Android 6.0.1
I can call with Zoiper - but I don`t hear the other site - I don`t hear the caller.
to change the Audio codec doesn`t solve the Problem.
Untill the last update Zoiper works fine.
Best regards Jo
You can try to follow our guide regarding one way or missing audio, here.
If no sound i resolve problem.
Settings... my account... tune network....
To use STUN.... NO.
Turn to NO !!