H.248 represents a resource control protocol concerning the control of media gateway-level resources. There are two major categories concerning resource control strategies: push mode and pull mode. Push mode is an inherent architectural characteristic of the H.248 master-slave model, where the master entity MGC is pushing the slave entity MG into a particular mode. Pull mode is also supported by the H.248 protocol architecture, but requires additional protocol elements to control a particular pull mode scenario. Recommendation ITU-T H.248.55 defines a generic set of such capabilities.