Original post is here: eklausmeier.goip.de
For internet connection I use a cable modem EPC3208 from Cisco, which was supplied by the cable provider, Unitymedia (now Vodafone) in my case.
It shows the following measurements regarding signal-to-noise ratio, modem is at 192.168.100.1:
More information on this modem can be found here: Cisco EPC3208. According to Cisco modem (dead link) the user and password credentials are admin/atlanta.