:language: xml
+Star Zone
+---------
+
+In a Star topology, as the name says, nodes are organized following a star.
+It's similar to a cluster topology but you have the flexibility to set
+different route for every component in the star.
+Unfortunately, it's only available in the C++ interface.
+
+.. image:: img/starzone.svg
+ :scale: 80%
+ :align: center
+
+The particularity of this zone is how routes are declared. Instead of declaring the
+source and destination, routes are described from a node to everybody else or from
+everybody else to the node. In the example, the node *A* uses the *Link1* and *Backbone*
+to communicate with other nodes (note that this is valid for both nodes inside or outside
+the zone). More precisely, a communication from node *A* to *B* would use links: *Link1, Backbone,
+Link3_down*. Note that duplicated links are removed from the route, i.e. in this example we'll use *Backbone*
+only once.
+
+Also, note that the nodes (A, B and C) can be either hosts or other zones. In case of using zones,
+set the gateway parameter properly when adding the route.
+
+The following code illustrates how to create this Star Zone and add the appropriates routes.
+
+.. code-block:: cpp
+
+ auto* zone = sg4::create_star_zone("star");
+ /* create hosts */
+ const sg4::Host* hostA = zone->create_host("A", 1e9)->seal();
+ const sg4::Host* hostB = zone->create_host("B", 1e9)->seal();
+
+ /* create links */
+ sg4::Link* link1 = zone->create_link("link1", 1e6)->seal();
+ sg4::Link* link3_up = zone->create_link("link3_up", 1e6)->seal();
+ sg4::Link* link3_down = zone->create_link("link3_down", 1e6)->seal();
+ sg4::Link* backbone = zone->create_link("backbone", 1e9)->seal();
+
+ /* symmetric route route: A->ALL and ALL->A, shared link1 */
+ zone->add_route(hostA->get_netpoint(), nullptr, nullptr, nullptr,
+ std::vector<sg4::Link*>{link1, backbone}, true);
+ /* route host B -> ALL, split-duplex link3, direction UP */
+ zone->add_route(hostB->get_netpoint(), nullptr, nullptr, nullptr,
+ std::vector<sg4::Link*>{link3_up, backbone}, false);
+ /* route host ALL -> B, split-duplex link3, direction DOWN */
+ zone->add_route(nullptr, hostB->get_netpoint(), nullptr, nullptr,
+ std::vector<sg4::Link*>{backbone, link3_down}, false);
+
.. todo:: Complete this page of the manual.
SimGrid comes with an extensive set of platforms in the
