Noise margin and phone ringing

[Tacitus]

Typically when you see this uncancelled echo entry it's usually a problem with something inside the house. ........

I'm getting it with the modem plugged directly into the main (not test) socket, so unless it's a problem with the faceplate filter, I don't know where it is.  The only other thing could be feedback from the phone side of the faceplate....

[Rik]

I think it's one of those to put in the 'if the router doesn't mind, it doesn't matter' drawer, Tac. See what happens next time you resync. I have seen the error on my own line very occasionally, which is the exception which proves the rule.