UNE-ETS 300368 Ed1:2022 Integrated Services Digital Network (ISDN);Explicit Call Transfer (ECT) supplementary service;Functional capabilities and information flows (Endorsed by Asociación Española de Normalización in July of 2022.)
2022UNE-ETS 300368 Ed1:2022 Integrated Services Digital Network (ISDN);Explicit Call Transfer (ECT) supplementary service;Functional capabilities and information flows (Endorsed by Asociación Española de Normalización in July of 2022.)