In the past I worked in an office that uses virtual desktops stored on a remote server. Access to these desktops was over an internet connection. There are times when the system became very unresponsive. Kind of like if you have been running a version of Windows for a long time without doing any maintenance on it. Clicks took a long time to register on screen and there was a long delay when typing a document before the characters appeared on screen. Now I knew that this had to have something to do with the internet connection and did the usual checks of the Bandwidth which appeared to be adequate to do the job. What I hadn’t been checking was the latency.
What is Latency?
Latency is defined as the delay you experience in sending a packet of data. It is measured as the time it takes for a packet of data to be sent to its destination and back (the roundtrip). The longer it takes the higher the latency. Basically what it boils down to is that latency = speed.
The ISP’s have done a good job to convince us that all we need to worry about is bandwidth. In fact the way they advertise speed is by bandwidth. This is not entirely correct. Bandwidth has more to do with the capacity of the line than the out and out speed of the line. This is why you will see advertised “up to” before the 10mbps. If you are on a connection with high latency you won’t achieve the target advertised.
The Road Analogy
I think it helps to think of it as a road on which traffic travels. If you consider Bandwidth as the number of lanes on the road, latency as the speed limits and the vehicles as packets of data.
Where You’ll Notice Latency
Most people do not think of latency on their internet connection unless they are doing something in real time online. Those who will notice it most are office environments like mine that use cloud computing and the online gaming commuity. (Nothing worse than when you are just about to pull off that finishing move and you have pressed your buttons but rather than take out your opponent your character does nothing and your opponent nails you instead)
Others may notice it in the time it takes a webpage to start loading from the time you clicked on a link or entered the url into the address bar. (This can be a function of the website you are visiting if it is on a slow server or it could be the latency on your connection)
My friends in the podcasting world will notice it if they are using Skype (or another VOIP proivder) to record their podcast. As the packets of data sent by these applications are not large in size it is a pure latency issue that effects the quality of the call. (Tip: Have the person with the least latency on the line host the call for best results)
Why Does it Matter?
It matters in an office environment if the slowdowns are regular occurrences and persist over a long time (you will get times when there is a brief delay). This will effect productivity and the moral of the team if they can’t get their work done. It is very frustration to be trying to be productive and have the system mess up your flow.
For the pleasure user unless it is a persistant problem then it probaly doesnt matter too much. If you find that you are constantly getting frustrated by the speed of your connection then it will obviously matter to you.
What Causes Latency?
Latency can be caused by a number of different factors. The distance you are from your local exchange if on DSL will have an impact on the latency on your line. The medium you use to connect to the web will also have an effect. This is why fibre optic is faster than copper wire. Also there may be latency in the hardware you are using to connect to the web. Some routers deal with this better than others.
What to do About Latency?
You can try to work with your ISP to see if they have a solution to the problem. This may not be a successful outcome as in my experience with our ISP the person in support only wanted to talk about bandwidth. They had no concept of latency. I once tried to polietly educate them but they resisted all my advice and explinations.
If you find this to be the case then maybe it is time for a change of ISP. Outside of you ISP taking action to fix the problem or changing to an ISP with lower latency there is not much you can do about it unless you want to move to a different area with better internet connections. Check to see if there is a better quality service in your area. Look at your hardware. Is it older? Does it support newer technologies? If not think of upgrading.
How to Test for Latency?
You can use ping tests to check the latency of your connection. On a Mac you can use the network utility for this. On Windows you can run the Ping command from the Command Line. You will need an address to check.
Running a trace route test Can help identify a bottleneck along the packets route to an address on the Internet. Once again the Network Utility on a Mac can be used to run this test. On Windows you can use the tracert command from the command line.
In addition you could use a site like speedtest.net to test both the latency and capacity of your connection. Note: Speedtest.net requires Flash. Don’t fall for the scan your Mac rubbish on their home screen either.
Conclusion
As business look to cloud computing as a solution to their IT challenges latency and reducing it down to a satisfactory level will become of key importance. As consumers we are always looking for the best connection possible. Be aware of the latency factor in your Internet life and don’t settle for anything but the best possible connection to meet your needs.
