Megaco facilitates the separation of call control and media conversion in distributed VoIP architectures. It defines the communication between a media gateway, which handles media stream processing, and a media gateway controller (MGC), which manages call signaling and session logic.
The protocol enables the MGC to instruct the gateway on actions such as creating media streams, setting codecs, or playing tones. Megaco supports scalability and modularity in carrier-grade systems and is typically used in large deployments such as telecom backbones or softswitch frameworks. It supersedes the earlier MGCP protocol by offering more advanced features, such as richer signaling descriptions, enhanced failover support, and broader codec handling. Megaco messages are encoded in either text (ASN.1) or binary (BER) format, depending on implementation.
As VoIP evolved toward SIP and more integrated architectures, Megaco’s use declined but it remains relevant in hybrid or transitional systems that require high control over media gateway behavior in multiservice environments.
