Network Design A Step by Step Process

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

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

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

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, , web –Thin-client server Single-user computers –Average user, power user –Application suite

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

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

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

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

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

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

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