Business TeleCommunications (BTC) - 64 kbit/s digital unrestricted leased line with octet integrity (D64U) - Network interface presentation; English version ETS 300288:1994/A1:1995
Accesss and Terminals (AT) - 64 kbit/s digital unrestricted leased line with octet integrity (D64U) - Network interface presentation (Endorsement of the English version EN 300288 V 1.2.1 (2001-07) as German Standard)— 1 стр.