SmartNode

A VoIP gateway, a.k.a. analog telephone adapter (ATA), is a networking device that converts a traditional (legacy) phone signal (analog or digital) into a (digitized) packet-based, Internet Protocol (IP) communication stream. The gateway serves as the conversion point between Time Division Multiplexed (TDM) telephone network and an IP-based network such as the Internet or private corporate LAN or WAN.

VoIP Gateways can support numerous use cases (application scenarios) to enable IP telephony implementations. A media gateway may provide several types of bi-directional conversion, including Session Initiation Protocol (SIP)-to-Time Division Multiplexing (TDM) and TDM-to-SIP. Some high-end models may even provide such session border controller (SBC) functions as transcoding, security firewall, failover, and others.