Network Design Process
The network planning and design methodology describes a process with 9 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.
STEP 1: BUSINESS REQUIREMENTS
Any design project starts with an understanding of what the company does and what they need to accomplish from a business perspective. This begins with an understanding of their business model, which really describes how their company works from an operational and business perspective to generate revenues and reduce costs. Many vendors today have conducted their own return on investment (ROI) studies for new implementations such as Unified Communications and Telephony. It is an effective sales tool that illustrates the cost benefits compared with investment over a specified period of time.
This is a list of some typical business drivers:
• Reduce Operating Costs
• Generate Revenue
• Client Satisfaction
• Employee Productivity
This is a list of some typical project business requirements:
• Budget Constraints
• Office Consolidations
• Company Mergers and Acquisitions
• Business Partner Connectivity
• Telecommuter Remote Access
• Implement New Offices and Employees
• New Data Center Applications
• Reduce Network Outage Costs
• Cost Effective Network Management
• Vendor Contracts
STEP 2: DESIGN REQUIREMENTS
Now that you understand the basic business requirements of the company, you can determine the standard and specific design requirements. The design requirements process is focused on defining requirements from a technical perspective. Those requirements along with the business requirements will build the framework that is used to define infrastructure, security and management. Design requirements are defined as standard and miscellaneous. The standard design requirements are generic and represent those considered with many design projects. Miscellaneous requirements are those that aren’t defined with any of the standard requirements.
• Standard Design Requirements
• Standards Compatibility
• Rapid Deployment
STEP 3: NETWORK ASSESSMENT
A network assessment is conducted after we have finished the business and design requirements of the company. A network assessment provides a quick snapshot of the current network with an examination of the infrastructure, performance, availability, management and security. That information is utilized for making effective strategy recommendations and design proposals to the client concerning specific information systems modifications. The network assessment model has 3 sequential activities, which are assessment, analysis and recommendations. The current network is examined using five primary surveys: infrastructure, performance, availability, management and security. When the surveys are completed, the information collected is then reviewed for trends, problems and issues that are negatively affecting the network.
STEP 4: INFRASTRUCTURE SELECTION
After doing an network assessment we are ready to start selecting specific infrastructure components for the network design. This phase starts building the infrastructure with a specific sequence that promotes effective equipment selection and design. It is important that you consider business requirements, design requirements and the network assessment when building your infrastructure.
The following numbered list describes the specific infrastructure components and their particular sequence.
1. Enterprise WAN Topology
2. Campus Topology
3. Traffic Model
4. Equipment Selection
6. Routing Protocol Design
8. Naming Conventions
9. iOS Services
10. Domain Name Services
11. DHCP Services
STEP 5: SECURITY STRATEGY
We must now define a security strategy for securing the infrastructure. The need for enterprise network security shouldn’t be ignored with the proliferation of the Internet. Companies are continuing to leverage the public infrastructure for connecting national and international offices, business partners and new company acquisitions. The security requirements and network assessment recommendations should drive the selection of security equipment, protocols and processes. It identifies what assets must be protected, what users are allowed access and how those assets will be secured.
STEP 6: NETWORK MANAGEMENT STRATEGY
This section will define a network management strategy for managing all equipment defined from infrastructure and security. It is necessary to define how the equipment is going to be monitored and determine if the current management strategy is adequate or if new applications, equipment, protocols and processes must be identified. Management components are then integrated with infrastructure and security to finish building the proposed design. These primary elements comprise any well-defined management strategy and should be considered when developing your strategy.
• 7 Management Groups
• SNMP Applications
• Monitored Devices and Events
STEP 7: PROOF OF CONCEPT
All infrastructure, security and management components must now be tested with a proof of concept plan. It is important to test the current design, configuration and iOS versions in a non-production environment or on the production network with limited disruption. Implementation of newer network modules at a router, for instance, could require that you change the current iOS version that is implemented. Making those changes could affect WAN or campus modules already installed at production routers. That is the real value of doing a proof of concept and certifying that the new equipment and iOS versions integrate with each device as well as the network. The following list describes the advantages of doing a proof of concept with your network design. The proof of concept test results should be examined and used to modify current infrastructure, security and management specifications before generating a design proposal. The proof of concept model suggested here involves prototype design, equipment provisioning, defining tests, building equipment scripts and examining test results.
1. Prototype Design
2. Provision Equipment
3. Define Tests
4. Build Equipment Scripts
5. Review Test Results
STEP 8: DESIGN PROPOSAL/REVIEW
With the proof of concept finished, you are now ready to build a design proposal for the design review meeting. Your intended audience could be the Director, CIO, CTO, Senior Network Engineer, Consultant or anyone that is approving a budget for the project. It is important to present your ideas with clarity and professionalism. If a presentation is required, power point slides work well and could be used to support concepts from the design proposal document. The focus is on what comprises a standard design proposal and the sequence for presenting that information.
The working design proposal is presented to the client after addressing any concerns from proof of concept assurance testing. The design review is an opportunity for you to present your design proposal to the client and discuss any issues. It is an opportunity for the client to identify concerns they have and for the design engineer to clarify issues. The focus is to agree on any modifications, if required, and make changes to the infrastructure, security and management before implementation starts. Business and design requirements can change from when the project started which sometimes will necessitate changes to infrastructure, security and management specifications. Any changes should then go through proof of concept testing again before final changes to the design proposal.
STEP 9: IMPLEMENTATION
The final step will have us defining an implementation process for the specified design. This describes a suggested implementation methodology of the proposed design, which should have minimal disruption to the production network. As well it should be efficient and as cost effective as possible. As with previous methodologies there is a sequence that should be utilized as well. 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.