I'm cancelling my landline at the end of the month and going naked ADSL. In doing so, I decided I'd tidy up my wiring (yes, it's in totally the wrong order, I now realise). My house has a total of 5 jacks, including the outlet I'm currently using for ADSL. I've always gotten what I feel is quite poor performance (I only see 6Mb/s on ADSL2) and have always meant to improve it. So I spent a decent chunk of the public holiday yesterday tracing phone cables under my house and in the ceiling, and now have a pretty solid understanding of what lines run where. It turns out that the outlet I'm using for ADSL is an afterthought, as it already runs on its own cable pair from the demarc.
I could just disconnect everything except for the ADSL outlet, but figuring you never really know what might happen in the future, I figured it best to put in a master line filter, to give the best of both worlds (improve ADSL, while preserving the voice copper cabling for whatever possible reason in future).
From the tracing and testing I did, it appears all my phone jacks are wired in parallel. Apart from the master jack, which only has one other jack running off it, everything else runs back to the demarc. Each jack (other than the master) only has two wires inside, and if I disconnect it, everything else still runs. So I'm assuming everything is wired in parallel, other than the one pair that feeds the master, then onto its sole child jack.
But the jacks that are connected in parallel can travel some distance to reach their destination. One of them is in my garage, about 30m away from the demarc and through an underground run. So my question is, am I still likely to see an improvement in performance? I have been recording the performance stats of my ADSL connection to help compare, and the numbers there don't look particularly bad, but the sync speeds are just terrible, so I figure there must be a reason why.