Gateway is a device or software that serves as an interface for incompatible devices and networks that work under different protocols.
The Role of Gateways in Video Conferencing
During a video conferencing session, the gateway acts as an interface between the endpoint device and the server that operate under different protocols, and have different architecture (for example, a connection between H.323 terminal and a proprietary platform or SIP videophone).
Thus, during a multipoint video conferencing session, a gateway allows to transparently connect a proprietary MCU, such as video conferencing software server to any other incompatible device with the ability to transmit audio and video data through it. Moreover, such connection with the gateway will be transparent and familiar to an incompatible device too. This happens in a following manner: gateway emulates a familiar environment for each of the communication devices by re-encoding and converting video and audio streams, as well as service data from one format to another on-the-fly.