The following deployment scenarios for RPC over HTTP are supported on Exchange Server 2003 Service Pack 1:

• Front-end/back-end scenario
  In this scenario, you have the following roles:
  
  • One or more front-end servers running Exchange Server 2003 SP1
    
  • One or more back-end servers running either Exchange Server 2003 SP1 or Exchange Server 2003 without service packs
    
  • One or more global catalog servers
    
  These three roles can all be deployed on separate servers, or you can have a server that is both an Exchange back-end server and a global catalog server. Your Exchange back-end servers can be clustered.
  

  Note:
  If your back-end server is also a domain controller, it is recommended that you make this domain controller a global catalog server. If an RPC over HTTP back-end server is a domain controller but is not a global catalog server, you can experience problems with connectivity to this server.

  For detailed steps about how to deploy RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time on Exchange Server 2003 SP1 (Front-End/Back-End Scenario).
  
• No front-end server
  In this scenario, you have the following roles:
  
  • One or more back-end servers running Exchange Server 2003 SP1
    
  • One or more global catalog servers
    
  These two roles can be on separate servers, or you can have a single server that is both an Exchange back-end server and a global catalog server.
  

  Note:
  If your back-end server is also a domain controller, it is recommended that you make this domain controller a global catalog server. If an RPC over HTTP back-end server is a domain controller but is not a global catalog server, you can experience problems with connectivity to this server.

  If your back-end servers are clustered, you cannot designate them as RPC proxy servers. You must designate a separate server as the RPC proxy server.
  For detailed steps about how to deploy RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time on Exchange Server 2003 SP1, No Front-End Server.
  

In this scenario you are running a Windows Small Business Server 2003 that includes Exchange Server 2003. For detailed steps on deploying RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time in Small Business Server 2003 (Standard or Premium).

The following deployment scenarios for RPC over HTTP are supported on Exchange Server 2003 without server packs:

• Front-end/back-end scenario
  In this scenario, you have the following roles:
  
  • One or more front-end servers running Exchange Server 2003 without service packs
    
  • One or more back-end servers running Exchange Server 2003 without service packs
    
  • One or more global catalog servers
    
  These three roles are all deployed on separate servers. Your Exchange back-end servers can be clustered.
  For detailed steps for how to deploy RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time on Exchange Server 2003, Front-End/Back-End Scenario.
  
• Front-end/back-end scenario where at least one global catalog server is also a back-end Exchange server
  In this scenario, you have the following roles:
  
  • One or more front-end servers running Exchange Server 2003 without service packs
    
  • At least one server that is both an Exchange back-end server and a global catalog server. You can have additional back-end servers and global catalog servers on separate servers.
    
  Your Exchange back-end servers can be clustered.
  

  Note:
  If your back-end server is also a domain controller, it is recommended that you make this domain controller a global catalog server. If an RPC over HTTP back-end server is a domain controller but is not a global catalog server, you can experience problems with connectivity to this server.

  For detailed steps for how to deploy RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time on Exchange Server 2003, Front-End/Back-End Scenario, Back End on Global Catalog Server.
  
• No front-end server
  In this scenario, you have the following roles:
  
  • One or more back-end servers running Exchange Server 2003 without service packs
    
  • One or more global catalog servers
    
  These two roles are on separate servers.
  If your back-end servers are clustered, you cannot designate them as RPC proxy servers. You must designate a separate server as the RPC proxy server.
  For detailed steps about how to deploy RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time on Exchange Server 2003, No Front-End Server.
  
• No front-end server where at least one global catalog server is also a back-end Exchange server
  In this scenario, you have the following roles:
  
  • One or more back-end servers running Exchange Server 2003 without service packs.
    
  • At least one of these servers is also a global catalog server. You can have additional back-end servers and global catalog servers on separate servers.
    
  If your back-end servers are clustered, you cannot designate them as RPC proxy servers. You must designate a separate server as the RPC proxy server.
  

  Note:
  If your back-end server is also a domain controller, it is recommended that you make this domain controller a global catalog server. If an RPC over HTTP back-end server is a domain controller but is not a global catalog server, you can experience problems with connectivity to this server.

  For detailed steps for how to deploy RPC over HTTP in this scenario, see How to Deploy RPC over HTTP for the First Time on Exchange Server 2003, No Front-End Server, Back-End on Global Catalog Server.
  

In this scenario, you have already deployed RPC over HTTP in your Exchange Server 2003 organization and you are now upgrading to Exchange Server 2003 SP1. To use RPC over HTTP in the upgraded organization, you must configure your servers.

For detailed steps for how to upgrade your RPC over HTTP deployment in this scenario, see How to Upgrade an Exchange Server 2003 RPC over HTTP Deployment to Exchange Server 2003 SP1.

For more information, see the following topics:

• System Requirements for RPC over HTTP on Exchange Server 2003
  
• Recommendations for Deploying RPC over HTTP Communications
  
• Positioning Your RPC Proxy Server and Firewalls in a Corporate Environment
  
• Adding a Back-End Server to an RPC over HTTP Deployment
  
• Troubleshooting RPC over HTTP Communications