Speedstream 4100 different?

Your computer is not communicating with the router and modem it needs to reset to factory specs then reboot the computer,modem then router in that order.If this does not work contact your dsl provider for info as to your ip address ,gateway and reset with the provider.

usually the DSL would turn on if DSL connection is established. if you already replaced the modem. then your old modem might already be bad.

The problem is probably not your modem. The dsl or cable service is possibly out. DId you call your service rep for help? I would start there.

The modem advanced settings had VCI=35. It should be VCI=32 for QWest. See http://www.dslmodemsdirect.com/DSL%20Configuration/VPI_VCI%20configuration%20Page.htm for other providers.

you need to check the settings since most providers has different IP addresses or different settings. you might need to reset the device in order for it to detect the settings of the new provider. I suggest you get info from the provider and read your device manual.

Siemens SpeedStream Modem (4100) (SS4100) is better

Well, you are very correct with the activity light blinking and the increased blinking except the fact that modem will encounter a problem in future...
The 5 different lights on your modem namely Power, Ethernet, DSL, Internet and Activity have their own indications and explanations.
1. The Activity Light indicates the amount of activity that is takin place on the computer on the Internet though the activity might blink even when you are not browsing. This can be explained by stating that the computer constantly keep sending signals  about it being connected to the internet and any other acknowledgements..

So, you've got nothing worry about unless the Power or the Ethernet or the DSL or the Internet light Blinks....
Cause they are the resultants of a fried modem(check for the adapter), faulty LAN connections, interrupted Dsl line and the account verification failure indications respectively.....

you can't.
when the item name as modem/router. it means the main function is modem with added router function.
you can't connect 2 router/modem together. both need access to the internet and IPS for it function correctly.
however, you can connect 1 modem and one router.

can be a deffective modem.. they Bell.ca had replaced mine only 5 times..

Unfortunately it sounds like the modem may need to be replaced. I had the same issue. Even after doing a complete shutdown, resetting all the cables, restarting the modem and then the computer, it still did not work. After you get the modem replaced, I would suggest you get a spare, possibably from e-bay, so if this happens again, you will not be without DSL Service.