A package manager of a media gateway component is described, which is configured to receive requests to encode or decode a message containing package descriptors. The package manager determines the type of package descriptor, and invokes the appropriate helper function which carries out the encoding or decoding operation. The package manager includes a package resolver portion that interfaces with other elements of the media gateway component, and a package helper portion that stores the helper functions. The package resolver portion includes a package list that describes the correlation between package descriptors and the corresponding helper functions.