The bandwidth of a PTZ camera will depend on its signal type, resolution, frame rate...:

On HDMI

720p (1280 × 720) 

@ 30fps: 720 Mbit/s    

@ 60fps: 1.45 Gbit/s

1080p (1920 × 1080):

@ 30fps: 1.58 Gbit/s

@ 60fps: 3.20 Gbit/s

On IP output

 It is much lighter because it is compressed: 

720p (1280 × 720) : 1,3 Mbit/s    

1080p (1920 × 1080): from 1 to 40 Mbit/s, all depending on encoder setttings