I have a Un-common issue here, One of my customers (FreePBX 126.96.36.199). have an issue when they call out they can hear another Extention talking (only the Extension - no audio from remote Party.)
I have tested this. as below
I called from my 1001 extension to my mobile(0822222222). and i answered the call. I could then hear extension 212 talking but not the person they are talking to.