How to Start Overlay Topology Projects using NS3
To create an Overlay Topology is create a top of underlying physical network and permitting their nodes to communicate via virtual connections or paths. Overlay networks are used in content distribution, peer-to-peer networks, and VPNs.
Steps to Start Overlay Topology Projects using NS3
Step 1: Set Up NS-3
- Install NS-3:
- Download NS-3.
- Follow the installation instructions.
- Verify Installation: Test NS-3 with a basic script:
./waf –run scratch/my_first
Step 2: Understand Overlay Topology
- Overlay Topology:
- Logical topology over an underlying physical network.
- The Nodes are connected in a virtual connection.
- General applications:
- Content delivery networks (CDNs).
- Peer-to-peer systems (e.g., BitTorrent).
- Virtual private networks (VPNs).
Step 3: Plan the Topology
- Define the physical and overlay networks:
- For Sample:
- Physical network: Mesh connected in five nodes.
- Overlay network: Three virtual connections among specific nodes.
- For Sample:
- Set simulation goals:
- Replicate the data exchange over the overlay network.
- Analyze performance metrics such as throughput and latency.
Step 4: Set Up the Physical Topology
- Create Physical Nodes: State the nodes for the physical network.
NodeContainer physicalNodes;
uint32_t numPhysicalNodes = 5; // Number of physical nodes
physicalNodes.Create(numPhysicalNodes);
- Set Up Point-to-Point Links: utilized their PointToPointHelper we describe their properties of the physical connections.
PointToPointHelper p2p;
p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));
p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));
- Connect Physical Nodes: Build a mesh or custom topology for the physical network.
NetDeviceContainer physicalDevices;
for (uint32_t i = 0; i < numPhysicalNodes; ++i) {
for (uint32_t j = i + 1; j < numPhysicalNodes; ++j) {
NetDeviceContainer link = p2p.Install(physicalNodes.Get(i), physicalNodes.Get(j));
physicalDevices.Add(link);
}
}
- Install Internet Stack: Improve the Internet stack to all physical nodes.
InternetStackHelper stack;
stack.Install(physicalNodes);
- Assign IP Addresses: Allocate the unique IP addresses to every physical link.
Ipv4AddressHelper address;
uint32_t subnetIndex = 1;
for (uint32_t i = 0; i < physicalDevices.GetN(); ++i) {
std::ostringstream subnet;
subnet << “10.1.” << subnetIndex++ << “.0”;
address.SetBase(subnet.str().c_str(), “255.255.255.0”);
address.Assign(physicalDevices.Get(i));
}
Step 5: Set Up the Overlay Network
- Define Overlay Connections: Specify virtual connections for the overlay network.
std::vector<std::pair<uint32_t, uint32_t>> overlayLinks = {
{0, 3}, {1, 4}, {2, 3}
};
- Create Applications for Overlay Communication: Utilizing their socket programming we create the virtual connections over the physical network.
for (auto &link : overlayLinks) {
Ptr<Node> src = physicalNodes.Get(link.first);
Ptr<Node> dest = physicalNodes.Get(link.second);
// Source application
OnOffHelper onOff(“ns3::UdpSocketFactory”, InetSocketAddress(dest->GetObject<Ipv4>()->GetAddress(1, 0).GetLocal(), 9));
onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));
onOff.SetAttribute(“PacketSize”, UintegerValue(1024));
ApplicationContainer srcApp = onOff.Install(src);
srcApp.Start(Seconds(1.0));
srcApp.Stop(Seconds(10.0));
// Sink application
PacketSinkHelper sink(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), 9));
ApplicationContainer sinkApp = sink.Install(dest);
sinkApp.Start(Seconds(1.0));
sinkApp.Stop(Seconds(10.0));
}
Step 6: Run and Analyze
- Run the Simulation:
Simulator::Run();
Simulator::Destroy();
- Enable Packet Capture: Utilized the .pcap files for traffic analysis.
