How to Begin Implement a ABR Protocol in NS3

To implement Associativity-Based Routing (ABR) protocol in NS3 which is a reactive protocol that intended for mobile ad hoc networks (MANETs). It chooses the paths according to the degree of “associativity” stability among the nodes to create it which are specifically used within highly dynamic topologies. To execute ABR using ns3 encompass to make a custom routing protocol, which frequently utilizes associativity parameters for route discovery and maintenance.

Overview of ABR

1. Key Features:
   • According to the associativity stability, routes are selected.
   • Nodes sustain associativity ticks the counts for neighbors.
   • Route discovery is introduced only if required (reactive).
2. Components:
   • Associativity Ticks: A count of connection stability including a neighbor.
   • Route Discovery: It supports Route Request (RREQ) and Route Reply (RREP) messages.
   • Route Maintenance: Dynamically modernizes routes rely on associativity.

Steps to Implement ABR in ns3

1. Set Up ns3 Environment

1. Install ns3:
   • We should download and install ns3 on the system.
   • Confirm the set up by executing a simple instance script as ./waf –run hello-simulator.
2. Enable Required Modules:
   • Make sure that we have contained necessary modules such as internet, wifi, mobility, and applications.

2. Understand ABR Protocol Logic

1. Associativity Metric:
   • Nodes sustain the associativity ticks for its neighbors.
   • The associativity tick maximizes once a periodic beacon is obtained.
2. Route Discovery:
   • A source propagates a RREQ.
   • Intermediate nodes are sending RREQs by inserting associativity data.
   • The destination selects the most stable path depends on the associativity.
3. Route Maintenance:
   • If a link obstructs then the protocol specifies a new route discovery.

3. Create a Custom ABR Protocol
4. Define the Protocol Class

Make a new protocol class to receive from Ipv4RoutingProtocol:

class AbrRoutingProtocol : public Ipv4RoutingProtocol {

public:

static TypeId GetTypeId();

AbrRoutingProtocol();

virtual ~AbrRoutingProtocol();

// Override required methods

Ptr<Ipv4Route> RouteOutput(Ptr<Packet> p, const Ipv4Header &header,

Ptr<NetDevice> oif, Socket::SocketErrno &sockerr) override;

bool RouteInput(Ptr<const Packet> p, const Ipv4Header &header,

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) override;

void NotifyInterfaceUp(uint32_t interface) override;

void NotifyInterfaceDown(uint32_t interface) override;

void NotifyAddAddress(uint32_t interface, Ipv4InterfaceAddress address) override;

void NotifyRemoveAddress(uint32_t interface, Ipv4InterfaceAddress address) override;

void SetIpv4(Ptr<Ipv4> ipv4) override;

private:

Ptr<Ipv4> m_ipv4;

std::map<Ipv4Address, uint32_t> m_associativityTicks; // Neighbor associativity ticks

};

1. Implement Core Methods

1. Maintain Associativity Ticks:
   • Modernize associativity parameters using periodic beacon packets.

void AbrRoutingProtocol::UpdateAssociativity(Ipv4Address neighbor) {

m_associativityTicks[neighbor]++;

}

1. Route Discovery:
   • Execute the RREQ and RREP messages.

void AbrRoutingProtocol::SendRouteRequest(Ipv4Address destination) {

Ptr<Packet> packet = Create<Packet>();

// Add RREQ header and broadcast

}

void AbrRoutingProtocol::ReceiveRouteRequest(Ptr<Packet> packet) {

// Process RREQ and append associativity information

}

void AbrRoutingProtocol::SendRouteReply(Ipv4Address destination, Ipv4Address source) {

Ptr<Packet> packet = Create<Packet>();

// Add RREP header and unicast

}

1. Route Maintenance:
   • Observe connections and manage the route failures.

void AbrRoutingProtocol::HandleLinkFailure(Ipv4Address brokenLink) {

// Remove route and initiate rediscovery

}

1. Routing Table:
   • We need to save routes including associativity indicators.

class RoutingTable {

public:

void AddRoute(Ipv4Address dest, Ipv4Address nextHop, uint32_t stability);

void RemoveRoute(Ipv4Address dest);

Ptr<Ipv4Route> Lookup(Ipv4Address dest);

private:

std::map<Ipv4Address, Ptr<Ipv4Route>> m_routes;

};

1. Define Protocol Messages

For RREQ and RREP messages, we can make custom headers:

class AbrHeader : public Header {

public:

void Serialize(Buffer::Iterator start) const override;

uint32_t Deserialize(Buffer::Iterator start) override;

void Print(std::ostream &os) const override;

};

4. Set Up Network Topology

1. Create Nodes:

NodeContainer nodes;

nodes.Create(20); // Create 20 nodes

1. Configure Wireless Links:

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211b);

YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default();

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default();

wifiPhy.SetChannel(wifiChannel.Create());

WifiMacHelper wifiMac;

wifiMac.SetType(“ns3::AdhocWifiMac”);

NetDeviceContainer devices = wifi.Install(wifiPhy, wifiMac, nodes);

1. Set Mobility:

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::RandomRectanglePositionAllocator”,

“X”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”),

“Y”, StringValue(“ns3::UniformRandomVariable[Min=0.0|Max=100.0]”));

mobility.SetMobilityModel(“ns3::RandomWaypointMobilityModel”,

“Speed”, StringValue(“ns3::UniformRandomVariable[Min=1.0|Max=20.0]”),

“Pause”, StringValue(“ns3::ConstantRandomVariable[Constant=2.0]”));

mobility.Install(nodes);

1. Install Network Stack:

InternetStackHelper internet;

AbrHelper abr;

internet.SetRoutingHelper(abr);

internet.Install(nodes);

1. Assign IP Addresses:

Ipv4AddressHelper ipv4;

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

ipv4.Assign(devices);

5. Simulate Traffic

1. Install Applications:

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(19)); // Server at node 19

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(Ipv4Address(“10.1.1.20”), 9);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(10));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(1.0)));

echoClient.SetAttribute(“PacketSize”, UintegerValue(1024));

ApplicationContainer clientApps = echoClient.Install(nodes.Get(0)); // Client at node 0

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

6. Enable Tracing

1. Enable PCAP:

wifiPhy.EnablePcapAll(“abr-protocol”);

1. Enable ASCII Logging:

AsciiTraceHelper ascii;

wifiPhy.EnableAsciiAll(ascii.CreateFileStream(“abr-protocol.tr”));

1. FlowMonitor:

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

7. Run and Analyze

1. Run the Simulation:

Simulator::Run();

Simulator::Destroy();

1. Analyze Results:
   • Compute the performance of protocol leveraging PCAP and FlowMonitor data.
   • Envision the behavior with NetAnim tools.

8. Extend and Optimize

1. Scalability:
   • Experiment the ABR scalability within larger networks.
2. QoS:
   • Refine route selection including QoS parameters such as bandwidth or delay.
3. Energy Efficiency:
   • Add energy patterns for measuring the performance of ABR within resource-constrained environments.

This technique will guide you through the implementation approach for ABR Protocol with their instances and their extension using NS3 tool. We will also offer the extra information on any other protocol, if needed.