Documentation debt: TCP sockets and CA extensions configuration (#1115)

Signed-off-by: zesk1999 <zesk1999@gmail.com>

Author: zesk1999

docs/fastdds/security/auth_plugin/auth_plugin.rst

@@ -179,7 +179,7 @@ However, all other commands are only compatible with Linux OS.
     #default_keyfile = privkey.pem
     distinguished_name= req_distinguished_name
     #attributes = req_attributes
-    #x509_extensions = v3_ca # The extentions to add to the self signed cert
+    x509_extensions = root_ca_extensions # The extensions to add to the self signed cert
     string_mask = utf8only
 
     [ req_distinguished_name ]
@@ -190,6 +190,12 @@ However, all other commands are only compatible with Linux OS.
     commonName = eProsima Main Test CA
     emailAddress = mainca@eprosima.com
 
+    [root_ca_extensions]
+    basicConstraints = critical, CA:true
+
+.. note::
+   For a self-signed **root CA**, the X.509 extension ``basicConstraints = CA:true`` is **required**. Without it, stacks might not recognize the certificate as a CA.
+
 After writing the configuration file, next commands generate the certificate using the
 Elliptic Curve Digital Signature Algorithm (ECDSA).
 

docs/fastdds/use_cases/large_data/large_data.rst

@@ -124,6 +124,27 @@ For receiving sockets, the command is:
 
     $> sudo sysctl -w net.core.rmem_max=12582912
 
+Linux also defines per-socket TCP buffer sizes as triplets:
+
+.. code-block:: text
+
+    $> net.ipv4.tcp_wmem = <min> <default> <max> (TCP send buffer)
+    $> net.ipv4.tcp_rmem = <min> <default> <max> (TCP receive buffer)
+
+The middle value is the default used for most connections. If only the global maxima are raised, sockets may still
+use a small default and saturate during bursts.
+Set the current values for sending sockets with:
+
+.. code-block:: bash
+
+    $> sudo sysctl -w net.ipv4.tcp_wmem="4096 12582912 12582912"
+
+For receiving sockets, the command is:
+
+.. code-block:: bash
+
+    $> sudo sysctl -w net.ipv4.tcp_rmem="4096 12582912 12582912"
+
 Windows
 .......