Question about Ethernet cable

Question regarding the cable connecting the router to the network streamer:
Does the length or “quality” of this cable affect sound quality?
to answer your second question, an emphatic yes. I noticed a dramatic improvement when I went from a generic unshielded ethernet cable to a "shielded" ethernet cable, which I run in a 5 meter length from router to streamer. The change was much more detail and dynamics so some kind of noise pollution was being removed.
For longer runs of ethernet cables the use of fibre optics reduces the noise considerably over cable and is cheaper. Highly recommended .

Check out the computer audiophile site for detail info on how and what's needed.