ISDN Interface Cards¶

ISDN Interface Cards were extension cards, typically for ISA or PCI bus, installed into a computer for interfacing with the ISDN network.

• active cards, where an on-board microprocessor implemented the ISDN protocol stack (Q.921 / Q.931)
• passive cards, where the ISDN protocol stack ran on the main processor of the computer

Initially, active cards such as those of ICN or AVM were the only available cards, while later on the muhc lower cost passive cards became the predominant way for users to attach computers to ISDN

• AVM A1 PCMCIA
• AVM ADSL ISDN Controller
• AVM B1 PCMCIA
• AVM Fritz!Card A1
• AVM Fritz!Card PCI
• Digium Bxxx
• ELSA MicroLink MC all pro
• Hermstedt Leonardo
• Teles S0163
• Winbond W6692 PCI