I just figured out the Asterisk 11.12.0 does not know “h264” codec.
I get the follwoing messages in the log:
[2014-08-26 09:42:27] WARNING frame.c: Cannot allow unknown format ‘allow=h264’
[2014-08-26 09:42:27] WARNING chan_sip.c: Codec configuration errors found in line 718 : allow = allow=h264
I only enabled video support via FreePBX including h264.