Make OVS timeouts configurable

On loaded nodes (gtw) with lots of ovs ports (> 1000)
OVS interaction timeouts should be increased.

Change-Id: I8423e48b96fac5dc0d6edde45bbbe4410a1fff3e
Related-Prod: PROD-28959 (PROD:28959)
Related-Prod: PROD-28559 (PROD:28559)
diff --git a/README.rst b/README.rst
index 657ca3e..3aa133d 100644
--- a/README.rst
+++ b/README.rst
@@ -1487,6 +1487,22 @@
     neutron:
       max_allowed_address_pair: 20
 
+Increase OVS timeouts for loaded nodes
+--------------------------------------
+
+Network node:
+
+.. code-block:: yaml
+
+    neutron:
+      gateway:
+        of_connect_timeout: 60
+        of_request_timeout: 30
+        ovs_vsctl_timeout: 30  # Pike
+        ovsdb_timeout: 30  # Queens and beyond
+        bridge_mac_table_size: 100000
+
+
 Enhanced logging with logging.conf
 ----------------------------------