[jitsi-users] not able to make calls, icons remain grey, no sound at all

Dear All,

I have tried several times to start using jitsi for voice calls, but it
doesn't seem to work. I keep seeing the other person as a grey icon and the
same goes for her/him. No sound at all, I just see "initializing call"
without any outcome. I've tried to deactivate most of the audio codecs and
the video codec, as suggested in one of the jitsi FAQ, but it still doesn't
seem to work. Could anybody help me with that?