docs/esp32: UDP multicast client/server example.

Signed-off-by: IhorNehrutsa <Ihor.Nehrutsa@gmail.com>

docs/esp32/quickref.rst

@@ -161,6 +161,11 @@ These are working configurations for LAN interfaces of popular boards::
     lan = network.LAN(id=0, mdc=Pin(23), mdio=Pin(18), power=Pin(5),
                       phy_type=network.PHY_IP101, phy_addr=1)
 
+UDP MULTICAST
+^^^^^^^^^^^^^
+
+See client/server example in the :ref:`esp32_udp_multicast` tutorial.
+
 Delay and timing
 ----------------
 

docs/esp32/tutorial/index.rst

@@ -16,8 +16,8 @@ to `<https://www.python.org>`__.
 
 .. toctree::
    :maxdepth: 1
-   :numbered:
 
    intro.rst
    pwm.rst
    peripheral_access.rst
+   udp_multicast.rst

docs/esp32/tutorial/udp_multicast.rst

@@ -0,0 +1,27 @@
+.. _esp32_udp_multicast:
+
+UDP MULTICAST
+=============
+
+Use UDP MULTICAST connections to communicate between two devices in different networks
+with IP-addresses 172.16.55.55 and 192.168.44.44.
+
+Run `udp_multicast_client.py <https://github.com/micropython/micropython/blob/master/examples/network/udp_multicast_client.py>`_ on one device.
+Client send GET and receive ACK from the server.
+Output is::
+
+    GET to   ('224.0.0.111', 5555)   sent     "client_ip:172.16.55.55  mac:b8-d6-1a-5a-c2-e4"
+    ACK from ('192.168.44.44', 5555) received "server_ip:192.168.44.44 mac:24-6f-28-7a-f3-9c"
+    GET to   ('224.0.0.111', 5555)   sent     "client_ip:172.16.55.55  mac:b8-d6-1a-5a-c2-e4"
+    ACK from ('192.168.44.44', 5555) received "server_ip:192.168.44.44 mac:24-6f-28-7a-f3-9c"
+    ...
+
+Run `udp_multicast_server.py <https://github.com/micropython/micropython/blob/master/examples/network/udp_multicast_server.py>`_ on another device.
+Server receive GET and send ACK to the client.
+Output is::
+
+    GET from ('172.16.55.55', 5555) received "client_ip:172.16.55.55  mac:b8-d6-1a-5a-c2-e4"
+    ACK to   ('224.0.0.111', 5555)  sent     "server_ip:192.168.44.44 mac:24-6f-28-7a-f3-9c"
+    GET from ('172.16.55.55', 5555) received "client_ip:172.16.55.55  mac:b8-d6-1a-5a-c2-e4"
+    ACK to   ('224.0.0.111', 5555)  sent     "server_ip:192.168.44.44 mac:24-6f-28-7a-f3-9c"
+    ...