Hi Dont know if you got a reply to your post but it would easier if you got Blueface to open a iax connection on your account.
using the Iax connection means you would only need to open UDP port 4569. and not all the above ports
On your out going settings add the below in the box
fromuser=type your blueface account name here
host=sip.blueface.ie
nat=yes
port=5060
qualify=no
secret= type account password here
type=peer
username=type your blueface account name here
On the incoming setting you will need to add the below in the box
context=ext-did
host=sip.blueface.ie
type=user
Register String:
username:[email protected]
make you sure you have forward the ports to your FreePbx
let me know if you need any more help
cheers
Govo