It looks as if I am being scanned for an active VoIP device. Yesterday I opened up ports 5004-5060 (TCP & UDP) so I may be getting port scanned. Since I deleted this port forwarding to these ports they seem to have stopped. There was no reason for me to manually open these ports as the Obi is working fine and opening its own ports via my VM Superhub.
Here is a screen shot of some of the calls this morning although it started around midnight last night :evil: