Speed Test
Benchmarking your Broadband
The main bottleneck for videoconference (VC) consultations will be your broadband speed and the delay in nulliseconds in your network (known as "latency") . Unfortunately in Australia broadband speeds vary greatly between different geographical locations and what is available in many major cities is often not available in most rural locations and by Telco providers offer different levels of service. VC requires high bandwidth and low latency to perform at an acceptable level, and therefore, if performing a VC over the Internet, it will preferably need to be the highest plan available for your area.
What factors affect the quality of your videoconference?
The difference between a smooth VC and a poor experience mainly relies on three factors:
- Bandwidth — the rate in bits per second at which the network connection can move data in the conference
i.e. how wide is the "road" from A to B - Latency — the delay in milliseconds in the network connection used by the conference
i.e. how smooth is the "road" and how much other traffic is between A and B - Routing — the network route take by data packets during the conference
i.e. how many turns does the "road" take between A and B
When all of these factors are optimal, the VC runs smoothly, but all three factors are subject to variables such as other network traffic, the equipment being used. Typically, low bandwidth, high latency, and inefficient routing will lead to low-quality conferences. Conditions on each participant's LAN also affect the VC. Proxy servers and firewalls, if too restrictive or improperly configured, may create bottlenecks, a problem that is more likely to occur when one of the parties is in a public hospital as these tend to have firewalls.
Choosing a Plan - the Faster the Better & check your upload and download speeds
Choosing the fastest broadband connection that is economically viable is critical to VC. ADSL and ADSL 2 are the most common types of broadband offered to rural practices and are usually adequate for most VC solutions. Download speeds are usually much higher than upload speeds, which is great if you are only receiving VC content from the other VC participant, but upload speed is equally important when communicating back. ADSL is rarely synchronous (where upload and download speeds are the same); therefore choosing a plan requires particular attention to the upload speed and not just the download speed. Some Internet service providers offer business plans with higher and more reliable upload speeds than standard Internet plans, which may be worth considering.
Broadband Speed Test
Bandwidth testing will give you an indication of how fast your Internet connection is, and perhaps guide you on what VC system your site can support. Often a business has had their Internet installed for some time, when VC was not a consideration. Browsing the Internet and downloading occasional files may be satisfactorily achieved using slower broadband speeds, but this will rarely suffice for VC. As broadband technology has matured, download and uploads have increased and pricing has reduced. In many cases there are much faster broadband plans available to what is currently installed at your site; often these can be cheaper.
There are many speed test sites available online to gain a quick overview of your broadband speed. These sites have the ability to test your download and upload speed and your "ping result" (See latency testing). The results should give you a basic understanding of how your broadband performs.
In the following example www.speedtest.net was used to test an ADSL 2 broadband connection:
Step 1
Open up your Internet browser and go to www.speedtest.net
Step 2
Press the BEGIN TEST button (see below)
Step 3
Review the result.
Conclusion
This result is handy to get a rough indication of your speed at one point in time. (Note that speed tests will differ to other locations and at different times of the day.)
Latency testing
Latency is the time delay between an event occurring, e.g. capturing video at one end of a VC and displaying it at the other end. Latency is introduced both by the encoding/decoding process (and hence depends on the equipment used) and also by the time it takes data packets to traverse the network. Usually there is little you can do to change the network latency on any large scale, beyond getting directly involved with a carrier or a research network.
Excessive latency increases the chances of people "talking over one another" because they do not realize that the person at the other end has started speaking too. This is less significant in calls with less than 50 milliseconds of network latency. It can become very troublesome in calls with more than 150 milliseconds. Another problem is that the latency for the audio and video may be different, resulting in lip movements that do not appear synchronised with the audio. This is a function of both the terminal and the network, and can vary dramatically — some products try to compensate for it. You should experiment to see if it is an issue for your applications.
Packet loss or dropped packets
Inevitably, some data packets are lost in the transmission of video conferencing data. This results in missing regions of the on-screen image, distortion in audio or video, and blank spaces in the session. Because most traditional video conferencing products use a format called UDP to transmit, which does not provide for resending dropped packets, poor network conditions can severely affect quality.
A quick latency and "jitter" test
A "ping test" determines whether your computer can communicate with another computer over the network. Then, if network communication is established, "ping tests" also determine the connection latency between the two computers.
"Jitter" is the variance in measuring successive ping tests of your computer.
There are many online Latency testing facilities available which will give you a rough guide on your latency. Most online Latency testers will "ping" a site several times and display the average result. For the following test the free service offered by www.pingtest.net was used. Pingtest.net uses predetermined sites to send multiple "pings" and displays the average result. Pingtest.net will also display Jitter and packet loss.
Test Option 1 - Online Latency Tester
Step 1
Open up your Internet browser and go to www.pingtest.net
Step 2
Click on the BEGIN TEST button
Step 3
Review the results
Conclusion
This result is handy to get a rough indication of your latency at one point in time. "Ping" test results will differ location to location and at different times of the day. Zero jitter means the results were exactly the same every time, and anything above zero is the amount by which they varied. Like the other quality measurements, a lower jitter value is better. And while some jitter should be expected over the Internet, having it as a small fraction of the ping result is ideal.
Test Option 2 - Direct "Ping" Test
Due to different network types, broadband speeds and routes from you to the other VC participants/s more accurate indication of your latency between your computer and those of other participant/s.
A direct "ping" from your computer to the other computer or VC system may provide a more accurate indication of the latency between two parties.
Depending on your operating system (i.e. Windows or Mac being the most common) you will perform this test differently. The following test is being conducted on a Windows 7 computer, but will be a similar process for most windows operating systems. For this test you will also need the public IP address of the other VC participant to "ping" too. If they don't know their public IP address, get them to perform a Public IP Address Test, from a computer connected to the same network as their VC system.
Step 1
Open the command prompt. This can be performed by clicking on the start icon, and in the search programs and files window, type cmd and then press enter on the keyboard. This will open the command prompt (see below).
Step 2
At the command prompt, type "ping" then your VC partner's public IP address e.g." ping 74.125.237.151" (this is one of Google's public IP addresses) and press enter on your keyboard (see below).
This will "ping" the desired site 4 times and give you the results at the end of the test.
e.g. Average = 88ms
Conclusion
This test is only a one point in time test and will vary at different times depending on network loads, broadband speeds routing paths.
Tip - If you are finding that certain times of the day you experience lesser quality VC consultations, it may be worth performing this test at different times of the day over several days/weeks; and you may find times that have lower latency and you could try to schedule your VC consultation to these times.