Jason's Computer Science Blog » Heron

Ns-3.2 on Ubuntu 8.04 Hardy Heron

Jason Ernst — Sat, 22 Nov 2008 18:18:22 +0000

For the next stage of my thesis instead of using the well known ns-2 simulator as originally planned, I have opted to instead use ns-3. I have chosen this particular environment because it seems to be designed from the ground up to be a wireless simulation tool while ns-2 was originally designed solely for wired network simulation. I have made some use of ns-2 however, so if you are looking for a guide to getting that working in Ubuntu see my post “NS-2.33 on Ubuntu 8.04 Hardy Heron“. In addition to this, ns-3 no longer uses the tcl scripting language. Instead the choice of pure c++ or a combination of c++ and python may be used to define the simulation parameters. I prefer this approach because I have no desire to learn tcl and find the c++ ns-3 ot be more intuitive than ns-2. Additionally, this guide will be used as a reference for myself while I learn the ns-3 environment. Check back for regular updates and useful infromation.

So back to the point of this article, a guide on how to install ns-3.2 on Ubuntu 8.04 Hardy Heron. Ns-3 installation is quite simple since an automatic build tool named waf is used to build the project. Enter the following in the terminal to download, untar and build ns-3.2.


wget http://www.nsnam.org/releases/ns-3.2.tar.bz2
tar -xvf ns-3.2.tar.bz2
./waf -d debug configure

How to start working with NS-3

So from here on out, all you have to do is use the waf tool for compiling and running your ns3 simulations. There are many example scenarios located in the /examples folder. You can run a simulation with any of the scenarios using the waf command. For example if you wanted to run a scenario file named first.cc you would enter the following command:


./waf --run=first

Notice that you do not need to include the .cc on the filename. If you do happen to misspell the file, ns3 will provide you with a list of all of the scenarios you are able to run. One other important note is that the /scratch folder automatically includes the .cc files as scenarios which you can run. This is likely where you will want to place your new scenarios when working on them. (If you try to put them in the examples folder you will need to edit the wscript file (see NS3 tutorial on how to do this). On other important thing to note is that ns3 supports improved logging / output compared with ns2 using the pcap file format which can be read using tcpdump or wireshark. These types of files were originally used for packet capturing in real working networks so it makes alot of sense to include this ability in simulation as well.

How to display exactly what is going on to the screen (Logging)

Sometimes when making changes and implementing something new, it is helpful to show everything that is happening on the screen. You can achieve this by entering the following at the linux command line:


export 'NS_LOG=*=level_all|prefix_func|prefix_time'

If you want to restrict the information to only certain parts of the simulation, for example the MAC layer of a wifi AP you could do something like this:


export 'NS_LOG=NqapWifiMac=level_all|prefix_func|prefix_time'

For more information on how to configure the logging to do exactly what you want, see the NS3 Tutorial section on logging.

If you have turned on logging, you have likely noticed that ns3 generates so much information that it scrolls by way to fast to be of any use. So you will probably want to output the results to a file. For example if you were running the first.cc file again and you have turned on logging you could do this:


./waf --run=first >& first.txt

which would send the logging output to the file first.txt where you could easily read it.

Useful Functions

So far I have found these functions make debugging scenarios easier:


static Vector
GetPosition (Ptr node)
{
  Ptr mobility = node->GetObject ();
  return mobility->GetPosition ();
}


static Ipv4Address
GetAddress (Ptr node, uint32_t interface)
{
  Ptr ipv4 = node->GetObject ();
  return ipv4->GetAddress(interface);
}

Tips

The following are a few important things I’ve discovered that may save you time when trying to work with ns3 on certain tasks:

When simulating an ad-hoc or wireless mesh network using OLSR, make sure you set your mobility model before you install the OLSR routing on the nodes. If you do not do this, OLSR may generate link pairs for links which are actually too far away to communicate because before the mobility model is installed on the nodes they are all close enough to communicate.
Also with OLSR, make sure you give OLSR enough time to determine the network topology before you allow the applications to start running on the network. I have read that about 100s of waiting time before starting is enough, however I imagine as the network size grows this may also grow (I have tested with a size of 4×4 and this is enough time – I will adjust this as I play with the numbers as well)

Useful Links

Tutorial: Ns-2.33 (and nam) on Ubuntu 8.04 (Hardy Heron)

Jason Ernst — Wed, 11 Jun 2008 14:57:54 +0000

Since I have been working with ns2 for the last few months in preparation for my thesis I have decided to write a guide on how to install the most recent version of ns2 on the most recent version of ubuntu (at the time of this writing, Monday June 9th, 2008).

