diff --git a/doc/SWITCH.md b/doc/SWITCH.md
index 4ec173457..44c317e0b 100644
--- a/doc/SWITCH.md
+++ b/doc/SWITCH.md
@@ -11,7 +11,32 @@ The core feature being that when we receive an incoming packet, trying to reach
 
 Another thing is the forget feature: if a line in the mac table hasn't been used since a long time, we forget it!
 
-## Why having 2 sides, EAST and WEST?
+## Basic example: connect 3 VMs to a NIC.
 
-Basically, if we heve a brick modifying packets such as VTEP, we should isolate it on a side. In fact, to manage packets faster, we do not copy them so be careful to do not modify them! The would be modified for all bricks on this side.<br>
-Please refer to the [warning section of the brick concept's overview](BRICK_CONCEPT.md) for more informations.<br>
\ No newline at end of file
+```
+
+ The outer     +---Host Machine---------------------------------------------------------------------+
+  World        |                                                                                    |
+               |   +--The GRAPH--------------------------------------+                              |
+               |   |                                                 |                              |
+               |   |                                             +-------+              +---------+ |
+               |   |      |                 |<------------------>| VHOST |<------------>|  VM     | |
+               |   |      |                 |                    +-------+              +---------+ |
+               |   |      |                 |                        |                              |
+           +---------+    |   +---------+   |                    +-------+              +---------+ |
+ <-------->|   NIC   |<-->|---|Switch   |---|<------------------>| VHOST |<------------>|  VM     | |
+           +---------+    |   +---------+   |                    +-------+              +---------+ |
+               |   |      |                 |                        |                              |
+               |   |      |                 |                    +-------+              +---------+ |
+               |   |      |                 |<------------------>| VHOST |<------------>|  VM     | |
+               |   |  WEST SIDE         EAST SIDE                +-------+              +---------+ |
+               |   |                                                 |                              |
+               |   +--------------------------------------------------                              |
+               |                                                                                    |
+               +------------------------------------------------------------------------------------+
+```
+
+Note: it's always a good practice to link at one side all "subnet" devices and to another the upper device (No matter if it's EAST or WEST!).<br>
+Here is the reason:<br>
+Basically, if we heve a brick modifying packets such as VTEP or VXLAN, we should isolate it on a side. In fact, to manage packets faster, we do not copy them so be careful to do not modify them! They would be modified for all bricks on this side.<br>
+Please refer to the [warning section of the brick concept's overview](BRICK_CONCEPT.md) for more informations.