Defining User Needs | Microsoft Exchange Server 2003 Administrators Companion (Pro-Administrators Companion)

Your first step in designing any system should be to determine what that system needs to accomplish. In an Exchange system, this means asking yourself several questions:

Will the system provide basic messaging services, that is, a way for users to send e-mail to one another?
Will the system provide access to Internet resources? Can users send and receive Internet e-mail or participate in Internet newsgroups?
Do you plan to offer public folders as a means of group discussion?
Do you plan to offer wireless access or synchronization for your users?
Are there any custom applications you want to use Exchange Server for? For instance, do you have a database of contact information that you want to make available as a public folder?

Your goals at this stage include gathering business requirements and understanding the corporate culture and technical environment—including the network topology and desktop systems—in which you will use Exchange Server 2003. When designing an Exchange organization, you must also find out what services and functionality your users require. After you’ve answered the questions presented in the following sections, you can effectively group users according to their needs. You can then use those groups to plan Exchange Server resources to accommodate user needs, as described in Chapter 6.

Messaging

Exchange Server 2003 is typically implemented as a messaging system. The odds are that your Exchange users will want to be able to send e-mail to one another. Ask the following questions to help describe the specific needs of your users:

To whom will most users be sending messages? Messaging on most networks follows a fairly typical pattern. Users tend to send messages primarily to other users in their workgroup. Users also need to send messages to other workgroups or to outside recipients, such as people on the Internet. Developing a picture of these traffic patterns can help you plan user and server placement.
How much e-mail do users expect to generate and receive? Some users rarely use e-mail; others send and receive dozens of messages per day. Knowing the average volume of messages for your users allows you to plan the capacity of your servers, the limits on your information stores, and the bandwidth requirements of your network.
Will users exchange scheduling and contact information? Microsoft Outlook 2003 provides the ability to share scheduling and contact information dynamically between users. This generates extra messaging traffic and needs to be accounted for when designing your system.
What kind of messages and attachments will you allow users to send? If your users will transfer large files to one another using e- mail, you must make allowances for this volume. Some organizations put limits on the amount of information that can be transmitted in a single message. Others put limits on the amount of space a single mailbox can consume. You can also apply different limits to different users. Executives, for example, might be given more flexibility than other employees.
Will user messages be stored primarily on an Exchange server or in local personal folders? If server-based storage is to be the primary repository of user messages, how much space do you intend to allot for your mailbox stores? Your organization might have business policies that require e-mail to be stored for long periods of time. For example, some government units must store e-mail forever. Such information can help you plan hardware capacity for both servers and clients.
What kind of security will users need? Do your users need to encrypt or digitally sign messages and attachments? If so, you will need to implement some sort of certificate server on your network, such as Microsoft Certificate Services. Exchange security is covered in Part VII, “Security.”

Public Folders

Public folders are the foundation for collaboration within Exchange Server 2003. As you might recall, they enable public access to, and collaboration on, centralized messaging information. Public folders require considerable planning. In addition to planning storage capacity for the Exchange servers that will hold public folder replicas, you must plan public folder replication and user access to public folder servers. The following questions will assist you in assessing public folder usage in the new Exchange organization:

Which users will need access to which public folders? Some workgroups will collaborate on certain documents and messages more than others. This information helps you decide where replicas of certain folders need to be placed and how often replication needs to occur.
Which users should be allowed to create public folders? By default, top-level public folders in a public folder tree are created on the home server of the user who creates them. Subfolders are created on the same server as the top-level folder in which they are created. By restricting which users can create top-level folders, you can govern the placement of public folders on servers. Such restrictions also help you keep the structure of public folder trees manageable.
How much information do users expect to post within those public folders? Both the type of information—documents, forms, executable files, or simple messages—and the size of a typical file help you determine the storage capacity required for public folder stores.
How long will the average message need to remain in a public folder? This information helps you determine the storage space that your public folder stores will consume and the load that users will place on your servers when accessing the public folders.
How often will users access the public folders? This information helps you further determine the load that your public folder servers will have to meet and to schedule public folder replication.
Will you use public folders to allow access to Internet newsgroups? It’s not uncommon to see thousands of messages come through an Internet newsgroup every day, and there are tens of thousands of groups available. You can create public folders that synchronize with Internet newsgroups, but you need to make sure your server can handle the message load.

Connections to Other Systems

Will any of your users need to access the Internet or a preexisting messaging system? Having this information can help you plan the placement of users and foreign messaging connectors. If one group of users tends to use a connector heavily, you might want to place those users on the server on which the connector is installed, to reduce the number of hops that messages have to take from your users to the foreign system. Any Exchange server can host a foreign messaging connector, and that messaging connector can be made available to all users in the organization. You might want to configure more than one connector to a foreign system to help balance the messaging load to that system.

You must decide between connector types when multiple connectors can support the same system. You will need to consider the types of foreign systems and the types of connectors they support, as well as the performance that those connectors will be expected to provide. For example, an X.400 Connector is highly reliable, but its reliability is due to a higher overhead that can affect performance. The X.400 Connector can also send and receive e-mail at scheduled times, thus reducing the impact e-mail has on other network applications.

Connectors also vary in the additional services they provide. A connector that enables the use of shared storage might be preferable to one that enables only e- mail between users. If you use a connector only to migrate from one version of Exchange Server to another, it will be a temporary addition to the Exchange organization. In such cases, choose the connector that makes the transition easiest for the users. In many cases, you can migrate the users transparently, with little interruption to their daily business, just by selecting the right connector. You’ll learn more about connectors in Chapter 13, “Connecting Routing Groups,” and Chapter 21, “Connecting to Other Messaging Systems with X.400.”

Remote Access

Often, you will want to allow users to access private and public folders from a remote location. In planning an Exchange organization, you need to take the requirements of these remote users into account. This information can help you plan the placement of users, as well as plan a Routing and Remote Access Service (RRAS), virtual private network (VPN) access, or Internet-based access for your network. Various manufacturers offer solutions that can enable remote access to Exchange. This information is also valuable in security planning. Ask these questions to assess the remote access needs of the organization:

Which users need to be able to access the Exchange organization remotely?
Will users dial in to an RRAS server or access your network over the Internet? Dialing directly into an RRAS server usually provides better control and security. Accessing the network over the Internet is often much cheaper and more convenient, and new features such as RPC over HTTP do increase the level of security on Internet-based access.
Where will you locate your RRAS server?
On average, how many users will need simultaneous access to the network? This information helps you determine the number of RRAS servers you will need and the number of modems and phone lines.

Custom Applications

Do your users have special needs that can be met only by custom-tailored applications? If so, can the users themselves design these applications, or will you need to hire special personnel? The time to think about custom applications is during the planning stage. The use of custom applications could change many of the answers to the questions in this section.

Training and Support Services

Your users will likely need special training in using the new system. Don’t make the mistake of assuming that e-mail is simple to use. Outlook 2003 and other messaging clients are sophisticated programs. Users might need to be taught how to use public folders or how to sign and encrypt messages. Do you plan to have users install the mail clients themselves? If so, they will need training, and you might need to set up a convenient way for them to do so.

Remember that users are often called upon to learn new things, including new versions of operating systems and software. Take the time to make sure that your users understand the system you are putting in place and know who their contact is for questions or problems. Public folders are a great place to store training materials so that they are available to all users. You could also use a public folder to list the contact information for support personnel. A public folder can use the same forms and views that are found in a user’s mailbox folders. In this case, a public folder that stores contact information and uses the Exchange Contact form is ideal for a list of support personnel contacts.