This is a sip client using the 2 FXS ports available on routers based on the Infineon Danube (lantiq xway) and running openwrt.
This is just a test to try and build it for openwrt 23.05.4, it works but I'm still working on it.
The original repository, working with openwrt 19.07.2 is here.
Based on the midge package oem-voip and sofia-sip.
See the INSTRUCTIONS for instructions.
Precompiled binaries for attitude adjustment, barrier breaker and chaos calmer are available here, binaries for openwrt 19.07.2 (and possibly later versions), are available as github releases.