Analog Telephony Adapter

An Analog Telephony Adapter, or ATA, is a device used to connect one or more standard analog telephones to a Voice over IP based network. It usually takes the form of a small box with a power adapter, one Ethernet port, and one or more FXS telephone ports. Users can then plug one or more standard analog Telephones into the device and they will operate, usually transparently of the VoIP network.

ATA's are used by many VoIP companies like Vonage selling a telco-alternative VoIP service, where the device is used to replace a user's connection to an existing telephone company. When sold in connection with a VoIP service like Vonage, the ATA is usually locked so it cannot be used with another company, and the user cannot change very much of its configuration.

ATA's generally use the SIP protocol, and are manufactured by many companies including Cisco, Grandstream, and Motorola.