Basic NS-3

ns-3 Key Abstracitons

• Node
• • Host (end system), switch, router in the Internet
• • Basic computing device abstraction
• Application
• • A user program that generates some activities to be simulated
• • NS-3 applications run on ns-3 Nodes to drive simulations
• Channel
• • Medium connected by nodes over which data flows transmitted
• New device
• • Like a specific kind of network cable and a hardware device, Network Interface Cards
• • NICs are controlled using the software driver, net devices
• • Provides mothods for managing connection to Node and Channel
• Topology helpers
• • Topology helpers make ns-3 core operations as easy as possible
• • Create a NetDevice, add an address, install that net device on a Node, configure the node's protocol stack and connect the NetDevice to a Channel
• • NodeContainer: Provide a convenient way to create, manage and access any Node object
• • PoinToPointHelper: Configure and connect PointToPointNetDevice and PointToPointChannel objects. Set DataRate on NetDevices and Delay on Channel
• • NetDeviceContainer: To install NetDevice at the nodes and create Channel between the nodes
• • InternetStackHelper: To install an Internet Stack (TCP, UDP, IP, etc.) on each of the nodes in the node container
• • Ipv4AddressHelper: Manage the allocation of IP address and assign addresses to the devices using Ipv4InterfaceContainer

ns-3 Script

• 1. Module Includes
• 2. Namespace declaration
• 3. Node Creation
• 4. Set Device & Channel Attribute
• 5. Install Net Device
• 6. Install Network Stack
• 7. Assigning IP Address
• 8. Creating Application
• 9. Creating Application Container
• 10. Running and Stopping Simulator
• 11. Destroying Simulator

• 아래의 명령어로 scratch directory에 있는 myfirst.cc simulator를 실행시킨 결과

./waf --run scratch/myfirst

• ./waf를 할 때는 ns-3.29 directory에서 실행해야함 (build directory가 있는 경로에서)

Logging Modules

• 아래와 같은 형식으로 Logging component를 정의함

NS_LOG_COMPONENT_DEFINE ("ScratchSimulator") //예시

• 아래의 명령어를 통해 logging을 enable 해줘야함

./waf configure --build-profile=debug

Running a Simulation

• Running space

cd ns-allinone-3.29/ns-3.29

• How to run

./waf --run <simulation scenario(script) filename>

Other Way for Enabling Log Components

export NS_LOG=UdpEchoClientApplication=level_all
./waf --run scratch/myfirst

Set Log Prefix

export 'NS_LOG=UdpEchoClientApplication=level_all|prefix_time'
./waf --run scratch/myfirst

Store Logs in a File

export 'NS_LOG=*=level_all|prefix_func|prefix_time'
./waf --run scratch/myfirst > log.out 2>&1

Initializing Logging Module

export NS_LOG=
./waf --run scratch/myfirst

Adding Logging to code

LogComponentEnable ("FirstScriptExample", LOG_LEVEL_INFO);
LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
LogComponentEnable ("UdpEchoServeerApplication", LOG_LEVEL_INFO);

NS_LOG_INFO ("Creating Topology");
NodeContainer nodes;
nodes.Create(2);

./waf --run scratch/myfirst