To simulate a Bus-Star Hybrid Topology using OMNeT++ that comprise of aggregating features of both bus and star topologies to make a network in which nodes are organized in a way that supports a shared bus with star segments. This hybrid topology can be advantageous in numerous applications, containing data center networks and IoT networks where flexibility and scalability are significant.phdprime.com will be your trusted partner to guide you with bst simulation and network evaluation results.
The following is a detailed instuction on how to simulate a Bus-Star Hybrid Topology in OMNeT++ using the INET framework:
Steps to Simulate Bus-Star Hybrid Topology in OMNeT++
- Install OMNeT++ and INET Framework:
Make sure that we have installed OMNeT++ and the INET framework, as these offer the essential modules and components for network simulation.
- We can download and install OMNeT++.
- Download and install the INET Framework.
- Understand the Hybrid Topology:
In a Bus-Star Hybrid Topology:
- Bus Topology: Nodes are connected along a shared communication medium (bus).
- Star Topology: Devices are connected to a central switch or hub.
- The hybrid aggregates these two designs, permitting flexibility and redundancy.
- Define the Bus-Star Hybrid Topology in NED File:
In the NED file, we will describe both the bus and star modules. Here’s an instance of how to configure a simple bus-star hybrid network:
network BusStarHybridNetwork
{
parameters:
int numStars = default(2); // Number of star networks connected to the bus
int numDevicesPerStar = default(3); // Number of devices in each star
submodules:
// Define the bus backbone
bus: <BusType> {
@display(“p=200,200”);
}
// Define switches for each star network
switch[numStars]: <SwitchType> {
@display(“p=100+200*i,300”);
}
// Define devices connected to each star’s switch
device[numStars][numDevicesPerStar]: <DeviceType> {
@display(“p=100+200*i,400+100*j”);
}
connections allowunconnected:
// Create the bus backbone, connecting the switches in a linear fashion
for i=0..numStars-2 {
switch[i].ethg++ <–> Eth100M <–> switch[i+1].ethg++;
}
// Connect the bus to each switch (creating a bus segment)
for i=0..numStars-1 {
bus.ethg++ <–> Eth100M <–> switch[i].ethg++;
}
// Connect devices to their respective switch (star topology for each switch)
for i=0..numStars-1 {
for j=0..numDevicesPerStar-1 {
device[i][j].ethg++ <–> Eth100M <–> switch[i].ethg++;
}
}
}
In this example:
- numStars shows the amount of star networks connected to the bus.
- numDevicesPerStar describes how many devices (e.g., computers) are connected to each switch.
- The bus is associated to switches that in turn connect to devices in a star configuration.
- Define Node Types in NED:
We can be used the INET framework’s EthernetSwitch for switches and StandardHost for devices. Here’s an instance for describing the node types:
import inet.node.ethernet.EthernetSwitch;
import inet.node.inet.StandardHost;
module BusType extends StandardHost
{
parameters:
@display(“i=device/bus”); // Icon for the bus backbone
}
module SwitchType extends EthernetSwitch
{
parameters:
@display(“i=device/switch”); // Icon for switches
}
module DeviceType extends StandardHost
{
parameters:
@display(“i=device/pc”); // Icon for devices
}
This configure describes the bus, switches, and devices, which framework the hybrid topology.
- Configure the INI File:
The omnetpp.ini file is utilized to set up the simulation parameters, like IP addressing, traffic generation, and particular protocols.
Here’s an instance INI configuration, which generates traffic among devices connected to distinct star networks:
[General]
network = BusStarHybridNetwork
sim-time-limit = 100s # Set the simulation time limit
# Configure IP addresses for devices in the network
*.device[*][*].networkLayer.ipv4.address = “10.0.x.y”
# Configure TCP traffic between devices in different star networks
*.device[0][0].numApps = 1
*.device[1][2].numApps = 1
# Define a TCP client on device[0][0] and a TCP server on device[1][2]
*.device[0][0].app[0].typename = “TcpBasicClientApp”
*.device[0][0].app[0].connectAddress = “10.0.1.3” # IP address of the target device
*.device[0][0].app[0].startTime = 2s
*.device[0][0].app[0].stopTime = 98s
*.device[1][2].app[0].typename = “TcpBasicServerApp” # TCP server on device[1][2]
In this configuration:
- IP addresses are allocated to each device, make sure that devices from distinct star networks can communicate.
