Designing a Home and SME Network Architecture
What is an architecture and why do I need to select one?
An architecture is an overall plan for your network. It is based on the requirements
you identified and outlines a standards-based structure on which to base your design.
You need to choose an architecture to make sure that the solution addresses your needs and
everything you design is targeted to meeting those needs.
What architecture should I choose?
This depends on your needs. The simplest solution for a home or small-business network
is a simple tree-structured network based on wired links to IEEE802.3 (Ethernet), wireless
links to IEEE802.11 (Wi-Fi) and the industry-standard Internet Protocol Suite (also known as
Transmission Control Protocol⁄Internet Protocol or TCP-IP).
More complicated architectures, such as fully-resilient tiered structures are more suited
to larger businesses and those with specific security or performance issues. Older ring
architectures such as IBM's Token Ring or Fiber Distributed Data Interface (FDDI) are,
generally, unsuitable for domestic and small installations unless you've already got a load
of kit to those standards.
So, it's a simple tree structure. Where do I start?
Firstly, the "trunk": this is your network hub or switch: the thing that allows all the
various bits of your network to talk to one another. More questions:
What else do you need it to do? Such as:
• Internet access router - to keep your private traffic off the internet
• DSL⁄cable modem - to handle the link to your ISP (Internet Service Provider)
• Firewall - To stop Internet users accessing your computer or the local traffic from your network getting onto the Internet
• NAT (Network Address Translation) server to hide your network from the Internet
and allow all your computers to talk to the Internet using the same IP address.
• DHCP (Dynamic Host Control Protocol) server - to automatically allow friends' PCs to connect to your network without the hassle of having to manually assign an IP address
• DNS (Dynamic Name Service) server - to allow the various PCs on your network
to contact one another (especially if they're not Windows PCs) and the Internet.
• Wi-Fi base station - to let wireless devices connect to your network
• Internal router - to allow you to divide your network up into segments and control what devices and services have access to each segment.
• Handle your print queues
There are other things you can get it to do as well. Of course, you could buy separate
devices to perform all or some of these functions, but the more devices, the more expensive
it becomes and the more there is to go wrong.
How many wired connections you need it to support. If you have run wires from the hub
location to each device location in a typical 3-bedroom house, then you might need the following:
• PC⁄entertainment console in the living room
• PC and networked printer in the study
• PC in the garage or shed
• PC⁄entertainment units in each of 3 bedrooms
That's seven. Most domestic switch-routers support four or fewer wired connections. If
you've got Wi-Fi enabled PCs then you can get away with fewer wired connections. If you've
got hard-wired peripherals such as most networked printers, you may need more. Fairly cheaply
you can buy miniature Ethernet switches to provide more wired ports.
So, that's the trunk. The branches are the wired or wireless connections between the
switch⁄router and your PCs and networked peripherals using Cat 5 or better cabling, Wi-Fi links
or, occasionally, more esoteric connections.