1. Network Design A Step by Step Process

2. Design with Change in Mind • Building the network is just the beginning • Growing the network for larger numbers of users • Growing the network for more services • Growing the network to include emerging technologies • It never stops • Design for this from the very beginning

3. A Design Process • Identify the uses of the network • List what happens on what computers • Client/server or P2P? • Diagram the network • Review your plans • Write a specification • Build the network

4. Identify the Uses of the Network • Organisational purpose • Network is not about technology • Network is to serve a purpose • Information collecting • Management: core business • Users: on-the-ground issues • Collect, collate, and bring back for review • Quantifying the Network • # of users, # of machines • Machines per user? Users per machine? • Examples: Pick’n’Pay, UWC, software devel company

5. What Happens Where? • Match applications/tasks to specific computers • Rightsize: choose the capabilities of the machines to match the use requirements • Multiuser computers • Servers: File, application, database, email, web • Thin-client server • Single-user computers • Average user, power user • Application suite

6. Centralisation • Client/server vs. Peer-to-Peer • Candidates for centralisation • File services: uniform location • Security: access and permissions • Backup: uniform location • Configuration Management • Ensuring all machines have the same software and hardware • Why? Easier to fix problems if everything is (supposed to be) configured the same • Network Management Software

7. The Network Diagram • Logical network diagram • Start with the user • Applications and resources • Pay attention to sharing and security • Physical network diagram • Machines • Network devices • Physical connectivity • Combined diagrams • Diagram physical connectivity • Show logical use with descriptive labels

8. Diagramming Best Practise • Choose appropriate icons/images • Label the icons clearly • List the additional details in small text close to the icons, e.g. machine name, IP address, etc. • Use conventional methods to depict connectivity, e.g. Token Ring vs Ethernet • Use colour and styles to denote different types of connectivity relationships, similar attributes, e.g. OS type, application, etc. • Keep the overall layout simple and within page boundaries • Use space to lay out the contents clearly – keep objects distinct with space • Resize objects to make best use of space and try to keep size of objects relative to reality • If using several different colours and/or line types, provide a legend in an isolated corner • Clearly identify the author(s) and target audience for the diagram

9. Write out Specification • Write out a document with everything so far • Why write a document? • It’s not real until it’s on paper • Defines the scope of the project (to protect you) • Tangible item for reference • Keep it short and clear • Pass around the document for review • Hold a review meeting and revise accordingly

10. Choose Hardware • Workstation and server computers • Network interface cards • Network devices • Wiring • Application software • Management software

11. Choose a Vendor • Best to get all the equipment from a single vendor to avoid “finger pointing” • Collect bids from multiple vendors • Detailed description of solution • Detailed quote • Rollout plan • What to look for in a vendor • How frequent they meet with you? How well do the meetings go? • Do they listen to your needs or push their product? • Can they provide references? • Meet with the techies as well as the salespeople

12. Build the Network • Decide how much of the actual building your vendor is going to do • If the network is very large and complex, or if you are adding services/technologies to an existing network, rather build a staging environment first • Be sure to pick a time (like a vacation) when no one will be around