examples: Update the traffic-control example
This commit is contained in:
Stefano Avallone
@@ -25,13 +25,14 @@
|
||||
#include "ns3/point-to-point-module.h"
|
||||
#include "ns3/applications-module.h"
|
||||
#include "ns3/traffic-control-module.h"
|
||||
#include "ns3/flow-monitor-module.h"
|
||||
|
||||
// This simple example shows how to use TrafficControlHelper to install a
|
||||
// QueueDisc on a device.
|
||||
//
|
||||
// The default QueueDisc is a pfifo_fast with max number of packets equal to
|
||||
// 1000 (as in Linux). However, in this example, we change from the default
|
||||
// to instead use a ns3::RedQueueDisc with a MaxPackets value of 10000.
|
||||
// The default QueueDisc is a pfifo_fast with a capacity of 1000 packets (as in
|
||||
// Linux). However, in this example, we install a RedQueueDisc with a capacity
|
||||
// of 10000 packets.
|
||||
//
|
||||
// Network topology
|
||||
//
|
||||
@@ -39,38 +40,27 @@
|
||||
// n0 -------------- n1
|
||||
// point-to-point
|
||||
//
|
||||
// The output will consist of a number of traced changes to queue lengths
|
||||
// such as:
|
||||
// The output will consist of all the traced changes in the length of the RED
|
||||
// internal queue and in the length of the netdevice queue:
|
||||
//
|
||||
// DevicePacketsInQueue 0 to 1
|
||||
// TcPacketsInQueue 5 to 4
|
||||
// TcPacketsInQueue 4 to 5
|
||||
// TcPacketsInQueue 7 to 8
|
||||
// TcPacketsInQueue 8 to 9
|
||||
// DevicePacketsInQueue 1 to 0
|
||||
// TcPacketsInQueue 9 to 8
|
||||
//
|
||||
// and an average throughput:
|
||||
// plus some statistics collected at the network layer (by the flow monitor)
|
||||
// and the application layer. Finally, the number of packets dropped by the
|
||||
// queuing discipline, the number of packets dropped by the netdevice and
|
||||
// the number of packets requeued by the queuing discipline are reported.
|
||||
//
|
||||
// Average throughput: 8.72854 Mbit/s
|
||||
//
|
||||
// The final output displays the number of drops at the TC layer and the
|
||||
// netdevice layer. These statistics highlight the fact that for
|
||||
// PointToPointNetDevice, the drops at the device layer are actually
|
||||
// requeued at the TC layer, so the true packet drops (39 in this case)
|
||||
// must be traced at the TC layer.
|
||||
//
|
||||
// *** Source stats ***
|
||||
// Number of packets dropped by the TC layer: 39
|
||||
// Number of packets dropped by the netdevice: 3914
|
||||
// Number of packets requeued by the TC layer: 3914
|
||||
// Number of actually lost packets: 39
|
||||
//
|
||||
// If one were to increase the size of the PointToPointNetDevice's
|
||||
// DropTailQueue from 1 to a larger number (e.g. 1000), one would observe
|
||||
// that the number of packets dropped would go to zero, but the latency
|
||||
// and QoS would not be controllable. This is the so-called bufferbloat
|
||||
// problem, and illustrates the importance of having a small device queue
|
||||
// so that the standing queues build in the traffic control layer where
|
||||
// they can be managed by advanced queue discs rather than in the
|
||||
// device layer.
|
||||
// If the size of the DropTail queue of the netdevice were increased from 1
|
||||
// to a large number (e.g. 1000), one would observe that the number of dropped
|
||||
// packets goes to zero, but the latency grows in an uncontrolled manner. This
|
||||
// is the so-called bufferbloat problem, and illustrates the importance of
|
||||
// having a small device queue, so that the standing queues build in the traffic
|
||||
// control layer where they can be managed by advanced queue discs rather than
|
||||
// in the device layer.
