Media gateways are any type of device that allows for the conversion of data from one format to another. This type of application is extremely helpful when moving data from one platform or network to a site that makes use of different criteria for the form and structure of the data. The media gateway is a common device in use in both home and office systems that are set to send and receive data through the Internet, as well as in most private networks that are employed by businesses with multiple locations.
Sometimes referred to as a softswitch, the purpose of the media gateway is to preserve the integrity of the data that is moved from a point of origin to a point of termination. At the same time, the gateway will allow for the conversion of the data from the original format to a format that can be recognized on the receiving end. This means that even if the end user is employing a different set of programs than the sender, it can still be possible to access the data and make use of the information.
One common application of a media gateway is found in the teleconferencing industry. As an alternative to making use of international freefone numbers, a media gateway can be set up at a local switch. When someone in the area of the switch wishes to participate in a conference call based in another country, the individual dials a number assigned to the gateway. The media gateway converts the digital phone transmission into a data stream, and routes the stream across the Internet to another media gateway that is co-located at the receiving end. The second media gateway reads the data stream and then converts the information into a format that can be read and received by the teleconference bridging equipment. This process makes it possible for international attendees to dial into a conference call without creating any added expense for the originator of the conference.
Three common examples of a media gateway include a circuit switch, and IP gateway, and a channel bank. These different types of gateways may provide a single portal for the conversion of data, or be located at different points in the transmission process. For example, the media gateway process could involve terminating channels from a circuit switch based network on a different type of network, or convert streaming media into packets that are handled by a packet-switched network, such as in the case of sending RPT streams through an IP network.