Media Gateway
A Media Gateway is a networking device that provides valuable and essential functions for organizations, service providers, and network operators. When interconnecting traditional time-division-multiplexed (TDM) telephony systems with modern voice-over-internet protocol (VoIP) systems, a VoIP media gateway works by providing protocol conversion (translation) and interoperability between the two network technologies. Also known as an IP media gateway or SIP media gateway, the device converts a traditional analog plain-old-telephone-system (POTS) voice signal or related digital telephony signals such as T1, DS3, STM1 or OC3 into packets for transmission over a data network such as the Internet, private IP Network or a corporate LAN. When the legacy system is based on digital integrated services digital network (ISDN) technology, the device may be called a digital VoIP gateway or ISDN media gateway. Some manufacturers combine gateway functionality with WAN-access (internet-access) capability into a single device or network appliance. Such a dual-purpose device may be known as an access media gateway.