Upper Tier Architecture
The Upper Tier architecture is designed around a multi deployment groups to support an environment with a large number of users across many organizations: up to 400 organizations at an average of 50 users per organization for a total of approximately 20,000 users with an average 60 percent concurrency rate.
Similar to the other architectural models, the Upper Tier architecture includes servers dedicated to CRM processes as well as servers running supporting infrastructure.
The following figure shows the architecture for an Upper Tier deployment, including supporting infrastructure.
For environments with even higher numbers of concurrent users, hosted Microsoft Dynamics CRM can scale beyond what is displayed in the upper tier diagram by adding more deployment groups and/or more front-end servers in similar proportion to the increase in organizations and users.
Figure 4: Microsoft Dynamics CRM 2011 Architecture for Upper Tier Deployment