The best replacement for rtsp is http.

The best alternatives to rtsp are rated as following:
★★★★★  http
★★★★  rtmp
★★★★  rtp
★★  mms
★  hls
★  mjpeg
★  http streaming
★  rtcp
★  udp
  rtsps

Your alternative for rtsp is not listed? Suggest!
Speaking about rtsp, one probably shouldn't forget about rtp.

Other search terms related to rtsp and their ratings are:
★★★★★ rtp
You have in mind a companion for rtsp and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of rtsp in all years. Click on graph for more.
rtsp
http
rtmp