+----------------+
                 |        [0..3] -+--> forward to STUN
                 |                |
                 |      [16..19] -+--> forward to ZRTP
                 |                |
     packet -->  |      [20..63] -+--> forward to DTLS
                 |                |
                 |      [64..79] -+--> forward to TURN Channel
                 |                |
                 |    [128..191] -+--> forward to RTP/RTCP
                 +----------------+

Figure 3: The DTLS-SRTP receiver's packet demultiplexing algorithm.