scope:

This I-ETS specifies the technical characteristics (electrical, functional, visual and acoustic) for videotelephony terminals to be used at the basic access of the coincident S and T interface of the ISDN. The characteristics of this I-ETS are meant to specify characteristics that are outside the scope of attachment standards or specifications, and outside the scope of standards specifying the end-to-end characteristics for videotelephony terminals. However, this I-ETS is not intended to be used for type approval purposes or other mandatory requirements.