Re: [connectivity] Fairport DSL margin db still drops after step
They make a filter that goes in the network interface box outside your house these tend to work better then the plug in jack style ones for some reason and you can give it a straight unfiltered run to your modem and this really helps....see this problem everyday.
If margin at the NID is the same as when the modem is connected normally you have pretty much eliminated inside wiring as the cause of the problem.
Not sure I understand Item 3. It sounds like you are using inline DSL filters at each phone. Running a dedicated line from the NID to the DSL modem is nice but as bruins55 posted using a whole house POTS/DSL splitter does a better job isolating voice telephones from the high frequencies used by DSL.
I prefer using a standalone splitter rather then messing with the phone company NID.
This is the same unit that was made by Siecor/Corning for many years.
The only way to determine if intermittent problem is within your residence or the phone line is to connect the DSL modem to the NID for an extended period and see of problem persists.
Does DSL share same line as telephone? If so how is voice quality? Any noise especially when phone is first picked up? What about crosstalk, other voices? If voice quality is not up to snuff call repair.