Provides a big-picture view of a VoIP system, identifying and explaining key VoIP components, jargon and buzzwords, plus the main standards and protocols. Reviews the many flavors of VoIP, comparing the various implementation and architecture choices. Progressing through Internet telephony, Managed IP Telephony, PBX replacement with distributed call manager systems and IP Centrex / Hosted PBX, you'll gain the knowledge to confidently differentiate VoIP architectures and discuss pros and cons of options.