ATA is the acronym for Analog Telephony Adapter (Analog Telephone Adapter). It acts as a hardware interface between aPSTN analog phone system and a VoIP service or digital network. ATAs are commonly used to connect or merge a PSTN phone system and VoIP services to a phone network in a business or other organization. An ATA will normally be contained in a small switchbox that has an Ethernet port, power adapter, and one or many telephone ports with an FXO link. This lets users plug one or many analog telephones into the ATA, permitting them to work without other modification on a VoIP network.

How Does an ATA Link with a VoIP Service Provider Work?

ATA adapters link with VoIP Service Providers using VoIP network protocols such as H.323 or SIP. The ATA directly communicates with the VoIP service and eliminates the need for additional software or a computer between the ATA and the network. ATAs are flexible enough for a computer to be connected to the device if required.

What Are Common Features of an ATA?

An ATA has the ability to support one or many VoIP protocols, although only the support of one standard is required. H.323 and SIP standards are commonly supported on newer ATAs. An ATA port should consist of at least one RJ-11 and one RJ-45 (or LAN) port in order to have the minimum number of connections for the ATA to carry out its function. It is becoming more common for ATAs to have an additional RJ-45 port to permit a concurrent connection to a computer in order to enable telephone to computer phone calls. Some manufacturers also include a USB port to provide the option of connecting to other periphery equipment. A modern ATA will also permit automatic switching between VoIP and PSTN without the end-user having to manually intervene. Advanced service features found on the latest ATAs include Call Waiting, Call Transfer, Call Forwarding, and Caller ID. Additionally, many ATAs support 3-way conferencing for businesses and collaborative academic environments.

ATA Power Failure Support

ATAs use electricity to operate and will not function in the event of a power loss. New ATAs have an automatic switching feature that defaults to the PSTN line in the event of a sustained power loss. This automatic switch is done in order to prevent a possible catastrophic loss of communication in organizations that rely on the device. Manufacturers are also incorporating additional voice quality improvement technologies such as the Digital Signal Processing standard to improve overall quality of service.