To simulate the distance vector routing projects using OMNeT++ that concentrate on the algorithms in which each router in the network shares its routing table with its neighbours, and routing decisions are created according to the “distance” (number of hops, delay, or cost) to the destination. One of the most general protocols for distance vector routing is RIP (Routing Information Protocol) that utilizes the Bellman-Ford algorithm to calculate the shortest path rely on the hop count. Other distance vector protocols would contain BGP (Border Gateway Protocol) or custom distance-vector protocols for particular use cases.
Below is a step-by-step instruction to replicate distance vector routing projects using OMNeT++ and the INET Framework.
Steps to Simulate Distance Routing Projects in OMNeT++
- Install OMNeT++ and INET Framework
- Download OMNeT++:
- We can download and install OMNeT++ from the official website.
- Install INET Framework:
- The INET Framework offers models for general routing protocols such as RIP that executes the Bellman-Ford distance vector algorithm.
- Clone the INET repository:
git clone https://github.com/inet-framework/inet.git
-
- Import INET into OMNeT++ through File > Import > Existing Projects into Workspace, and choose the inet directory.
- Build the project by right-clicking on the inet project within OMNeT++ and choosing the Build Project.
- Define the Network Topology in NED
Make a network in which distance vector routing (e.g., RIP) can be replicated. It can be described using NED (Network Description) that models the network topology, containing routers and hosts.
Example NED File for Distance Vector Routing (DistanceVectorRoutingNetwork.ned):
package distancevectorrouting;
import inet.node.inet.Router;
import inet.node.inet.StandardHost;
import inet.linklayer.ethernet.EthernetInterface;
import inet.networklayer.configurator.ipv4.Ipv4NetworkConfigurator;
network DistanceVectorRoutingNetwork
{
parameters:
int numRouters = 4; // Define the number of routers
submodules:
configurator: Ipv4NetworkConfigurator {
@display(“p=50,50”);
}
host1: StandardHost {
@display(“p=50,50”);
}
host2: StandardHost {
@display(“p=400,50”);
}
router[numRouters]: Router {
@display(“p=100+100*i,150”);
}
connections allowunconnected:
host1.ethg++ <–> EthernetInterface <–> router[0].ethg++;
router[0].ethg++ <–> EthernetInterface <–> router[1].ethg++;
router[1].ethg++ <–> EthernetInterface <–> router[2].ethg++;
router[2].ethg++ <–> EthernetInterface <–> router[3].ethg++;
router[3].ethg++ <–> EthernetInterface <–> host2.ethg++;
}
Explanation:
- StandardHost: Denotes the source (host1) and destination (host2) nodes for making and receiving traffic.
- Router: Routers that participate in distance-vector routing, like RIP, to forward traffic according to the distance.
- EthernetInterface: Wired connections among routers and hosts.
- Ipv4NetworkConfigurator: Automatically allocates IP addresses and network configurations to routers and hosts.
- Configure RIP for Distance Vector Routing in omnetpp.ini
The Routing Information Protocol (RIP) executes the Bellman-Ford distance-vector algorithm. In the omnetpp.ini configuration file, we will be allowed RIP on the routers and set up how it calculates the distances (based on hop count).
