[acropolite (Phil)]

I work in Telephony and my days are spent installing and troubleshooting PABX systems particularly with VOIP and FTTN & FTTP router installation and programming. There are a lot of misconceptions regarding NBN an VOIP, lots of urban myth and (inaccurate) hand me down statements from trained monkeys in carrier call centres.

Some older splitters are detrimental to higher speed Adsl signals and would be even more problematic with FTTN VDSL. There are specialty filters for VDSL but they have no application for FTTN.

Regardless, I would remove the filter, no great problem to do. I'd also disconnect all other wiring so that the VDSL connection to the FTTN router is as minimal as possible, i.e. no T junctions and or additional spurs past the router.

If you want to connect phones to the VOIP connection on the router then you can reconnect the disconnected house wiring to the VOIP port. (Ken's statement re additional phones having to be wireless is incorrect)

There are specialty VDSL filters available but as stated there is no reason to use one as there is no analog telephony signal or voltages on the line.

If your Modem/router is a self install be patient while waiting for sync, that can take in some cases up to 15 minutes, but most home grade routers will sync in a couple of minutes. Also some carriers have firmware in the routers that allows them to self configure, this can take additional time.

If you're porting your land line to VOIP there may be some downtime depending on the carrier.