analog telephone adapter (ATA)
An Analog Telephone Adapter(ATA) is a network component that converts analog voice signals into IP data packets and, on the other hand, IP data packets into voice signals and provides the audio signals for the connection status. One or more analog telephones or softphones can be connected to the IP network via such a VoIP adapter.
In the classic telephone structure, VoIP adapters can be an integral part of DSL routers, VoIP gateways or session border controllers(SBCs), but they can also be connected as a stand-alone component between the DSL router and analog telephone or integrated in the VoIP telephone. The decisive factor is the function, and this should support quality of services( QoS) to ensure uninterrupted voice communication, because quality of service is the only way to prioritize data packets for Internet telephony. If multiple data connections are established, a download to a personal computer could disrupt the voice data stream to the VoIP phone. Quality of Service prevents this.
VoIP adapters are usually housed in small boxes and have multiple output ports for analog phones, Ethernet, and the local exchange port via the DSL router. The analog phone is connected to the server using H.323, Session Initiation Protocol( SIP), Inter-Asterisk Exchange( IAX), MediaGateway Protocol( MGCP) or Skinny Client Control Protocol( SCCP). The voice codecs used are G.711, G.729, GSM 06.10 or the Internet Low BitrateCodec( iLBC). The VoIP adapter is configured using a personal computer; no PC is required for voice communication.