This Recommendation defines certain parameters and mechanisms for supporting the interconnection of a packet network with another network. It is only applicable to the IP-based H.248 termination and provides such information as the IP Realm Identifier used to indicate to which packet network the media represented by the termination belongs.

Amendment 1 introduces mechanisms that allow the media gateway controller to discover the IP realms that are available at the media gateway at a certain time. It also introduces a length limitation in the IP realm property.