said by Mr Anon :
Quick question would that also work for someone on fiber?
Nope. It is there but applies to the CMTS side of things. Pretty much any automated feature online won't work (eg. no bandwidth meter)
Any fiber based connection is going to be using Comcast's Metro Ethernet network.
Goes to an entirely different router and does not terminate to a CMTS. If your friend is having the same issue, doubt they are related.
Some more information (eg. MTR, traceroutes, etc) would be really useful here.