Book Description
VoIP Architectures and Implementation Choices Is a comprehensive overview of the many flavors of VoIP, comparing and contrasting the various implementation and architecture choices. Progressing from talking between computers over the Internet, through Internet telephony, VoIP from carriers, PBX replacement with call manager / softswitch systems, Hosted PBX and Cloud Services, to IP Centrex, we’ll deliver to you the knowledge to confidently differentiate VoIP architectures and discuss pros and cons of different options. VoIP Module 2 Detailed Outline 2. VoIP Architectures and Implementation Choices 2.1 Internet Telephony: Computer-Computer VoIP over the Internet ...... 2.1.1 Voice in Packets Over The Internet ...... 2.1.2 Call Setup ...... 2.1.3 Voice Quality ...... 2.1.4 Proprietary Web Phone Apps 2.2 Proprietary Internet Telephony Example: Skype ...... 2.2.1 Proprietary Internet Telephony ...... 2.2.2 Communicating to the Skype App Behind a NAT ...... 2.2.3 Proprietary Closed Ecosystems 2.3 VSPs: Internet to Phone ...... 2.3.1 Voice over IP Service Providers ...... 2.3.2 Connection to the Telephone Network ...... 2.3.3 VSP Gateway Required 2.4 VSP: Phone to Phone over the Internet e.g. Vonage ...... 2.4.1 POTS Telephones for VoIP ...... 2.4.2 Adapter ...... 2.4.3 Differences from POTS 2.5 VoIP Is The New POTS ...... 2.5.1 VoIP From The LEC ...... 2.5.2 Not Internet Communications 2.6 VoIP at Carriers ...... 2.6.1 Migrating to an All-IP Network ...... 2.6.2 Ending Switched-Access Tariffs 2.7 VoIP-Enabled PBX and Migration Options ...... 2.7.1 Choices for Business VoIP Systems ...... 2.7.2 Critical Operations Infrastructure ...... 2.7.3 Upgrading a PBX ...... 2.7.4 Migration Plan ...... 2.7.5 TDM over IP: Legacy Equipment Support ...... 2.7.6 Handset Gateways and BORSCHT ...... 2.7.7 Guinea Pigs 2.8 PBX Replacement: Premise Softswitch ...... 2.8.1 Call Manager ...... 2.8.2 Essential Function ...... 2.8.3 Special-Purpose Premise Hardware ...... 2.8.4 Standards-Based? ...... 2.8.5 Many Names ...... 2.8.6 Capabilities ...... 2.8.7 System Architectures ...... 2.8.8 Redundancy and Critical Functioning 2.9 Cloud Services and Hosted PBX: Softswitch as a Service (SaaS) ...... 2.9.1 Cloud Services ...... 2.9.2 Customer Management ...... 2.9.3 Additional Features ...... 2.9.4 Numerous Advantages ...... 2.9.5 Disadvantages 2.10 IP Centrex ...... 2.10.1 Outsourcing Everything To The Phone Company ...... 2.10.2 Advantages over Legacy Centrex ...... 2.10.3 Many Service Providers and Features ...... 2.10.4 Cost Structure 2.11 Asterisk and Open-Source Softswitch Software ...... 2.11.1 Open-Source Software ...... 2.11.2 Asterisk and sipX ...... 2.11.3 Advantages ...... 2.11.4 Disadvantages 2.12 IP Phone Features and Uses ...... 2.12.1 VoIP Phone Components ...... 2.12.2 Functions ...... 2.12.3 Numerous Methods for Dialing ...... 2.12.4 Special Features and Customization