嗨，我是NS3的新手，我正在尝试修改first.cc来做TCP而不是UDP。我没有得到任何错误，但也没有发生数据交换。有人能在这方面帮我吗？~非常感谢~下面是代码:基本上:
NS_LOG_INFO ("Creating Topology");
Config::SetDefault ("ns3::OnOffApplication::PacketSize", UintegerValue (137));
Config::SetDefault ("ns3::OnOffApplication::DataRate", StringValue ("14kb/s"));
NodeContainer nodes;
nodes.Create (2);
//
PointToPointHelper pointToPoint;
pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("100Mbps"));
pointToPoint.SetChannelAttribute ("Delay", StringValue ("20ms"));
//
NetDeviceContainer devices;
devices = pointToPoint.Install (nodes);
InternetStackHelper stack;
stack.Install (nodes);
Ipv4AddressHelper address;
address.SetBase ("109.11.12.0", "255.255.255.0");//address setting
Ipv4InterfaceContainer interfaces = address.Assign (devices);
OnOffHelper onOffHelper ("ns3::TcpSocketFactory", Address
(InetSocketAddress (Ipv4Address ("255.255.255.0"), 10)));
onOffHelper.SetAttribute ("OnTime", StringValue ("ns3::ConstantRandomVariable[Constant=1]"));
onOffHelper.SetAttribute ("OffTime", StringValue ("ns3::ConstantRandomVariable[Constant=0]"));
onOffHelper.SetAttribute ("DataRate",StringValue ("2Mbps"));
onOffHelper.SetAttribute ("PacketSize",UintegerValue(2000));
ApplicationContainer app = onOffHelper.Install (nodes.Get (0));
// Start the application
app.Start (Seconds (10.0));
app.Stop (Seconds (100.0));
// Create an optional packet sink to receive packets
PacketSinkHelper sink ("ns3::TcpSocketFactory",Address
(InetSocketAddress (Ipv4Address::GetAny (), 10)));
app = sink.Install (nodes.Get(1));
app.Start (Seconds (1.0));
app.Stop (Seconds (100.0));
pointToPoint.EnablePcapAll ("testtcp");
好的，我想现在解决了，首先，在onoff helper处的IP是错误的，它们应该和IPv4addresshelper相同。那么app启动时间错误，config onoff应用代码就不需要了。下面是代码:它可能不是很正确，但至少我现在可以从中读取结果。
NodeContainer nodes;
nodes.Create (2); //creat 2 nodes they are p2p
PointToPointHelper pointToPoint;
pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("2Mbps"));
pointToPoint.SetChannelAttribute ("Delay", StringValue ("20ms"));
NetDeviceContainer devices;// put nodes in ndc
devices = pointToPoint.Install (nodes);
////give them an address
InternetStackHelper stack;
stack.Install (nodes);
Ipv4AddressHelper address;
address.SetBase ("109.11.12.0", "255.255.255.0");//address setting
Ipv4InterfaceContainer interfaces = address.Assign (devices);
//sink for reciever????
PacketSinkHelper sink ("ns3::TcpSocketFactory",Address
(InetSocketAddress (Ipv4Address::GetAny (), 10)));
//set a node as reciever
ApplicationContainer app = sink.Install (nodes.Get(0));
app.Start (Seconds (1.0));
app.Stop (Seconds (10.0));
OnOffHelper onOffHelper ("ns3::TcpSocketFactory", Address
(InetSocketAddress (Ipv4Address ("109.11.12.1"), 10)));
onOffHelper.SetAttribute ("OnTime", StringValue ("ns3::ConstantRandomVariable[Constant=1]"));
onOffHelper.SetAttribute ("OffTime", StringValue ("ns3::ConstantRandomVariable[Constant=0]"));
onOffHelper.SetAttribute ("DataRate",StringValue ("2Mbps"));
onOffHelper.SetAttribute ("PacketSize",UintegerValue(1280));
// ApplicationContainer
app = onOffHelper.Install (nodes.Get (1));
// Start the application
app.Start (Seconds (1.0));
app.Stop (Seconds (10.0));
pointToPoint.EnablePcapAll ("testtcp");
Simulator::Run ();
您真的要将TCP流量发送到ip地址255.255.255.0吗？这不太可能奏效。也许你应该试试109.11.12.1
实际上TCP并不意味着支持广播，这就是为什么一些协议选择使用UDP而不是TCP来克服这样问题的原因。例如，Bootp在UDP上自行运行，因为TCP不支持该协议的初始状态。
