How to get the number of lost packets using TCP in NS-3 ? (80211n + MIMO example) - ns-3

Question

I am using this example : https://github.com/nsnam/ns-3-dev-git/blob/master/examples/wireless/80211n-mimo.cc .
For UDP, there's a function called "GetLost()" in UdpServer that returns the number of lost packets but for TCP there's not. I ask if there's any solution to solve this please. Thanks
/* Setting applications */
ApplicationContainer serverApp;
if (udp)
{
//UDP flow
uint16_t port = 9;
UdpServerHelper server (port);
serverApp = server.Install (wifiStaNode.Get (0));
serverApp.Start (Seconds (0.0));
serverApp.Stop (Seconds (simulationTime + 1));
UdpClientHelper client (staNodeInterface.GetAddress (0), port);
client.SetAttribute ("MaxPackets", UintegerValue (4294967295u));
client.SetAttribute ("Interval", TimeValue (Time ("0.00001"))); //packets/s
client.SetAttribute ("PacketSize", UintegerValue (payloadSize));
ApplicationContainer clientApp = client.Install (wifiApNode.Get (0));
clientApp.Start (Seconds (1.0));
clientApp.Stop (Seconds (simulationTime + 1));
}
else
{
//TCP flow
uint16_t port = 50000;
Address localAddress (InetSocketAddress (Ipv4Address::GetAny (), port));
PacketSinkHelper packetSinkHelper ("ns3::TcpSocketFactory", localAddress);
serverApp = packetSinkHelper.Install (wifiStaNode.Get (0));
serverApp.Start (Seconds (0.0));
serverApp.Stop (Seconds (simulationTime + 1));
OnOffHelper onoff ("ns3::TcpSocketFactory",Ipv4Address::GetAny ());
onoff.SetAttribute ("OnTime", StringValue ("ns3::ConstantRandomVariable[Constant=1]"));
onoff.SetAttribute ("OffTime", StringValue ("ns3::ConstantRandomVariable[Constant=0]"));
onoff.SetAttribute ("PacketSize", UintegerValue (payloadSize));
onoff.SetAttribute ("DataRate", DataRateValue (1000000000)); //bit/s
AddressValue remoteAddress (InetSocketAddress (staNodeInterface.GetAddress (0), port));
onoff.SetAttribute ("Remote", remoteAddress);
ApplicationContainer clientApp = onoff.Install (wifiApNode.Get (0));
clientApp.Start (Seconds (1.0));
clientApp.Stop (Seconds (simulationTime + 1));
}
Simulator::Stop (Seconds (simulationTime + 1));
Simulator::Run ();
uint64_t nb = 0;
uint64_t lost = 0;
if (udp)
{
//UDP
nb = DynamicCast<UdpServer> (serverApp.Get (0))->GetReceived ();
lost = DynamicCast<UdpServer> (serverApp.Get (0))->GetLost();
double window = DynamicCast<UdpServer> (serverApp.Get (0))->GetPacketWindowSize();
std::cout << "Window Size :" << window << std::endl;
}
else
{
//TCP
uint64_t totalPacketsThrough = DynamicCast<PacketSink> (serverApp.Get (0))->GetTotalRx ();
nb = totalPacketsThrough / payloadSize ;
/*need help here to get the number of lost packets using TCP Thanks*/
}
dataset1.Add (d, nb);
dataset2.Add (d, lost);
std::cout << nb << " Received packets" << std::endl;
std::cout << lost << " Lost packets" << std::endl;
d += step;
Simulator::Destroy ();
}
plot1.AddDataset (dataset1);
plot2.AddDataset (dataset2);
}

Answer 1

Use the "Tx" trace for the OnOffApplication to call a function every time a packet is transmitted -
void SourceUdpTrace(Ptr<const Packet> pkt)
{
nPacketsSent++;
}
Inside main(), use the following Config::Connect statement to set up the trace and link it with SourceUdpTrace. This statement has to be placed before Simulator::Run()
Config::ConnectWithoutContext("/NodeList/*/ApplicationList/*/$ns3::ManualOnOffApp/Tx",MakeCallback(&SourceUdpTrace));
Once you know the number of sent packets, you can easily determine the number of lost packets by comparing it the value of nb, as found by your line of code - nb = totalPacketsThrough / payloadSize;