Office Communications Server 2007 extends the architecture of Live Communications Server 2005 to include components that support VoIP and conferencing. This section discusses the following architectural features:

• Pool Configurations
  
• Conferencing Components on the Front End Server
  
• Perimeter Network Configuration for IM and Conferencing
  
• Call Flows Among Conference Components
  
• VoIP Components
  
• VoIP Configuration
  
• Conference Data Storage
  
• SIP Protocols
  

Figure 6 illustrates a generic Office Communications Server topology, including the new VoIP and conferencing components.

Figure 6 . Office Communications Server 2007 reference architecture