The KX-TAW848 will work just fine if you have DSL service from your phone
company, even if the idiots at the phone company lie to you and say you can't use a
phone system with DSL.
As far as the phone company is concerned, your 848 is one big single-line phone.
The DSL filter goes ahead of one of the CO line inputs on the KX-TAW848.
DON'T put a filter at each phone.
DSL installation
TAWsystems.info