+ - HOST 1(Physical port → virtual switch → VNF → virtual switch → Physical port) → HOST 2(Physical port → virtual switch → VNF → virtual switch → Physical port)
+
+<pre><code>
+
+ +--------------------------------------------+ +------------------------------------------+
+ | +---------------------------------+ | | +--------------------------------+ |
+ | | Application | | | | Application | |
+ | +----------------------------+----+ | | +-------------------------+------+ |
+ | ^ | | | ^ | |
+ | | v | | | v |
+ | +-------+----------+ +------------------+ | | +---------+--------+ +----------------+ |
+ | | Logical port 0 | | Logical port 1 | | | | Logical port 0 | |Logical port 1 | |
+ +-+------------------+--+------------------+-+ +-+------------------+--+------+---------+-+
+ ^ | ^ |
+ | | | |
+ | v | v
+ +-+-------+----------+--+------------------+-+ +-+---------+--------+--+----------------+-+
+ | | Logical port 0 | | Logical port 1 | | | | Logical port 0 | | Logical port 1 | |
+ | +------------------+ +----------+-------+ | | +------------------+ +------+---------+ |
+ | ^ | | | ^ | |
+ | | | | | | | |
+ | | vswitch v | | | vswitch v |
+ | +--------+---------+ +------------------+ | | +---------+--------+ +----------------+ |
+ | | phy port | | phy port | | | | phy port | | phy port | |
+ +-+--------+---------+--+----------+-------+-+ +-+---------+--------+--+------+---------+-+
+ ^ +---------------------------------------+ |
+ | v
+ +----------+----------------------------------------------------------------------------------+-----------+
+ | |
+ | traffic generator |
+ | |
+ +---------------------------------------------------------------------------------------------------------+
+</code></pre>
+