|I had a conventional DSL system with splitters at all telephone units except the DSL modem. It worked fine until the apartment management installed an entrance door communication system that worked through the phone line and we couldn't let people in or out when the modem was on.|
The telephone company installed a special duplex jack that dedicated to the modem, and obviated the need for splitters at the other jacks. I inadvertently pulled the modem cord out, and now only one of the outlets in that jack will work and I can't get telephone service in any of my other phones. So I can now use only have telephone service or the modem through that one outlet, not both.
I have been googling to find that type of jack, but without any success.