1. Download X-Lite here.
2. Go to "Softphone - Account settings".
3. Create a new account and enter the following information:
Account name: Zadarma
User ID: Your sip number (for example 111111) from your personal account
Domain: sip.zadarma.com
Password: Your sip number password from your personal account
Display name: Your sip number (for example 111111) from your personal account
Authorization name: Your sip number (for example 111111) from your personal account
Account name: Zadarma
User ID: Your PBX extension number (for example 1234-100) from your personal account
Domain: pbx.zadarma.com
Password: Your PBX extension number password from your personal account
Display name: Your PBX extension number (for example 1234-100) from your personal account
Authorization name: Your PBX extension number (for example 1234-100) from your personal account
4. Softphone status should now appear as "Available", and you can make calls.