Computer networks are as important to today's libraries as electricity. Having stable and fast internet service has become an expected library service, and a necessity for staff as many of the required forms to go about the running of the library are only available online. In this chapter, we'll give you a basic outline of the various parts of a computer network and internet service to the building.

The first part of a library's internet service is the source, or Internet Service Provider (ISP) that connects the building to the outside world and the internet. In many libraries, it is through the phone or cable company. There are a few that receive their internet for the building through a city-wide Wi-Fi system or even cellular data network, but those are relatively rare. The line into the building will usually attach to a modem of some sort. Some smaller libraries will only need this piece of equipment in the next step. Larger libraries will need more to connect many computers to this single source.

Internet to the Computers

Depending on the number of computers in your building, the size and age of your building, and some other variables - getting the internet from the source to the individual computers could happen in a few different ways. For the smallest libraries, what usually happens is that the modem they use to get the internet into their buildings also acts as a router that will route traffic among the computers in use. These usually have around four ports in the back that allow you to run Ethernet cable amongst them. If you have many computers, you probably have a "switch" or a "hub," possibly a series of them. They do similiar things, but a switch is probably the better option. These small devices act as traffic cop and send the signals to where they need to go within the building.

There are some libraries that don't have any wires to the computer, depending only on Wi-Fi. That can work, but is currently more susceptible to issues if a computer starts a bandwidth-heavy process (like watching hi-definition video) that causes all computers on the Wi-Fi to slow to a crawl.

How fast of internet do I need?

The measurement you should look at when comparing internet packages from providers is what the advertised bandwidth is. This is a way of expressing the capactiy of the network. Higher numbers mean that signals can go through faster and not get clogged up. When looking at internet packages from an internet provider, there is a formula recently developed by the EDGE initiative that suggests the following:

((# of computers x 1.3) x (target kbps))/1024 = mbps for the building

Let's walk through the formula:

First - number of computers is the number of library computers, laptops, or tablets that are used in the library. Include the staff computers when you use this formula! The 1.3 number is used to estimate that for every three computers in the library, there will be one person who brings their own device and uses only the Wi-Fi. If your library does not provide public Wi-Fi, you can ignore this multiplier. If you have heavy Wi-Fi usage from outside devices, then increase the multiplier to 1.6 or even 2.

Target kbps is a number that tries to measure the minimum bandwidth for a single user. The EDGE initiative suggests that one of three levels: 512 kbps, 758 kbps, or 1024 kbps.

Dividing the whole result by 1024 gets you the number in mbps, which is the unit often used to advertise internet packages.

So let's do a walkthrough. Let's say you haeve 1 staff computer and 4 public computers and we want traffic to flow a little bit faster than the slowest suggested individual's bandwidth. In this example, we then have 5 computers and 768 minimum bandwidth for each user, resulting in the following formula:

((5 x 1.3) x 768)/1024 = 4.875 mbps

We can take that number and look at internet providers, ignoring all plans that advertise speeds slower than 4.8 mbps.

This formula really is focused on the bare minimum you should get, so you shouldn't feel badly about getting something with a high mbps, as that would help you keep up as you get more users in the library.