This Recommendation defines a package that extends the applicability of the ITU-T H.248.1 gateway control protocol Recommendation. Specifically, this Recommendation defines the transport of ITU-T H.248.1 gateway control protocol messages over ATM. ATM transport is an alternative to UDP or TCP. Transport of ITU-T H.248.1 over UDP or TCP is defined in Annex D of [ITU-T H.248.1].