In our last blog, we talked about internet speed tests, and the many factors that can influence them. One of those factors which we did not discuss is called a “content delivery network.”
A Content Delivery Network, or CDN, is a term for a particular way of distributing internet content. Traditionally, when you browse to a website from your computer, the information is pulled from the website, carried over the internet, sent through an unknown amount of Internet Exchange Points to your local network, and then translated by your browsing software.
In a CDN, content providers (e.g. Netflix) place servers with the most accessed content in strategically placed locations at the very edge of where the Internet meets your local network (often in the central office of your ISP).
The benefit of a CDN structure for the end user is that the information is able to be delivered much more quickly and efficiently. The closer to the edge the content resides, the less devices it has to pass through, and the less likely it is to encounter some form of resistance or traffic.
Internet traffic is very similar to actual traffic in that the amount of it that is sustainable is dependent on how wide the road is and how many other people are traveling on it at the same time. If a typical internet connection is like driving a car down the information superhighway, a CDN is more like flying to an airport close to your destination, and then renting a car to drive the last 20 miles.
The benefit of a CDN structure for the ISP includes increased reliability, reduced costs, and improved security. Most ISPs purchase bandwidth from one of the Tier 1 internet providers, so by decreasing their need to download information from the internet-at-large, they can reduce costs.
CDN servers, by storing the content users are accessing most often in a local server, is one of the easiest ways to decrease that need. They also make it possible to download content even when that content provider’s website might be down. Finally, since less information is being transmitted from the Internet, there is less of a security risk since all routing is done locally.
CDN servers are usually obtained by the ISP directly from the content provider. This business arrangement can take many forms. Typically, the server is provided at no cost, as the content provider wants the end user to have the best experience with their content possible. However, the FCC’s removal of net neutrality rules in 2017 opened the doors to the possibility of ISPs favoring some traffic over others, which could take the form of “pay to play” CDN situations. More on that in a future blog on the topic of net neutrality.
You may have noticed that there are many websites that test your internet speed – otherwise known as internet speed tests. You might also have noticed that different sites will give you different results. Why is that? Today we’ll discuss how internet speed tests work, and delineate the many factors that influence them.
On the most basic level, the mechanics of an internet speed test are easy to understand. To test your download speed, the test site sends a file of a known size to your computer, and measures how long it takes for your computer to download it. Similarly, your upload speed is measured by how long it takes your computer to upload a file of a known size to the test site.
Simple, right? Well unfortunately, there are a host of variables between your home router and the test site that complicate matters considerably. Not only that, but conflation of the terms speed and bandwidth complicate the issue even further.
Most consumers assume that the number from their speed test should match, or at least approach, the number on their internet bill. But in actuality, their internet service provider is selling them bandwidth, not speed. The speed is impacted by many factors out of your ISPs control. It is important to note that speed and bandwidth are two different things, although they are closely related and the two terms are often used interchangeably.
Bandwidth is a measurement of the connection, not the speed going over that connection.
In other words, your bandwidth is your maximum speed. Internet service providers typically offer several tiers of service options, and they are usually differentiated mainly by download bandwidth, with cheaper options offering less download bandwidth and vice versa. The average download speed in the United States in Q2-Q3 of 2018 was 96.25 Mbps. (Download and upload speeds are typically measured in Megabits per second (Mbps)).
But again, bandwidth is a measurement of the connection, not the speed going over that connection. Your bandwidth is your maximum speed. So, an internet user with a service plan offering 100 Mbps of download bandwidth will not necessarily get a reading of 100 Mbps download speed from an internet speed test.
Once Internet traffic leaves your house through your router (which can itself limit throughput), depending on where it is routed, it may not have access to that same level of bandwidth. If it does encounter a lessening of bandwidth, at that point the speed gets choked down to whatever that connection is.
The analogy of car traffic is often used to illustrate this idea. If traffic is humming along on an 8-lane highway, and suddenly there are only 2 lanes, traffic is going to slow considerably. The same thing happens on the Internet when a 1 Gbps connection gets sent over a 100 Mbps connection. In the context of this analogy, bandwidth is your vehicle’s maximum speed on an open road, under perfect conditions, with no other traffic.
This bandwidth bottlenecking is often a result of physical network cabling. While you may be lucky enough to have an internet service provider build a fiber-optic connection right to your home, the internet-at-large is still constructed largely on the backbone of shared coaxial cable, which stands like Ozymandias over the desert of the cable TV industry.
In other words, despite information on the internet being transferred at a rate difficult to comprehend by the human mind, there are still constraints that are based on physical realities of how the internet is constructed. Among these are the amount of bandwidth physically able to be carried by different cable technologies, the processing speed and the amount of routers and/or firewalls along the path of the information, the distance between them, and the amount of other homes or devices hooked up to the same internet connection. Even your browser and operating system can place limits on your available bandwidth.
With all these factors at play, hopefully you can begin to see how the number on your internet speed test will not be the same number as the one on your internet plan. However, there are a few things you can do to achieve the most accurate possibly speed test.
Although the entire Internet is not equipped to handle speeds up to 1 Gbps, CTS Telecom offers that amount of bandwidth because we are on the leading edge of Internet technology, and we believe the Internet will eventually catch up to our level of service. In the meantime, regardless of the number on a speed test, we can confidently state that we are offering the fastest, most reliable Internet connections in our area.