Assuming still time, security is dandy. Else give whatever.
This chapter explains the various considerations for security in a VoIP deployment. It is a tough set of problems to deal with, there is no doubt, but don't let that scare you away. There are three stages in dealing with the problemsprevention, detection, and reactionand these are discussed in detail. Specific problem areas related to VoIP security are covered in depth, followed by the best recommendations known today.