yes you need an other vdsl modem, the one from your isp will do well (should give you when the installation day comes close by)... the 2830 has only a built in an adsl modem at wan 1, which is not good for fibre
models like the 2830 which are having extra incoming port (wan 2) needs to be powered by a separate modem
You need cable from the master socket to the incoming wan of the Vdsl supplied modem> from the Lan port of the vdsl supplied modem another cable to the second incoming wan (wan 2) of the 2830n (2 power electric units one to give power for the vdsl modem & and another to give power to the 2830 - i know they are coming with the modems free) ... then you need to set and the correct parameters/settings from your isp to the 2830
If you want all in one (no other cables running of power supply and from the vdsl modem to the 2830) you can look at the
2750n a bit old but for some still works fine ... no second wan 2 port
2760n (but not other/second incoming wan like the 2830)
2850n with another incoming wan
2860n with an other incoming wan
them mentioned are vdsl modems & will work direct with just a cable from the master socket to the modem, so you can have the supplied vdsl modem from your isp on the side or as backup
meaning all in one: build in wifi, vdsl, and all the lovely settings of the great range with the drayteks can offer like the 2830 has
