How to Begin Implement a Exterior Gateway Protocol in NS3

To stimulate an Exterior Gateway Protocol (EGP) in ns3 tool has contains the replicate a protocols such as BGP (Border Gateway Protocol), the most widely used EGP in real-world networks for inter-domain routing. The ns3 tool does not natively maintenance BGP, nevertheless we can achieve this using extensions, external tools, or by applying custom logic.

Here’s a step-by-step guide to begin implementing an EGP like BGP in ns-3:

Steps to Begin Implement an Exterior Gateway Protocol in NS3

1. Set up ns-3 Environment

1. Install ns-3:
   • Download and install ns-3 from the official site.
   • Validate the installation through process a basic sample: ./waf –run hello-simulator.
2. Include Required Modules:
   • Enable the internet, point-to-point, and applications designs are secured.

2. Define Objectives for EGP Implementation

• BGP Routing:
  • For replicate the inter-domain routing using BGP.
• Topology:
  • Configure the several autonomous systems (AS) associated through routers.
• Metrics:
  • Calculate the performance of parameter metrices such as convergence time, routing bring up-to-date, and protocol overhead.

3. Set Up Network Topology

1. Create Nodes:
   • Express the routers and close hosts for numerous ASes.

NodeContainer as1Routers, as2Routers, hosts;

as1Routers.Create(2); // Routers in AS 1

as2Routers.Create(2); // Routers in AS 2

hosts.Create(2);      // End hosts

1. Establish Links:
   • Use PointToPointHelper to link the routers among ASes.

PointToPointHelper p2p;

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

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

// AS 1 Internal Links

NetDeviceContainer as1Link = p2p.Install(as1Routers.Get(0), as1Routers.Get(1));

// AS 2 Internal Links

NetDeviceContainer as2Link = p2p.Install(as2Routers.Get(0), as2Routers.Get(1));

// Inter-AS Link

NetDeviceContainer interAsLink = p2p.Install(as1Routers.Get(1), as2Routers.Get(0));

// Host-to-Router Links

NetDeviceContainer host1Link = p2p.Install(hosts.Get(0), as1Routers.Get(0));

NetDeviceContainer host2Link = p2p.Install(hosts.Get(1), as2Routers.Get(1));

1. Install Network Stack:
   • Enhance the IP stack for the nodes.

InternetStackHelper internet;

internet.Install(as1Routers);

internet.Install(as2Routers);

internet.Install(hosts);

1. Assign IP Addresses:
   • Allocate the unique for IP subnets to every connection.

Ipv4AddressHelper ipv4;

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

ipv4.Assign(as1Link);

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

ipv4.Assign(as2Link);

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

ipv4.Assign(interAsLink);

ipv4.SetBase(“10.1.4.0”, “255.255.255.0”);

ipv4.Assign(host1Link);

ipv4.SetBase(“10.1.5.0”, “255.255.255.0”);

ipv4.Assign(host2Link);

4. Enable BGP Routing

1. Custom BGP Implementation:
   • The ns3 tool does not natively maintenance BGP. We can execute the BGP in one of the following path:
     • Use Quagga or FRRouting by ns3 for real-world BGP simulation.
     • Write the custom for BGP logic using ns3’s socket API.
2. Simulate BGP Behavior:
   • Use fixed routes or IGP like as RIP in ASes.
   • Apply for inter-AS communication logic for routing bring up-to-date and choose the path.

Example: Using Static Routes for Simulated BGP Behavior

Ipv4StaticRoutingHelper staticRouting;

Ptr<Ipv4StaticRouting> as1Router1Routing = staticRouting.GetStaticRouting(as1Routers.Get(0)->GetObject<Ipv4>());

as1Router1Routing->AddNetworkRouteTo(Ipv4Address(“10.1.5.0”), Ipv4Mask(“255.255.255.0”), Ipv4Address(“10.1.3.2”), 1);

Ptr<Ipv4StaticRouting> as2Router2Routing = staticRouting.GetStaticRouting(as2Routers.Get(1)->GetObject<Ipv4>());

as2Router2Routing->AddNetworkRouteTo(Ipv4Address(“10.1.4.0”), Ipv4Mask(“255.255.255.0”), Ipv4Address(“10.1.3.1”), 1);

5. Install Applications

1. Simulate Traffic:
   • Use the replicate a UDP or TCP applications for build congestion among ASes.

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(hosts.Get(1)); // Server in AS 2

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(Ipv4Address(“10.1.5.1”), 9);

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

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

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

ApplicationContainer clientApps = echoClient.Install(hosts.Get(0)); // Client in AS 1

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

1. Monitor Traffic:
   • Use PacketSink to track the received packets at the destination.

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

ApplicationContainer sinkApps = sinkHelper.Install(hosts.Get(1));

sinkApps.Start(Seconds(1.0));

sinkApps.Stop(Seconds(10.0));

6. Enable Tracing

1. Enable PCAP Tracing:
   • Seizure the packet traces for study.

p2p.EnablePcapAll(“bgp-simulation”);

1. Enable Ascii Tracing:
   • Metrices routing for packet actions.

AsciiTraceHelper ascii;

p2p.EnableAsciiAll(ascii.CreateFileStream(“bgp-simulation.tr”));

1. Use FlowMonitor:
   • Gather the performance metrics such as throughput and latency.

FlowMonitorHelper flowmon;

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

7. Run the Simulation

1. Start the Simulation:

Simulator::Run();

Simulator::Destroy();

1. Export Results:
   • Store the FlowMonitor data for analysis.

monitor->SerializeToXmlFile(“bgp-simulation-results.xml”, true, true);

8. Analyze and Visualize Results

1. Traffic Analysis:
   • Use PCAP or FlowMonitor data for estimate the congestion flow and routing effectiveness.
2. NetAnim Visualization:
   • Transfer the replication of envision the inter-AS communication.

AnimationInterface anim(“bgp-simulation.xml”);

9. Extend and Optimize

1. Integrate Real BGP:
   • It used integrate for Quagga or FRRouting with ns-3 to replicate a real BGP routing behavior.
   • Connect the tool ns3 to a virtualized or containerized routing daemon.
2. Scalability:
   • Enhance the further ASes and estimate the routing performance in larger topologies.
3. Dynamic Topology:
   • Replicate the connection failures or node variations for follow the BGP route convergence.

Example Use Cases

• Internet Routing:
  • Validate the BGP’s performance in large-scale inter-domain networks.
• Data Centers:
  • Estimate the EGP routing for congestion among many data center places.
• Disaster Recovery:
  • It replicates the BGP’s adaptability for dynamic network environment.

Through the use of ns3, the Exterior Gateway Protocol projects were efficiently and successfully completed. Further details regarding the implementation of the Exterior Gateway Protocol in different simulations will be provided.