Unlike a Media Gateway, which bridges disparate networks, a Media Server is concerned purely with the manipulation and processing of media streams. It operates under the control of an application server or call controller, responding to instructions sent via protocols like SIP, MRCP, or MSCML. Media servers are essential in applications like conferencing, call queuing, voicemail, automated attendants, and interactive voice response (IVR) systems.
For instance, during a conference call, the media server mixes multiple audio streams into a unified stream for each participant. In voicemail systems, it records incoming messages and plays greetings. Scalability and processing power are critical – modern systems often employ software-based media servers that run on standard hardware or in virtual environments, allowing for dynamic resource allocation. Redundancy, failover capabilities, and codec support are also important considerations in media server deployment.
By offloading resource-intensive tasks from call controllers, media servers enable more efficient, feature-rich, and scalable VoIP services.
