ns-3 as a SimGrid model
#######################
-You can use the well-known `ns-3 <http://www.nsnam.org>`_ packet-level network
-simulator as a SimGrid model, for example to investigate the validity of your
-simulation. Just install ns-3 and recompile SimGrid accordingly.
+You can use the well-known `ns-3 packet-level network simulator
+<http://www.nsnam.org>`_ as a SimGrid model, for example to investigate the
+validity of your simulation. Just install ns-3 and recompile SimGrid
+accordingly.
-Installing ns-3
-***************
-
-The easiest is to install it with the package manager. Under Debian/Ubuntu,
-simply type as root:
-
-.. code-block:: shell
+Compiling the ns-3/SimGrid binding
+**********************************
- apt-get install libns3-dev ns3
+Installing ns-3
+===============
-You can also install it from scratch with the following commands:
+SimGrid requires ns-3 version 3.26 or higher, and you probably want the most
+recent version of both SimGrid and ns-3. While the Debian package of SimGrid
+don't have the ns-3 bindings activated, you can still use the packaged version
+of ns-3 by grabbing the ``libns3-dev ns3`` packages. Alternatively, you can
+install ns-3 from scratch as follows:
.. code-block:: shell
# Download the source
- wget http://www.nsnam.org/release/ns-allinone-3.26.tar.bz2
- tar -xf ns-allinone-3.26.tar.bz2
- cd ns-allinone-3.26/ns-3.26/
+ wget http://www.nsnam.org/release/ns-allinone-3.29.tar.bz2
+ tar -xf ns-allinone-3.29.tar.bz2
+ cd ns-allinone-3.29/ns-3.29/
# Configure, build and install
./waf configure --prefix="/opt/ns3" # or give another path if you prefer
./waf
For more information, please refer to the ns-3 documentation
(`official website <http://www.nsnam.org>`_).
-Enabling SimGrid's support for ns-3
-***********************************
+Enabling ns-3 in SimGrid
+========================
-Normally, you just have to enable ns-3 in ccmake or cmake as
-follows. If you installed ns-3 in a regular path, just drop the
-NS3_HINT configuration item.
+SimGrid must be recompiled with the ``enable_ns3`` option activated in cmake.
+Optionally, use ``NS3_HINT`` to hint cmake about where to find ns-3.
.. code-block:: shell
By the end of the configuration, cmake reports whether ns-3 was found,
and this information is also available in ``include/simgrid/config.h``
If your local copy defines the variable ``SIMGRID_HAVE_NS3`` to 1, then ns-3
-was correctly detected. If it's defined to 0, then something went
-wrong. Explore ``CMakeFiles/CMakeOutput.log`` and
+was correctly detected. Otherwise, explore ``CMakeFiles/CMakeOutput.log`` and
``CMakeFiles/CMakeError.log`` to diagnose the problem.
-Afterward, you can test your installation as follows:
+Test your installation after compilation as follows:
.. code-block:: shell
ctest -R ns3
+Troubleshooting
+===============
+
+If you use a version of ns-3 that is not known to SimGrid yet, edit
+``tools/cmake/Modules/FindNS3.cmake`` in your SimGrid tree, according to the
+comments on top of this file. Conversely, if something goes wrong with an old
+version of either SimGrid or ns-3, try upgrading everything.
+
.. _ns3_use:
Using ns-3 from SimGrid
***********************
-The SimGrid-ns3 binding only contains features that are common to both
+The SimGrid/ns-3 binding only contains features that are common to both
systems: ns-3 wireless models are not available, while SimGrid routes
cannot be longer than 1. Also, the platform built in ns-3 from the
SimGrid description is very basic.
+Platform files compatibility
+============================
+
Any route longer than one will be ignored when using ns-3. They are
harmless, but you still need to connect your hosts using one-hop routes.
