What are the 2 major issues when measuring network performance?
The 2 major issues are latency and bandwidth. Bandwidth refers to the rate at which data moves through the network once communication inside the network is established.
You’ve probably seen bandwidth measured as MB/s (1 MB/s is a pretty common internet speed for people at home, who have fast service available to them). Latency refers to how long it takes a given bit of information to get through the network. The perfect network would have infinite bandwidth and zero latency.
Think of a network as a water pipe. In a pipe, latency would be the time it takes for a single drop of water to travel through the entire length of the pipe. The longer the pipe, the more latency. The wider the pipe, the more water can pass through the pipe at a given time – this is comparable to bandwidth. If your bandwidth is 1 MB/second, then 5 MB/second would be considered more bandwidth.
When loading a Web page, you can see bandwidth and latency in action. If it takes a long time for the web page to display, but then it appears quickly, then this is an indication of good bandwidth but high latency (remember high latency is not desirable). However, if the web page loads immediately but it takes a long time to start downloading then this is an indication of a low latency, low bandwidth connection.
What is stealing bandwidth?
Let’s say that you have internet at home, like most people, and then all of a sudden 10 of your friends come to your home with their laptops and decide to use your internet connection. Because 10 other people are using your internet, it means that your personal bandwidth will go down – so basically the amount of data that you are able to receive at a given time will decrease and you may not be able to load webpages as fast as you normally would (depending on how much data those pages contain). So, your 10 friends can be said to be “stealing” your bandwidth.