You can download the soft phone from here.

1. Download and install xlite.
2. After installation run xlite by shortcut on your desktop.

3. right-click on software and click on “SIP account settings”

4. Click on “ADD”

5. Type your name as Display Name
6. Type user Extension number under username
7. Type your password under password
8. Type your Extension number under “Authorization user name”
11. Type “voip.ultratone.asia” under “Domain”
10. Check “Register with domain and receive incoming calls”
11. Select Domain.

12. Click OK and then click close