How to Calculate Network Accounting in ns3

To calculate the network accounting in ns3, we need to monitor and estimate the network resources by different users or devices over time. This is usually contains monitoring metrics like bandwidth usage, number of packets sent and received, and duration of active sessions. Here, are the procedures on how to setup the network accounting in ns3:

Steps to Simulate and Calculate Network Accounting in ns3

1. Set Up the ns3 Environment:
   • Make sure ns3 is installed.
2. Define the Network Topology:
   • Create a network topology with nodes representing clients and servers.
3. Configure Accounting Mechanisms:
   • To track network usage metrics for each user or device by implementing the mechanism.
4. Install Applications:
   • Install traffic-generating applications on the nodes to simulate network traffic.
5. Monitor Performance Metrics:
   • Use trace sources or callbacks to monitor metrics such as bandwidth usage, packet counts, and session durations.
6. Analyze Accounting Data:
   • Compute and log the network usage metrics to perform network accounting.

Example Code

The given below is the sample on how to setup a basic ns3 simulator to estimate the network accounting. This is the sample illustrative to monitor the number of packets sent and received by each node.

#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”

#include “ns3/flow-monitor-module.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“NetworkAccountingExample”);

std::map<uint32_t, uint64_t> packetsSent;

std::map<uint32_t, uint64_t> packetsReceived;

void TxCallback (Ptr<const Packet> packet, const Address &address)

{

uint32_t nodeId = packet->GetUid();

packetsSent[nodeId]++;

}

void RxCallback (Ptr<const Packet> packet, const Address &address)

{

uint32_t nodeId = packet->GetUid();

packetsReceived[nodeId]++;

}

void CalculateNetworkAccounting ()

{

for (auto it = packetsSent.begin (); it != packetsSent.end (); ++it)

{

uint32_t nodeId = it->first;

uint64_t sent = it->second;

uint64_t received = packetsReceived[nodeId];

NS_LOG_UNCOND (“Node ” << nodeId << “: Packets Sent = ” << sent << “, Packets Received = ” << received);

}

}

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

{

CommandLine cmd;

cmd.Parse (argc, argv);

Time::SetResolution (Time::NS);

// Create nodes

NodeContainer nodes;

nodes.Create (4); // Two clients and two servers

// Create point-to-point links

PointToPointHelper pointToPoint;

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

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

NetDeviceContainer devices01 = pointToPoint.Install (NodeContainer (nodes.Get (0), nodes.Get (1)));

NetDeviceContainer devices12 = pointToPoint.Install (NodeContainer (nodes.Get (1), nodes.Get (2)));

NetDeviceContainer devices23 = pointToPoint.Install (NodeContainer (nodes.Get (2), nodes.Get (3)));

// Install the internet stack on nodes

InternetStackHelper stack;

stack.Install (nodes);

// Assign IP addresses to the devices

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces01 = address.Assign (devices01);

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

Ipv4InterfaceContainer interfaces12 = address.Assign (devices12);

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

Ipv4InterfaceContainer interfaces23 = address.Assign (devices23);

// Enable routing

Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

// Create UDP server on node 2 and node 3

UdpServerHelper server (9);

ApplicationContainer serverApp1 = server.Install (nodes.Get (2));

ApplicationContainer serverApp2 = server.Install (nodes.Get (3));

serverApp1.Start (Seconds (1.0));

serverApp1.Stop (Seconds (10.0));

serverApp2.Start (Seconds (1.0));

serverApp2.Stop (Seconds (10.0));

// Create UDP client on node 0 and node 1

UdpClientHelper client1 (interfaces12.GetAddress (1), 9);

client1.SetAttribute (“MaxPackets”, UintegerValue (320));

client1.SetAttribute (“Interval”, TimeValue (MilliSeconds (10)));

client1.SetAttribute (“PacketSize”, UintegerValue (1024));

UdpClientHelper client2 (interfaces23.GetAddress (1), 9);

client2.SetAttribute (“MaxPackets”, UintegerValue (320));

client2.SetAttribute (“Interval”, TimeValue (MilliSeconds (10)));

client2.SetAttribute (“PacketSize”, UintegerValue (1024));

ApplicationContainer clientApp1 = client1.Install (nodes.Get (0));

ApplicationContainer clientApp2 = client2.Install (nodes.Get (1));

clientApp1.Start (Seconds (2.0));

clientApp1.Stop (Seconds (10.0));

clientApp2.Start (Seconds (2.0));

clientApp2.Stop (Seconds (10.0));

// Trace packet transmission and reception

Config::ConnectWithoutContext (“/NodeList/*/ApplicationList/*/$ns3::UdpClient/Tx”, MakeCallback (&TxCallback));

Config::ConnectWithoutContext (“/NodeList/*/ApplicationList/*/$ns3::UdpServer/Rx”, MakeCallback (&RxCallback));

// Install flow monitor to capture performance metrics

FlowMonitorHelper flowHelper;

Ptr<FlowMonitor> flowMonitor = flowHelper.InstallAll ();

Simulator::Stop (Seconds (11.0));

Simulator::Run ();

CalculateNetworkAccounting ();

Simulator::Destroy ();

return 0;

}

Explanation

1. Setup: The code sets up a network topology with four nodes: two clients and two servers, connected by point-to-point links.
2. Internet Stack and Routing: The internet stack is installed on all nodes, and global routing is enabled.
3. Applications: UDP servers are installed on the server nodes (nodes 2 and 3), and UDP clients are installed on the client nodes (nodes 0 and 1) to generate traffic.
4. Packet Tracing: The TxCallback and RxCallback functions are connected to trace the transmission and reception of packets. These functions update counters for packets sent and received by each node.
5. Network Accounting Calculation: The CalculateNetworkAccounting function logs the number of packets sent and received by each node.

Running the Simulation

Compile and run the simulation using the following commands in your ns3 environment:

./waf configure

./waf build

./waf –run your-script-name

Replace your-script-name with the actual name of your script file.

Here, we explore how to implement and estimate the network accounting in various users and devices in ns3. We will deliver more details on how the network accounting is conducted in other simulations. To Calculate Network Accounting in ns3tool, you can share with us all your parameters and get best results from our team.