A comparison of data limits on web-hosting vs residential broadband services

A question we frequently get asked is why do web hosting plans come with lower bandwidth limits compared to residential xDSL plans?

First lets explain the terminology

What is bandwidth?

Bandwidth or traffic in web hosting plans means the amount of Gigabytes or Megabytes of data is transferred in a month. Data is transferred every time a visitor opens a web page, a file is uploaded to the website or email is downloaded. If your website has large images, videos or flash animations or files available for download it will increase the amount of bandwidth that is utilised.

How much bandwidth is used by each visitor to your web page?

That's all dependent on what the user does on your web page. For example if a user is streaming flash video from your website they are using about 2.5MB a minute, your average photo at 1024x768 resolution is about 100Kb, these numbers may not seem like much, but when you have a large number of users viewing your site each month the data usage adds up very quickly.

Price disparity

The reasons behind why your pay a premium in the cost of bandwidth for hosting a website include contention ratios, latency, reliability, upload/download/total usage measurements, bandwidth availability, shapping and data caps as we'll discuss below.

Contention Ratio

What is contention ratio? It's the amount of bandwidth a supplier (or ISP) purchases from their suppliers compared to the amount that is sold to customers. For example many ISP's will sell around 105 Mbps of bandwidth for every 1.5 Mbps they purchase from their suppliers, or a ratio of around 70:1. This ratio differs based on the ISP and the amount of customers on the network. Contending bandwidth to some degree works because in reality, not every user is on the Internet at the same time and when they are they're not always downloading large volumes of data at full speed. The critical part is how large the contention ratio is. The more contention, the more chances that the network will become congested during peak periods.

Latency

What is latency? Latency is the time between your request going to the server and then coming back to you, it's affected by both your connection and the connection the other party is hosted on, think of it as a delay like on international phone calls. Latency is measured in milliseconds (ms).

For example, the next hop on a DSL service is typically 25-60ms where as on the Anchor network most hops between nodes are under 3ms.

Reliability of bandwidth

Your home xDSL does not have what's called a Service Level Agreement (SLA). An SLA usually provides strict targets on both availability of the Internet connection along with performance requirements (in terms of Latency). If the targets aren't met the SLA provides a formula for a reduction in the cost of the service that month, tied to the amount of time it is not performing.

Aggregate usage upload vs download

Most xDSL and other broadband type plans are geared towards download, therefore your ISP's network is geared towards giving users the maximum amount of download speed and they buy bandwidth based on this formula. The upload speed of a residential DSL service (critical for hosting applications) can often be 1/10th of the download speed.

Availability of bandwidth

As pointed out above most providers networks are geared towards downloads, Anchors network and most other pure web hosting providers networks are geared towards maximum available bandwidth for uploads.

Web hosting contention ratios are normally 1:1. This is because you pay a premium to be able to give each of the visitors to the website enough bandwidth to do everything they want without experiencing a slowdown on the host server for your site. The connection that the servers hosting your website are on are much larger than any available to residential customers. For example our servers are hosted on multible 100Mbps connections routed via providers including international and domestic providers ensuring maximum speed and redundancy.

The Anchor network uses 3 fully redundant providers with automatic fail over, this sort of redundancy for the average home user would require 3 separate connections from 3 separate providers! For example Internode Business 1.5Mbps Power 25 plan comes with 25GB data on a 1.5Mbps link $109/month, even if you want 3 separate connections, you're looking at $327/month for 75GB,but this is not a fully redundant link, it doesn't take into account if Internode have a problem with their back haul or core network, trying to compare residential bandwidth to bandwidth supplied via Anchor is just not possible.

Shaping and data caps

A majority of residential grade connections have what are often referred to as “shaped” or “capped” plans, once your usage limits are exceeded your Internet provider slows your connection down to dial-up speed or about 64kb/s is the industry average, this is great for the home user but very very bad for website hosting.

  1. If your websites connection became shaped it would allow only about 1 user access to your site, any high bandwidth applications with be VERY VERY SLOW.
  2. If you have ever been shaped think about how slow your Internet browsing was, now think of it from your customers point of view when they are trying to view your website to buy a product or service.

Summary

Residential bandwidth is cheaper because its lower quality bandwidth with a high contention ratio and is priced that most of your data will be inbound with very little consideration for outbound data.

See also