（四）NS3中示例：second.cc和third.cc程序的注释
1. second.cc
<span style="font-size:18px;">#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"
// Default Network Topology拓扑分布
//
// 10.1.1.0
// n0 -------------- n1 n2 n3 n4
// point-to-point | | | |
// ================
// LAN 10.1.2.0
//n0和n1实现点到点通信，n1~n4是个csma有线局域网。网络可以实现n0经由n1，和n4进行通信。
using namespace ns3;
NS_LOG_COMPONENT_DEFINE ("SecondScriptExample");//定义日志组件
int
main (int argc, char *argv[])
{
bool verbose = true;//定义bool变量用于决定是否开启日志组件，默认开启
uint32_t nCsma = 3;//变量，用于定义csma网络中有多少个node
CommandLine cmd;
cmd.AddValue ("nCsma", "Number of \"extra\" CSMA nodes/devices", nCsma);
cmd.AddValue ("verbose", "Tell echo applications to log if true", verbose);
//命令行参数，设置是否开启logging
cmd.Parse (argc,argv);
if (verbose)
{
LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);
}
nCsma = nCsma == 0 ? 1 : nCsma;
//********网络拓扑部分********//
//p2p链路的两个节点创建
NodeContainer p2pNodes;
p2pNodes.Create (2);
//创建csma网络节点
NodeContainer csmaNodes;
csmaNodes.Add (p2pNodes.Get (1));//将p2p节点1加到csma网络中
csmaNodes.Create (nCsma);
//设置p2p传输速率和信道延迟
PointToPointHelper pointToPoint;
pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));
pointToPoint.SetChannelAttribute ("Delay", StringValue ("2ms"));
//安装p2p网卡到p2p网络节点
NetDeviceContainer p2pDevices;
p2pDevices = pointToPoint.Install (p2pNodes);
//设置csma传输速率和信道延迟，注意传输速率有channel指定，而非device属性。（CSMA不允许同一信道上有多个不同数据率的设备）
CsmaHelper csma;
csma.SetChannelAttribute ("DataRate", StringValue ("100Mbps"));
csma.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (6560)));
NetDeviceContainer csmaDevices;
csmaDevices = csma.Install (csmaNodes);
//安装协议
InternetStackHelper stack;
stack.Install (p2pNodes.Get (0));//p2p的n0节点，n1节点在csma网络中安装协议栈
stack.Install (csmaNodes);
Ipv4AddressHelper address;
address.SetBase ("10.1.1.0", "255.255.255.0");
Ipv4InterfaceContainer p2pInterfaces;
p2pInterfaces = address.Assign (p2pDevices);
address.SetBase ("10.1.2.0" , "255.255.255.0");
Ipv4InterfaceContainer csmaInterfaces;
csmaInterfaces = address.Assign (csmaDevices);
//********应用程序部分********//
UdpEchoServerHelper echoServer (9);//服务器端口号
//将server服务器安装在csma网络的n4节点。假定nCsma=3
ApplicationContainer serverApps = echoServer.Install (csmaNodes.Get (nCsma));
serverApps.Start (Seconds (1.0));
serverApps.Stop (Seconds (10.0));
UdpEchoClientHelper echoClient (csmaInterfaces.GetAddress (nCsma), 9);//设定远程服务器的IP地址和端口号
echoClient.SetAttribute ("MaxPackets", UintegerValue (1));
echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
echoClient.SetAttribute ("PacketSize", UintegerValue (1024));
ApplicationContainer clientApps = echoClient.Install (p2pNodes.Get (0));
clientApps.Start (Seconds (2.0));
clientApps.Stop (Seconds (10.0));
//********建立网络路由********//
Ipv4GlobalRoutingHelper::PopulateRoutingTables ();
//********开启pcap追踪********//
//开启p2pHelper,csmaHelper类对象的pcap
pointToPoint.EnablePcapAll ("second");
csma.EnablePcap ("second", csmaDevices.Get (1), true);
Simulator::Run ();
Simulator::Destroy ();
return 0;
}</span><span style="font-size:24px;">
</span>
2. third.cc
<span style="font-size:18px;">#include "ns3/core-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/network-module.h"
#include "ns3/applications-module.h"
#include "ns3/wifi-module.h"
#include "ns3/mobility-module.h"
#include "ns3/csma-module.h"
#include "ns3/internet-module.h"
// Default Network Topology网络拓扑
//
// Wifi 10.1.3.0
// AP
// * * * *
// | | | | 10.1.1.0
// n5 n6 n7 n0 -------------- n1 n2 n3 n4
// point-to-point | | | |
// ================
// LAN 10.1.2.0
//n0,n5-n7:wifi网络，n0为AP，n5,n6,n7为无线STA； n0和n1：p2p通信； n1-n4：csma网络。示例中实现了节点n7和n4通信。
using namespace ns3;
NS_LOG_COMPONENT_DEFINE ("ThirdScriptExample");
int
main (int argc, char *argv[])
{
bool verbose = true;//用于是否启用logging组件
uint32_t nCsma = 3;//设置nCsma和nWifi的额外STA个数
uint32_t nWifi = 3;
CommandLine cmd;
cmd.AddValue ("nCsma", "Number of \"extra\" CSMA nodes/devices", nCsma);
cmd.AddValue ("nWifi", "Number of wifi STA devices", nWifi);
cmd.AddValue ("verbose", "Tell echo applications to log if true", verbose);
cmd.Parse (argc,argv);
if (nWifi > 18)
{
std::cout << "Number of wifi nodes " << nWifi <<
