High Quality Content by WIKIPEDIA articles! Megaco (officially H.248) is a gateway control protocol. and an implementation of the Media Gateway Control Protocol architecture for controlling media gateways in Internet Protocol (IP) networks and the public switched telephone network (PSTN). It is for the control of elements of a physically decomposed multimedia gateway, which enables separation of call control from media conversion. Though H.248 performs the same functions as MGCP, it uses different commands and processes and supports a broader range of networks. H.248 can operate with H.323 or SIP.