I have Vigor 100 modem and I am having problems with the connection. The "DSL Link" light is on and steady but the "DSL Data" light is off.

What does this mean?

what are you mean the dls data light?
as far i know the 120 has POWER, ACT, LAN, DSL, INTERNET
http://www.i-lan.net.au/downloads/Vigor120/Images/Vigor120.jpg

the LAN will be on if anything will connect to the back single lan port (such a pc, laptop, or other router)
the DSL if is on it means that the line has detect adsl activity (the line of your isp is working)
the INTERNET if is on it works everything normal

If the DSL is on and the INTERNET off then usually is something wrong with the settings in your end (user name, pass, vpi, vci, etc)
If the DSL if off then it is something wrong with your isp & not your end (wrong settings)

Just release you need the 100 ... is the same function DSL link as DSL & DSL Data same as Internet on the 120 ... so
If the DSL Link is not on it means it something wrong with your isp
If the DSL Data is not on, it means is something wrong with your settings

babis3g wrote: Just release you need the 100 ... is the same function DSL link as DSL & DSL Data same as Internet on the 120 ... so
If the DSL Link is not on it means it something wrong with your isp
If the DSL Data is not on, it means is something wrong with your settings

Thanks. Sound like a settings problem then.