@turris-admin
The only PBX software in the TurrisOS repository seems to be yate, which is quite outdated. The repository contains the luci packages for Asterisk but no Asterisk packages. 
Please add the OpenWRT telephony feed to the TurrisOS buildroot.
We have telephony feed but unfortunately some of the software included there doesn’t build in our current setup and as it is not our main focus, we currently have no resources to try to fix it.
Asterisk, Freeswitch and Kamailio fail? Is there any way to build one of the three, possibly without some modules?