ITU-T H.812.4 PDF

This Recommendation defines two certified device classes. Both certified device classes contain guidelines that document a secure mechanism by which a WAN application can initiate communications with an application residing within a transient piece of customer premises equipment known as an application hosting device (AHD). The two certified device classes are for the WAN application (APS-CDC-WAN) and for the AHD (APS-CDC-AHD).

The mechanism addresses: (1) the establishment and management of a persistent long term session between the WAN-Application and the AHD application, (2) the use of the MQTT protocol for message exchange and (3) the use of short message service (SMS) to re-establish IP level connectivity with transient AHDs that have a cellular interface.