How to Start Point-to-Multipoint Topology Projects Using OMNeT++

To make a Point-to-Multipoint Topology project using OMNeT++ which encompasses to configure a network in which central node in the “point” interacts including several other nodes within the “multipoint”. This kind of topology is typically utilised for broadcasting, multicast communication, or in client-server models.

Below is a stepwise method to get started with Point-to-Multipoint Topology in OMNeT++:

Steps to Start Point-to-Multipoint Topology in OMNeT++

Step 1: Install OMNeT++ and INET Framework

Make sure that OMNeT++ and the INET Framework are installed.

  1. Install OMNeT++:
    • We should download and install the OMNeT++ on the system and we adhere to the installation guidance based on the OS.
  2. Install INET Framework:

Step 2: Create a New OMNeT++ Project

  1. Go to OMNeT++ IDE.
  2. Make a New OMNeT++ Project:
    • By navigating File → New → OMNeT++ Project.
    • Then, name it to the project as PointToMultipointTopology and select a position for the project to save it.

Step 3: Define the Point-to-Multipoint Topology

In OMNeT++, Point-to-Multipoint Topology can describe using .ned file. One node (the central point) interacts with numerous nodes which is called multipoints in this topology.

Example: Basic Point-to-Multipoint Topology with 1 central node and 3 client nodes

  1. We need to create the network topology using .ned file like PointToMultipoint.ned:

network PointToMultipoint

{

parameters:

int numNodes = 3;  // Number of client nodes (multipoint nodes)

submodules:

centralNode: Node;                  // Central point (hub) node

clients[par(numNodes): Node];        // Client nodes (multipoint nodes)

connections:

// Connect central node to all client nodes (Point-to-Multipoint)

for i = 0..numNodes-1 {

centralNode.ethg++ <–> EtherInterface <–> clients[i].ethg++;

}

}

Explanation:

  • centralNode: This node performs like the central “point” of the topology.
  • clients: An array denoting the “multipoint” or client nodes, which associate to the central node of the network.
  • connections: From the central node to each of the client nodes, we make a connection with the support of Ethernet interfaces that generates point-to-multipoint interaction.

Step 4: Define the Node Module

Now, we will want to specify the each node’s behavior. A simple EtherHost is a basic form of a node that mimics network interface for interaction.

  1. Describe the node module to utilise a .ned file like Node.ned:

module Node

{

parameters:

@display(“i=block/server”);

submodules:

ethg: EtherHost;  // Ethernet host (communication interface)

connections:

ethg++ <–> EtherInterface <–> ethg++;

}

Explanation:

  • EtherHost: It denotes a simple node including Ethernet network interface.
  • EtherInterface: In the topology, links the node to the network to permit interaction through the defined connections.

Step 5: Configure the Simulation Parameters

When the network topology and node components are described then we set the simulation performance metrics using omnetpp.ini configuration file.

  1. Create or edit omnetpp.ini:

network = PointToMultipoint   # Name of the network model

# Simulation settings

sim-time-limit = 100s          # Total simulation time

*.numNodes = 3                 # Number of client nodes (multipoint nodes)

# Packet generation configuration for client nodes

*.clients[*].app.packetRate = 100pkts/s   # Example packet rate for client nodes

Explanation:

  • network: Indicates the network model using defined .ned file.
  • sim-time-limit: Specify the simulation time limit.
  • numNodes: Describes the volume of client nodes (multipoint).
  • packetRate: It denotes the packet generation rate for every single client node.

Step 6: Build and Run the Simulation

  1. Build the Project:
    • In OMNeT IDE, right-click on the project and select the Build to create the project. It will be compiled the .ned files and any connected components.
  2. Run the Simulation:
    • When the project is constructing then we need to select on the Run button for executing the simulation.
  3. Visualize the Simulation:
    • OMNeT++ environment offers a GUI in which we can observe the network topology functioning, monitor packet transmission, and see the performance parameters like throughput, packet loss, and latency.

Step 7: Enhance the Point-to-Multipoint Topology

After executing the basic simulation then we need to improve it by means of integrating more complex aspects.

  1. Traffic Patterns:
  • We can be executed diverse types of traffic like UDP or TCP, and allocate them to the central node or clients. It will be replicated various kinds of applications like data transfer, streaming, and so on.
  1. Multicast or Broadcast Communication:
  • From the central node, execute the multicast or broadcast communication. OMNeT++ environment performs for multicast communication execution that appropriate to concurrently transmit the similar information to every client nodes.
  1. Routing Protocols:
  • Even though point-to-multipoint interaction is comparatively simple then we can add routing protocols such as DVR, OSPF for more complex traffic routing as required.
  1. Mobility:
  • We will need to integrate the mobility to the client nodes for replicating mobile interaction scenarios. It will helpful to learn about the mobile ad hoc networks (MANETs) or vehicular networks (VANETs).
  1. Error Handling:
  • Launch node failures or link failures for mimicking error conditions and also experiment the point-to-multipoint interaction configuration’s robustness.
  1. Security Attacks:
  • Replicate the security attacks like Denial of Service (DoS) attacks or eavesdropping to analyse how the topology responds to network disruptions or malicious activities.

Step 8: Analyze the Results

When simulation is executing then we can measure the network performance to utilise OMNeT++’s analysis tools which permit to:

  • Monitor the performance parameters like packet flow, latency, throughput, and packet loss.
  • Analyse the interaction details to utilise Wireshark as configured to seizure the packets.
  • Observe how central node propagates the information effectively to every client and then assess the overall performance of network.

Conclusion

In OMNeT++, making a Point-to-Multipoint Topology:

  1. Utilise .ned file to create the network topology by means of making one central node and associating it to several client nodes.
  2. Specify the behavior of the node to utilise EtherHost modules for replicating interaction among the nodes.
  3. Set the simulation metrics like packet rates, simulation time, and node sets up using omnetpp.ini configuration file.
  4. Execute the simulation, envision the network and examine their performance to utilise OMNeT++’s GUI.
  5. Improve the simulation by means of integrating traffic models, multicast/broadcast interaction, routing, mobility, or security aspects.

By following these structured methods, we can make and replicate the point-to-multipoint topology projects which are helpful for client-server models, broadcasting, or multicast interaction using OMNeT++ simulation tool. More insights will be added later.