How to Begin Implement Network Proxies in NS3

To begin a network proxy in ns-3 involves setting a node that performs as intermediary among clients and servers. A proxy can perform functions like as caching, filtering, or forwarding requirements. Below is demonstrating the execution of network proxies in ns-3.

Steps to Begin Implement Network Proxies in NS3

1. Understand Network Proxy Role

• Proxy Server: An intermediate node which sends the client requests to servers for replies to clients.
• Use Cases:
  • Caching responses for decrease the latency.
  • Filtering congestion for security or policy enforcement.
  • Interpreting protocols or addressing schemes for instance HTTP to HTTPS.

2. Set Up ns-3 Environment

• Ensure ns-3 is installed:

git clone https://gitlab.com/nsnam/ns-3-dev.git

cd ns-3-dev

./ns3 configure –enable-examples –enable-tests

./ns3 build

• Prove installation:

./ns3 run hello-simulator

3. Design Network Topology

• Express the network topology in which a proxy node placed among their clients and servers.
• Example:
  • Clients: Nodes are builds a request.
  • Proxy: An intermediate node has sending the requests to servers.
  • Servers: Nodes are answering the client requests.

4. Steps to Implement a Proxy Node

(a) Create Nodes

• Build a nodes for clients, servers, and proxy.

NodeContainer clients, servers, proxy;

clients.Create(1);

servers.Create(1);

proxy.Create(1);

(b) Set Up Network Links

• Use PointToPointHelper or CsmaHelper to links the clients, proxy, and servers.

PointToPointHelper p2p;

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

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

NetDeviceContainer clientToProxy = p2p.Install(NodeContainer(clients.Get(0), proxy.Get(0)));

NetDeviceContainer proxyToServer = p2p.Install(NodeContainer(proxy.Get(0), servers.Get(0)));

(c) Install Internet Stack

• Install the InternetStackHelper for assure the IP-based transmission.

InternetStackHelper stack;

stack.InstallAll();

(d) Assign IP Addresses

• Use Ipv4AddressHelper for allocate the IP addresses to network interfaces.

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer clientProxyInterfaces = address.Assign(clientToProxy);

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

Ipv4InterfaceContainer proxyServerInterfaces = address.Assign(proxyToServer);

(e) Configure Proxy Node

• Permit the packet forwarding for the proxy node:

Ptr<Ipv4> ipv4 = proxy.Get(0)->GetObject<Ipv4>();

ipv4->SetAttribute(“IpForward”, BooleanValue(true));

• Enhance the fixed or dynamic routes for assure the transmission:

Ipv4StaticRoutingHelper staticRouting;

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

clientRouting->SetDefaultRoute(proxyServerInterfaces.GetAddress(0), 1);

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

serverRouting->SetDefaultRoute(clientProxyInterfaces.GetAddress(1), 1);

(f) Install Applications

• Congestion replicates among the clients and servers through proxy:
  • Server:

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApp = echoServer.Install(servers.Get(0));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

• • Client:

UdpEchoClientHelper echoClient(Ipv4Address(“10.1.2.2”), 9);

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

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

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

ApplicationContainer clientApp = echoClient.Install(clients.Get(0));

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

5. Enhance Proxy Functionality

(a) Packet Filtering

• Improve the callback on the proxy’s network mechanism to examine the alternation packets:

proxy.Get(0)->GetObject<NetDevice>()->SetReceiveCallback(

MakeCallback(&YourCustomPacketHandlerFunction));

(b) Caching

• Save the responses for the proxy and directly answer to clients for cached requirements.

(c) Protocol Translation

• Executes the logic to translate requests for sample HTTP to HTTPS before forwarding.

6. Example Code for Proxy Implementation

Under is a complete sample for a simple proxy setup:

#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[]) {

CommandLine cmd;

cmd.Parse(argc, argv);

// Create nodes

NodeContainer clients, servers, proxy;

clients.Create(1);

servers.Create(1);

proxy.Create(1);

// Create links

PointToPointHelper p2p;

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

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

NetDeviceContainer clientToProxy = p2p.Install(NodeContainer(clients.Get(0), proxy.Get(0)));

NetDeviceContainer proxyToServer = p2p.Install(NodeContainer(proxy.Get(0), servers.Get(0)));

// Install Internet stack

InternetStackHelper stack;

stack.InstallAll();

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer clientProxyInterfaces = address.Assign(clientToProxy);

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

Ipv4InterfaceContainer proxyServerInterfaces = address.Assign(proxyToServer);

// Enable IP forwarding on the proxy

Ptr<Ipv4> ipv4 = proxy.Get(0)->GetObject<Ipv4>();

ipv4->SetAttribute(“IpForward”, BooleanValue(true));

// Set up routing

Ipv4StaticRoutingHelper staticRouting;

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

clientRouting->SetDefaultRoute(clientProxyInterfaces.GetAddress(1), 1);

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

serverRouting->SetDefaultRoute(proxyServerInterfaces.GetAddress(0), 1);

// Set up applications

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApp = echoServer.Install(servers.Get(0));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(Ipv4Address(“10.1.2.2”), 9);

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

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

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

ApplicationContainer clientApp = echoClient.Install(clients.Get(0));

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

// Run simulation

Simulator::Run();

Simulator::Destroy();

return 0;

}

7. Test and Validate

• Use the tool like FlowMonitor or logging to assure the congestion passes through the proxy.
• Validate the alter packets, caching, or protocol conversions at the proxy.

We demonstrate and provide the valuable insights on how to calculate and simulate the results for network proxy in ns3 tool. For questions about the project, consult the additional manual we will provide.