X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7f520befbc8418c442bc9bac3c30accbd73ac9ed..e709643ef0c5b61c6c878016c418bffa2b1b20cd:/docs/source/ns3.rst diff --git a/docs/source/ns3.rst b/docs/source/ns3.rst index 969ca7d5f2..3a20e28aaa 100644 --- a/docs/source/ns3.rst +++ b/docs/source/ns3.rst @@ -56,10 +56,11 @@ version of either SimGrid or ns-3, try upgrading everything. Using ns-3 from SimGrid *********************** -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. +The SimGrid/ns-3 binding only contains features that are common to +both systems. Not all ns-3 models are available (only the TCP and wifi +ones are), while not all SimGrid platform file can be used with ns-3 +(routes must be of length 1). Also, the platform built in ns-3 from +the SimGrid description is very basic. Platform files compatibility ============================ @@ -71,13 +72,15 @@ example of an invalid platform: .. code-block:: shell - - + + + + - - + + @@ -92,15 +95,17 @@ ns-3 automatically routes from point to point. .. code-block:: shell - + + + - - + + @@ -113,7 +118,7 @@ ns-3 automatically routes from point to point. Once your platform is OK, just change the :ref:`network/model -` configuration option to "ns-3" as follows. The rest +`_ configuration option to "ns-3" as follows. The rest is unchanged. .. code-block:: shell @@ -125,20 +130,127 @@ ns-3 model, such as `examples/platforms/dogbone.xml `_ to see which ones are used in our regression tests. +Build a wifi-compatible platform +=================================== + +We describe here a simple platform allowing ns3 wifi communication +between two SimGrid hosts. + +First, here are the mandatory information necessary to create a +simgrid platform: + +.. code-block:: shell + + + + + + +Then, we create our access point and station hosts: + +.. code-block:: shell + + + + +We must specify that alice will be our access point. To do that we +simply add the property ``wifi_link`` to the host ``alice``: + +.. code-block:: shell + + + + + + + +The value ``net0`` of this property defines the name of the wifi network +generated. To generate this wifi network we create a wifi link: + +.. code-block:: shell + + + +The important information here are: + * The id of the link, ``net0``, must match the network name defined by the property ``wifi_link`` of the access point node + * The sharing policy must be set to ``WIFI`` + +Note: bandwidth and latency are mandatory by simgrid to create a link but are NOT used to create a wifi network. Instead the +wifi network capabilities are defined by its MCS, NSS and distance from access point to station. Those properties are described in section :ref:`Optional access point node properties `_ + +To connect the station node to the access point node, we +create a route between the hosts: + +.. code-block:: shell + + + + + +Finally, we end the xml file with the missing closing tags: + +.. code-block:: shell + + + + +.. _optional_prop: + +Optional access point node properties +-------------------------------------- + +The MCS (`Modulation and Coding Scheme `_) can be set with the property ``wifi_mcs``: + +.. code-block:: shell + + + + + + +Its default value is 3. + +The NSS (Number of Spatial Streams, also known as the `number of antennas `_) can be set with the property ``wifi_nss``: + +.. code-block:: shell + + + + + + +Its default value is 1. + +Note: not all value of MCS and NSS are valid nor compatible. Check `802.11n standard `_ for more information. + +Optional station node properties +--------------------------------- + +The distance in meter at which the station is placed from the access point can +be set with the property ``wifi_distance``. + +.. code-block:: shell + + + + + +Its default value is 10. + 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 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 - SimGrid hosts should be connected to the platform through only - one link. Otherwise, your SimGrid host will be considered as a - router. - + * 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 + SimGrid hosts should be connected to the platform through only + one link. Otherwise, your SimGrid host will be considered as a + router (FIXME: is it still true?). + 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