Example omnetpp.ini Configuration for RIP:
[General]
network = DistanceVectorRoutingNetwork
sim-time-limit = 200s
# IP Address Configuration for Hosts and Routers
*.host1.ipv4.address = “10.0.0.1”
*.host1.ipv4.netmask = “255.255.255.0”
*.host2.ipv4.address = “10.0.0.2”
*.host2.ipv4.netmask = “255.255.255.0”
# Enable RIP (Distance Vector Routing) on Routers
*.router[*].hasRip = true
*.router[*].ripRouter.routingTable = “RipRoutingTable”
# Traffic Configuration (UDP Traffic Generation)
*.host1.numApps = 1
*.host1.app[0].typename = “UdpBasicApp”
*.host1.app[0].destAddresses = “10.0.0.2” # Send traffic to Host2
*.host1.app[0].destPort = 5000
*.host1.app[0].messageLength = 1024B
*.host1.app[0].sendInterval = exponential(1s)
*.host2.numApps = 1
*.host2.app[0].typename = “UdpSink” # Host2 is the UDP receiver
*.host2.app[0].localPort = 5000
# RIP Parameters (Bellman-Ford Distance Vector Algorithm)
*.**.ripRouter.updateInterval = 10s # Interval for RIP updates
*.**.ripRouter.timeoutInterval = 30s # Time before a route is declared invalid
*.**.ripRouter.holdDownInterval = 15s # Hold-down time for unreachable routes
Explanation:
- RIP Configuration: Allows RIP on all routers that will calculate the shortest path rely on hop count and occasionally exchange routing data with neighbours.
- UDP Traffic Generation: Host1 transmits UDP traffic to Host2 via the routers using the RIP-generated routes.
- RIP Parameters: Sets up the frequency of routing table updates, route timeout intervals, and hold-down periods for unreachable routes.
- Run the Simulation
- Build the Project:
- Right-click on the OMNeT++ project and choose Build Project to compile the simulation files.
- Run the Simulation:
- Right-click on omnetpp.ini and choose Run As > OMNeT++ Simulation.
- We can be utilized the Qtenv graphical interface to monitor how RIP calculates the routing tables for each router and forwards packets from Host1 to Host2 according to the hop count (distance).
- Analyze the Results
When the simulation is complete then we can analyse the following features of the distance-vector routing:
- Routing Table Convergence:
- Monitor how rapidly each router calculates the shortest paths (in terms of hop count) and updates its routing table.
- Traffic Flow:
- Check that traffic from Host1 to Host2 follows the shortest paths as calculated by RIP.
- RIP Control Traffic:
- Observe the RIP updates exchanged among the routers. Each router occasionally transmits its distance vectors (routing table) to its neighbours.
- Performance Metrics:
- End-to-End Delay: Estimate how long it takes for packets to travel from Host1 to Host2.
- Throughput: Examine how much data is sent effectively among the hosts.
- Packet Delivery Ratio: Ascertain if any packets were dropped because of invalid routes or delays in route convergence.
- Simulate Dynamic Network Conditions
Replicate dynamic network conditions to monitor how distance vector routing adjusts to changes in network topology:
- Link Failures:
- Replicate a link failure by disabling one of the links among the routers and monitor how RIP recomputes routes and reroutes traffic consequently.
# Disable a link between router[1] and router[2] to simulate a link failure
*.router[1].ethg[1].disable = true
- Traffic Congestion:
- Launch several traffic flows to mimic network congestion and examine how the distributed routing protocol reacts to maximized traffic loads.
- Latency and Packet Loss:
- Launch delays or packet loss on specific links to mimic unreliable network conditions and then monitor how RIP adjusts to changing conditions.
- Extend the Simulation
- Test with Larger Topologies:
- Maximizes the amount of routers and hosts to replicate a larger network and experiment the scalability of the distance vector routing protocol.
- Compare with Other Routing Protocols:
- Replicate other routing protocols like OSPF (Link-State Routing) or AODV (Ad-hoc On-demand Distance Vector) and compare their performance with RIP such as convergence time, control traffic overhead, and path optimality.
- Custom Distance Vector Protocol:
- Execute the own custom distance-vector routing protocol using C++ to experiment more particular distance metrics (e.g., cost, delay, bandwidth).
In this simulation, we comprehensively explained the simulation approach on how to simulate and analyse the Distance Routing Projects within OMNeT++ simulation tool. We will also be presented advance informations on this topic, if required.
We assist you with detailed, step-by-step instructions for distance vector routing projects using OMNeT++. Just share your information with phdprime.com, and we’ll offer you the best guidance for your simulations.
