To simulate Network Layer projects using OMNeT++ has usually operates with routing protocols, packet forwarding, and addressing mechanisms. The network layer manages the movement of data via multiple networks and it is accountable for logical addressing such as IP addressing, routing, and packet forwarding.
The INET framework in OMNeT++ deliver a robust set of tools for replicating diverse network layer features, that contain routing algorithms such as RIP, OSPF, DSR, AODV, IP addressing, fragmentation, and more.
Here’s a step-by-step guide to simulate Network Layer projects using OMNeT++:
Steps to Simulate Network Layer Projects in OMNeT++
- Install OMNeT++ and INET Framework
- Download and install OMNeT++ from here.
- Clone or download the INET framework from INET GitHub repository. INET deliver network layer components such as IP, routing, and packet forwarding.
- Understand the Components of the Network Layer
The network layer is responsible for:
- Logical Addressing: Assigning IP addresses to devices.
- Routing: Defining the best path to deliver packets via different networks.
- Packet Forwarding: Transmitting packets in terms of routing decisions.
- Fragmentation: Breaking down large packets for transmission through networks with different Maximum Transmission Units (MTUs).
- Set up a Simple Network Topology in NED
For a network layer project, we will need to describe a network topology that contains routers, hosts, and connections. Below is an instance NED file for a simple network with two routers and three hosts.
Example NED File:
network NetworkLayerSimulation {
submodules:
router[2]: Router {
@display(“p=” + (100 + index * 200) + “,200”);
}
host[3]: StandardHost {
@display(“p=” + (index * 150) + “,100”);
}
connections allowunconnected:
host[0].ethg++ <–> Eth100M <–> router[0].ethg++;
host[1].ethg++ <–> Eth100M <–> router[0].ethg++;
router[0].ethg++ <–> Eth100M <–> router[1].ethg++;
host[2].ethg++ <–> Eth100M <–> router[1].ethg++;
}
This example sets up:
- Two routers (router[0] and router[1]), that will forward packets according to their routing tables.
- Three hosts (host[0], host[1], host[2]) associated to the routers through Ethernet connections.
- Configure the Network Layer in omnetpp.ini
The omnetpp.ini file is in which we configure IP addresses, routing protocols, and any additional settings such as packet fragmentation.
Example omnetpp.ini Configuration:
network = NetworkLayerSimulation
sim-time-limit = 100s
# IP address configuration for each host and router
**.host[0].ipv4.address = “192.168.1.1”
**.host[1].ipv4.address = “192.168.1.2”
**.host[2].ipv4.address = “192.168.2.1”
**.router[0].ipv4.address = “192.168.1.254”
**.router[1].ipv4.address = “192.168.2.254”
# Configure routing tables on the routers
**.router[0].routingTableRouter = true # Enable routing on router 0
**.router[1].routingTableRouter = true # Enable routing on router 1
# Static routing setup
**.router[0].ipv4.routingTable[0].destination = “192.168.2.0”
**.router[0].ipv4.routingTable[0].netmask = “255.255.255.0”
**.router[0].ipv4.routingTable[0].gateway = “192.168.1.254”
**.router[1].ipv4.routingTable[0].destination = “192.168.1.0”
**.router[1].ipv4.routingTable[0].netmask = “255.255.255.0”
**.router[1].ipv4.routingTable[0].gateway = “192.168.2.254”
# UDP traffic generation between hosts
**.host[0].numApps = 1
**.host[0].app[0].typename = “UdpBasicApp”
**.host[0].app[0].destAddresses = “host[2]”
**.host[0].app[0].sendInterval = 1s
**.host[0].app[0].messageLength = 512B
**.host[2].numApps = 1
**.host[2].app[0].typename = “UdpSink”
Explanation:
- IP Addresses: Each host and router is assigned an IP address in diverse subnets (e.g., 192.168.1.x and 192.168.2.x).
- Routing: Static routes are defined on routers to forward traffic among subnets.
- UDP Traffic: Traffic is created among host[0] (source) and host[2] (destination) to test routing.
- Routing Protocols
If we need to utilize dynamic routing protocols like RIP or OSPF, we need to setup them in omnetpp.ini rather than static routing.
Example Configuration for RIP:
# Enable RIP on the routers
**.router[0].routingProtocol = “RIP”
**.router[1].routingProtocol = “RIP”
This will enable the routers to automatically learn routes to each other according to the Routing Information Protocol (RIP).
- Simulate Fragmentation
If we need to simulate fragmentation of packets at the network layer (for instance, if a router has an MTU smaller than the packet size), we need to allow this features in the configuration.
Example Fragmentation Configuration:
# Simulate fragmentation on router 0
**.router[0].ipv4.fragmentationEnabled = true
**.router[0].ipv4.mtu = 512 # MTU size
This will force router 0 to fragment packets larger than 512 bytes before forwarding them.
- Run the Simulation
- Open OMNeT++ and run the simulation.
- During the simulation, we need to envision packet forwarding, track on how routers manage routing, and validate on how traffic is flowing across the network.
- Analyze the Simulation Results
OMNeT++ delivers several tools for gathering parameter and envisions the performance of the network layer. We need to observe:
- Routing Table Updates: observe on how dynamic routing protocols update their routing tables.
- Packet Forwarding: Monitor on how packets are forwarded via the routers and make sure correct delivery.
- Packet Loss: Track if any packets are dropped because of fragmentation or routing concerns.
- End-to-End Delay: Assess the time taken for packets to traverse from source to destination.
- Throughput: Assess on how much data is successfully routed among hosts.
OMNeT++’s plove tool enable you to plot scalar and vector data, allowing detailed evaluation of network layer performance.
- Extend the Simulation
We can prolong the network layer simulation by adding:
- More Routing Protocols: Exam other routing protocols such as OSPF, AODV, or DSR and relate their performance.
- Different Topologies: Replicate more complex networks, like tree, mesh, or star topologies, and measure on how routing behaves.
- Traffic Flows: Establish different kinds of traffic, like TCP, and evaluate the effect of network congestion or routing delays.
- Network Failures: Replicate network link or node failures and measure on how the network layer adjusts by recalculating routes.
Example Projects for Network Layer Simulation:
- Routing Protocol Performance Comparison: mimic different routing protocols (e.g., RIP, OSPF, and AODV) and evaluate their performance according to convergence time, packet loss, and routing overhead.
- Network Fragmentation: Emulate packet fragmentation in a network in which the routers have changing MTUs and measure the impacts on throughput and packet reassembly.
- Mobile Ad Hoc Network (MANET): Utilize dynamic routing protocols such as DSR or AODV to emulate a MANET and track on how the network layer manages frequent topology changes.
- QoS-Aware Routing: Apply and replicate a Quality of Service (QoS) aware routing protocol and assess its performance in delivering real-time and high-priority traffic.
From the entire page, we had collected the most essential information that will very helpful to simulate the Network Layer projects in OMNeT++ tool that is used to maintain the routing. More information will be shared according to your needs.
We request you to communicate your requirements regarding Network Layer projects, and we will provide you with the most effective simulation guidance.
