Write It Down

My first rule of Network Architecture is "write it down". Yes, some may think the first rule would be about routing protocols or physical design. Nope. To have a network architecture you have to write it down. The biggest problem when designing a network is the lack of documented standards. If a networking engineer cannot find the standard configuration for a LAN port, he/she is going to do what he/she thinks the best design is. And, as we all know, every engineer has their own idea of what the "best" is. Relying on each engineer to do what they feel is best will lead to a network that is different in every location. That makes operational cost skyrocket.

Now that I've established the first rule, there are a few sub-rules to "write it down". First, the documents need to be readily accessible to all engineers. Creating an architecture that is not shared is not useful. Other engineers, management, and IT staff need to be able to read the architecture to use its standards and understand how the network works.

Second, the architecture needs to be narrative. Diagrams (we'll assume Visios) are crucial, but are only one part of the architecture. The narrative portion explains the diagrams and the design concepts. A diagram can only show show much.

Third, the architecture documents need to keep relevant. Have a plan for updating the documents which should include an engineer's time to do the work. Having standards requires time to maintain and update. This should be seen as a recurring project for an engineer/architect on your team. Remember, all other projects will suffer if the standards are not kept up to date.

I have found Wiki to be a very easy tool for architecture documentation. It is easy to create and edit web pages, it tracks changes and can revert changes, and is accessible by any web browser. Other options include general web pages and Microsoft Sharepoint. A first thought may be to use Word or PowerPoint to build an architecture, but these formats are generally limited to Windows, the file sizes can grow very large, and the files are slow to load. I would recommend against using these files as your primary documentation medium (though they can be very useful for certain sections).