" specified exceeds the mobility bounding box" << std::endl;
exit (1);
}
if (verbose)
{
LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);
}
//创建p2p链路2个节点
NodeContainer p2pNodes;
p2pNodes.Create (2);
PointToPointHelper pointToPoint;
pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));
pointToPoint.SetChannelAttribute ("Delay", StringValue ("2ms"));
NetDeviceContainer p2pDevices;
p2pDevices = pointToPoint.Install (p2pNodes);
//创建csma网络的4个节点。默认nCsma=3
NodeContainer csmaNodes;
csmaNodes.Add (p2pNodes.Get (1));
csmaNodes.Create (nCsma);
CsmaHelper csma;
csma.SetChannelAttribute ("DataRate", StringValue ("100Mbps"));
csma.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (6560)));
NetDeviceContainer csmaDevices;
csmaDevices = csma.Install (csmaNodes);
//*********创建wifi网络的4个节点，默认STA=3；**********//
NodeContainer wifiStaNodes;
wifiStaNodes.Create (nWifi);//创建STA
NodeContainer wifiApNode = p2pNodes.Get (0);//设置wifi的AP
//配置PHY和Channel通道助手
YansWifiChannelHelper channel = YansWifiChannelHelper::Default ();
YansWifiPhyHelper phy = YansWifiPhyHelper::Default ();
phy.SetChannel (channel.Create ());//Channel对象与PHY对象关联
//MAC层配置==============================
WifiHelper wifi = WifiHelper::Default ();
wifi.SetRemoteStationManager ("ns3::AarfWifiManager");//使用AARF速率控制算法
NqosWifiMacHelper mac = NqosWifiMacHelper::Default ();//non-Qos的MAC
//配置wifi网络STA网络设备的MAC类型和基础设施网络的SSID
Ssid ssid = Ssid ("ns-3-ssid");//IEEE 802.1服务集标识符对象
mac.SetType ("ns3::StaWifiMac", //设置为特定种类MAC层，non-AP
"Ssid", SsidValue (ssid),//设置SSID
"ActiveProbing", BooleanValue (false));//设置ActiveProbing,false意味着助手创建的mac将不会发送探测请求。
NetDeviceContainer staDevices;//STA 网络设备
staDevices = wifi.Install (phy, mac, wifiStaNodes);//wifi的STA安装PHY层和MAC层
//配置wifi网络AP网络设备的MAC类型和基础设施网络的SSID
mac.SetType ("ns3::ApWifiMac",
"Ssid", SsidValue (ssid));
NetDeviceContainer apDevices;
apDevices = wifi.Install (phy, mac, wifiApNode);//与STA共同的PHY特性
//********移动模型********//
MobilityHelper mobility;
mobility.SetPositionAllocator ("ns3::GridPositionAllocator", //网格位置分配器
"MinX", DoubleValue (0.0),
"MinY", DoubleValue (0.0),
"DeltaX", DoubleValue (5.0),
"DeltaY", DoubleValue (10.0),
"GridWidth", UintegerValue (3),
"LayoutType", StringValue ("RowFirst"));
mobility.SetMobilityModel ("ns3::RandomWalk2dMobilityModel", //以随机游走的方式移动
"Bounds", RectangleValue (Rectangle (-50, 50, -50, 50)));
mobility.Install (wifiStaNodes); //安装到wifi网络的STA
mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");
mobility.Install (wifiApNode);//安装到wifi网络的AP
//安装协议栈
InternetStackHelper stack;
stack.Install (csmaNodes);
stack.Install (wifiApNode);
stack.Install (wifiStaNodes);
Ipv4AddressHelper address;
address.SetBase ("10.1.1.0", "255.255.255.0");
Ipv4InterfaceContainer p2pInterfaces;
p2pInterfaces = address.Assign (p2pDevices);
address.SetBase ("10.1.2.0", "255.255.255.0");
Ipv4InterfaceContainer csmaInterfaces;
csmaInterfaces = address.Assign (csmaDevices);
address.SetBase ("10.1.3.0", "255.255.255.0");
address.Assign (staDevices);
address.Assign (apDevices);
//安装应用
UdpEchoServerHelper echoServer (9);
ApplicationContainer serverApps = echoServer.Install (csmaNodes.Get (nCsma));//csma网络的最后节点作为服务器
serverApps.Start (Seconds (1.0));
serverApps.Stop (Seconds (10.0));
UdpEchoClientHelper echoClient (csmaInterfaces.GetAddress (nCsma), 9);//设置客户机的远程服务器IP地址和端口号
echoClient.SetAttribute ("MaxPackets", UintegerValue (1));
echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
echoClient.SetAttribute ("PacketSize", UintegerValue (1024));
ApplicationContainer clientApps =
echoClient.Install (wifiStaNodes.Get (nWifi - 1));//在随后建立的wifi STA上安装客户机
clientApps.Start (Seconds (2.0));
clientApps.Stop (Seconds (10.0));
//建立网络路由
Ipv4GlobalRoutingHelper::PopulateRoutingTables ();
Simulator::Stop (Seconds (10.0));//无线接入点会一直产生信标，模拟器时间列表一直非空，仿真无法结束
//
pointToPoint.EnablePcapAll ("third");
phy.EnablePcap ("third", apDevices.Get (0));
csma.EnablePcap ("third", csmaDevices.Get (0), true);
Simulator::Run ();
Simulator::Destroy ();
return 0;
}
</span>
参考文献：
[1] ns-3project. ns-3 Software Tutorial. ns-3 project. 2015年2月26日
[2]《ns-3网络模拟器基础及应用》，人民邮电出版社，马春光 姚建盛，2014年1月
部分参考网络资料，未一一列举，敬请原谅！
时间： 2024-10-30 22:25:59