What is a firewall? Well, it is the one piece of software that helps to filter out unwanted people, data or programs from your computer system through what is known as "layer" or "protocol" which only allows those people and data that you want to let through to be able to affect your computer/web browsing/browsing activities. A good firewall helps you prevent downtime, data loss and unauthorized access from the outside. If you've ever had problems with unauthorized access on your PC's system, then chances are your firewall is either disabled not working or is not working correctly.
Set up Zoiper: To enable the application to work, first click on the "Search Field" icon on the menu of the Zoiper browser, which is usually located at the bottom left-hand corner of your screen. On the search field select "Search", and on the search result screen click on "OK". You'll be given the option to either enable or disable the application. By default, Zoiper is enabled, and if enabled, there should be a white Search Bar by your clock on top of your desktop with your most recent incoming call details in the center of the search field.
Configure your settings: In your main settings menu click on "zoiper". On the new window click on "Settings", and on the left side you'll see a list of options. The most important options here are those relating to outgoing calls, voice mailboxes, contact management and other miscellaneous options. Click on any of these options to add the new entry. That's all there is to the quick setting changes made in the mac os x Zoiper configuration manager utility.