The asterisk setup with bristuff-patched zap and the qozap driver failed bigtime: a call to the internal phone failed and diverted to voicemail within 2 seconds. Back to a working mISDN version. But I can't unload the mISDN drivers correctly so it took a few reboots to get things right again.
Outgoing calls without echo are nice, but I also need incoming calls to work. According to the kernel messages I should have working echo cancellation:[ 132.157748] mISDN_dsp: Audio DSP Rev. 1.29 (debug=0x0) EchoCancellor MG2 dtmfthreshold(100) [ 132.157753] mISDN_dsp: DSP clocks every 80 samples. This equals 1 jiffies.Time to start testing stuff on a testserver so I don't have to reboot the home server greenblatt so often.