strange things happened: I connected Jitsi version 3885 via my Fritzbox 7320 Firmware 100.04.89. and called an internal line. (after complaints of people I called )
Everything I say into Jitsi's mike comes out sounding like a boar or pig - the other way is mute. (the VU meter shows 2 or 3 bars and keeps frozen)
Disabling G722 solves the problem. Interestingly it keept working even though I switched of the two G711 flavours (PCMU/PCMA) as well.
Calling from the other line to Jitsi works fine though (probably it wouldn't select G722 anyway - I don't know why)
The piggy sound gets sent to the person called outside - so there is big fun there.
Any ideas, what's wrong? How are audio codecs selected?
PS. Nothing of use in the logs.