The network planning and design methodology describes a process with nine specific steps and a sequence for those activities. As mentioned it is an engineering life cycle that supports technical initiatives such as Windows migration, IP telephony and wireless design to name a few examples. The methodology begins with examining company business requirements. It is absolutely essential that you understand the company business model, business drivers and how they are growing from a business perspective. That will build the foundation for a design proposal that serves the business, technical and operational requirements of the company.
The company design requirements can be defined as standard and miscellaneous requirements. Standard design requirements are common to any design project and address performance, availability, security, manageability, scalability, cost-effectiveness, standards compatibility and rapid deployment.
Miscellaneous design requirements focus on anything that isn’t defined with standard groups and tend to be issues such as locations, affected number of users, traffic that must be prioritized, Internet connectivity for particular users, redistribution issues, static route usage and protocols to name some examples. With business and design requirements understood, it is then necessary to do a network assessment.
It is important to survey the company network to identify trends and problems that would affect the design proposal and support the design process. The assessment surveys five primary groups: Infrastructure, Performance, Availability, Management and Security.
It builds a snapshot of the current network using a structured methodology with interviews, surveys and performance monitoring. Interviews are conducted with technical, operational and executive staff.
The information obtained from requirements and assessment activities are then used for defining the enterprise infrastructure. There is a specific sequence of events for defining the infrastructure that is described with this book. For example you wouldn’t define an addressing plan before topology and equipment is selected. Furthermore you wouldn’t select equipment without running a traffic model. The wireless site survey isn’t part of the standard network assessment. It is conducted after equipment is selected. The site survey must be performed with the selected access points and client adapter. Signal strength, antennas and coverage is device specific.
Security/Management/Proof of Concept
Security is considered from a layered perspective that is consistent with the company security requirements defined from the design requirements phase of the methodology. It is integrated with the infrastructure that has been defined. The result is specified with perimeter, network, transaction and monitoring security. Network management strategy is then defined considering the management design requirements specified from the requirements phase of the methodology. The resulting strategy defines processes, applications, monitoring strategy, and IOS services. Proof of concept testing is an opportunity to test your proposed design, confirm that it works as expected and identify problems that affect the design proposal.
A design proposal is then built that utilizes information from all previous methodology processes. The document structure follows the same groups as used with the planning methodology. The methodology is designed to build the design proposal as each phase is finished. The design proposal is presented to the Client, Director, CIO or any person that is approving either the budget and/or the proposal with a design review. The design review is an opportunity for the client to discuss concerns they have with the design proposal, ask questions and recommend modifications. If changes are necessary, the design proposal is modified before implementation.
With the design proposal finished and the approval from the client, it is the implementation that is considered. This book suggests a methodology that minimizes disruption to the production network. That is accomplished with consideration of impact on to the production network and specifying contingencies should there be any problems. Preliminary testing is conducted at selected locations and an implementation plan is generated that specifies locations, activities and dates.
Once the implementation is finished, there is monitoring of the network for any problems. Design and configuration modifications are then made to address any problems or concerns. This chapter discusses each element of the planning and design methodology starting with business requirements.
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