How to Begin Implement Multicast Routing in NS3

To begin a Multicast Routing in NS-3 have been concludes the pattern or developing a routing protocol to distribute packets for numerous destinations continuously. Multicast routing is effective for group communication applications, like as video conferencing or allocate the replications, and prevent the terminated packets of transmission through utilize their distribute delivery paths.

Here’s how you can begin implementing multicast routing in NS-3:

Steps to Begin Implement Multicast Routing in NS3

Step 1: Understand Multicast Routing

1. Core Concepts:
   • Multicast Group: The set of nodes recognized through a multicast address for sample 224.0.0.0/4.
   • Multicast Tree: The logical organization for linked the group members.
   • Protocols:
     • Source-Based Tree: Distinct the tree for every sender for sample PIM-SM.
     • Shared Tree: Single tree distribute between all transmitters.
2. Routing Protocols:
   • Protocol Independent Multicast (PIM)
   • Distance Vector Multicast Routing Protocol (DVMRP)
   • Multicast Open Shortest Path First (MOSPF)

Step 2: Set Up NS3 Environment

1. Prepare Environment:
   • It allows the NS3 is installed and setting.
   • Generate a new protocol directory like if creating a custom multicast routing protocol for sample src/multicast-routing/.
2. NS-3’s Built-In Multicast Support:
   • NS-3 has simple multicast maintenance using an Ipv4StaticRouting.

Step 3: Use Built-In Multicast Routing

Static Multicast Routing Example

We can setting the fixed multicast routes using Ipv4StaticRouting.

Example Code

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/applications-module.h”

using namespace ns3;

int main (int argc, char *argv[]) {

// Create nodes

NodeContainer nodes;

nodes.Create (4); // Sender + 3 receivers

// Install internet stack

InternetStackHelper internet;

internet.Install (nodes);

// Create point-to-point channels

PointToPointHelper p2p;

p2p.SetDeviceAttribute (“DataRate”, StringValue (“10Mbps”));

p2p.SetChannelAttribute (“Delay”, StringValue (“2ms”));

NetDeviceContainer devicesAB = p2p.Install (nodes.Get (0), nodes.Get (1));

NetDeviceContainer devicesBC = p2p.Install (nodes.Get (1), nodes.Get (2));

NetDeviceContainer devicesBD = p2p.Install (nodes.Get (1), nodes.Get (3));

// Assign IP addresses

Ipv4AddressHelper ipv4;

ipv4.SetBase (“10.1.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfacesAB = ipv4.Assign (devicesAB);

ipv4.SetBase (“10.1.2.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfacesBC = ipv4.Assign (devicesBC);

ipv4.SetBase (“10.1.3.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfacesBD = ipv4.Assign (devicesBD);

// Configure static multicast routing

Ipv4StaticRoutingHelper multicastHelper;

// Sender node multicast configuration

Ptr<Ipv4> ipv4Sender = nodes.Get (0)->GetObject<Ipv4> ();

Ptr<Ipv4StaticRouting> staticSender = multicastHelper.GetStaticRouting (ipv4Sender);

staticSender->SetDefaultMulticastRoute (1); // Outgoing interface index

// Receiver node 1 configuration

Ptr<Ipv4> ipv4Receiver1 = nodes.Get (2)->GetObject<Ipv4> ();

Ptr<Ipv4StaticRouting> staticReceiver1 = multicastHelper.GetStaticRouting (ipv4Receiver1);

staticReceiver1->AddMulticastRoute (Ipv4Address (“224.1.1.1”), Ipv4Address (“10.1.2.1”), 1);

// Receiver node 2 configuration

Ptr<Ipv4> ipv4Receiver2 = nodes.Get (3)->GetObject<Ipv4> ();

Ptr<Ipv4StaticRouting> staticReceiver2 = multicastHelper.GetStaticRouting (ipv4Receiver2);

staticReceiver2->AddMulticastRoute (Ipv4Address (“224.1.1.1”), Ipv4Address (“10.1.3.1”), 1);

// Install multicast sender application

OnOffHelper onOff (“ns3::UdpSocketFactory”, InetSocketAddress (Ipv4Address (“224.1.1.1”), 9));

onOff.SetAttribute (“DataRate”, StringValue (“5Mbps”));

ApplicationContainer apps = onOff.Install (nodes.Get (0));

apps.Start (Seconds (1.0));

apps.Stop (Seconds (10.0));

// Install multicast receiver applications

PacketSinkHelper sinkHelper (“ns3::UdpSocketFactory”, InetSocketAddress (Ipv4Address (“224.1.1.1”), 9));

ApplicationContainer sinkApps = sinkHelper.Install (nodes.Get (2));

sinkApps.Add (sinkHelper.Install (nodes.Get (3)));

sinkApps.Start (Seconds (1.0));

sinkApps.Stop (Seconds (10.0));

// Run simulation

Simulator::Run ();

Simulator::Destroy ();

return 0;

}

Step 4: Implement a Custom Multicast Protocol

If we require a additional advanced multicast protocol, we can apply the own routing protocol.

Define Multicast Routing Protocol

Encompass the Ipv4RoutingProtocol class for execute the custom multicast routing logic.

Header File (multicast-routing-protocol.h)

#include “ns3/ipv4-routing-protocol.h”

#include “ns3/socket.h”

#include “ns3/timer.h”

#include <map>

class MulticastRoutingProtocol : public ns3::Ipv4RoutingProtocol {

public:

static ns3::TypeId GetTypeId (void);

MulticastRoutingProtocol ();

virtual ~MulticastRoutingProtocol ();

virtual ns3::Ptr<ns3::Ipv4Route> RouteOutput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<ns3::NetDevice> oif,

ns3::Socket::SocketErrno &sockerr);

virtual bool RouteInput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<const ns3::NetDevice> idev,

ns3::UnicastForwardCallback ucb,

ns3::MulticastForwardCallback mcb,

ns3::LocalDeliverCallback lcb,

ns3::ErrorCallback ecb);

void AddMulticastRoute (ns3::Ipv4Address group, ns3::Ipv4Address source, ns3::Ipv4Address nextHop);

void RemoveMulticastRoute (ns3::Ipv4Address group, ns3::Ipv4Address source);

private:

struct MulticastRoute {

ns3::Ipv4Address group;

ns3::Ipv4Address source;

ns3::Ipv4Address nextHop;

};

std::vector<MulticastRoute> m_routes;

};

Implementation File (multicast-routing-protocol.cc)

Execute the logic for increase/decrease the routes and sending multicast packets.

Step 5: Write a Simulation Script for Custom Protocol

Experiment the custom multicast protocol for a replication script, exchanging Ipv4StaticRoutingHelper by the custom helper.

Step 6: Compile and Run

1. Build the Protocol:

./waf configure

./waf build

1. Run the Simulation:

./waf –run your-script

Step 7: Validate and Extend

1. Use Tracing:
   • Utilized for the seizure packet flows PcapHelper and AsciiTraceHelper.
2. Analyze Metrics:
   • Calculate the delivery ratio, bandwidth efficiency, and latency.
3. Enhance Protocol:
   • Execute the group management for sample IGMP for adding/removing the multicast groups.
   • Increase the helps for dynamic variation topology.

This project will explore you more ideas on how the multicast routing projects simulated and evaluated the outcomes using the tool of ns3 simulation. Additional queries regarding this project will be addressed in another document.