1. Download Linphone here and install it.
2. After successful installation launch Linphone and choose menu "Settings" - "Parameters".
3. Under the "Manage SIP account" tab click "Add"
4. Enter the following information and click "OK"
SIP identifier: email@example.com (replace 111111 with your sip number from personal account)
SIP-proxy address: sip.zadarma.com
5. Enter your SIP number password from personal account and click "OK"
6. Click "Done"
7. If settings were entered correctly, "Registration is successful" will appear at the bottom of the screen.
When connecting to IP PBX from Zadarma you need to use the internal IP PBX information that appears under "My PBX - Extension numbers".
SIP identifier: firstname.lastname@example.org ( replace 1234-100 with your internal PBX number from personal account)
SIP-proxy address: pbx.zadarma.com
Password: Your internal PBX number password from personal account