1. You can download Telephone from the AppStore.
2. At the time of the first launch, "Add new account" window will appear. On subsequent launches, if other accounts are already setup in the program, you can add a new account by going to the main menu: Telephone> Preferences… > Accounts.
Create a new account and enter the following data:
Full Name: Your SIP number (for example 111111) from your personal account
Domain: sip.zadarma.com
User Name: Your SIP number (for example 111111) from your personal account
Password: SIP number password from your personal account
Full Name: PBX extension number (for example 1234-100) from your personal account
Domain: pbx.zadarma.com
User Name: PBX extension number (for example 1234-100) from your personal account
Password: PBX extension number password that can be generated in the "My PBX - Extension numbers" section of your personal account
3. You can make calls If the status appears as “Available”.