I learned that ISDN Basic Rate Interface has
- 1 D-Channel à 16kbit/s for connection and config
- 2 B-Channels à 64kbit/s for Data
- 1 YY à 48kbit/s for Framing Info
Summarized that are 192kbit/s. But in Wikipedia I read about 144kbit/s without YY. What is YY? I can't possibly imagine that this is overhead for framing/transportation of ISDN...
It seems that the transmission protocol actually needs 48kbit/s.