In all my years of fixing network issues I've never had to check such things. We let the telco swap modems and repair/replace lines.
How did you come to this inspection?
My internet connection profile is vdsl2 -8b. I was wondering what the SNR Downstream and Upstream levels should be? Currently they are 19 db and 13 db. Also started to get very high 30 Minute Far End FEC Interleave numbers and 30 Minute Near End FEC Interleave numbers. It is very difficult to find information on what to expect and ISP is of no help. Reason I am asking is when playing online games we experience bad lag and when I do a trace route test to an IP not even 5 miles away it will take 15 hops and each hop ranges from 20ms - 280ms. My first hop is always very high, usually 60-80ms.