If you are in charge of implementing a VoIP phone system for your firm then you need this book which covers the subject in depth. Written by an expert author who knows his subject you will find such topics as:

# Understand how VoIP works, common misconceptions about it, and the pros and cons for your organization
# Compare and comprehend hardware and software choices
# Discover the options for touch tones and faxing via VoIP systems
# Analyze network devices, IP addresses, connections to remote sites, and other aspects that will affect VoIP implementation
# Draw up a test plan, check out both voice and fax transmission, get a report, and schedule the installation
Read more:

VoIP Deployment For Dummies (For Dummies (Computer/Tech))