Question

What would I do if Ican't be able to register my account in my windows phone?

Answer 1

If experiencing “registration failure” it is very likely to be related to a network discovery issue, please try the following settings:

Go to Settings -> Accounts -> choose your account and select "Edit" -> swipe to Network Settings and enable or disable STUN.

Default STUN values:
Server hostname/IP: stun.zoiper.com
Port: 3478 UDP/TCP
Refresh period: 30