我是NS-3的初学者,我想通过NS-3在我的网络中配置多路径路由,这里是代码:
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/csma-module.h"
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/applications-module.h"
#include "ns3/ipv4-global-routing-helper.h"
using namespace ns3;
using namespace std;
NS_LOG_COMPONENT_DEFINE ("TestRoutingExample");
int main(int argc, char *argv[])
{
LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);
Ptr<Node> n0 = CreateObject<Node>();
Ptr<Node> n1 = CreateObject<Node>();
Ptr<Node> n2 = CreateObject<Node>();
Ptr<Node> n3 = CreateObject<Node>();
Ptr<Node> n4 = CreateObject<Node>();
Names::Add("n0", n0);
Names::Add("n1", n1);
Names::Add("n2", n2);
Names::Add("n3", n3);
Names::Add("n4", n4);
NodeContainer n0n1(n0, n1);
NodeContainer n1n2(n1, n2);
NodeContainer n1n3(n1, n3);
NodeContainer n3n4(n3, n4);
NodeContainer n2n4(n2, n4);
NodeContainer global(n0, n1, n2, n3, n4);
// create link
PointToPointHelper p2p;
p2p.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));
p2p.SetChannelAttribute ("Delay", StringValue ("2ms"));
NetDeviceContainer d0d1 = p2p.Install(n0n1);
NetDeviceContainer d1d2 = p2p.Install(n1n2);
NetDeviceContainer d1d3 = p2p.Install(n1n3);
NetDeviceContainer d2d4 = p2p.Install(n2n4);
NetDeviceContainer d3d4 = p2p.Install(n3n4);
// create internet stack
InternetStackHelper internet;
internet.Install (global);
Ipv4AddressHelper ipv4;
ipv4.SetBase ("10.0.0.0", "255.255.255.0");
Ipv4InterfaceContainer i0i1 = ipv4.Assign (d0d1);
ipv4.SetBase ("10.1.1.0", "255.255.255.0");
Ipv4InterfaceContainer i1i2 = ipv4.Assign (d1d2);
ipv4.SetBase ("10.2.2.0", "255.255.255.0");
Ipv4InterfaceContainer i1i3 = ipv4.Assign (d1d3);
ipv4.SetBase ("10.3.3.0", "255.255.255.0");
Ipv4InterfaceContainer i2i4 = ipv4.Assign (d2d4);
ipv4.SetBase ("10.4.4.0", "255.255.255.0");
Ipv4InterfaceContainer i3i4 = ipv4.Assign (d3d4);
Config::SetDefault("ns3::Ipv4GlobalRouting::RandomEcmpRouting", BooleanValue(true)); // enable multi-path routing
Ipv4GlobalRoutingHelper::PopulateRoutingTables ();
// install application
UdpEchoServerHelper echoServer1(9999);
ApplicationContainer serverApps1 = echoServer1.Install (n4);
serverApps1.Start (Seconds (1.0));
serverApps1.Stop (Seconds (1000.0));
// n0 -> n4
UdpEchoClientHelper echoClient1(i2i4.GetAddress (1), 9999);
echoClient1.SetAttribute ("MaxPackets", UintegerValue (200));
echoClient1.SetAttribute ("Interval", TimeValue (Seconds (1)));
echoClient1.SetAttribute ("PacketSize", UintegerValue (1024));
ApplicationContainer clientApps1 = echoClient1.Install (n0);
clientApps1.Start (Seconds (2.0));
clientApps1.Stop (Seconds (10.0));
// dump config
p2p.EnablePcapAll ("test");
Simulator::Run ();
Simulator::Destroy ();
return 0;
}
拓扑结构如下:
n0会定期向n4发送UDP数据包,但是我发现所有数据包都通过路径:n0→n1→n2→n4检查.pcap文件,为什么?
答案 0 :(得分:1)
看看dynamic-global-routing.cc示例。基本上,您可以通过启用RespondToInterfaceEvents:
来执行此操作Config::SetDefault ("ns3::Ipv4GlobalRouting::RespondToInterfaceEvents", BooleanValue (true));
RespondToInterfaceEvents:如果要在接口通知事件(上/下或添加/删除地址)时动态重新计算全局路由,则设置为true
关闭节点n1或n4上的一个接口(因为它们都有两个接口)。所以看起来应该是这样的:
Ptr<Ipv4> ipv41 = n1->GetObject<Ipv4> ();
// The first ifIndex is 0 for loopback, then the first p2p is numbered 1,
// then the next p2p is numbered 2
uint32_t ipv4ifIndex1 = 1; // since you first installed d1d2
Simulator::Schedule (Seconds(4), &Ipv4::SetDown, ipv41, ipv4ifIndex1);
Simulator::Schedule (Seconds(6), &Ipv4::SetUp, ipv41, ipv4ifIndex1);
按照这种方法,您可以扩展它并随机触发SetDown和SetUp事件。我希望这会有所帮助。
更新:如果您想使用RandomEcmpRouting
,则必须将SetDefault
电话移至最前面(在创建接口之前)。