Network not working
 

My computer connects to the router through an ethernet cable. The router is connected to the phone line. No other cables or devices are used.

When I use my Huawei DSL ethernet router with Network Manager, then my DSL works:
1. /etc/network/interfaces
2. /etc/NetworkManager/NetworkManager.conf
3. /etc/init.d/network-manager restart

4. I go to whatismyip.com and my host name looks like this: static-12-345-67-89.ipcom.mydslprovider.net

But when I use my Speedtouch DSL ethernet router, the previously mentioned method does not work. (3 of the 4 lights are green but the ethernet light is blinking.)

I tried using the pppoeconf method but it will not work either. (Again, 3 of the 4 lights are green but the ethernet light is blinking.)
1. /etc/init.d/network-manager stop
2. /etc/network/interfaces
3. run pppoeconf (input user name and password)
Now /etc/network/interfaces looks like this:
4. /etc/init.d/networking restart

How can I make my Speedtouch router work ?

either you have a router or you have a modem. You're not going to be using pppoe if your router is a proper (albeit home based) router. Now saying "3 or the 4 lights are green" means nothing. what lights? You've not said anything about what this speedtouch router is, so how we're meant to know what these lights mean i'm not sure.

a dsl router is a bunch of different things, a switch, a router and a modem. you need to see if, for example, you're getting a dhcp address from the router, not just jump straight to saying you can't reach google. can you get an IP? can you hit the default gateway etc.??