Downloading
You can download Zoiper using the link http://www.zoiper.com/freec.php

Installation
Run the installation program and follow the steps.

Configuration Steps
Start Zoiper by going to Start Programs – Attractel – Zoiper – Zoiper Free or from the icon on the desktop.

Right Click – Select Options

Click Add new IAX account

Any name can be given here

Server Hostname/IP: sip.acrodelon.com
Username: 301
Password: password301
CallerId name/ number not required, field should be empty.

Click Show advanced option in the bottom right portion of the window.

Then click IAX options under Protocol Options.

Change it to 95 from 4569. Needed only for UAE or countries where 4569 is blocked.

If the server connection is ok, you should be getting the (Registered) under the account option with the Unregister button enabled.
You are now ready to make calls, just ensure your speakers/mic or headset is connected and working properly before making calls.
Please prefix country code with 00 for making calls. For eg. Calls to Ernakulam in India would begin with 0091, like 00914842123456