The original version of this article was published on the iWeb blog. Read it here.
Unmetered hosting means a hosting plan with unmetered traffic. The price you pay each month does not depend on the amount of traffic (data) sent to and from your server during the month. But unmetered does not mean unlimited.
In fact, unmetered hosting plans are often very limited in the amount of data you can send and receive, because data is often transferred between your servers and the public web at a lower speed. This blog post will look at the terminology of server traffic and bandwidth, and explain how to get a clear picture of exactly what you are buying.
Traffic, bandwidth & throughput
When you buy a server, you can choose specifications relating to the amount of traffic included in the server package. It doesn’t matter if you’re buying a dedicated server, VPS or cloud deployment. With the number and variety of hosting providers in the market, you can always find a provider who gives a clear picture of what to expect in terms of traffic limits, data transfer speed and pricing.
Let’s look at the terminology first, then move on to the calculations and pricing.
Traffic is sometimes called data transfer, or, the volume of data passed between your server and the public web over a certain period. For ease of comparison, as well as to fit with billing cycles, the period of calculation is nearly always a month.
Traffic is measured in bytes. Usually terabytes (TB). So if you see a server whose traffic (meaning traffic limit) is 30TB, that means there’s a limit of 30TB of data that can be passed between your servers and the public web during the month before you start to incur additional fees. These additional fees should be published on a provider’s website as well as in the terms of service.
Traffic between your servers and the public web can be categorized as inbound or outbound (sometimes denoted I/O). The public web is “the rest of the Internet”.
For a simple website, the outbound traffic from the website to the public web is the information served in the form of a web page. If people can upload data via your website to your server’s database, that would count as inbound traffic from the public web to your servers.
In the world of hosting, traffic is often incorrectly referred to as bandwidth. You may see an offer for a server with ‘bandwidth 10TB/mo’. In this case, you can tell from the fact it’s measured in TB/mo that the provider means traffic (or data transfer, if you prefer), not bandwidth.
Bandwidth is actually the speed limit at which data can be transferred between your servers and the public web.
Bandwidth is measured in Megabits per second (Mbps) and sometimes Gigabits per second (Gbps). Hosting bandwidth typically ranges between 10Mbps and 1Gbps, with 100Mbps a common bandwidth for high-performance dedicated servers.
Bandwidth is sometimes referred to by the size of the port. For example, a dedicated server with a dedicated 100Mbps port affords you 100Mbps bandwidth.
Throughput is the actual rate of data transfer achieved. It will always be less than the bandwidth (which is the capacity and therefore upper limit). Like bandwidth, the actual throughput is measured in Megabits per second (Mbps).
The reasons that actual throughput will be less than the bandwidth include the network overhead required to transmit and route data, the nature and number of users, their location and the fact that bandwidth is sometimes shared with several other servers. This is very common in VPS (Virtual Private Server) hosting, where several virtual servers exist on one physical server, and certain elements are shared between the virtual servers. One of these elements is the bandwidth.
Unmetered is not unlimited
When you buy unmetered hosting, especially an unmetered VPS, it’s important to understand that you are not buying unlimited traffic. Traffic is always limited, in practice, by the other factors: time and throughput.
Because not all of this information is always published, it can be difficult to understand how much bandwidth your server will be able to use and how much traffic you can realistically expect to achieve in a month. It is important to find out this information before you buy, and to compare this to your requirements in terms of speed and overall traffic consumption.
For a website, this is essentially a question of how many visitors you expect to receive in a month, and how quickly you and your users need the data to be transferred between your server and the Internet.
Indirect factors in this evaluation will include your users’ network speeds, the weight of the page (how much data needs to be transferred for the page to load) and the expectations of your users as to what is acceptable.
Unmetered often means slow
Every server and hosting package should be taken on its own merits. If you have a small blog read by a few hundred people, you will find that a cheap hosting package with a reputable company is enough for your needs. You may not even want to find out about the speeds and traffic involved if you trust the provider.
But any kind of application or project that is worthy of investment in a VPS or dedicated server deserves a little more attention to the traffic and bandwidth specifications. Find out from the company what you can expect (or better still what they guarantee), and use the opportunity to gauge the nature of the provider and their customer service from this interaction.
As we have seen, an unmetered VPS is still limited in traffic, it is just limited by the speed, not the traffic pricing. That doesn’t necessarily mean that the speed is slow. And slow doesn’t necessarily mean bad. But it does mean you need to know what you’re buying.
Essentially, when you buy a VPS, you usually need to choose between a guaranteed bandwidth (speed) or pricing that is based partly on traffic (volume). Whatever your preference, it shouldn’t stop you from enquiring as to what bandwidth and traffic you might realistically achieve. This can sometimes be found in the terms and conditions, or can be found out by contacting the provider.
An example scenario might be an unmetered VPS with 100 users sharing a 1Gbps port. That would leave you with about 3TB traffic (or data transfer) per month as a hard traffic limit. It also means that your bandwidth may be limited and when many people are accessing your website or application at once, they will experience slower page loads or downloads.
If traffic to your website or application is ‘bursty’ and inconsistent, you might be better off with a hosting package with a traffic limit (and price tied to traffic) than to limit your actual performance at busy times by sharing bandwidth with other customers.
Make an informed choice
When buying any server or hosting plan, it’s all a question of understanding the dynamics of your website or application and knowing what you’re buying. Think about the future too – how scalable is the solution you are considering, and will it be able to handle traffic growth without you needing to migrate to a new server?
And don’t forget the other factors to consider like a provider’s reputation, support and location.