Hosted Office Communications Server 2007 supports tiered architectures for specific customers.

The reference architecture supports a tiered approach to implementation of services. The architecture supports service providers entering the market with plans to grow their services offerings on pace with the growth of the business.

The architecture targets three design points:

• Entry Tier - Subscriber base from 1 - 30,000
  
• Middle Tier - Subscriber base from 30,000 - 50,000
  
• Upper Tier - Subscriber base from 50,000 - 250,000
  

The solution design defines the number of servers required for each design point with a set of formulas as part of the solution to provide the tools service providers can use to grow their service from one design point to the next.