIP.
  4. Scalability of Inter-domain Routing:
    • Mimic large-scale networks including numerous border routers for scalability.
  5. BGP Load Balancing:
    • We will execute the BGP load-balancing mechanisms through border routers.

In this simulation, an outlined structure has been provided, enhanced with NS2-specific content including environment setup, simulation of BGP, analysis, enhancement and advanced project ideas with code snippets for replicating Border Gateway Protocol Projects in NS2. If you need further details, please ask.