To simulate Distance Vector Routing projects using OMNeT++, which comprises executing or utilizing an existing Distance Vector Routing (DVR) protocol, like RIP (Routing Information Protocol). Distance vector routing protocols find out the finest path for data packets according to the distance (hop count) to a destination, and nodes are share routing tables with their neighbours.
In the simulation tool OMNeT++, we can be mimicked Distance Vector Routing using the INET framework by either leveraging built-in protocols such as RIP or developing own custom DVR execution.
The following is a step-by-step instruction to replicating Distance Vector Routing projects in OMNeT++:
Steps to Simulate Distance Vector Routing Projects in OMNeT++
Step 1: Install OMNeT++ and INET Framework
Make certain that OMNeT++ and the INET framework are installed on the system. INET offers support for IP routing protocols, containing Distance Vector Routing such as RIP.
- Download OMNeT++: OMNeT++ official website
- Download INET Framework: INET Framework
Step 2: Define the Network Topology in the NED File
Describe a network topology in which several routers exchange routing data to find out the best paths. This network can be contained numerous routers and hosts, which communicate via distance vector routing.
Here’s an instance NED file defining a simple network with three routers and two hosts:
network DVNetwork
{
submodules:
host1: StandardHost {
@display(“p=100,200”);
}
host2: StandardHost {
@display(“p=500,200”);
}
router1: Router {
@display(“p=200,300”);
}
router2: Router {
@display(“p=300,300”);
}
router3: Router {
@display(“p=400,300”);
}
connections:
host1.ethg++ <–> Eth100M <–> router1.ethg++;
router1.ethg++ <–> Eth100M <–> router2.ethg++;
router2.ethg++ <–> Eth100M <–> router3.ethg++;
router3.ethg++ <–> Eth100M <–> host2.ethg++;
}
In this topology:
- host1 and host2 are the end devices.
- router1, router2, and router3 are the routers, which will exchange distance vector routing data to find out the best path for forwarding data among the hosts.
Step 3: Configure Distance Vector Routing (RIP) in the INET Framework
The INET framework offers support for the Routing Information Protocol (RIP), a Distance Vector Routing protocol. RIP occasionally shares routing tables among routers and uses the hop count as a metric to ascertain the finest path.
In the omnetpp.ini file, allow RIP on the routers and set up their interfaces.
Step 3.1: Assign IPv4 Addresses
Allocate an IPv4 addresses to each router and host in the network:
[Config DVNetworkSimulation]
network = DVNetwork
sim-time-limit = 100s
# Assign IPv4 addresses to hosts and routers
*.host1.ipv4.config = “manual”
*.host1.ipv4.addresses = “10.0.0.1/24”
*.host2.ipv4.config = “manual”
*.host2.ipv4.addresses = “10.0.1.1/24”
*.router1.ipv4.config = “manual”
*.router1.ipv4.addresses = “10.0.0.254/24 10.0.2.1/24”
*.router2.ipv4.config = “manual”
*.router2.ipv4.addresses = “10.0.2.2/24 10.0.3.1/24”
*.router3.ipv4.config = “manual”
*.router3.ipv4.addresses = “10.0.3.2/24 10.0.1.254/24”
This configuration assigns:
- host1 the address 10.0.0.1/24,
- host2 the address 10.0.1.1/24,
- router1, router2, and router3 each have two interfaces with distinct subnets.
Step 3.2: Enable RIP on Routers
Allow RIP on the routers and set up their interfaces to participate in the RIP protocol:
# Enable RIP on the routers
*.router1.hasRip = true
*.router2.hasRip = true
*.router3.hasRip = true
# Configure interfaces for RIP
*.router1.interfaceTable[0].ripEnabled = true
*.router1.interfaceTable[1].ripEnabled = true
*.router2.interfaceTable[0].ripEnabled = true
*.router2.interfaceTable[1].ripEnabled = true
*.router3.interfaceTable[0].ripEnabled = true
*.router3.interfaceTable[1].ripEnabled = true
# Enable logging for RIP events (optional)
*.router1.routingTable.ripDebug = true
*.router2.routingTable.ripDebug = true
*.router3.routingTable.ripDebug = true
In this configuration:
- RIP is allowed on all three routers, permitting them to exchange routing data.
- The ripEnabled setting make certain that RIP is active on each interface of the routers.
- The ripDebug option is allowed to log RIP events and monitor routing table updates.
Step 4: Simulate Traffic between Hosts
When the RIP protocol is set up then we can be replicated traffic among host1 and host2. For instance, generate UDP traffic from host1 to host2 to experiment the routing functionality.
