How to Implement interior protocol in OMNeT++
To implement an Interior Gateway Protocol (IGP) in OMNeT++ need to encompass set up the surroundings, accepting the protocol wish to implement, generating the protocol module, participating it through the INET framework, and trying it.
The given below is the process to implement the interior protocol in OMNeT++ by using the Open Shortest Path First (OSPF) protocol as an example of an IGP.
Step-by-Step Implementations:
Step 1: Set Up OMNeT++ and INET Framework
- Install OMNeT++: From the OMNeT++ to download and install the new form of it.
- Install INET Framework: From the INET repository to install and download the INET framework.
Step 2: Understand OSPF Protocol
OSPF protocol is a link-state routing protocol castoff in a single autonomous system (AS). This key perception is contain:
- Link-State Advertisements (LSAs): This is used to promote the state of links.
- Hello Protocol: For neighbour discovery and keeping neighbour relationships by using this protocol.
- Shortest Path First (SPF) Algorithm: This is used to estimate the shortest path tree for separate route.
Step 3: Explore Existing Implementations
For different routing protocol execution involved by the INET framework. Go through these afford insights into constructing the OSPF implementation.
Step 4: Create the OSPF Protocol Module
Define the Module in .ned File
To build a .ned file for the OSPF protocol module.
simple OSPF
{
parameters:
double helloInterval @unit(s) = default(10s);
double lsaInterval @unit(s) = default(30s);
gates:
input in[];
output out[];
}
Implement the Module in C++
Make a corresponding .cc and .h files.
OSPF.h
#ifndef __OSPF_H_
#define __OSPF_H_
#include <omnetpp.h>
#include “inet/networklayer/contract/IRoutingTable.h”
#include “inet/networklayer/common/L3AddressResolver.h”
#include “inet/networklayer/ipv4/IPv4Datagram.h”
using namespace omnetpp;
using namespace inet;
class OSPF : public cSimpleModule
{
private:
double helloInterval;
double lsaInterval;
IRoutingTable *routingTable;
cMessage *helloMsg;
cMessage *lsaMsg;
protected:
virtual void initialize() override;
virtual void handleMessage(cMessage *msg) override;
void sendHello();
void sendLsa();
void processHello(cMessage *msg);
void processLsa(cMessage *msg);
public:
OSPF();
virtual ~OSPF();
};
#endif
OSPF.cc
#include “OSPF.h”
Define_Module(OSPF);
OSPF::OSPF()
{
helloMsg = nullptr;
lsaMsg = nullptr;
}
OSPF::~OSPF()
{
cancelAndDelete(helloMsg);
cancelAndDelete(lsaMsg);
}
void OSPF::initialize()
{
helloInterval = par(“helloInterval”);
lsaInterval = par(“lsaInterval”);
routingTable = getModuleFromPar<IRoutingTable>(par(“routingTableModule”), this);
helloMsg = new cMessage(“sendHello”);
lsaMsg = new cMessage(“sendLsa”);
scheduleAt(simTime() + helloInterval, helloMsg);
scheduleAt(simTime() + lsaInterval, lsaMsg);
}
void OSPF::handleMessage(cMessage *msg)
{
if (msg == helloMsg)
{
sendHello();
scheduleAt(simTime() + helloInterval, helloMsg);
}
else if (msg == lsaMsg)
{
sendLsa();
scheduleAt(simTime() + lsaInterval, lsaMsg);
}
else if (strcmp(msg->getName(), “Hello”) == 0)
{
processHello(msg);
}
else if (strcmp(msg->getName(), “LSA”) == 0)
{
processLsa(msg);
}
else
{
// Handle other message types
}
}
void OSPF::sendHello()
{
cMessage *hello = new cMessage(“Hello”);
send(hello, “out”);
}
void OSPF::sendLsa()
{
cMessage *lsa = new cMessage(“LSA”);
send(lsa, “out”);
}
void OSPF::processHello(cMessage *msg)
{
// Implement processing of Hello message
delete msg;
}
void OSPF::processLsa(cMessage *msg)
{
// Implement processing of LSA message
delete msg;
}
Step 5: Integrate with Simulation Model
Participate the OSPF module addicted to a network simulation model.
Network Configuration .ned File
network OSPFNetwork
{
submodules:
host1: StandardHost {
parameters:
@display(“p=100,100”);
routingTableModule = “^.routingTable”;
}
host2: StandardHost {
parameters:
@display(“p=300,100”);
routingTableModule = “^.routingTable”;
}
connections:
host1.pppg++ <–> { @display(“m=100,100”); } <–> host2.pppg++;
}
omnetpp.ini Configuration
[General]
network = OSPFNetwork
*.host1.ipv4Routing = “inet.networklayer.ipv4.IPv4Routing”
*.host2.ipv4Routing = “inet.networklayer.ipv4.IPv4Routing”
*.host1.routingTableModule = “host1.routingTable”
*.host2.routingTableModule = “host2.routingTable”
*.host1.ospf = “OSPF”
*.host2.ospf = “OSPF”
Step 6: Test and Debug
- Run Simulations: To implement simulations to test the behaviour of the OSPF module below the different network settings.
- Analyze Results: Substantiate the rightness and concert of the enactment.
- Debugging: To troubleshoot any problems by using the OMNeT++’s debugging tools.
This approach will guide you through implementing a simplified version of an Interior routing protocol, such as OSPC, in OMNeT++. We plan to provide the extra details on Interior protocol as per your requirements.