Chapter Summary

The configuration of Exchange 2000 resources relies primarily on the Active Directory and MMC snap-ins. Snap-ins for Exchange 2000 Server are added to the standard console when you install the Exchange 2000 Management utilities. Exchange 2000 also changes the Active Directory schema definition to include new classes and attributes, extend existing classes, and modify existing attribute definitions to support the configuration of the messaging system.

Exchange 2000 Server modifies a variety of directory attributes to include them in Global Catalog replication, such as the user class's givenName attribute. This is necessary to provide similar address book information to Outlook users, as in Exchange Server 5.5. For address list lookups, Outlook users connect to the computer running Exchange 2000 Server, where a specific process known as DSProxy intercepts the request and forwards it without modification to the Global Catalog server. DSProxy returns the results from the Global Catalog to the Outlook client as well. Smart MAPI-based clients, such as Outlook 2000, can store referral information received from DSProxy in their messaging profile to subsequently contact the Global Catalog directly without the help of DSProxy.

MAPI-based clients communicate with Exchange 2000 Server using synchronous RPCs that can be carried over a variety of network protocols. In a Windows 2000/Active Directory/Exchange 2000 environment, communication via TCP/IP and Windows Sockets is preferred. Server-to-server communication, on the other hand, relies primarily on SMTP. Unlike previous versions of Exchange Server, Exchange 2000 Server does not utilize RPCs for server-to-server communication. Asynchronous SMTP offers more flexibility and independence from the underlying network than RPCs. Exchange 2000 Server extends the SMTP and NNTP services that ship with IIS 5.0 through event sinks to implement the required functionality for a top-class enterprise messaging and collaboration solution.