The ADSL cable from my telco is connected to the Draytek yes. The draytek acts as DHCP server to all devices on "My LAN" (i.e. anything that sits on the internal lan side of the draytek).
The Obi202 has 2 ethernet jacks - one labelled INTERNET and one labelled LAN.
At present, I have the the one labelled INTERNET with a Cat5 connection into "My LAN", which is as described in Step 2 (B) of the obi setup. In that picture, although it is labelled INTERNET, it clearly shows that port connected to the internal network side of an Internet Router/Modem (in my case the draytek)
On the Obi "how to" for making the Obi act as a SIP server to a Cisco SIP IP handset though, it shows the Cisco going into the LAN port on the Obi, which at present in my setup has no cable in it at all. It also states this setup will only work if the Cisco is connected to the LAN port.
In my case, it's a Gigaset not a Cisco, and I don't want it moved off my internal lan and sitting behind the Obi if I can possibly avoid it.
Note that aside from trying to figure how to make the Obi work as a SIP server to a local IP phone on my subnet, the Obi seems to be working e.g. Google Voice is working fine, and if I pair my mobile phone to the Bluetooth dongle, the physical phone lines on the Obi ring when I get a call on my mobile.