scope:

This Interim European Telecommunication Standard (I-ETS) is applicable to Integrated Services Digital Network (ISDN) basic access video telephony terminal equipment for connection at the S-reference point or coincident S/T-reference point. It describes the D-channel signalling procedures which may be implemented by terminals connected to the pan-European ISDN for use in cases where either: The originating network hasn't implemented the procedures accord. to ETS 300267-1 [1] or when interworking with a terminal connected to a digital network which doesn't support fully compatible procedures.