You can read about splitters in
http://en.wikipedia.org/wiki/ADSL_splitter and
http://en.wikipedia.org/wiki/ADSL
The easiest way is to connect the splitter at the spot where the telephone line enters the house/apartment. Here in the Netherlands, most providers offer a Do It Yourself kit to install ADSL. e.g.
http://www.xs4all.nl/helpdesk/adsl/s...atel1000sp.php (sorry text is in Dutch).
A splitter has three connections:
- the telephone line as is input (carries telephone+ADSL signal)
- output line to ADSL modem/router (telephone signal filtered out)
- output line to telephone (ADSL filtered out )
Can you post links to the models your ISP offers (English please, our Farsi is terrible
)
If you can put a ADSL modem/router into bridging mode it usually is no problem to connect it to a Free/Net/OpenBSD firewall.