Introduction
Planning is the first step in building a reliable, secure, high-performance and highly available Windows Server 2003-based network. In this chapter, we begin with an overview of network infrastructure planning, introducing you to planning strategies and how to use planning tools.
We will review the fundamentals of network design, including analysis of organizational needs. These include factors such as information flow, management model, organizational structure, and issues of centralization versus decentralization. We discuss management priorities, including availability and fault tolerance, security, scalability, performance, and cost. Next, we address user priorities, which include e-mail communications, scheduling and task management, project collaboration, data storage and retrieval, Internet research, application services, print services, and graphics/audio/video services.
This chapter also looks at legal and regulatory considerations, how to calculate total cost of ownership (TCO), and how to plan for future growth. We discuss how to develop a test network environment, and how to document the planning and network design process.
Overview of Network Infrastructure Planning
Proper planning of a network infrastructure is essential to ensuring high performance, availability, and overall user satisfaction with your network operations. In order to create a viable network design, you’ll need an understanding of both the business requirements of your organization as well as current and emerging networking technologies. Accurate network planning will allow your organization to maximize the efficiency of its computer operations, lower costs, and enhance your overall business processes.
When planning for a new infrastructure or upgrading an existing network, you should take some or all of the following steps:
■ Document the business requirements of your client or organization.
■ Create a baseline of the performance of any existing hardware and network utilization.
■ Determine the necessary capacity for the physical network installation, including client and server hardware, as well as allocating network and Internet bandwidth for network services and applications.
■ Select an appropriate network protocol and create an addressing scheme that will provide for the existing size of the network and that will allocate room for any foreseeable expansions, mergers, or acquisitions.
■ Specify and implement technologies that will meet the existing needs of your network, while allowing room for future growth.
■ Plan to upgrade and/or migrate any existing technologies, including server operating systems and routing protocols.
In this section, we’ll discuss best practices and strategies for planning your network implementation. We’ll then look at the various tools that you can use for network planning, both from Microsoft and from other vendors. We’ll conclude with some fundamentals of network design that will provide you with a good starting point for designing a network that will best meet the needs of your organization and its users.
Planning Strategies
When designing a new network, you should first use the business requirements of your organization as the primary source of planning information. You’ll need to create a network infrastructure that addresses the needs of your management structure, such as fault tolerance, security, scalability, performance, and cost. You’ll need to balance these requirements with the types of services that your users and clients will expect from a modern network, including e-mail, calendaring, project collaboration, Internet access, file, print, and application services.
After you’ve determined the business requirements of your network, you should then analyze the technical requirements of your organization. These requirements may apply to any applications that are already in use or that you plan to implement, as well as to the associated hardware and operating system. You should carefully note all of these requirements so that you won’t create any difficulties later on during the implementation process. Be sure to analyze and document the existing network, including any hardware, software, and network services that are already in place. This will make it easier to take the existing configuration into account when planning the new or upgraded network.
Finally, any well-formed network plan should make allowances for future changes to the organization, including support for new technologies and operating systems, as well as additional hardware and users. Your organization’s business requirements can change—through a merger, an acquisition, or simple growth and expansion. Although it is impossible to foresee all possible changes of this nature, a good network design will be flexible enough to accommodate as many adjustments as possible.
Using Planning Tools
There are a number of tools available to assist you in developing a plan for your network infrastructure. The first and best of these, however, might be the simplest: pencil and paper. As we discussed in the previous section, you should begin your planning by determining the requirements of the business that will be using the network. The best way to do this is through face-to-face interactions, by interviewing relevant managers and staff members of each department, branch, or business unit. Not only does this allow you to construct a complete picture of your network requirements, but it also involves stakeholders from the various departments. This sort of involvement is critical in ensuring the successful deployment of any new or upgraded technology.
After you have a high-level understanding of your company’s organizational structure and computing needs, you should inventory the hardware and software that is already in place. In a small office environment, you can accomplish this by simply taking a walk to determine the physical layout of network cables, routers, and the like. In a medium- to large-sized enterprise network, you will probably want to rely on automated inventory tools such as Microsoft’s Systems Management Server (SMS) or a third-party equivalent. Take as detailed of an inventory as possible, including the hardware configuration of server and workstation machines as well as vendor names and the version numbers of the operating system and business applications the systems are running.
You can use a network analyzer, such as the Network Monitor utility built into the Windows Server 2003 operating system or the more full-featured version of Network Monitor included in SMS, to create a baseline of the current utilization of your network bandwidth. If this utilization is already near capacity, you can use this baseline to justify and plan upgrades to your network infrastructure (moving from 10 MB Ethernet to 100 MB Ethernet, for example).
The version of Network Monitor that ships with Windows Server 2003 can analyze only traffic addressed to the network interface card (NIC) on the server itself or that is sent by the server on which it is running. The SMS version of Network Monitor operates in promiscuous mode, enabling it to capture all network traffic on a given segment, even if the traffic isn’t addressed to or from the local server.
Windows Server 2003 has introduced new management features that will assist you in planning your network configuration, especially in the areas of user and computer management. The Resultant Set of Policy (RSoP) Microsoft Management Console (MMC) snap-in contains a Group Policy modeling function that will allow you to simulate changes to Group Policy Objects (GPOs) in an Active Directory (AD) environment before actually applying them to a production network. For example, if you want to apply a new GPO to a departmental Organizationa...