What is ATA (Analog Telephone Adapter)?

This article is a brief introduction about ATA, that is a support device for analog phones to connect to a digital system. Read about its ports and how you can use it with the Ozeki Phone System.

ATA (Analog Telephone Adapter) is a device used for connecting a standard analog phone to a digital phone system, like VoIP or a non-standard phone system (Figure 1).

what is ata
Figure 1 - What is ATA?

As it was mentioned, ATA is a device that is a little box, that requires an adapter, one Ethernet port and more FXS ports. Analog telephones need some support to connect to a VoIP system. If you want to connect your traditional phone to the Internet, you need adapters for synchronising different devices. Analog phones use FXS and FXO ports.

FXS port

FXS port is a plug on the wall where you can plug your cables to. This port is responsible for transporting an analog line to the subscriber. It sends dialtone, battery current and also ring voltage. It is used to connect an analog phone to a VoIP phone system. You need FXS port because FXO port connects to the adapter.


FXO is a port that receives the transported analog line. It is a plug on a phone/fax machine, and a plug on an analog phone system.

ATA is able to communicate with a VoIP server directly, there is no need for special software for them to run. ATA is a connection between the Internet and a telephone jack.

To be able to connect an analog phone to a VoIP phone system or provider you need an adapter, called ATA. The device can be seen on Figure 1.

The Ozeki Phone System is able to implement ATAs. If you have an analog telephone, get an ATA, connect it to Ozeki Phone System you gain access to every functionalities VoIP and digital systems provide.

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What is ATA? (Video tutorial)

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