You have 2 options (I did go through the same). You can log into your speedstream modem using 192.168.0.1 address. Under the advance options you have 3 choices PPPoE on modem, PPPoE on computer and the last one as PPPoE bridge or similar. The default is the first choice. I would suggest you to change it to second option on which the PPPoE is on the PC save it and modify your Suse box DSL setup. Specify the gateway as your modem IP address in your NIC detail setup. For DNS I would leave it auto,activation at bootup, include your username and password and save it. I remember there is an option for keep alive in modem setup choose it as auto will make your connection always on. ( I am using a router now so the instructions are almost 2 year old on the above setup
) anyway try it.