ISDN(Integrated Services Digital Network)
RNIS-BE : Interfaces

Base Access = 2B + 1D
Primary Accès = 23B + 1D (US), 30B + 1D
B = 64kbps MIC voices or datas
D = 16 ou 64kbps outside band signal

ISDN has a transfear rate of either :
64 Kbps or 8KB/s
128 Kbps or 16KB/s

IDSL(ISDN Digital Subscriber Line)
ISDL has a transfear rate of 128Kbps or 16KB/s