p2p.EnablePcapAll(“overlay_topology”);
- Trace Logs: Ensure the NS-3 logging for debugging:
export NS_LOG=”OnOffApplication=level_all|prefix_func”
./waf –run scratch/overlay_topology
Example: Minimal NS-3 Script for Overlay Topology
#include “ns3/core-module.h”
#include “ns3/network-module.h”
#include “ns3/internet-module.h”
#include “ns3/point-to-point-module.h”
#include “ns3/applications-module.h”
using namespace ns3;
int main(int argc, char *argv[]) {
uint32_t numPhysicalNodes = 5;
// Create physical nodes
NodeContainer physicalNodes;
physicalNodes.Create(numPhysicalNodes);
// Set up Point-to-Point links
PointToPointHelper p2p;
p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));
p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));
// Connect physical nodes in a mesh
NetDeviceContainer physicalDevices;
for (uint32_t i = 0; i < numPhysicalNodes; ++i) {
for (uint32_t j = i + 1; j < numPhysicalNodes; ++j) {
NetDeviceContainer link = p2p.Install(physicalNodes.Get(i), physicalNodes.Get(j));
physicalDevices.Add(link);
}
}
// Install Internet stack
InternetStackHelper stack;
stack.Install(physicalNodes);
// Assign IP addresses
Ipv4AddressHelper address;
uint32_t subnetIndex = 1;
for (uint32_t i = 0; i < physicalDevices.GetN(); ++i) {
std::ostringstream subnet;
subnet << “10.1.” << subnetIndex++ << “.0”;
address.SetBase(subnet.str().c_str(), “255.255.255.0”);
address.Assign(physicalDevices.Get(i));
}
// Define overlay links
std::vector<std::pair<uint32_t, uint32_t>> overlayLinks = {
{0, 3}, {1, 4}, {2, 3}
};
// Create overlay applications
for (auto &link : overlayLinks) {
Ptr<Node> src = physicalNodes.Get(link.first);
Ptr<Node> dest = physicalNodes.Get(link.second);
// Source application
OnOffHelper onOff(“ns3::UdpSocketFactory”, InetSocketAddress(dest->GetObject<Ipv4>()->GetAddress(1, 0).GetLocal(), 9));
onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));
onOff.SetAttribute(“PacketSize”, UintegerValue(1024));
ApplicationContainer srcApp = onOff.Install(src);
srcApp.Start(Seconds(1.0));
srcApp.Stop(Seconds(10.0));
// Sink application
PacketSinkHelper sink(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), 9));
ApplicationContainer sinkApp = sink.Install(dest);
sinkApp.Start(Seconds(1.0));
sinkApp.Stop(Seconds(10.0));
}
// Enable packet capture
p2p.EnablePcapAll(“overlay_topology”);
// Run the simulation
Simulator::Run();
Simulator::Destroy();
return 0;
}
Step 7: Compile and Run
- Save the script as overlay_topology.cc.
- We compile and run it:
./waf –run overlay_topology
Step 8: Enhance the Simulation
- Experiment with Traffic Models:
- Validate the various traffic models such as FTP, HTTP.
- Simulate Dynamic Overlays:
- Dynamically improve or remove the overlay connections during the replication.
- Analyze Performance:
- Calculate the parameter metrics such as throughput, delay, jitter, and packet loss.
- Visualize:
- Utilized their NetAnim we show together the physical and overlay topologies.
Next Steps
- Incorporate Real Protocols:
- Execute the P2P protocols such as BitTorrent or application-layer routing.
- Add Scalability:
- Size of the physical and overlay networks are increased.
- Dynamic Reconfiguration:
- Replicate the overlay adaptation we alter in the physical network.
Step 1: Set Up NS-3
- Install NS-3:
- Download NS-3.
- Observe the installation Process.
- Verify Installation: Run a basic NS-3 script:
./waf –run scratch/my_first
Step 2: Understand Overlay Topology
- Overlay Topology:
- The Logical connections among nodes over a physical network.
- The Nodes are communicating by virtual connections state at the application layer.
- General use cases:
- Peer-to-peer applications like BitTorrent.
- Virtual private networks (VPNs).
- Content delivery networks (CDNs).
Step 3: Plan the Topology
- Define the physical network:
- For example:
- Mesh topology has included in five nodes.
- For example:
- Define the overlay network:
- Logical connections among nodes and independent of physical topology.
Step 4: Set Up the Physical Network
- Create Physical Nodes: State the nodes in the physical topology.
NodeContainer physicalNodes;
uint32_t numPhysicalNodes = 5;
physicalNodes.Create(numPhysicalNodes);
- Set Up Point-to-Point Links: Utilized their PointToPointHelper we describe the physical connections.
PointToPointHelper p2p;
p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));
p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));
- Connect Physical Nodes: Build a mesh topology for the physical network.
NetDeviceContainer physicalDevices;
for (uint32_t i = 0; i < numPhysicalNodes; ++i) {
for (uint32_t j = i + 1; j < numPhysicalNodes; ++j) {
NetDeviceContainer link = p2p.Install(physicalNodes.Get(i), physicalNodes.Get(j));
physicalDevices.Add(link);
}
}
- Install Internet Stack: Improve the Internet stack to all nodes.
InternetStackHelper stack;
stack.Install(physicalNodes);
- Assign IP Addresses: Allocate the unique IP addresses to every physical connection.
Ipv4AddressHelper address;
uint32_t subnetIndex = 1;
for (uint32_t i = 0; i < physicalDevices.GetN(); ++i) {
std::ostringstream subnet;
subnet << “10.1.” << subnetIndex++ << “.0”;
address.SetBase(subnet.str().c_str(), “255.255.255.0”);
address.Assign(physicalDevices.Get(i));
}
Step 5: Set Up the Overlay Network
- Define Overlay Links: Specify logical connections for the overlay network.
std::vector<std::pair<uint32_t, uint32_t>> overlayLinks = {
{0, 3}, {1, 4}, {2, 3}, {0, 4}
};
- Set Up Virtual Connections: Utilized their UDP sockets we create overlay communication.
