With reference to, Wowza RTSP/RTP streaming with variable bitrate (Adaptive Streaming) as described in this link "http://www.wowza.com/forums/content.php?36#ABR".

How Wowza detects server to client bandwidth?
Do we need to use RTCP for that or there is something in Wowza that detects bandwidth?

I have gone through RTMP bandwidth detection described in this link but my question is related to RTSP/RTP streaming.