ns3网格udp流量错误

Question

我创建了以下代码来模拟ns3中的网格场景。当节点数（m_nnodes）为15时，脚本正常执行并正确接收流量。当节点数（m_nnodes）设置为4时，似乎没有接收到数据包。我尝试了不同的拓扑，但结果是一样的。 什么可能导致这种行为？任何想法都将不胜感激。

#include "ns3/wifi-module.h"
#include "ns3/mesh-module.h"
#include "ns3/mobility-module.h"
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/hwmp-protocol.h"
#include "ns3/applications-module.h"
#include "ns3/random-variable.h"
#include "ns3/wifi-phy.h"
#include "ns3/flow-monitor.h"
#include "ns3/flow-monitor-helper.h"
#include "ns3/ipv4-flow-classifier.h"
#include "ns3/boolean.h"
#include "ns3/object.h"
#include "ns3/enum.h"
#include "ns3/double.h"
#include "ns3/simulator.h"
#include "ns3/log.h"
#include <cmath>
#include "ns3/uinteger.h"
#include "ns3/traced-value.h"
#include "ns3/trace-source-accessor.h"
#include "../src/mesh/model/dot11s/airtime-metric.h"
#include "ns3/mesh-wifi-interface-mac.h"
#include "ns3/wifi-remote-station-manager.h"
#include "ns3/wifi-mode.h"
#include <iostream>
#include <sstream>
#include <fstream>
#include <vector>

using namespace ns3;
NS_LOG_COMPONENT_DEFINE ("ConstantPosition");

class MeshTest {
public:
    /// Init test
MeshTest();
    /// Run test
    int Run();

private:
    int m_nnodes;
    double m_step;
    double m_randomStart;
    double m_totalTime;
    uint16_t m_packetSize;
    double m_packetInterval;
    uint32_t m_nIfaces;
    bool m_chan;
    bool m_pcap;
    uint8_t port;
    int maxPacketCount;
    std::string m_stack;
    std::string m_root;

    /// List of network nodes
    NodeContainer nodes;
    /// List of all mesh point devices
    NetDeviceContainer meshDevices;
    //Addresses of interfaces:
    Ipv4InterfaceContainer interfaces;
    // MeshHelper. Report is not static methods
    MeshHelper mesh;

private:
    /// Create nodes and setup their mobility
    void CreateNodes();
    /// Install internet m_stack on nodes
    void InstallInternetStack();
    /// Install applications
    void InstallApplication();

};    

MeshTest::MeshTest() :
    m_nnodes(4), m_step(10.0), m_randomStart(0.1), m_totalTime(100),
            m_packetSize(1024), m_packetInterval(0.1), m_nIfaces(1),
            m_chan(true), m_pcap(false), maxPacketCount(1000),
            m_stack("ns3::Dot11sStack"), m_root("00:00:00:00:00:01") {
}

void MeshTest::CreateNodes() {

    // Calculate nnodes stations random topology
    nodes.Create(m_nnodes);

    // Configure YansWifiChannel
    YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default();

    YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default();
    wifiPhy.SetChannel(wifiChannel.Create());
    mesh = MeshHelper::Default();

    mesh.SetStackInstaller(m_stack, "Root",
            Mac48AddressValue(Mac48Address(m_root.c_str())));

    if (m_chan) {
        mesh.SetSpreadInterfaceChannels(MeshHelper::SPREAD_CHANNELS);
    } else {
        mesh.SetSpreadInterfaceChannels(MeshHelper::ZERO_CHANNEL);
    }

    mesh.SetMacType("RandomStart", TimeValue(Seconds(m_randomStart)));
    // Set number of interfaces - default is single-interface mesh point
    mesh.SetNumberOfInterfaces(m_nIfaces);
    // Install protocols and return container if MeshPointDevices
    meshDevices = mesh.Install(wifiPhy, nodes);
    // Setup mobility

    //        wifiPhy.EnableAsciiAll (std::string("mp-"));
    MobilityHelper mobility;
    mobility.SetPositionAllocator("ns3::RandomRectanglePositionAllocator", "X",
            RandomVariableValue(UniformVariable(0, m_step)), "Y",
                RandomVariableValue(UniformVariable(0, m_step / 2)));
    mobility.SetMobilityModel("ns3::ConstantPositionMobilityModel");

    mobility.Install(nodes);

    for (NodeContainer::Iterator j = nodes.Begin(); j != nodes.End(); ++j) {
        Ptr<Node> object = *j;
    Ptr<MobilityModel> position = object->GetObject<MobilityModel> ();
        // NS_ASSERT (position != 0);// to verify the condition
        Vector pos = position->GetPosition();
        std::cout << "x=" << pos.x << ", y=" << pos.y << std::endl;
    }

    if (m_pcap)
        wifiPhy.EnablePcapAll(std::string("mp-"));

    // Create mesh helper and set stack installer to it
    // Stack installer creates all needed protocols and install them to device

}

void MeshTest::InstallInternetStack()

{
    //Install the internet protocol stack on all nodes
    InternetStackHelper internetStack;
    internetStack.Install(nodes);
    //Assign IP addresses to the devices interfaces (m_nIfaces)
    Ipv4AddressHelper address;
    address.SetBase("192.168.1.0", "255.255.255.0");
    interfaces = address.Assign(meshDevices);
}

void MeshTest::InstallApplication() {

    //
    // Create one UdpServer applications on node 0
    //


        //
    // Create UdpClient application to send UDP datagrams.
    //    

    for (int i = 1; i < m_nnodes; i += 2) {

        int server_id = i - 1;
        uint16_t port = 2000 + i;
        UdpServerHelper server(port);
        ApplicationContainer apps = server.Install(nodes.Get(server_id));
        apps.Start(Seconds(1.0));
        apps.Stop(Seconds(80.0));

        UdpClientHelper client(interfaces.GetAddress(server_id), port);
        client.SetAttribute("MaxPackets", UintegerValue(maxPacketCount));
        client.SetAttribute("Interval", TimeValue(Seconds(m_packetInterval)));
        client.SetAttribute("PacketSize", UintegerValue(m_packetSize));
        ApplicationContainer apps2 = client.Install(nodes.Get(i));
        apps2.Start(Seconds(2.0));
        apps2.Stop(Seconds(50.0));
    }

}

int MeshTest::Run() {
    CreateNodes();
    InstallInternetStack();
    InstallApplication();
    Simulator::Stop(Seconds(m_totalTime));
    Simulator::Run();
    Simulator::Destroy();
    return 0;
}

int main(int argc, char *argv[]) {
    LogComponentEnable("UdpClient", LOG_LEVEL_INFO);
    LogComponentEnable("UdpServer", LOG_LEVEL_INFO);
    MeshTest t;
    return t.Run();
}