Network Simulator - ns-3

This is for discrete-event network simulator ns-3.

Developing with ns-3

ns-3 heavily relies on way for running simulations (examples, tutorials, etc.), but we can start developing using a simple Makefile and a shell.nix. We will use hello-simulator.cc for this example.

First create a shell.nix, with the requirements to compile our simulation.

{
  pkgs ? import <nixpkgs> { },
}:
pkgs.callPackage (
  {
    mkShell,
    pkg-config,
    ns-3,
  }:
  mkShell {
    strictDeps = true;
    nativeBuildInputs = [ pkg-config ];
    buildInputs = [ ns-3 ];
  }
) { }

Then we can create our Makefile, do note the LIBS argument, which is the modules required (not all are build by default, might have to override some settings in ns-3).

CC ?= gcc
CXX ?= g++
PKG_CONFIG ?= pkg-config

DEBUG=-DNS3_LOG_ENABLE

LIBS = ns3-core

# compiler flags:
#  -g    adds debugging information to the executable file
#  -Wall turns on most, but not all, compiler warnings
CFLAGS  = -g -Wall -Wextra $(shell $(PKG_CONFIG) --cflags $(LIBS))
LDFLAGS=$(shell $(PKG_CONFIG) --libs $(LIBS))

# the build target executable:
TARGET = hello-simulator

all: $(TARGET)

$(TARGET): $(TARGET).cc
	$(CXX) $(DEBUG) $(CFLAGS) $(LDFLAGS) -o $(TARGET) $(TARGET).cc

clean:
	$(RM) $(TARGET)

Then just place hello-simulator.cc in the same directory as the other files, then run the following commands.

$ nix-shell
$ make
$ ./hello-simulator

Please keep in mind our flag when we compile, regarding debug NS3_LOG_ENABLE.