I have found many people already who have had difficulty setting it up so maybe this will be of some help to someone. For this tutorial I am assuming you have installed the most recent version of Ubuntu (8.04). (At the time of writing)

Step 1: Update Ubuntu

Since it has already been a month or so since Hardy Heron has been released its probably best, if you haven’t already done so to update Ubuntu. The easiest way I’ve found is to go to System>>Administration>>Update Manager. Alternatively, you can enter this into the terminal:

sudo apt-get update
sudo apt-get upgrade

Step 2: Download all of the required pieces to make ns2 work

Here is a list of archives required for ns2 to work properly (you can download them by clicking the links or just enter all of the commands in the code sections below for automatic download and untar). I saved each archive to the desktop so I could find each one easily but you could use anywhere you like.

Step 2.5: Install Ubuntu Packages

Before installing everything else, I have found that it is helpful to get a few packages from the ubuntu repositories or else it wont build correctly. Grab a cup of coffee it might take a while since kdebase-dev is somewhat large. I’m sure there is a way to do this with fewer packages however I know this works. If anyone figures out exactly which packages are required let me know so I can update this.

sudo apt-get install libx11-dev kdebase-dev

Step 3: Install tcl

wget http://www.jasonernst.com/wp-content/uploads/2008/06/tcl8.4.19-src.tar.gz
tar xvf tcl8.4.19-src.tar.gz
cd tcl8.4.19/unix
./configure
make
sudo make install

Step 4: Install tk

cd ..
cd ..
wget http://www.jasonernst.com/wp-content/uploads/2008/06/tk8.4.19-src.tar.gz
tar xvf tk8.4.19-src.tar.gz
cd tk8.4.19/unix
./configure
make
sudo make install

Step 5: Install oTcl

Important Note: The ‘./configure –with-tcl=’ portion of the following two code fragments should point to the source files for tcl. If you have been following the guide by copying and pasting the previous commands what we have here will work just fine. Otherwise you will need to change this to point to the correct location of your tcl source files.

cd ..
cd ..
wget http://www.jasonernst.com/wp-content/uploads/2008/06/otcl-src-1.13.tar.gz
tar xvf otcl-src-1.13.tar.gz
cd otcl-1.13
./configure --with-tcl=../tcl*/
make
sudo make install

Step 6: Install tclcl

cd ..
wget http://www.jasonernst.com/wp-content/uploads/2008/06/tclcl-src-1.19.tar.gz
tar xvf tclcl-src-1.19.tar.gz
cd tclcl-1.19
./configure --with-tcl=../tcl*/
make
sudo make install

Step 7: Install ns2

cd ..
wget http://www.jasonernst.com/wp-content/uploads/2008/06/ns-2.33.tar.gz
tar xvf ns-2.33.tar.gz
cd ns-2.33
./configure
make
sudo make install

You will likely get alot of warnings for deprecated conversions. Just ignore these or if you really are concerned about them visit the nsnam troubleshooting page. If you want to make sure your version of ns-2 is working correctly after the install you can run the validation test from within the ns2 source directory. You can do this by entering:

./validate

You should see that the test output agrees with the reference output. Congratulations you have a working version of ns-2 installed.

Step 8: (optional) Install nam

cd ..
wget http://www.jasonernst.com/wp-content/uploads/2008/06/nam-src-1.13.tar.gz
tar xvf nam-src-1.13.tar.gz
cd nam-1.13
./configure
make
sudo make install

Note: if you get this error:

error: X11/Xmu/WinUtil.h: No such file or directory

it may be necesary to do this:

sudo apt-get install libxmu-dev

You are now ready to start working with ns2 and nam. If you are like me and working on a new protocol or something you will want to start modifying the ns-2 source code and recompile again so you might want to keep that folder handy. The rest of the source can be safely removed as far as i know. Keep in mind after you have modified the source you will want to do another make install so that when you type ns in your terminal the version you just compiled is used.

Getting Started with NS2

These are some quick tips to get you started using ns2 if you are a beginner.

All example files are located in ns/tcl/ex. You can run these scenarios on ns2 using ns filename.tcl The best way to start is probably changing things in these files until you understand what is happening more thoroughly.

The output will usually be a trace file with a similar name: ex) filename.tr. Trace files can usually be viewed with a text-editor program. There are also tools to analyze the trace files and pull stats from them. These may require some tweaking however depending on the format of the trace file. Additionally, a nam output file for visualization may be generated as well. This will usually be named filename.nam. To view the visualization use: nam filename.nam

Useful Links

I thought it might be useful to add a section on useful links here since this article has become quite popular. If you would like to suggest a link feel free to contact me.