The filters are necessary to seperate the voice signals and broadband signals. They seperate the signals and so we can use the phone and internet at atime.I didn't have any problems with this so far.
Filters are necessary for ADSL connection and cable connection.
In ADSL connection the filter seperates the voice signals and the broadband signals, whereas in cable connection it seperates the tv channel frequeny and the broadband frequency.
Yeah the filters are strongly important we look up to them.You connect your phone line through a filter so you can free up your line when your on the internet.On dialup the line was blocked when you was online.