There are two major connection properties: Latency and throughput.

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Latency is the time it takes to establish a connection. Latency is influenced by hardware i.e. which connection device is used (e.g., wireless connections take longer than wired) and also other factors such as the length of the route or latency bottlenecks in the route. Latencies are easiest measured with the Linux tool ping. Ping takes a hostname or IP address as a parameter and sends a small test packet to the node that is echoed by it. Once the echo is received time is measured. If the host does not send an echo back in a reasonable time, a timeout is signaled indicating the host is offline. This is repeated until the user presses CTRL+C.

Under Linux ping is sometimes accessible as /usr/sbin/ping and on Mac it's sometimes /sbin/ping.

Go ahead and try:


Ping can also be used on entire networks. This is called broadcast ping, whereby all online hosts on the Ethernet bus will respond. In order to ping your network you need to find out the IP address of your own host and derive the network IP. There are several ways to determine your own IP but the easiest is way (when you are not behind a router) is to open your browser to and search for "my IP".  Then replace the last digits of the IP (say XXX.YYY.ZZZ.001) address with 255. So if your IP address is, your replacement would be

Then you execute:

ping -b XXX.YYY.ZZZ.255

Go ahead and try it!

Note that this may not always work as some networks forbid the broadcast ping or are configured differently. Nevertheless, for a system administrator it's an easy way to test all the hosts along the bus at once.


Throughput is a term which describes how much data is being transferred at a time. You may also be familiar with another term, bandwidth, which means the same thing. It is usually measured in terms of "bps" or bits per second. For example, you may have an internet connection capable of 5Mbps. This means, that (in theory!) each second you computer could download 5 megabits of data from another location. Of course, in reality, throughput varies widely, and it's quite difficult to obtain the maximum speeds of any connection.
Throughput is much harder to measure. It also massively depends on what other processes (applications) running on your computer take bandwidth, as well as any other devices connected through the same Ethernet port or wireless access device. A simple way but not necessarily very accurate way to measure bandwidth is to use a website designed to test your connection. One example is provided by the website Give it a quick try and answer the following questions:
  1. Run the speed test three times. How much did the throughput vary?
  2. Is upload speed different than download speed? If so, why?
  3. Synchronize with your peers and measure the speed concurrently. How much did it drop?