- device[0][0] acts as a TCP client, and device[1][2] performs as a TCP server.
- Simulate Traffic Using TCP or UDP:
We can generate traffic among the devices using either TCP or UDP. Here’s an instance configuration for replicating UDP traffic:
# Configuring UDP traffic from device[0][0] to device[1][2]
*.device[0][0].app[0].typename = “UdpBasicApp”
*.device[0][0].app[0].destAddresses = “10.0.1.3” # IP address of the target device
*.device[0][0].app[0].destPort = 5000
*.device[0][0].app[0].packetLength = 1024B
*.device[0][0].app[0].sendInterval = uniform(1s, 2s)
*.device[0][0].app[0].startTime = 2s
*.device[0][0].app[0].stopTime = 98s
# Configure device[1][2] as a UDP sink to receive packets
*.device[1][2].app[0].typename = “UdpSink”
*.device[1][2].app[0].localPort = 5000
This configuration generates UDP traffic from device[0][0] to device[1][2].
- Run the Simulation:
- We can open OMNeT++ IDE, compile the project, and run the simulation.
- Utilize Qtenv to envision the bus-star hybrid topology and monitor how data packets flow among the devices via the interconnected switches.
During the simulation, we will monitor how traffic from one star network is routed via the bus to attain devices in other star networks.
- Test Fault Tolerance by Introducing Link Failures:
We can replicate link or device failures to experiment the fault tolerance of the bus-star hybrid topology. For instance, disabling a link on the bus can experiment the network’s ability to manage such failures.
To introduce a link failure during the simulation, change the omnetpp.ini file:
# Disable the link between Switch 0 and Switch 1 at time 30s
**.switch[0].ethg++ <–> Eth100M <–> switch[1].ethg++**.disableAt = 30s
This configuration disables the link among the Switch 0 and Switch 1 at 30 seconds, concentrating traffic to take alternative paths if any are obtainable.
- Analyze the Results:
OMNeT++ offers detailed logs and statistical information to examine the performance of the simulation. We can calculate:
- Throughput: The data transmission rate among the devices.
- Latency: The time delay for packets traveling among devices.
- Packet Loss: Track any lost packets, especially when experimenting fault tolerance.
- Link Utilization: Estimate how much each link is utilized in the network, particularly in the bus section.
Use Plove or Scave to plot graphs and examine the performance metrics.
- Advanced Features (Optional):
- Routing Protocols: We can execute dynamic routing protocols (e.g., OSPF or RIP) to handle routes in the network and make certain traffic is successfully routed via the bus and star segments.
- Quality of Service (QoS): We can execute QoS mechanisms to prioritize distinct kinds of traffic (e.g., voice or video) in the hybrid network.
- Dynamic Topology: Insert mobility to some nodes or replicate a dynamic network in which nodes can join and exit the star networks.
Example for Adding Routing (OSPF):
# Enable OSPF routing for switches
*.switch[*].ipv4.routingProtocol = “Ospf”
This allows OSPF routing, permitting switches to actively find routes.
Summary:
- Topology Definition: Utilize NED to describe a bus-star hybrid topology with interconnected switches and associated devices.
- Node Configuration: Use INET’s EthernetSwitch for switches and StandardHost for devices.
- Traffic Simulation: Replicate TCP or UDP traffic among the devices and experiment the topology’s fault tolerance.
- Run and Analyze: We can run the simulation and use OMNeT++ tools to handle parameters like throughput, latency, and packet loss.
In this step-by-step technique, we had utterly distributed the instructions with samples snippets and summary to replicate and analyse the Bust Star Hybrid Topology within OMNeT++ analysis tool. Moreover, we will also be offered more concepts and ideas about this projects rely on your needs.
