How “Fast” Is My Internet?

Have you ever called up Comcast or CenturyLink and asked them, “How fast is my internet?  Because loading webpages is really slow”?

Have you ever been frustrated at the end of that conversation?

The problem is that there different ways of measuring speed, and you are not using the same metric they are.

3 Different Speed Measurements

Here is the technical bit of the article, but it’s only 4 sentences, so stick with me.

When network professionals talk about speed, it is measured in 3 different ways:

Bandwidth – The theoretical maximum amount of data that can move from point A to point B in a given period of time
Throughput – The actual amount of data moving from point A to point C in a given period of time (Yes, points C and B are different)
Latency – Time it takes to get a tiny bit of data to go from point A to point C

Can you see the problem?  They all refer to “speed,” but Comcast talks about speed in terms of bandwidth, and you talk about speed in terms of throughput.

Car Analogy

Instead of bits, points, and internet lines, let’s use a couple  transportation analogies.

Latency vs. Bandwidth

You have 8 people you want to move from Boulder to Denver and you want to know how long it will take them to get there. You have a Tesla and a minivan available to you. Clearly, the Tesla can get make the trip faster than the minivan. This is latency: the speed at which a small group of people can go from point A to point B. The latency of the Tesla is 200 MPH, the latency of the minivan is more like 85 MPH. (We’re breaking speed limit in the name of this thought experiment).e

However, the minivan can carry all 8 people at once, where the Tesla would have to take many trips, so the minivan has more “bandwidth” and can deliver all people in less overall time.  It’s not as fast on the speedometer, but it gets everyone there in a shorter period of time.

As far as technology goes, VoIP systems rely on latency.  They deliver small bits of data and it needs to get there fast to sound good.  Streaming video relies on bandwidth, because videos are large and it’s more important to get the whole thing at the same time than a little bit faster than another part.

Bandwidth vs. Throughput

To illustrate the difference between bandwidth and throughput, let’s take a different transportation example.

You are driving down US-36, a 3-lane highway with a 65MPH speed limit.  If you call the Colorado Department of Transportation, they might tell you that you that this highway can handle 500 cars per minute.  That is the “bandwidth” of the highway, the theoretical maximum number of cars that can travel along that road.

You’re calling them because you are stuck in traffic and 500 cars per minute are definitely not passing through the highway at that time.  This is “throughput,” the actual number of cars that are traveling along the road at that time.

How Fast Is My Internet?

This is why it is frustrating to call Comcast and tell ask them “how fast is my internet?” They tell you you have plenty of speed on your line, because they are talking about bandwidth.  You care about throughput, because it’s the speed you actually experience when downloading a webpage or video.

The trouble is, so many things affect throughput: your computer, your local network, your internet connection, potential troubles on the internet at large between you and the where the webpage is hosted, their hosting company, their internal network, their servers, etc.  When you call the ISP and complain about speed, they can only address 1 link in that grand chain of networks.

If you are having troubles with internet speed, it may not be as simple to fix as calling your ISP and telling them to give you more bandwidth.  There may be other problems that are causing your throughput to be diminished.  Call us for a free network evaluation if you are having troubles with your internet speeds and don’t know how to fix them.