Can i get bit rate with connect with RTSP?? (in flutter)

I just think if I can connect rtsp url than get streaming data incoming from rtp ,So I can check bit rate(streaming) of rtsp url.(Is it right?)

I have url info it looks like this

rtsp://ip.ip.ip.ip:port/video1?key = token (rtsp is always open if the camera is turned on)

And I want to know this url is available and how fast it can streaming the video with out seeing video.

(I am not good at english so the question might be hard to understand... I'm sorry..)