To simulate Open Systems Interconnection (OSI) layer protocol projects in OMNeT++ has needs to set up and design the numerous layers of the OSI model in the network stack. OMNeT++ with the INET framework delivers built-in support for protocols via numerous layers of the OSI model, that contain Layer 1 (Physical), Layer 2 (Data Link), Layer 3 (Network), and higher layers.
Here is a detailed guide to simulate OSI layer protocol projects using OMNeT++.
Steps to Simulate OSI Layer Protocol Projects in OMNeT++
Step 1: Install OMNeT++ and INET Framework
Make sure OMNeT++ and the INET framework is installed since INET deliver models for numerous OSI layers.
- Download OMNeT++: OMNeT++
- Download INET Framework: INET Framework
INET deliver modules for replicating multiple OSI layers that contain:
- Layer 1: Physical layer (e.g., signal propagation, wireless communication).
- Layer 2: Data link layer (e.g., Ethernet, Wi-Fi, MAC protocols).
- Layer 3: Network layer (e.g., IP routing protocols, ARP).
- Layer 4 and above: Transport and application layers (e.g., TCP, UDP, HTTP).
Step 2: Choose Which OSI Layers to Simulate
Classify which OSI layers and protocols that need to concentrate on project. For example:
- Layer 2: Ethernet, VLAN, or MAC protocols.
- Layer 3: IP, ARP, routing protocols (such as OSPF, RIP).
- Layer 4: TCP, UDP for transport layer simulations.
- Application layer: Utilize HTTP, FTP, or custom application protocols.
For instance, if we need to replicate a combination of Layer 2 (Ethernet) and Layer 3 (IP), we can set up a simple network with routers and switches.
Step 3: Set Up the Network Topology in NED File
In the .ned file, we can describe a network topology that signifies the network elements corresponding to the OSI layers that need to simulate.
Here’s an instance NED file that replicates a basic Layer 2 (Ethernet) and Layer 3 (IP) network:
network OSIModelNetwork
{
submodules:
host1: StandardHost {
@display(“p=100,100”);
}
host2: StandardHost {
@display(“p=500,100”);
}
switch1: EthernetSwitch {
@display(“p=300,200”);
}
router1: Router {
@display(“p=300,300”);
}
connections:
host1.ethg++ <–> Eth100M <–> switch1.ethg++;
host2.ethg++ <–> Eth100M <–> switch1.ethg++;
switch1.ethg++ <–> Eth100M <–> router1.ethg++;
router1.pppg++ <–> Ppp0 <–> router1.ethg++;
}
In this setup:
- host1 and host2 signify Layer 2 Ethernet hosts with Layer 3 IP capabilities.
- switch1 is an Ethernet switch operating on Layer 2.
- router1 perform on both Layer 2 (Data Link) and Layer 3 (Network) for routing packets.
Step 4: Configure Protocols for OSI Layers in omnetpp.ini
we can set up certain protocols for each OSI layer in the omnetpp.ini file.
Layer 1 (Physical) and Layer 2 (Data Link) Configuration:
# Configure Layer 2 Ethernet settings
*.host1.eth[0].mac.address = “00:00:00:00:01:00”
*.host2.eth[0].mac.address = “00:00:00:00:02:00”
*.switch1.numPorts = 2
*.switch1.eth[*].macForwardingTableSize = 100 # Set MAC address forwarding table size
*.switch1.eth[*].macLearning = true # Enable MAC address learning
Layer 3 (Network) Configuration (IP, ARP, Routing):
[Config OSIModelNetworkSimulation]
network = OSIModelNetwork
sim-time-limit = 1000s
# IP address configuration (Layer 3)
*.host1.ipv4.ip = “10.0.0.1”
*.host2.ipv4.ip = “10.0.0.2”
*.router1.ipv4.ip = “10.0.0.3”
# Enable routing on the router
*.router1.hasIpv4RoutingTable = true
*.router1.routingTable.useDefaultRoutes = true
# Enable ARP (Address Resolution Protocol) for resolving IP to MAC addresses (Layer 3 to Layer 2)
*.host1.ipv4.arp.cacheTimeout = 60s
*.host2.ipv4.arp.cacheTimeout = 60s
Layer 4 (Transport) Configuration (TCP/UDP):
# Enable TCP communication between hosts (Layer 4)
*.host1.numApps = 1
*.host1.app[0].typename = “TcpBasicClientApp”
*.host1.app[0].localAddress = “10.0.0.1”
*.host1.app[0].connectAddress = “10.0.0.2”
*.host1.app[0].startTime = 10s
*.host1.app[0].numRequestsPerSession = 10
*.host2.numApps = 1
*.host2.app[0].typename = “TcpBasicServerApp”
Step 5: Implement Traffic and Applications
If you are replicating higher OSI layers (such as Layers 4 and above), we can execute application protocols like HTTP, FTP, or your own custom protocol. For instance, for replicating HTTP traffic:
# Simulate HTTP traffic between host1 (client) and host2 (server)
*.host1.numApps = 1
*.host1.app[0].typename = “HttpClient”
*.host1.app[0].localAddress = “10.0.0.1”
*.host1.app[0].connectAddress = “10.0.0.2”
*.host1.app[0].startTime = 5s
*.host2.numApps = 1
*.host2.app[0].typename = “HttpServer”
Step 6: Run the Simulation
After configuring the NED and INI files, we can execute the simulation using the OMNeT++ GUI or command-line interface.
- Build and compile the project.
- Run the simulation.
- Monitor the simulation results: we can track on how packets traverse across the layers (from physical to application layer) in the OMNeT++ simulation environment.
Step 7: Analyse Simulation Results
OMNeT++ creates .sca and .vec files that contain complete statistics and parameters for the simulation. We can evaluate and visualize:
- Packet delivery ratios (Layer 3).
- Latency and throughput (Layer 4).
- Data transmission rates (Layer 1 and Layer 2).
Utilize OMNeT++’s evaluation tools to plot and relate these parameters.
Example Scenarios:
- Layer 2 Performance: Experiment on how different Ethernet switch configurations impact network performance, like packet forwarding efficiency or loop mitigation with STP.
- Layer 3 Routing: Emulate dynamic IP routing with protocols such as RIP or OSPF.
- Layer 4 Transport: Measure TCP versus UDP performance in different network conditions.
Step 8: Advanced Customization
We can customize the OSI layer simulation to reflect specific real-world network environment:
- Add QoS (Quality of Service) mechanisms at Layer 2 or Layer 3.
- Simulate mobility by adding movement models to nodes that impacts interaction at all layers.
- Custom protocols: Execute own protocol at any OSI layer by expanding INET or writing own modules.
Example:
For a custom Layer 3 protocol:
class CustomRouting : public cSimpleModule
{
protected:
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
void routePacket(cMessage *msg);
};
You can replace INET’s IP module with custom implementation if we are simulating non-standard Layer 3 behaviour.
In this page, we clearly showed the simulation process on how the Open Systems Interconnection perform in the OMNeT++ tool and also we offered the sample snippets to understand the concept of the simulation. We plan to deliver the more information regarding the Open Systems Interconnection in further manual.
You can look forward to excellent simulations and research concepts from us. We design tailored projects specifically for you. Receive support on various levels of the OSI model, including Layer 1 (Physical), Layer 2 (Data Link), Layer 3 (Network), and more, delivered promptly with clear explanations. phdprime.com will assist you with simulations for your OSI Layer Protocol Projects using OMNeT++.
