The Analogue Line Supervision package defined in Annex E/H.248.1 supports basic telephony services, using on-hook and off-hook events, and a ringing signal. Some telephony services
delivered over analogue line terminations have additional supervisory sig
ITU-T H.248.26-2005 history
2013ITU-T H.248.26-2013 Gateway control protocol: Enhanced analogue lines packages (Study Group 16)
2005ITU-T H.248.26-2005 Gateway control protocol: Enhanced analogue lines packages Study Group 16