Before you begin designing your network, have a clear sense of what you need it to accomplish. One prerequisite to network design is a complete assessment of expected functionality. Set aside some time to think about all the tasks you want to automate or make more efficient through your computer network. What business applications do you need to support? Do you simply need to provide shared access to word processing files, or do you have multiuser databases to support? Do you need electronic mail? Web servers? Point-of-sale operations? Will you require Internet access? Once you have considered all the business tasks and functions you expect to implement on the network, write them down and assign priorities to each item. As you begin deploying your plan, you might need to consider which parts you can do now and which can be addressed later. Take care of critical business functions first.

Sizing the Network

Have a clear idea of your network's expected size, considering its number of users and their intensity of use. Be sure to plan for future growth by building in lots of extra capacity from the beginning. Calculate what capacity you might need in two or three years. Consider the number of new users as well as dramatic increases in data storage needs per user. Your network should be designed to grow easily with incremental additions of existing technologies.

Follow a Standard Approach

It is important that you build your small business network using standard, industry-proven components. As business relationships change, you may need to interconnect your network with others. Protect your investment by building a network that is likely not to pose compatibility problems. If you are an independent branch of a larger organization, be consistent with umbrella group's practices and standards. Even if you are expected to maintain a separate network today, you may need to be part of its wide-area network in the future.

Connectivity

What types of external connections will your network need? Is Internet access necessary? If so, will a dial-up connection suffice, or will you need a full-time dedicated link? How much bandwidth? Will you need to connect with private networks, such as your home office network? One of the most challenging aspects of the small office network involves setting up links to external networks. Not only are these the most technically complex tasks of implementing a network, but they also carry significant costs.

Creating the General Design

Once you have assessed the new network's functional requirements and relative scale, you are ready to begin the design work. Network design involves several layers. You will need to make decisions on each of the following:

• Network type. Options include Ethernet, ATM or token ring. Most small networks are based on Ethernet, but even within this category there are options: Shared media 10Base-T, switched 10Base-T, shared media 100Base-T, and switched 100Base-T. To make a decision, you will need to scrutinize the relative bandwidth the network must support. The greater your need to support multimedia applications such as streaming audio or video, the more you will need a pricier high-bandwidth solution.

• The physical network. This includes network cabling, faceplates, and other issues of basic infrastructure. The kind of cabling you install depends on the network type you selected.

• Network communications equipment. To operate the network, you will need devices such as Ethernet hubs and routers.

• Network operating system. Currently, Microsoft Windows NT Server and Novell NetWare dominate this area. Some environments may require Unix-based servers. It is also possible to design a peer-to-peer network based on NT Workstation.

• Network server hardware.

• Data backup hardware and software.

• Client workstations. Consider the hardware (PC, Mac, etc.) and operating system (Windows 95 or 98, Windows NT, MacOS, etc.).

Final Design: Making Technology Choices

In the early design phase, we were painting in broad strokes. Now we must consider each aspect in detail. Each section below will take a closer look at the technology choices available, and describe how they apply to the small business network environment.