How to Start Hierarchical Topology Projects Using OMNeT++
To start a Hierarchical Topology Simulation using OMNeT++, we will create a network including several layers like a core layer, distribution layer, and access layer in which traffic flows via these layers for attaining the destinations. This topology is broadly utilised for large-scale enterprise networks and data centers.
Below is a comprehensive method to starting a Hierarchical Topology Project in OMNeT++:
Steps to Start Hierarchical Topology Project in OMNeT++
- Understand Hierarchical Topology
- Definition: A hierarchical topology arranges the nodes in layers including certain roles:
- Core Layer: High-speed support for the network.
- Distribution Layer: It combines traffic from the access layer and links to the core.
- Access Layer: Offers end-user connectivity.
- Characteristics:
- Higher cost and complexity.
- Easier traffic management and fault isolation.
- Scalable and modular.
- Applications:
- It is frequently utilised in enterprise networks, data centers, multi-tier IoT systems.
- Set Up OMNeT++ and INET Framework
- Install OMNeT++: We can download and install the new version of OMNeT++ on the system.
- Install INET Framework:
- INET framework offers modules for wired and wireless interaction.
- Define Project Scope
Step 3.1: Goals
- Replicate the hierarchical traffic flows via numerous layers of the topology.
- Measure the performance parameters like:
- Latency.
- Throughput.
- Packet delivery ratio (PDR).
Step 3.2: Metrics
- Packet Delivery Ratio (PDR): Percentage of successfully delivered packets.
- Latency: Time taken for packets to traverse through layers.
- Throughput: Total data transferred across the network.
- Design the Hierarchical Topology
We need to create a network including nodes which are arranged to core, distribution, and access layers.
Example .ned File:
network HierarchicalTopology {
submodules:
coreRouter: Router; // Core layer
distributionRouter[2]: Router; // Distribution layer
accessSwitch[4]: Switch; // Access layer
host[8]: StandardHost; // End devices
connections allowunconnected:
// Core to Distribution connections
coreRouter.ethg++ <–> EthernetLink <–> distributionRouter[0].ethg++;
coreRouter.ethg++ <–> EthernetLink <–> distributionRouter[1].ethg++;
// Distribution to Access connections
distributionRouter[0].ethg++ <–> EthernetLink <–> accessSwitch[0].ethg++;
distributionRouter[0].ethg++ <–> EthernetLink <–> accessSwitch[1].ethg++;
distributionRouter[1].ethg++ <–> EthernetLink <–> accessSwitch[2].ethg++;
distributionRouter[1].ethg++ <–> EthernetLink <–> accessSwitch[3].ethg++;
// Access to Hosts connections
accessSwitch[0].ethg++ <–> EthernetLink <–> host[0].ethg++;
accessSwitch[0].ethg++ <–> EthernetLink <–> host[1].ethg++;
accessSwitch[1].ethg++ <–> EthernetLink <–> host[2].ethg++;
accessSwitch[1].ethg++ <–> EthernetLink <–> host[3].ethg++;
accessSwitch[2].ethg++ <–> EthernetLink <–> host[4].ethg++;
accessSwitch[2].ethg++ <–> EthernetLink <–> host[5].ethg++;
accessSwitch[3].ethg++ <–> EthernetLink <–> host[6].ethg++;
accessSwitch[3].ethg++ <–> EthernetLink <–> host[7].ethg++;
}
- Configure Node Behavior
Step 5.1: Data Transmission
Replicate the traffic from hosts to a central server or among hosts to utilise INET’s UdpBasicApp.
Example .ini File Configuration:
[Config HierarchicalTopologySimulation]
network = HierarchicalTopology
# Traffic configuration for hosts
**.host[0].numApps = 1
**.host[0].app[0].typename = “UdpBasicApp”
**.host[0].app[0].destAddress = “host[7]”
**.host[0].app[0].startTime = 1s
**.host[0].app[0].sendInterval = uniform(1s, 2s)
**.host[0].app[0].packetLength = 512B
**.host[7].numApps = 1
**.host[7].app[0].typename = “UdpSink”
# Additional traffic
**.host[3].numApps = 1
**.host[3].app[0].typename = “UdpBasicApp”
**.host[3].app[0].destAddress = “host[5]”
**.host[3].app[0].startTime = 2s
**.host[3].app[0].sendInterval = uniform(2s, 4s)
**.host[3].app[0].packetLength = 512B
**.host[5].numApps = 1
**.host[5].app[0].typename = “UdpSink”
# Simulation time
sim-time-limit = 50s
- Run and Visualize the Simulation
- Run the Simulation: In OMNeT++, we execute the simulation
- Monitor Behavior:
- Data flowing via hierarchical layers.
- Mesure the performance indicators such as latency and throughput.
- Analyze Results
Metrics to Evaluate:
- Packet Delivery Ratio (PDR):
- Estimate the rate of packets that are effectively distributed via layers.
- Latency:
- Measure the delay launched by passing through numerous layers.
- Throughput:
- Examine the data transfer rate over the network.
Visualization:
- Make use of OMNeT++’s built-in tools for envisioning traffic patterns and node communications.
- Enhance the Project
Step 8.1: Add Redundancy
- For fault tolerance, integrate the redundant connections among distribution and core layers.
Example Redundant Connections:
coreRouter.ethg++ <–> EthernetLink <–> distributionRouter[0].ethg++;
coreRouter.ethg++ <–> EthernetLink <–> distributionRouter[1].ethg++;
Step 8.2: Wireless Access Layer
- Mimic a wireless access layer for hosts to utilise INET’s wireless components.
Example Wireless Configuration:
*.host[*].wlan.radio.channelNumber = 11
*.accessSwitch[*].wlan.radio.channelNumber = 11
*.host[*].mobility.typename = “StationaryMobility”
Step 8.3: Simulate Faults
- In the distribution or core layers, launch the node or link failures to experiment fault tolerance.
Step 8.4: Add Dynamic Routing
- Adjust to network modifications to utilise the routing protocols such as OSPF, AODV.
Step 8.5: Scale the Network
- We need to replicate a larger hierarchical network as maximize the volume of nodes within every single layer.
- Example Output
- Before Enhancements:
- Data efficiently floods among the layers including anticipated latency and throughput.
- After Enhancements:
- Redundancy and routing adapt to failures for sustaining interaction after improvements.
This guide walks you through the above simulation mechanisms to replicate and analyse the Hierarchical Topology Projects using MATLAB simulation tool. If you want more instruction regarding to execute further aspects like fault tolerance, wireless communication, or routing protocols in the hierarchical topology, we will deliver it.