Olaf_R wrote:now it works!
I guess I'm giving up. After I thought I had it working I had to realize that, since all my (Outlook-) phone numbers are stored canonical, i.e. "+49 (123) 4567", I need to either a) manually change them before dialing or b) change the dialplan as ADA itself doesn't come with any means of dealing with this.
Since a) is not an option I tried changing the dialplan but it seems that I'd need a newer version of Asterisk than my 1.2.13 as users.conf is not being utilized at all with my version - it obviously doesn't matter if the file is there or not. The manual doesn't offer any insight at all with this respect. Any changes I incorporate into extensions_custom.conf will - except for a "include => from-internal" (for Trixboxes, the default-context won't work) - simply be ignored.
Hence, I can't solve the international prefix problem (for those who could: see http://www.freepbx.org/book/export/html/2030
- look for "How to strip or replace the + character at the beginning of a called number" there).
Neither do I seem to find a way of telling ADA/Asterisk which outbound CID needs to be used - all calls routed through ADA will use my primary ISDN-MSN instead of the one that is being used by the affected extension. Again, this seems to be connected to fact that I do not have any influence on the dialplan, maybe ADA's usage of Originate/Local could be the cause here.
If anyone has a little pointer into the right direction - after having spent two days with something that was running just fine with Snap, I will otherwise need to look for something else or stick with AstTapi ...