I just finished my CVOICE test. A requirement for work, the nice thing is that this will grant me the CCNA-Voice certification. Big thanks to Cisco Press CVOICE by Kevin Wallace.
The toughest hurdle in this book for was getting pass chapter 2 which goes in great lengths describing how a fax transmission flows through a VoIP network. I found myself re-reading certain paragraphs and full pages several times. Just to grasp the concept.
After reading this book I have defiantly walked away a better understating of dial-peers and how h.323 works. I want to emphasize that reading this book alone will not help you pass your CVOICE exam, this was merely an addendum of various materials I have gathered, to include a Cisco 1751 router purchased from eBay for 15 bucks.