A device that adapts a subscriber's analog telephones to a digital voice service from a VoIP, cable or DSL provider. Connecting to the modem, router or directly to the cable coming into the premises, the analog telephone adapter (ATA) delivers dial-tone, manages the call setup and provides the conversion between digital and analog voice.
With this adapter, an analog telephone is connected to either a router (LAN) or the Internet (WAN) for VoIP service. For telco company (PSTN) backup, it includes an FXO port. See SIP
. (Image courtesy of Grandstream Networks, Inc., www.grandstream.com)
In this Comcast cable example, the coax line is split between the ATA and cable modem. The ATA is wired to an analog telephone for voice, and the cable modem connects to the router for data. See VoIP modem