What is DAA?
Short for Data Access Arrangement, part of a modem system for interfacing with a telephone network. The DAA provides the analog circuits that electrically isolate the modem from the phone line, separating the modem from the telephone line higher voltage. The FCC requires this feature of any device that connects to the PSTN, including fax machines and set-top boxes, and most manufacturers build modems around an FCC-approved DAA design.