|
||||
|
||||
using namespace ns3;
|
||||
|
||||
@@ -169,21 +159,41 @@ main (int argc, char *argv[])
|
||||
apps.Start (Seconds (1.0));
|
||||
apps.Stop (Seconds (simulationTime + 0.1));
|
||||
|
||||
Simulator::Stop (Seconds (simulationTime + 0.1));
|
||||
FlowMonitorHelper flowmon;
|
||||
Ptr<FlowMonitor> monitor = flowmon.InstallAll();
|
||||
|
||||
Simulator::Stop (Seconds (simulationTime + 5));
|
||||
Simulator::Run ();
|
||||
|
||||
Ptr<Ipv4FlowClassifier> classifier = DynamicCast<Ipv4FlowClassifier> (flowmon.GetClassifier ());
|
||||
std::map<FlowId, FlowMonitor::FlowStats> stats = monitor->GetFlowStats ();
|
||||
std::cout << std::endl << "*** Flow monitor statistics ***" << std::endl;
|
||||
std::cout << " Tx Packets: " << stats[1].txPackets << std::endl;
|
||||
std::cout << " Tx Bytes: " << stats[1].txBytes << std::endl;
|
||||
std::cout << " Offered Load: " << stats[1].txBytes * 8.0 / (stats[1].timeLastTxPacket.GetSeconds () - stats[1].timeFirstTxPacket.GetSeconds ()) / 1000000 << " Mbps" << std::endl;
|
||||
std::cout << " Rx Packets: " << stats[1].rxPackets << std::endl;
|
||||
std::cout << " Rx Bytes: " << stats[1].rxBytes << std::endl;
|
||||
std::cout << " Packets Dropped by Queue Disc: " << stats[1].packetsDropped[Ipv4FlowProbe::DROP_QUEUE_DISC] << std::endl;
|
||||
std::cout << " Bytes Dropped by Queue Disc: " << stats[1].bytesDropped[Ipv4FlowProbe::DROP_QUEUE_DISC] << std::endl;
|
||||
std::cout << " Packets Dropped by NetDevice: " << stats[1].packetsDropped[Ipv4FlowProbe::DROP_QUEUE] << std::endl;
|
||||
std::cout << " Bytes Dropped by NetDevice: " << stats[1].bytesDropped[Ipv4FlowProbe::DROP_QUEUE] << std::endl;
|
||||
std::cout << " Throughput: " << stats[1].rxBytes * 8.0 / (stats[1].timeLastRxPacket.GetSeconds () - stats[1].timeFirstRxPacket.GetSeconds ()) / 1000000 << " Mbps" << std::endl;
|
||||
std::cout << " Mean delay: " << stats[1].delaySum.GetSeconds () / stats[1].rxPackets << std::endl;
|
||||
std::cout << " Mean jitter: " << stats[1].jitterSum.GetSeconds () / (stats[1].rxPackets - 1) << std::endl;
|
||||
|
||||
Simulator::Destroy ();
|
||||
|
||||
std::cout << std::endl << "*** Application statistics ***" << std::endl;
|
||||
double thr = 0;
|
||||
uint32_t totalPacketsThr = DynamicCast<PacketSink> (sinkApp.Get (0))->GetTotalRx ();
|
||||
thr = totalPacketsThr * 8 / (simulationTime * 1000000.0); //Mbit/s
|
||||
std::cout << "Average throughput: " << thr << " Mbit/s" <<std::endl;
|
||||
std::cout << "*** Source stats ***" << std::endl;
|
||||
std::cout << "Number of packets dropped by the TC layer: " << q->GetTotalDroppedPackets () << std::endl;
|
||||
std::cout << "Number of packets dropped by the netdevice: " << queue->GetTotalDroppedPackets () << std::endl;
|
||||
std::cout << "Number of packets requeued by the TC layer: " << q->GetTotalRequeuedPackets () << std::endl;
|
||||
std::cout << "Number of actually lost packets: " << q->GetTotalDroppedPackets ()
|
||||
+ queue->GetTotalDroppedPackets ()
|
||||
- q->GetTotalRequeuedPackets () << std::endl;
|
||||
std::cout << " Rx Bytes: " << totalPacketsThr << std::endl;
|
||||
std::cout << " Average Goodput: " << thr << " Mbit/s" << std::endl;
|
||||
std::cout << std::endl << "*** TC Layer statistics ***" << std::endl;
|
||||
std::cout << " Packets dropped by the TC layer: " << q->GetTotalDroppedPackets () << std::endl;
|
||||
std::cout << " Bytes dropped by the TC layer: " << q->GetTotalDroppedBytes () << std::endl;
|
||||
std::cout << " Packets dropped by the netdevice: " << queue->GetTotalDroppedPackets () << std::endl;
|
||||
std::cout << " Packets requeued by the TC layer: " << q->GetTotalRequeuedPackets () << std::endl;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
@@ -2,7 +2,7 @@
|
||||
|
||||
def build(bld):
|
||||
obj = bld.create_ns3_program('traffic-control',
|
||||
['internet', 'point-to-point', 'applications', 'traffic-control'])
|
||||
['internet', 'point-to-point', 'applications', 'traffic-control', 'flow-monitor'])
|
||||
obj.source = 'traffic-control.cc'
|
||||
|
||||
obj = bld.create_ns3_program('queue-discs-benchmark',
|
||||
|
||||
Reference in New Issue
Block a user