# Simulate UDP traffic from host1 to host2
*.host1.numApps = 1
*.host1.app[0].typename = “UdpBasicApp”
*.host1.app[0].localAddress = “10.0.0.1”
*.host1.app[0].connectAddress = “10.0.1.1”
*.host1.app[0].sendInterval = 1s
*.host1.app[0].messageLength = 512B
*.host1.app[0].startTime = 10s
# Configure host2 to receive UDP traffic
*.host2.numApps = 1
*.host2.app[0].typename = “UdpSinkApp”
In this configuration:
- host1 generates UDP traffic and transmits it to host2 at regular intervals.
- host2 is configured as a sink, receiving the UDP traffic from host1.
Step 5: Run the Simulation
After configuring the network and setup the RIP protocol:
- Build and compile the project in OMNeT++.
- Run the simulation in the OMNeT++ GUI or from the command line.
- Observe RIP routing behavior: Utilize the OMNeT++ GUI to envision the packet flows and routing updates. Also, we can verify the simulation logs for RIP debug messages to monitor how routing tables are updated.
Step 6: Analyze Simulation Results
OMNeT++ makes .sca and .vec files comprising simulation outcomes. We can examine several key parameters for Distance Vector routing, containing:
- Routing Table Updates: Investigate how often routing tables are updated and how paths are studied by the routers.
- End-to-End Delay: Estimate the delay experienced by packets as they pass through the network.
- Packet Delivery Ratio: Ascertain how many packets are effectively delivered from host1 to host2.
- RIP Convergence Time: Assess the time it takes for the network to attain a stable routing state.
We can be utilized OMNeT++’s analysis tools to plot and analyse these metrics, supporting to know how Distance Vector Routing executes under distinct network conditions.
Step 7: Extend the Simulation
We can expand the simulation by inserting additional aspects and scenarios, like:
7.1: Simulate Link Failures and Recovery
Launch link failures among the routers and monitor how RIP reacts by recalculating paths. It can support to learn how RIP adapts to network changes and how rapidly it converges after a failure.
# Simulate a link failure between router1 and router2 at 50 seconds
*.router1.interfaceTable[1].downAt = 50s
7.2: Increase the Network Size
Extend the network by inserting more routers and hosts to mimic a larger network with more complex routing scenarios.
7.3: Modify RIP Timers
We can tweak RIP timers, like the update interval or the timeout period, to investigate their influence on performance.
# Adjust RIP update and timeout timers
*.router1.routingTable.ripUpdateInterval = 15s
*.router2.routingTable.ripUpdateInterval = 15s
*.router3.routingTable.ripUpdateInterval = 15s
7.4: Simulate Network Congestion
Launch congestion or maximized traffic to observe how RIP performs under high network load and whether alternate routes are used.
Step 8: Implement Custom Distance Vector Routing Protocol (Optional)
If we require to exceed RIP and make a custom Distance Vector Routing protocol then we can execute the routing logic manually within C++. The following is a simple outline of a custom DVR:
class CustomDVR : public cSimpleModule
{
protected:
std::map<int, int> routingTable; // Destination -> Next Hop
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
void sendRoutingUpdate();
void processRoutingUpdate(cMessage *msg);
};
Define_Module(CustomDVR);
void CustomDVR::initialize()
{
// Initialize routing table and set up periodic updates
scheduleAt(simTime() + 10, new cMessage(“routingUpdate”));
}
void CustomDVR::handleMessage(cMessage *msg)
{
if (strcmp(msg->getName(), “routingUpdate”) == 0) {
sendRoutingUpdate();
scheduleAt(simTime() + 10, msg); // Schedule the next update
} else {
processRoutingUpdate(msg);
}
}
void CustomDVR::sendRoutingUpdate()
{
// Send routing table to neighbors
}
void CustomDVR::processRoutingUpdate(cMessage *msg)
{
// Process incoming routing update and modify routing table
}
This basic DVR framework transmits routing updates periodically and processes incoming routing updates from neighbouring routers. We can extend it by executing the logic for conserving and updating routing tables rely on the distance vector algorithm.
We presented the fundamental approach with example code for Distance Vector Routing projects that were simulated and implemented using OMNeT++ tool. Further specific insights will be added later, if required. We assist you by offering comprehensive, step-by-step instructions for Distance Vector Routing Projects utilizing OMNeT++. Please share all relevant details with phdprime.com, and we will ensure you receive the finest simulation guidance.