The best solution is to add routers to split your route. Here is an
<link id="l2" bw="1Mbps" />
<route src="alice" dst="bob">
- <link_ctn id="l1"/> <!-- INVALID WITH NS-3 -->
- <link_ctn id="l2"/> <!-- length=2 IS TOO MUCH -->
+ <link_ctn id="l1"/> <!-- !!!! INVALID WITH ns-3 !!!! -->
+ <link_ctn id="l2"/> <!-- !!!! length=2 IS TOO MUCH !!!! -->
</route>
</platform>
-Here is the same platform expressed in a way that ns-3 will understand.
+This can be reformulated as follows to make it usable with the ns-3 binding.
There is no direct connexion from alice to bob, but that's OK because
-ns-3 will find the path from point to point.
+ns-3 automatically routes from point to point.
.. code-block:: shell
</platform>
Once your platform is OK, just change the :ref:`network/model
-<options_model_select>` configuration option to "NS3" as follows. The rest
+<options_model_select>` configuration option to "ns-3" as follows. The rest
is unchanged.
.. code-block:: shell
- ./network-ns3 --cfg=network/model:NS3 (other parameters)
+ ./network-ns3 --cfg=network/model:ns-3 (other parameters)
Many other files from the ``examples/platform directory`` are usable with the
ns-3 model, such as `examples/platforms/dogbone.xml <https://framagit.org/simgrid/simgrid/tree/master/examples/platforms/dogbone.xml>`_.
Check the file `examples/deprecated/msg/network-ns3/network-ns3.tesh <https://framagit.org/simgrid/simgrid/tree/master/examples/deprecated/msg/network-ns3/network-ns3.tesh>`_
to see which ones are used in our regression tests.
-Shortcomings of the ns-3 bindings in SimGrid
---------------------------------------------
+Limitations
+===========
A ns-3 platform is automatically created from the provided SimGrid
platform. However, there are some known caveats:
- * The default values (e.g., TCP parameters) are the ns3 default values.
+ * The default values (e.g., TCP parameters) are the ns-3 default values.
* ns-3 networks are routed using the shortest path algorithm, using
``ns3::Ipv4GlobalRoutingHelper::PopulateRoutingTables``.
* End hosts cannot have more than one interface card. So, your
one link. Otherwise, your SimGrid host will be considered as a
router.
-Our goal is to keep the ns-3 plugin of SimGrid as easy (and hopefully
-readable) as possible. If the current state does not fit your needs,
-you should modify this plugin, and/or create your own plugin from the
-existing one.
-
-Troubleshooting with ns-3 and SimGrid
-*************************************
-
-I fail to compile ns-3 within SimGrid
--------------------------------------
-
-If you have a ns-3 version that is not known to SimGrid yet, edit
-``tools/cmake/Modules/FindNS3.cmake`` in your SimGrid tree, according to
-the comments on top of this file.
-
-If the compilation fails on Debian/Ubuntu when linking the library
-because of some .a file that cannot be used dynamically, then you are
-probably using a very old (and buggy) ``libns3-dev``
-package. Update it, or install ``libns3-3`` manually.
-
-The simulation hangs at some point
-----------------------------------
-
-If your simulation hangs in a communication, this is probably because
-one host is sending data that is not routable in your platform. Make
-sure that you only use routes of length 1, and that any host is
-connected to the platform.
-
-Arguably, SimGrid could detect this situation and report it, but
-unfortunately, this is still to be done.
+Our goal is to keep the ns-3 plugin of SimGrid as easy (and hopefully readable)
+as possible. If the current state does not fit your needs, you should modify
+this plugin, and/or create your own plugin from the existing one. If you come up
+with interesting improvements, please contribute them back
-I get a warning that some routes are ignored
---------------------------------------------
+Troubleshooting
+===============
-Any routes longer than one hop are ignored in ns-3. Please refer to
-:ref:`ns3_use` for details.
+If your simulation hangs in a communication, this is probably because one host
+is sending data that is not routable in your platform. Make sure that you only
+use routes of length 1, and that any host is connected to the platform.
+Arguably, SimGrid could detect this situation and report it, but unfortunately,
+this is still to be done.
