Media Gateway Control Protocol (MGCP) is a protocol developed by Cisco. The goal of MGCP is to handle signals and session management. It is a communication mechanism between media gateway controllers and media gateways. Thus, the control is centralized. In other words, the controller communicates with many media gateways. The controller also supervises terminals and registers the new ones in its zone. H.248 is also like H.323, an ITU-based protocol. It is an enhanced version of MGCP. As you can see in the diagram, MGCP is a master-slave protocol:
