Analog Telephone Adapters (or ATAs) are one of the recent developments in IP Telephone technology. These adapters allow you to use your existing analog telephones to place calls over the Internet using IP Telephone. Because of these adapters, using IP Telephone is not much different today than using a regular telephone service. They allow your IP Telephony service to “act like” a traditional phone – you hear a dial tone when you pick up the phone and dial the number.
An ATA, like many of the devices in today’s digital world, is actually a small, highly dedicated computer. It performs several functions that are required for IP Telephony communications. One function is that of providing an analog interface for the telephone. This includes providing a dial tone to your analog telephone, as well as a ring signal for incoming calls. Another function it provides is that of converting the analog voice signal into a digital form that can be carried over the internet. Similarly, it must also convert the incoming digital signal into an analog one that your telephone can understand. The final function is that of handling the IP Telephony connection to the Internet. This includes the connection to your IP Telephony service provider as well as the routing of digital voice packets – the “protocol” portion of IP Telephony.