RTSP/RTP over TCP has very limited value

RTSP/RTP over TCP can address UDP blocking problem, but it has both the overhead disadvantage of RTSP over HTTP and requiring a port that may be often blocked.  RTSP over HTTP almost guarantees firewall traversal.  RTSP/RTP over TCP has no advantage over HTTP tunneled RTSP.

Unfortunately, many network cameras lack the support of RTSP over HTTP that is mandated by ONVIF.  In this case RTSP/RTP over TCP is the only lossless transport protocol. 

It is highly beneficial to use network cameras supporting RTSP over HTTP.