NS3之first.cc注解

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */  //emacs模式,这行告诉源代码使用的预订格式(代码风格)
/*
 * GNU---
 * GPL---General Public License许可
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
//引入头文件
#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/applications-module.h"

using namespace ns3;//使用ns3命名空间

NS_LOG_COMPONENT_DEFINE ("FirstScriptExample");//这段代码的作用是向ns-3系统注册一个名为FirstScriptExample的记录组件，只有定义了记录组件才能在仿真脚本中使用Logging系统来定义输出

int
main (int argc, char *argv[])
{
  Time::SetResolution (Time::NS);////设置时间单位为纳秒
  //下面两行脚本是用来使2个日志组件生效的，它们被内建在Echo Client和Echo Server的应用中
  //这两行代码将UdpEcho应用程序的客户端和服务器端的日志级别设置为“INFO”级
  LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
  LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);

  LogComponentEnable ("FirstScriptExample", LOG_LEVEL_INFO);


  NS_LOG_INFO("Create Simulator");//输出该字符串
  //LogComponentEnable("UdpEchoClientApplication", LOG_LEVEL_FUNCTION);
  //LogComponentEnable("UdpEchoServerApplication", LOG_LEVEL_FUNCTION);

  NodeContainer nodes;//创建ns3节点对象
  nodes.Create (2);//它们在仿真中代表计算机创建两个节点

  PointToPointHelper pointToPoint;//初始化一个PointToPointHelper的对象pointToPoint
  pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));//DataRate属性值为”5Mbit/s“
  //从上层的角度告诉PointToPointHelper对象当创建一个PointToPointNetDevice对象时使用”5Mbit/s“来作为数据速率
  pointToPoint.SetChannelAttribute ("Delay", StringValue ("2ms"));
  //Delay属性告诉PointToPointHelper使用“2ms”作为没一个被创建的点到点信道的传输延迟值

  //下面两行代码完成信道和设备的配置
  NetDeviceContainer devices;
  devices = pointToPoint.Install (nodes);

  //为计算机安装协议栈
  InternetStackHelper stack;
  stack.Install (nodes);

  Ipv4AddressHelper address;
  address.SetBase ("10.1.1.0", "255.255.255.0");

  Ipv4InterfaceContainer interfaces = address.Assign (devices);

  UdpEchoServerHelper echoServer (9);

  ApplicationContainer serverApps = echoServer.Install (nodes.Get (1));
  serverApps.Start (Seconds (1.0));
  serverApps.Stop (Seconds (10.0));

  //下面设置客户端应用层
  UdpEchoClientHelper echoClient (interfaces.GetAddress (1), 9);
  echoClient.SetAttribute ("MaxPackets", UintegerValue (1));
  echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
  echoClient.SetAttribute ("PacketSize", UintegerValue (1024));

  ApplicationContainer clientApps = echoClient.Install (nodes.Get (0));
  clientApps.Start (Seconds (2.0));
  clientApps.Stop (Seconds (10.0));

  //AsciiTraceHelper ascii;//使用AsciiTraceHelper生成ASCII格式的包
  //pointToPoint.EnableAsciiAll(ascii.CreateFileStream("myfirst.tr"));

  pointToPoint.EnablePcapAll("myfirst");//生成pcap格式的包

  Simulator::Run ();
  Simulator::Destroy ();
  return 0;
}