How to Implement Mixed Topology in OMNeT++
To implement a mixed topology in OMNeT++ has encompasses to generate the network that incorporate the diverse kinds of topologies like star, ring, bus, and mesh, inside a single network and the Mixed topologies are frequently used in large and complex networks where diverse parts of the network serve various purposes or have diverse needs. The given below are the brief procedures on how to implement the mixed topology in OMNeT++ tool:
Step-by-Step Implementation:
- Set up OMNeT++ and INET Framework
- Make sure that OMNeT++ and the INET framework are installed and properly configured. The INET framework delivers the necessary modules for emulating the numerous network topologies that concludes the mixed topologies.
- Define the Mixed Topology in a NED File
- Generate a .ned file to describe the network topology. In a mixed topology, diverse parts of the network can monitor different topological structures, such as star, ring, or mesh.
Example:
package mixedTopologyExample;
import inet.node.inet.StandardHost;
import inet.node.inet.Router;
import inet.node.inet.Switch;
network MixedTopology
{
parameters:
int numStarNodes = default(4); // Number of nodes in the star topology
int numRingNodes = default(4); // Number of nodes in the ring topology
int numMeshNodes = default(4); // Number of nodes in the mesh topology
submodules:
starSwitch: Switch {
parameters:
@display(“p=200,200”);
}
starNode[numStarNodes]: StandardHost {
parameters:
@display(“p=100+100*i,300”);
}
ringNode[numRingNodes]: StandardHost {
parameters:
@display(“p=400+100*cos(i*2*pi/numRingNodes),400+100*sin(i*2*pi/numRingNodes)”);
}
meshNode[numMeshNodes]: StandardHost {
parameters:
@display(“p=600+100*cos(pi/2+i*2*pi/numMeshNodes),600+100*sin(pi/2+i*2*pi/numMeshNodes)”);
}
router: Router {
parameters:
@display(“p=400,500”);
}
connections allowunconnected:
// Star topology connections
for i=0..numStarNodes-1 {
starNode[i].ethg++ <–> Eth10G <–> starSwitch.ethg++;
}
// Ring topology connections
for i=0..numRingNodes-2 {
ringNode[i].ethg++ <–> Eth10G <–> ringNode[i+1].ethg++;
}
ringNode[numRingNodes-1].ethg++ <–> Eth10G <–> ringNode[0].ethg++; // Complete the ring
// Mesh topology connections
for i=0..numMeshNodes-2 {
for j=i+1..numMeshNodes-1 {
meshNode[i].ethg++ <–> Eth10G <–> meshNode[j].ethg++;
}
}
// Connecting star, ring, and mesh topologies to the router
starSwitch.ethg++ <–> Eth10G <–> router.ethg++;
ringNode[0].ethg++ <–> Eth10G <–> router.ethg++;
meshNode[0].ethg++ <–> Eth10G <–> router.ethg++;
}
- Star Topology: Nodes are connected to a central switch.
- Ring Topology: Nodes are connected in a loop, with each node connected to two other nodes.
- Mesh Topology: Nodes are connected to multiple other nodes, forming a mesh-like structure.
- Router: The router connects the different topologies, allowing communication between them.
- Configure the Nodes in OMNeT++ INI File
- In the omnetpp.ini file, configure the properties of the nodes like IP addresses, routing, and the applications they will run.
Example:
network = mixedTopologyExample.MixedTopology
# Configure IP addresses for star, ring, and mesh nodes
*.starNode[*].ipv4.arp.typename = “GlobalArp”
*.starNode[*].eth[0].ipv4.address = “10.0.1.x”
*.starNode[*].eth[0].ipv4.netmask = “255.255.255.0”
*.ringNode[*].ipv4.arp.typename = “GlobalArp”
*.ringNode[*].eth[0].ipv4.address = “10.0.2.x”
*.ringNode[*].eth[0].ipv4.netmask = “255.255.255.0”
*.meshNode[*].ipv4.arp.typename = “GlobalArp”
*.meshNode[*].eth[0].ipv4.address = “10.0.3.x”
*.meshNode[*].eth[0].ipv4.netmask = “255.255.255.0”
# Example application setup: starNode[0] communicates with ringNode[0]
*.starNode[0].numApps = 1
*.starNode[0].app[0].typename = “UdpBasicApp”
*.starNode[0].app[0].destAddresses = “10.0.2.1” # IP address of ringNode[0]
*.starNode[0].app[0].destPort = 5000
*.starNode[0].app[0].messageLength = 1024B
*.starNode[0].app[0].sendInterval = 1s
*.ringNode[0].numApps = 1
*.ringNode[0].app[0].typename = “UdpSink”
*.ringNode[0].app[0].localPort = 5000
- IP Addressing: Diverse IP address ranges are used for nodes in the star, ring, and mesh topologies.
- Applications: Nodes are configured to send and receive data to emulate the network traffic across the numerous topologies.
- Run the Simulation
- After setting up the network topology and configuration compile and run the simulation in OMNeT++. Monitor how traffic flows among nodes in diverse topologies and how the mixed topology manages the interaction among diverse network segments.
- Analyze the Results
- Use OMNeT++’s built-in tools to visualize and measure the network traffic. Investigate how information is routed among the nodes in numerous topologies, how the router facilitates communication, and how network performance scales as more nodes are added.
- Enhancements and Variations
- Scalability Testing: Increase the number of nodes in each topology to check the scalability of the mixed topology. measure how the network handles increased traffic and node density.
- Failure Scenarios: Introduce node or link failures to see how the network behaves in a mixed topology and how resilient it is to disruptions.
- Traffic Analysis: Experiment with various traffic patterns to study how information flows via the mixed topology and how the network manages the congestion.
Example Files
- MixedTopology.ned: Describes the mixed topology.
- omnetpp.ini: Contains configuration settings for the simulation.
We successfully executed the mixed topology in OMNeT++ tool that generates the network then form the topologies in the large network and analyse the outcomes. We plan to elaborate how the mixed topologies will perform in other simulation scenarios. Be in touch with or developers to get best simulation and project ideas on mixed topology