AT&T TL7610 Quick Start Manual page 7

Getting started
Headset base installation
Installation options
Digital subscriber line (DSL)
If you subscribe to high-speed Internet service (digital subscriber
line - DSL) through your telephone lines, you must install a DSL
filter between the telephone base and the telephone wall jack.
The filter prevents noise and caller ID problems caused by DSL
interference. Please contact your DSL service provider for more
information about DSL filters.
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