HI!
If you wanna get an idea of how stuff actually works in VoIP, we cover the topics in depth every two weeks in our Expert Q&A sessions (next one is on Porting here:[0])
Here's a link[1] to 4 of the past ones so you can get an idea. We'll be publishing the videos on youtube soon. If you attend these, you'll quickly start to get a good handle on the world of communication; it's just a TON of acronyms.
Here's a link to one of my favorite blogs on VoIP [2].
Hope that helps!!!
[0] http://www.eventbrite.com/myevent?eid=7476736119
[1] http://blog.2600hz.com/post/52151527067/2600hz-expert-q-a-re...