How to Implement Content Delivery Networks in OMNeT++

To implement the Content Delivery Network (CDN) in OMNeT++, we have to create a network topology that has servers, caches, and clients and Deliver the content from the nearby cache or server to the client by simulating them. The INET Framework in OMNeT++ provides a good foundation for this. Follow the step-by-step guide to implement them:

Step-by-Step Implementation:

Install OMNeT++ and INET Framework

Make sure to install the OMNeT++ and the INET Framework in your computer.

Create a New OMNeT++ Project

Open OMNeT++ IDE: Start the OMNeT++ IDE.
Create a New Project: Go to File -> New -> OMNeT++ Project. Name your project (example: CDNSimulation).

Import INET into Your Project

Import INET: In the Project Explorer, right-click on your project, select Properties. Go to Project References and check the INET project.
Copy INET Examples: For reference, we have to copy the configurations of a sample from the INET framework.

Define the Network Topology

Create a new NED file to state the network topology that has clients, CDN servers, and intermediate network nodes.

Example: CDN Network Topology (CDNNetwork.ned)

package cdn;

import inet.node.inet.StandardHost;

import inet.node.inet.Router;

network CDNNetwork

{

parameters:

@display(“bgb=600,400”);

submodules:

client1: StandardHost {

@display(“p=100,200”);

}

client2: StandardHost {

@display(“p=500,200”);

}

edgeServer1: StandardHost {

@display(“p=200,100”);

}

edgeServer2: StandardHost {

@display(“p=400,100”);

}

originServer: StandardHost {

@display(“p=300,50”);

}

router: Router {

@display(“p=300,200”);

}

connections:

client1.ethg++ <–> Eth10M <–> router.ethg++;

client2.ethg++ <–> Eth10M <–> router.ethg++;

edgeServer1.ethg++ <–> Eth10M <–> router.ethg++;

edgeServer2.ethg++ <–> Eth10M <–> router.ethg++;

originServer.ethg++ <–> Eth10M <–> router.ethg++;

}

In this sample:

client1 and client2 are standard hosts acting as clients.
edgeServer1 and edgeServer2 are CDN edge servers.
originServer is the origin server that has the originally stored content.
router is a router facilitating interaction among the clients and servers.
The Eth10M channel models a 10 Mbps Ethernet link.

Configure the Simulation

Create an OMNeT++ initialization file to configure the simulation’s parameters.

Example: Configuration File (omnetpp.ini)

[General]

network = cdn.CDNNetwork

sim-time-limit = 100s

# Visualization

*.visualizer.canvasVisualizer.displayBackground = true

*.visualizer.canvasVisualizer.displayGrid = true

# Host Configuration

*.client*.numApps = 1

*.client*.app[0].typename = “TcpBasicClientApp”

*.client*.app[0].localPort = -1

*.client*.app[0].connectAddress = “edgeServer1 edgeServer2”

*.client*.app[0].connectPort = 80

*.client*.app[0].sendBytes = 1000

*.client*.app[0].tOpen = 1s

*.client*.app[0].tSend = 2s

*.client*.app[0].tClose = 10s

*.edgeServer*.numApps = 1

*.edgeServer*.app[0].typename = “TcpBasicServerApp”

*.edgeServer*.app[0].localPort = 80

*.originServer.numApps = 1

*.originServer.app[0].typename = “TcpBasicServerApp”

*.originServer.app[0].localPort = 80

# TCP Configuration

*.client*.hasTcp = true

*.edgeServer*.hasTcp = true

*.originServer.hasTcp = true

# IP Address Configuration

*.client1.ipv4.config = xmldoc(“client1.xml”)

*.client2.ipv4.config = xmldoc(“client2.xml”)

*.edgeServer1.ipv4.config = xmldoc(“edgeServer1.xml”)

*.edgeServer2.ipv4.config = xmldoc(“edgeServer2.xml”)

*.originServer.ipv4.config = xmldoc(“originServer.xml”)

*.router.ipv4.config = xmldoc(“router.xml”)

Create IP Address Configuration Files

Create XML files to define the IP address configuration for all host and the router.

Example: IP Configuration File for client1 (client1.xml)

</interface>

<route>

</route>

</routing>

</config>

Example: IP Configuration File for client2 (client2.xml)

</interface>

<route>

</route>

</routing>

</config>

Example: IP Configuration File for edgeServer1 (edgeServer1.xml)

</interface>

</config>

Example: IP Configuration File for edgeServer2 (edgeServer2.xml)

</interface>

</config>

Example: IP Configuration File for originServer (originServer.xml)

</interface>

</config>

Example: IP Configuration File for router (router.xml)

</interface>

</config>

Implement Content Caching Logic

To simulate the behavior of a CDN, we need to execute content caching and request routing logic. In the INET framework, we have to expand the existing application or creating custom applications to accomplish it.

Example: Simple Content Caching Logic (Pseudo-Code)

class ContentCacheApp : public cSimpleModule

{

protected:

virtual void initialize() override;

virtual void handleMessage(cMessage *msg) override;

private:

std::map<std::string, std::string> contentCache;

};

void ContentCacheApp::initialize() {

// Initialization code

}

void ContentCacheApp::handleMessage(cMessage *msg) {

// Check if content is in cache

std::string contentID = …; // Extract content ID from the message

if (contentCache.find(contentID) != contentCache.end()) {

// Content found in cache, send cached content

sendCachedContent(contentID);

} else {

// Content not found, forward request to origin server

forwardRequestToOriginServer(msg);

}

void ContentCacheApp::sendCachedContent(const std::string& contentID) {

// Logic to send cached content

}

void ContentCacheApp::forwardRequestToOriginServer(cMessage *msg) {

// Logic to forward request to origin server

}

Run the Simulation

Build the Project: Right-click on the project and choose the Build Project.
Run the Simulation: Start the simulation by clicking on the green play button in the OMNeT++ IDE.

This approach helps you to know more like how to set up the basic simulation and implement the Content Delivery Networks by following the step-by-step instructions. You can also get any additional details of the content delivery or the INET frameworks from us.

We also offer simulation and project performance analysis of Content Delivery Networks in OMNeT++.