中科大高网实验报告

运用ns-3模拟数据中心（datacenter）实验报告一.实验工具

Ubuntu、Vmware虚拟机、ns-3仿真器、Wireshark抓包工具

二.实验步骤

1.编写程序模拟网络拓扑及网络消息传输状态（多对一和多对多）

2.利用Wireshark抓包工具对输出的.pcap文件进行分析

3.实验总结

三.网络拓扑

图（1）

四.重要代码解释

//备注：以下是实现主机间多对一通信的代码，其中多指的为主机h2—h8，一为主机//h1.

//库函数调用

#include "ns3/core-module.h"

#include "ns3/network-module.h"

#include "ns3/csma-module.h"

#include "ns3/internet-module.h"

#include "ns3/applications-module.h"

#include "ns3/ipv4-global-routing-helper.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("SecondScriptExample");

int

main (int argc, char *argv[])

{

bool verbose = true;

uint32_t nCsma = 3;

uint32_t nFlows = 7;

uint16_t port = 5000;

//cmd.AddValue ("nCsma", "Number of \"extra\" CSMA nodes/devices", nCsma); cmd.AddValue ("verbose", "Tell echo applications to log if true", verbose);

cmd.Parse (argc,argv);

if (verbose)//为真

{////定义两个LOG模块,用于收到和发出数据包时输出LOG消息

LogComponentEnable ("PacketSink", LOG_LEVEL_INFO);

LogComponentEnable ("OnOffApplication", LOG_LEVEL_INFO);

}

nCsma = nCsma == 0 ? 1 : nCsma;

//创建底层的4个小csma网络

NodeContainer csmaNodes1;

csmaNodes1.Create (3);

NodeContainer csmaNodes2;

csmaNodes2.Create (3);

NodeContainer csmaNodes3;

csmaNodes3.Create (3);

NodeContainer csmaNodes4;

csmaNodes4.Create (3);

//创建中层的csma中左侧网络

NodeContainer csmaNodes5;

csmaNodes5.Create (1);

csmaNodes5.Add (csmaNodes1.Get (0));

csmaNodes5.Add (csmaNodes2.Get (0));

//创建中层的csma中右侧网络

NodeContainer csmaNodes6;

csmaNodes6.Create (1);

csmaNodes6.Add (csmaNodes3.Get (0));

csmaNodes6.Add (csmaNodes4.Get (0));

//创建总的csma大csma网络

NodeContainer csmaNodes7;

csmaNodes7.Create (1);

csmaNodes7.Add (csmaNodes5.Get (0));

csmaNodes7.Add (csmaNodes6.Get (0));

//CMSA1网络拓扑

CsmaHelper csma1;

csma1.SetChannelAttribute ("DataRate", StringValue ("1.0Mbps"));

csma1.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500)));

NetDeviceContainer csmaDevices1;

csmaDevices1 = csma1.Install (csmaNodes1);

//CMSA2网络拓扑

csma2.SetChannelAttribute ("DataRate", StringValue ("1.0Mbps"));

csma2.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500)));

NetDeviceContainer csmaDevices2;

csmaDevices2 = csma2.Install (csmaNodes2);

//CMSA3网络拓扑

CsmaHelper csma3;

csma3.SetChannelAttribute ("DataRate", StringValue ("1.0Mbps"));

csma3.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500)));

NetDeviceContainer csmaDevices3;

csmaDevices3 = csma3.Install (csmaNodes3);

//CMSA4网络拓扑

CsmaHelper csma4;

csma4.SetChannelAttribute ("DataRate", StringValue ("1.0Mbps"));

csma4.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500)));

NetDeviceContainer csmaDevices4;

csmaDevices4 = csma4.Install (csmaNodes4);

//CMSA5网络拓扑

CsmaHelper csma5;

csma5.SetChannelAttribute ("DataRate", StringValue ("1.0Mbps"));

csma5.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500))); NetDeviceContainer csmaDevices5;

csmaDevices5 = csma5.Install (csmaNodes5);

//CMSA6网络拓扑

CsmaHelper csma6;

csma6.SetChannelAttribute ("DataRate", StringValue ("1.0Mbps"));

csma6.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500))); NetDeviceContainer csmaDevices6;

csmaDevices6 = csma6.Install (csmaNodes6);

//CMSA7网络拓扑

CsmaHelper csma7;

csma7.SetChannelAttribute ("DataRate", StringValue ("1.5Mbps"));

csma7.SetChannelAttribute ("Delay", TimeValue (NanoSeconds (500))); NetDeviceContainer csmaDevices7;

csmaDevices7 = csma7.Install (csmaNodes7);

//安装协议栈（每个node只有一个stack）

InternetStackHelper stack;

stack.Install (csmaNodes1);

stack.Install (csmaNodes2);

stack.Install (csmaNodes3);

stack.Install (csmaNodes4);