Enterprise-Quality Features

Microsoft Exchange Server 2003 actually comes in two editions. The first is the Standard Edition (or, simply, Microsoft Exchange Server 2003), which is targeted for use by small- to medium- sized businesses. The other edition is Microsoft Server 2003 Enterprise Edition. It is designed to be an enterprise messaging system, meaning one that is more scalable and includes features meant for larger organizations. Table 1.1 details the key specifications of both Microsoft Exchange Server 2003 Standard Edition and Microsoft Exchange Server 2003 Enterprise Edition.

Table 1.1: Exchange Server 2003 Version Comparison

Feature	Standard Edition	Enterprise Edition
Maximum database size	Limited to 16 GB	Limited only by hardware
Number of regular storage groups supported	One	Four
Supports the recovery storage group (above the regular storage groups)	Yes	Yes
Number of databases per storage group	Two	Five
Supports clustering	No	Yes
Supports front-end and back-end server configuration	Yes	Yes
Supports Volume Shadow Copy	Yes	Yes
X.400 connector	Not included	Included

For Exchange to be an enterprise messaging system, a large number of technologies had to be included or leveraged from other products (such as Microsoft Windows Server 2003). This section briefly discusses the technologies that make Exchange a true enterprise messaging system. Those technologies fall into six categories:

• Enterprise-quality application platform

• Scalability

• Interoperability

• Performance

• Administration

• Reliability

Enterprise-Quality Application Platform

Before a determination can be made as to whether or not a product can scale to the size an organization needs, it must be determined that the product can do the things it needs to do. Exchange provides the necessary application platform to meet the requirements of almost any organization. The following are some of the elements of the Exchange application platform:

Supports a large number of messaging services E-mail, electronic forms, groupware, and add-on products for faxing, paging, videoconferencing, voice-mailing, and many other services are supported.

Supports a large number of client platforms There is client software that runs on MS-DOS, Windows 3. x, Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP, Windows Server 2003, Apple Macintosh, Unix, and IBM OS/2, as well as virtually every other operating system available today.

Provides open architecture/extensibility Exchange is based on an open architecture, meaning that the specifications of many of its protocols are available in the public domain. Examples of published protocols include the Messaging Application Programming Interface ( MAPI ), Internet protocols, and various Comite Consultatif International Telegraphique et Telephonique (CCITT) protocols. Developers can use this openness to create additional applications and programs that work with or extend Exchange. That is what is meant by extensible. One example of the way Microsoft encourages this is by including a single- user version of the Microsoft Visual InterDev product with Exchange Server. Developers can use Visual InterDev to create web-based applications that enable web clients to access Exchange resources.

Based on industry standards The Exchange protocols, along with being open and extensible, are based on industry standards (protocols can be open and extensible but not based on industry standards). The MAPI protocol is considered an industry standard. Some of the industry standard Internet and CCITT protocols used in Exchange are as follows :

Internet mail Simple Mail Transfer Protocol ( SMTP ), Post Office Protocol, version 3 (POP3), and Internet Message Access Protocol, version 4 (IMAP4). See Chapter 7.

Internet directory access Lightweight Directory Access Protocol ( LDAP ). See Chapter 7.

Internet news services Network News Transfer Protocol ( NNTP ). See Chapter 7.

Internet management Simple Network Management Protocol ( SNMP ). See Chapter 10, ‚“Administration and Maintenance. ‚½

Internet security Secure MIME (S/MIME) , Secure Sockets Layer, version 3 (SSL), and Simple Authentication and Security Layer (SASL).

Internet web protocols HyperText Transfer Protocol ( HTTP ) and HyperText Markup Language (HTML). See Chapter 7.

CCITT message transfer Comit Consultatif International Telegraphique et Telephonique (International Telegraph and Telephone Consultative Committee): X.400. See the section ‚“Industry Standards ‚½ later in this chapter.

CCITT directory X.500. See the section ‚“Industry Standards ‚½ later in this chapter.

Security features Using the Internet security protocols listed above, along with other protocols, Exchange can provide advanced security features. For example, messages can be sent with a digital signature to confirm the identity of the sender, and message content can be encrypted to prevent unauthorized viewing. Exchange Server 2003 supports many of the most popular encryption algorithms today, including 3DES and SHA. Chapter 15, ‚“Securing Exchange Server 2003, ‚½ discusses the protocols and administration of advanced security in Exchange. Further security features, and ones that are leveraged from Microsoft Windows Server 2003, include:

Mandatory logon A user must have a domain account and password to log on to a Windows Server 2003 or a Windows 2000 Server domain.

Discretionary access control An Exchange administrator can use Windows Server 2003 or Windows 2000 Server security to control access to Exchange resources. For example, one administrator could have permission to manage particular Exchange servers or features but not others.

Auditing Windows Server 2003 or Windows 2000 Server can be configured to monitor and record certain events. This can help diagnose security events. The audit information is written to the Windows Event Log.

