I am having a half duplex problem with my Mac---OS 10.10.2
That is, when the party I FaceTime with is talking, they cannot hear me.
I can hear then other party when we both talk---it happens whether or not
I initiate the call or the other party does. It doesn't happen with my iPhone
on the same home wifi network. And it happens on the Mac when
the iPhone FaceTime is turned off too.