How to Cheat at Securing a Wireless Network--Wireless Network Design--Part IV

Formalizing the Detailed Design Phase
The detailed design phase of the NEM is the last step before implementation begins on the network. This phase builds on the architecture phase and fills in the details of each of the high-level documents. This is the shortest and easiest phase of the design (assuming the plan and architecture phase was completed thoroughly and with accurate information). Basically, the detail design is a compilation of the entire planning process. This is absolutely where the rewards of the prior arduous tasks are fully realized.

Reviewing and Validating the Network Architecture
The first step of a detailed design phase is to review and validate the network architecture. The network architecture is the basis for the design, and there must be a sanity check to ensure that the architecture is on track. This involves making sure all of the functionality is included. As you did at the beginning of the architecture phase, you may be validating work done by other people. Once the network architecture has been validated, you begin the detailed design by creating a detailed topology.

Creating the Detailed Topology
The detailed topology builds on the high-level topology, adding information specific to the network topology, such as:

• Devices and device connectivity
• Data/voice traffic flows and service levels
• Traffic volume
• Traffic engineering
• Number of subscribers
• IP addressing
• Routing topology
• Types of technology
• Location of devices
• Data-link types
• Bandwidth requirements
• Protocols
• Wireless topology

The detailed topology is a functional design, not a physical design. The detailed topology is where client dreams become a reality. By this point the client should be fully aware of what they would like the network to offer, and your job is to make it happen. In addition to the documented results, you should have detailed drawings of the various topologies listed earlier. Once the detailed topology is complete, a detailed collocation design can be created.

Creating a Detailed Service Collocation Design
As with the detailed topology, the detailed service collocation design builds on the collocation architecture. This step will provide the details necessary to install equipment in collocation facilities. Include the following information with the design:

• Network Equipment Building Standards (NEBS) compliance
• Facilities
• Cabling

Creating the Detailed Services
This step will define and document the specific services that the client will offer to its customers. The services offered are a continuation of the services list identified in the high-level services design step. When creating the design, be sure to include information such as timeline for offering. This information will most likely be of interest to the client's marketing department. You can easily understand that in a service provider environment the customers and the resulting revenue justify the network. Some of the information to provide with each service includes:

• Service definition
• Service name
• Description
• Features and benefits
• SLAs
• Service management
• Functionality
• Configuration parameters
• Access options
• Third-party equipment requirements
• Service provisioning
• Network engineering
• Customer engineering
• Service options

Not only do you need to provide information regarding when these services will be available, but you should include how they will be offered and how they will interface with the network. Once the detailed services have been created, they can be put to the implementation process.

Creating a Detailed Physical Design
The detailed physical design builds on the high-level physical design. It specifies most of the physical details for the network including:

• Equipment model
• Cabling details
• Rack details
• Environment requirements
• Physical location of devices
• Detailed RF design

The detailed physical design builds on information identified in the following documents:

• High-level physical design
• Detailed topology
• Detailed service collocation
• Product evaluation
• Site survey details

The detailed physical design is a compilation of these items as well as finalized equipment configuration details including IP addressing, naming, RF details, and physical configuration. When you finish this step you should have a detailed physical drawing of the network as well as descriptions of each of the devices.