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.

They were available in two fashions:
  • 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

Updated by laforge 10 months ago · 1 revisions

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