Scalability

Once a product has been determined to accomplish the types of things you need to get done, then you must find out if it can do them on the scale you need. Exchange is extremely scalable due to the following features:

Software scalable Exchange can be implemented with a single Exchange server, or dozens of servers, depending on the messaging requirements. Even with multiple Exchange servers, a single enterprise messaging system exists. This is due to the Exchange features that enable communication between servers. This functionality permits Exchange to scale from single-server to multiple-server implementations . Microsoft itself uses Exchange for its worldwide messaging system.

Hardware scalable Scalability is also evidenced by the maximum hardware specifications that Exchange can utilize.

CPUs Scalable from 1 to 64 processors, depending on the operating system in use.

RAM Maximum addressable by Exchange is 4 GB.

Disk storage Storage is limited only by hardware capacity. The Standard Edition of Microsoft Exchange Server 2003 has a 16-GB storage limit on each of the Exchange databases. The Enterprise edition has no limit on the databases.

Interoperability

For a product to fit into an enterprise, it might need to work with an existing messaging system. This is called interoperability or coexistence . An organization might need to move all of its existing messaging data to a new messaging product. This is called a migration. Exchange addresses both of these issues.

To interoperate with various non-Exchange systems, referred to as foreign systems, Microsoft had to write special software programs called connectors . Connectors are similar to translators that understand both Exchange and the foreign system and translate between them. Third-party companies have also written similar programs. Microsoft refers to these programs as gateways. Messaging systems that Exchange can interoperate with include the following:

• Internet mail

• X.400 mail systems

• Lotus Notes

• Novell GroupWise

• Digital Equipment Corporation (DEC) All-IN-1

• Verimation MEMO

Exchange Server 2003 ships with connectors for Internet mail, Lotus Notes, and Novell GroupWise systems. Connectivity to other systems, such as DEC ALL-IN-1 or Verimation MEMO, is provided through third-party gateway products.

Note ‚  

For Exchange to interoperate with some of the previous systems, third-party software is required. Chapter 13, ‚“Connecting with Other Messaging Systems, ‚½ discusses interoperability in more detail.

Exchange Server 2003 can perform a migration from the following messaging systems:

• Microsoft Mail

• Microsoft Exchange

• Lotus cc:Mail

• Lotus Notes

• GroupWise 4. x

• GroupWise 5. x

• Internet Directory LDAP via ADSI

• Internet IMAP4 mail

  Note ‚  

  If you have other messaging systems in place, such as Verimation MEMO, you will need to migrate them to Exchange 2000 Server first and then upgrade them to Exchange Server 2003. Alternatively, you may find a third-party conversion utility that can be used for this task.

Performance

A messaging system requires adequate performance to be used on an enterprise scale. Exchange meets that requirement by being a 32-bit, multithreaded program running on a high-performance operating system, Microsoft Windows Server 2003 or Windows 2000 Server. Many features are built into the Exchange System Manager to help optimize server performance.

Administration

An important element of any enterprise application is the ability to effectively and efficiently administer it. Exchange meets this need by including powerful administration programs, one of which is the Exchange System Manager snap-in for the Microsoft Management Console (MMC). This program provides a single point of administration for an entire Exchange organization. Exchange servers anywhere in the enterprise can be managed from this program, as well as such activities as configuring a server, managing connections to foreign systems, and monitoring services centrally .

Along with its own administrative utilities, Exchange can leverage the administrative capabilities of the Windows Server 2003 or Windows 2000 Server operating system. Exchange integrates with Windows utilities such as Performance Monitor and Event Viewer. Another powerful administration feature in Exchange Server 2003 involves Active Directory. Exchange- related user features (such as mailbox properties) are now managed using the Active Directory Computers and Users utility ‚ the same tool used by Windows administrators to manage users and groups.

Exchange Server 2003 also supports the Simple Network Management Protocol (SNMP). This enables third-party SNMP monitor programs to collect various management information about an Exchange server, such as the performance information gathered by Performance Monitor. The topic of Exchange Server administration is covered in Chapter 10.

Reliability

Because of the importance of a messaging system to an enterprise, it must be reliable. Exchange provides reliability through the following ways:

Transaction log files Data that is to be written to an Exchange database is first written to these log files (which can be done very fast). The data is later written to the appropriate database, which takes longer because of the structured nature of a database. If, for whatever reason, a server has an unintended shutdown, data that has not been written to the database is not lost; it can be automatically reconstructed from the transaction log files. Chapter 2 and Chapter 14, ‚“Backup and Recovery, ‚½ discuss this topic further.

Windows Backup utility When Exchange is installed, it adds extensions to the Windows Backup utility, allowing that program to back up Exchange information.

Replicas Exchange can be configured to have multiple copies, called replicas, of a single public folder on different servers. This prevents a single point of failure in terms of data access and provides quicker access by putting folders on servers closer to the users in an organization.

Intelligent message routing This feature allows multiple routes to a destination, thereby preventing a single point of failure for message delivery.

Windows Server fault tolerance Exchange takes advantage of the many fault-tolerant features of the Windows Server 2003 and Windows 2000 Server operating systems, such as disk mirroring and disk striping with parity. Exchange Server 2003 Enterprise Edition also supports Active/Passive and Active/Active clustering, which provides fault tolerance in the event of a server malfunction. If one server fails, another server can take its place, thereby providing uninterrupted service to users.