Since Picture Quality is monitored at the video (program) layer, even if you receive all your bits you may still be facing Picture Quality issues. First, if the video signal entering your network has noise, your signal may already be compromised and at risk of deteriorating even more if you are compressing the signal in any way: blockiness, blurriness, etc. Second, noise and compression defects occupy bits that would normally be allocated to the video signal; thus you are receiving video that is compromised by errors.