I have a DSL modem connected upstairs in my house and I have a telephone connected downstairs(this is the only telephone that I have connected). My dsl modem phone line is plugged in to a dsl 2 wire filter. Is it necessary that I have it plugged into this filter or is it alright if I take the filter downstairs and plug the telephone phone into the 2 wire dsl filter? Or should I buy a 2nd dsl 2 wire filter?