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Chapter 1

Planning a Network Topology

Planning a Network Infrastructure

Planning the infrastructure is by far the most complicated part of building a network

because during this phase you create the blueprint you will use to implement the

network and maintain it later. A complete network infrastructure plan consists of a

great deal more than a physical infrastructure layout and a list of hardware and soft-

ware products. To plan the infrastructure properly, a network designer must consider

the requirements of the network’s users, its owners, and its hardware and software

components.

A basic question the network designer has to ask is: What tasks do the network users

have to accomplish? Answering this question requires the designer to define the types

of communications the users need and the software they need to accomplish their

tasks. However, the process is not as simple as selecting an application. The users’

needs can affect many aspects of the network infrastructure.

For example, if the network has users who must be able to view video streamed from

the Internet in real time, the ramifications for the network infrastructure design go well

beyond the selection of an application that can display a video stream. The designer

must also consider other elements, such as the bandwidth that streaming video con-

sumes on the local network and the speed of the Internet connection needed to sup-

port the application.

In addition to selecting applications, a network designer must also be conscious of the

services the network’s users need for their computers to function properly.

Exam Tip

A large part of the 70-293 exam is devoted to the planning, implementation, and

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maintenance of Windows Server 2003 services, such as the DHCP Server service, the DNS

Server service, and the Windows Internet Name Service (WINS) service. The planning process

for services like these involves not only determining whether to use them, but also designing

an IP addressing strategy and a Domain Name System (DNS) namespace, both of which are

complex issues covered in depth in Chapter 2, “Planning a TCP/IP Network Infrastructure,”

and Chapter 4, “Planning a Name Resolution Strategy,” respectively.

Security is also an omnipresent consideration in planning a network infrastructure. The

designer must attempt to anticipate all possible dangers to the network and plan a

suitable security infrastructure to protect it from those dangers. The security infra-

structure might include advanced configuration of the operating systems, services,

and applications, as well as the use of additional components, such as IPSec and dig-

ital certificates. Many of the lessons in this book are devoted to the determination of

security requirements and the implementation of security mechanisms on a Windows

Server 2003 network.