NS3学习（一）

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * 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
 */

#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;	//用了ns3的名字空间

NS_LOG_COMPONENT_DEFINE ("FirstScriptExample");		//定义自己的日志名称

int
main (int argc, char *argv[])
{
  CommandLine cmd;
  cmd.Parse (argc, argv);
  
  Time::SetResolution (Time::NS);
    //UdpEchoClientApplication是系统已经定义好的模块，启动该日志，级别为INFO
  LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
  LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);
	//Container就是个数组，存储需要的对象
    //Helper是用来调用对象的封装
    
  NS_LOG_UNCOND ("Welcome! Ns3 Simulator! "); //添加无条件记录相关消息
    
  NS_LOG_INFO ("Creating Topology"); //记录程序进展信息
    								 //需要当命令行设置export NS_LOG=
    								 //FirstScriptExample=info才会显示
  NodeContainer nodes;	//节点数组
  nodes.Create (2);		//建立两个node，node0和node1

  PointToPointHelper pointToPoint;	//点对点信道操作
  pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));	//设置带宽
  pointToPoint.SetChannelAttribute ("Delay", StringValue ("2ms"));	//设置时延

  NetDeviceContainer devices;	//网卡数组
  devices = pointToPoint.Install (nodes);	//点对点的信道中添加两个node，得到两个网卡，放在devices中

  InternetStackHelper stack;	//协议栈操作
  stack.Install (nodes);	//在两个节点上安装协议栈

  Ipv4AddressHelper address;	//IPv4地址操作
  address.SetBase ("10.1.1.0", "255.255.255.0");	//设置地址网段和掩码

  Ipv4InterfaceContainer interfaces = address.Assign (devices);	//给两个网卡分配IP地址（10.1.1.1和10.1.1.2）

  UdpEchoServerHelper echoServer (9);	//UdpEcho服务器操作
    									//使用端口号为9
  ApplicationContainer serverApps = echoServer.Install (nodes.Get (1));	//在Node1安装UdpEcho服务器（端口9）
  serverApps.Start (Seconds (1.0));	//服务开始时间
  serverApps.Stop (Seconds (10.0));	//服务结束时间

  UdpEchoClientHelper echoClient (interfaces.GetAddress (1), 9);	//UdpEcho客户端操作
    																//目的服务器是IP为10.1.1.2：9
  echoClient.SetAttribute ("MaxPackets", UintegerValue (1));
  echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
  echoClient.SetAttribute ("PacketSize", UintegerValue (1024));

  ApplicationContainer clientApps = echoClient.Install (nodes.Get (0));	//在Node0上面安装echoClient
  clientApps.Start (Seconds (2.0));
  clientApps.Stop (Seconds (10.0));

  Simulator::Run ();	//开始模拟
  Simulator::Destroy ();//结束
  return 0;
}