How much bandwidth do you need to teach online?


One concern understandably raised by people considering teaching English online is whether or not their Internet connection is going to be fast enough. You don’t want to go to all the trouble of finding a student and preparing a lesson for them, only to find your lesson breaks down after 5 minutes because you can’t communicate properly. So in this article I’ll try and break down some of the main issues and examine the numbers. I’m not tech wizard so if you’re a techie, please correct or confirm anything I’m saying in the comments below.

A Need for Reliability

The single most important thing you need is a reliable Internet connection, one that won’t drop out. WiFi is prone to dropping out even at home because of interference from other devices like your microwave oven, mobile phones or remote controls, and in a public WiFi hotspot, such as in a coffee shop, the problem is increased simply because other people are also using the WiFi hotspot. A good WiFi router should be able to cope with lots of different users at once, but some ISPs and coffee shops install cheap models which struggle to deal with lots of requests for data at the same time. Basically, a wired connection is always going to be more reliable than WiFi.

The problems with WiFi can be exaggerated, but it’s good to be aware of the potential obstacles to a smooth connection, and if your connection does drop, you can usually reconnect quite quickly, opening up opportunities for language use such as “sorry about that! I don’t know what happened there!” Students are very forgiving! As long as it doesn’t happen too often. Check out some solutions at the bottom of this post.

A Need for Speed?

As well as a reliable Internet connection that doesn’t drop out, you need a ‘fast enough’ Internet connection. I say ‘fast enough’ rather than fast because communication software, like Skype, doesn’t actually need a lightning-fast connection. Here’s a graph, based on Skype’s own figures, for the different bandwidths required for different types of call, using different types of webcam. These figures are for both download and upload speeds because your voice and your video is being uploaded to your student while your student’s voice and video is being downloaded by you. So you’re usually uploading as much as you’re downloading. This is important to remember because the speeds advertised in big headlines by ISPs usually only refer to the download speed – upload speeds are often as little as one tenth that of the download speed: if you’re getting 10Mbps download, you might only be getting 1Mbps upload. As you can see in the graph, that would be a problem if you have an HD camera (one with 720 pixels or more vertically).

How much bandwidth does Skype need?

The first thing you’ll notice is how little bandwidth is required for a voice-only call: Skype recommends just 100kbps. You can also see how much extra bandwidth an HD webcam demands compared to a normal webcam. The differences are quite startling! If you want to check out the full figures, then take a look at this page from Skype Support.

How to check your speed

You can easily check your Internet speed by going to Speedtest. This will show you the upload and download speed of your connection. In a public WiFi hotspot, such as in a coffee shop, you should check the WiFi speed and also bear in mind that because you’re sharing the WiFi with the people around you, the speed you’re getting will fluctuate. If someone a few metres away suddenly decides to download a movie from iTunes, backup their files on Dropbox or listen to music on Spotify, your connection speed may be affected. So when using public WiFi, choose carefully. Do your homework before you use somewhere for a lesson. Check out different coffee shops at different times of the day, not just using Speedtest but by seeing how busy they are, and only use a coffee shop for lessons once you have some idea of the connection speed. I sometimes do my lessons in a local Starbucks in Bangkok, but only in the evenings when it’s quiet; between 4.30 and 6pm it’s busy from the exodus of local office workers. My favourite coffee shop (at the moment) is in a quiet part of a fairly old shopping mall where I can regularly get upload and download speeds in excess of 50Mbps because there’s nobody else around!

What about 3G and 4G?

Incidentally, you may find that your 3G mobile network is fast enough for online lessons. 3G is supposed to give you a minimum speed of 2Mbps as long as you’re not moving and I’ve actually done video lessons on Skype using my 3G network. If you’re lucky enough to have 4G in your hometown, you should be able to get speeds between 10 and 20Mbps, sometimes much faster.

What do do if your connection has a problem?

1. Turn off the video

Turn off the video and use audio only. A video broadcast takes up the lion’s share of your bandwidth, so this usually resolves any connection problems. In fact, many online English teachers only ever use audio, saying that video can be distracting. It also means you can teach in your underwear!

2. Use a standard webcam, not an HD webcam

When I lived in Chiang Mai in the north of Thailand, I used my brand-spanking new Microsoft HD Pro SuperDuper webcam connected to my computer, but the Internet connection in my apartment sucked. The webcam gobbled up the bandwidth, so I dug out my 4 year old laptop with a built-in cheapo webcam, dusted it off and used that instead. The video quality wasn’t great, but it was more than good enough and the connection problems were solved. The latest and greatest technology isn’t always the most fit for purpose.

3. Use a different communication tool

I’ve almost always used Skype, but many online English teachers swear by Google Hangouts, which is said to work better than Skype. FaceTime is another option. I’ve even heard the old-timer of the Internet, ICQ, is still knocking about.

4. Plug in the cable

If you’re at home and you’re having connection problems, try connecting your WiFi router to your computer using an Ethernet cable.

I’ve had occasional connection problems, but these have almost always been brief stutters which either rectified themselves within seconds or just meant having to call my student again. A few problems were solved by solutions 1 and 2 above. Only twice in the last 3 years have I had to abandon lessons due to connection problems…far fewer than the number of lessons cancelled by students in the days when I taught “offline”!

Please feel free to add comments below, including any factual or technological errors!