Q: FaceTime Receiver not seeing my Video & Audio

When I setup an FT conversation I'm able to see and hear the person on the other side.

The issue is that this person does not see or hear me. We did setup a video/audio conversation at that time.

We both have iOS 8.1.3.

Could it have something to do with working on a Cellular line from the other person's side, other country?

Where can I start looking?

Thanks in advance.