for (auto &link : overlayLinks) {
Ptr<Node> src = physicalNodes.Get(link.first);
Ptr<Node> dest = physicalNodes.Get(link.second);
// Source application
OnOffHelper onOff(“ns3::UdpSocketFactory”, InetSocketAddress(dest->GetObject<Ipv4>()->GetAddress(1, 0).GetLocal(), 9));
onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));
onOff.SetAttribute(“PacketSize”, UintegerValue(1024));
ApplicationContainer srcApp = onOff.Install(src);
srcApp.Start(Seconds(1.0));
srcApp.Stop(Seconds(10.0));
// Sink application
PacketSinkHelper sink(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), 9));
ApplicationContainer sinkApp = sink.Install(dest);
sinkApp.Start(Seconds(1.0));
sinkApp.Stop(Seconds(10.0));
}
Step 6: Run and Analyze
- Run the Simulation:
Simulator::Run();
Simulator::Destroy();
- Enable Packet Capture: Save .pcap files for traffic analysis.
p2p.EnablePcapAll(“overlay_topology”);
- Trace Logs: Ensure the NS-3 logging for debugging:
export NS_LOG=”UdpClientApplication=level_all|prefix_func”
./waf –run scratch/overlay_topology
Example: Minimal NS-3 Script for Overlay Topology
#include “ns3/core-module.h”
#include “ns3/network-module.h”
#include “ns3/internet-module.h”
#include “ns3/point-to-point-module.h”
#include “ns3/applications-module.h”
using namespace ns3;
int main(int argc, char *argv[]) {
uint32_t numPhysicalNodes = 5;
// Create physical nodes
NodeContainer physicalNodes;
physicalNodes.Create(numPhysicalNodes);
// Set up Point-to-Point links
PointToPointHelper p2p;
p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));
p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));
// Connect physical nodes in a mesh
NetDeviceContainer physicalDevices;
for (uint32_t i = 0; i < numPhysicalNodes; ++i) {
for (uint32_t j = i + 1; j < numPhysicalNodes; ++j) {
NetDeviceContainer link = p2p.Install(physicalNodes.Get(i), physicalNodes.Get(j));
physicalDevices.Add(link);
}
}
// Install Internet stack
InternetStackHelper stack;
stack.Install(physicalNodes);
// Assign IP addresses
Ipv4AddressHelper address;
uint32_t subnetIndex = 1;
for (uint32_t i = 0; i < physicalDevices.GetN(); ++i) {
std::ostringstream subnet;
subnet << “10.1.” << subnetIndex++ << “.0”;
address.SetBase(subnet.str().c_str(), “255.255.255.0”);
address.Assign(physicalDevices.Get(i));
}
// Define overlay links
std::vector<std::pair<uint32_t, uint32_t>> overlayLinks = {
{0, 3}, {1, 4}, {2, 3}, {0, 4}
};
// Create overlay applications
for (auto &link : overlayLinks) {
Ptr<Node> src = physicalNodes.Get(link.first);
Ptr<Node> dest = physicalNodes.Get(link.second);
// Source application
OnOffHelper onOff(“ns3::UdpSocketFactory”, InetSocketAddress(dest->GetObject<Ipv4>()->GetAddress(1, 0).GetLocal(), 9));
onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));
onOff.SetAttribute(“PacketSize”, UintegerValue(1024));
ApplicationContainer srcApp = onOff.Install(src);
srcApp.Start(Seconds(1.0));
srcApp.Stop(Seconds(10.0));
// Sink application
PacketSinkHelper sink(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), 9));
ApplicationContainer sinkApp = sink.Install(dest);
sinkApp.Start(Seconds(1.0));
sinkApp.Stop(Seconds(10.0));
}
// Enable packet capture
p2p.EnablePcapAll(“overlay_topology”);
// Run the simulation
Simulator::Run();
Simulator::Destroy();
return 0;
}
Step 7: Compile and Run
- Save the script as overlay_topology.cc.
- We compile and run it:
./waf –run overlay_topology
Step 8: Enhance the Simulation
- Simulate Dynamic Overlays:
- Enhance or eliminate the overlay connections during the replication.
- Analyze Performance:
- Calculate their throughput, latency, jitter, and packet loss.
- Visualize:
- Utilized their NetAnim we display together physical and overlay topologies.
- Scale Up:
- Number of physical nodes and overlay connections are increased.
Next Steps
- Simulate Real Applications:
- Validate through real-world P2P protocols such as BitTorrent.
- Implement Advanced Overlays:
- Research through content delivery or distributed hash table systems.
- Incorporate Failures:
- Replicate the connection or node failures we analysis the fault tolerance.
In this manual, we illustrate the Overlay topology performed a comprehensive project analysis through given simulation process. We will also deliver further additional details about this topology in another report work.
Our team of developers focuses on content distribution, peer-to-peer networks, and VPNs, so feel free to reach out for more help. If you’re looking to start an Overlay Topology Project in NS-3, it can be quite challenging. That’s why at phdprojects.org, we provide tailored support whenever you need it. Just drop us a message, and we’ll assist you with the best simulations and topics.