Idea: DAHDI backend for mISDN
There are various multi-port BRI and PRI cards supported by DAHDI, which would be interesting to also get exposed to mISDN for application support.
I've briefly looked at the interface between mISDN core and the individual hardware drivers, and I think it would not be too hard to provide some kind of shim/adaptation so the mISDN core can use a DAHDI device.
In theory, this should even mean one could use CAPI applications on top of those DAHDI cards.
The original liene of thought was around the hardware driver interface, i.e. at the physical layer.
Thinking more about it, it is probably much simpler to have some adapter between mISDNuser (the Q.931 implementation that normally talks to Q.921 on the mISDN kernel side) and the dahdi timeslot/channel character devices. This would be pure userspace code, and enable mISDNuser [and its capi20 plugin] to run on top of unmodified DAHDI drivers. See Linux_Grand_Unified_ISDN_Theory for some diagrams