4.3 Active Directory replication

Chapter 5 - Managing Exchange Servers
Monitoring and Managing Microsoft Exchange 2000 Server
by Mike Daugherty
Digital Press 2001

Overview

What is an Exchange server? The obvious answer is that it is a server running the Exchange Server 2000 software. However, there are many Exchange Server 2000 components, and it is rare to find them all installed and operational on a single hardware platform. It is much more common to deploy specialized servers, each using one or more of the Exchange 2000 Server components . This allows you to tailor each dedicated server to meet specific requirements. For example, you can configure one dedicated server to handle user mailboxes and a separate server to only handle connectivity to other messaging environments.

There are several reasons for using dedicated servers, including:

• To isolate services that use excessive hardware resources so that these services will not negatively impact other messaging services;

• The number of users and/or services offered exceeds that capacity of a single server;

• To separate services that have conflicting hardware configuration or tuning requirements;

• To limit the number of servers and services exposed to the Internet or other external networks;

• To provide redundancy for various messaging services;

• To isolate certain groups of users, such as accounting or human resources, from other users for legal reasons.

The number of dedicated servers you elect to deploy will depend primarily on the set of services you choose to offer, the number of users you have, and your network topology. Some of the more common types of dedicated Exchange servers are:

• Mailbox servers . A dedicated mailbox server is one that supports only user mailboxes. It supports no connectors, instant messaging, conferencing, or other Exchange services. Deploying dedicated mailbox servers prevents user access of their mailboxes from being impacted by other services that may demand significant server resources. Dedicated mailbox servers are recommended for all but the smallest of organizations. A dedicated mailbox server can provide reliable and predictable service to a larger number of users. Implementing dedicated mailbox servers will also facilitate the ability to designate storage groups to isolate user mailboxes.

• Public folder servers . If you plan to make heavy use of public folders, you should consider a dedicated public folder server. Exchange 2000 supports features such as anonymous public folder access that can be designed to allow access to public folders via the Internet. If you plan to allow Internet access to your public folders, you should definitely implement a dedicated public folder server to help protect your network by restricting Internet access to the public folder server.

• Outlook Web access (OWA) servers . If you need to offer Outlook Web Access to a large number of users, a dedicated OWA server can be used to isolate the OWA network traffic. If you plan to support OWA access through the Internet, a dedicated OWA server can increase network security by making only the dedicated server visible to the Internet.

• Connector servers . Microsoft offers connectors to other messaging environments, including SMTP, X.400, Active Directory, Microsoft Mail, cc:Mail, Lotus Notes, and Novell GroupWise. Additional connectors are available from other manufacturers. If you expect to send and/or receive a large quantity of mail from other environments, you should implement a dedicated connector server to isolate the processor demand required to handle the high amount of traffic. Each of these connectors can be installed independent of each other or in combination with each other on one or more dedicated servers.

• Internet mail servers . For security reasons, your SMTP connection to the Internet should always be on a dedicated server. Your dedicated Internet servers can be configured to offer SMTP, IMAP4, POP3, and NNTP services using the protocol virtual servers.

• Conferencing services servers . The Exchange data and video conferencing services are probably the most demanding Exchange services. If you plan to use these services, you should consider using a dedicated server to keep from negatively affecting the responsiveness of other Exchange services and to improve the performance of the conferencing services. Video conferencing is the more demanding and will require careful hardware and network analysis before implementation. IP multicast video conferencing will tax a servers CPU and memory. Video conferencing requires that all participating users have IP multicast capabilities. Data conferencing does not place as much demand on the server. Depending upon the expected user load, the T.120 data conferencing services can be installed on dedicated servers or in combination with other services.

• Chat Servers . If you plan to offer chat services to a large number of users and expect them to use the service heavily, you should implement a dedicated chat server. A dedicated chat server will be more reliable and more secure by limiting the number of servers exposed to the Internet.

• Instant Messaging Servers . Instant Messaging requires two types of servers: home servers and IM routers. Instant Messaging home servers provide the bulk of the IM functionality, and each home server can support multiple simultaneous connections. If you plan to make heavy use of Instant Messaging, you should deploy one of more dedicated IM home servers. Instant Messaging routers route network traffic to the appropriate home servers. If you plan to support Instant Messaging through the Internet, you should use dedicated IM routers to help protect your internal network.

Of course, you can install all of the Exchange components on a single hardware platform. This is very easy to do, and it may be appropriate for organizations with a very small number of users and minimal messaging needs. However, the server performance will decrease as user demand increases .

This chapter provides an overview of the more common Exchange server configurations, and guidelines for managing the server components that you deploy on these servers.