Hi Arnd, I'm a long time ISDN user and I cannot fully agree to the assessment of current ISDN usage. It is of course true that ISDN is no longer a main protocol for telephone connections and therefore the number of users has dropped. But still there are people with public ISDN telephone links, e.g. in Germany. Not everything has been converted into voice over ip.
More importantly however, there are still many *private* ISDN networks. The simple reason is that beyond the public networks, there are still a lot of people who have ISDN telephone installations in their buildings. Those installations date from the time when many public telephone connections used ISDN. Those private ISDN telephone installations have a *very* long lifetime (> 20 years), as many people, especially individuals shy at the cost and effort to get a new internal telephone installation. A reliable indicator for that is that one of the most widespread wifi router products in Germany and beyond, AVM Fritz!Box still supports ISDN even in its most recent version (7590). Speaking for myself, I still use the capi based b1pci driver for active AVM cards in several installations. Please do not base your assessment of ISDN usage on the size and number of public ISDN networks and please do not remove capi and isdn4linux support from the kernel. Thank you for commitment to the kernel development! Kind regards, Christoph Kling
