Every router brand has their own control panel and hence a different setup method but if you know some generic settings, you can setup any ADSL router. We strongly advise you refer to your ADSL modems manual.

Step1

Access your modems control panel by typing the default IP address into your browsers address bar, this can be found in your router manual. 

With our Billion routers, the IP address is 192.168.1.254

Here is an article on finding your routers IP through your command prompt.

Step 2

Login using the default username and password which can be found in your manual.

With our Billion routers the details are as follows:

Username: admin

Password: admin

Step 3 

These are the details that need to be set, the location of these settings will vary depending on your router.

Encapsulatio: "PPPoE LLC" or "PPP over ethernet"

Under ATM
VPI: 8
VCI: 35

MTU: 1492

Bridge: Disabled (optional)

Username: "Your ADSL account username given to you in your welcome email"
Password: "Your ADSL account password given to you in your welcome email"

The rest of the options you can leave as default

Note: Dont forget to save the settings to memory. Many Routers require you to "Save settings and reboot"