I must admit, I found that it was certainly not as easy as coping the same format from their legacy accounts over to the UC.
The settings I have found that are needed are;
I don’t believe nat=yes is required as you may well have that set in your SIP settings, also I’m not sure it matters but I have qualify=yes
My settings are the same
I found that there is no need for the Username at the end, however as Stewart1 recommends, you do need the port number after the domain.
Format that works;
With luck that should get you registered. If it does and you can make calls but can’t receive them you may need to update the /etc/hosts with Blueface’s IP addresses.
Lastly I did find one other small issue, whereby on the Blueface Web GUI, under ‘Device connections’ there is an option for DNIS presentation, this needs to be On.
Best of luck.