How to configure Openfire for VoIP

Currently I have an Openfire 3.7.1 (I am yet to upgrade to 3.8.1) server hosted in a virtual machine running Ubuntu 12.10. I have my network adapter for the VM set to a bridged adapter so the IP address of the VM is available for others to interact with in my network. This works great and I’m really happy with the server’s functionality so far. I have instant messaging capabilities within my network working great. I can send messages between Spark and my own self-coded IM without any issues. But I need to move on to the next step in my project; VoIP functionality.

Can anyone provide me with some pointers as to how I should configure Openfire to allow for this feature? I’m quite lost on this, and I feel that I need a starting point to get myself running in the right direction. What other applications are recommended? Which Openfire plugins will I require? I’m very lost on this matter so any help would be greatly appreciated!

Joe