Experimental Data Analysis Lab

Overview

Ping is the name a command-line network utility which was initially written for Unix to be able to tell if a remote server was online and reachable. Over time, ping has turned into a verb which is even used in common conversation to indicate the process of checking in on somebody. Anyone who has played online games has also probably worried about their 'ping times' and the lagging associated with slow responses.

Operating Systems

Because ping is really a Unix utility, and the Mac OSX is fundamentally based on a variant of Unix, ping and other related utilities like traceroute work most seamlessly on Unix or OS X. Because ping is so useful, however, Windows has incorporated this into the operating system ages ago, and there are doubtlessly many different graphical ping and traceroute applications available for free on Windows.

To run ping and other command-line tools on a Mac, you need to open the Terminal application, which can be found under Applications/Utilities. On Windows, the equivalent tool is the 'Command Prompt' which can be found under Accessories in the Start menu.

Oregon Network

This lab really will not work out well for you if you try to make your ping measurements from a computer which is not connected to the UOregon network. There are several reasons for this, but the most fundamental is that commercial internet service providers often send their traffic all over the place and make it very difficult to figure out the actual route taken by internet traffic. It also may be difficult to find a site to ping which is a short distance away.

Academic institutions in the US share a 'private internet' called Internet2 which has higher intrinsic bandwidth and less traffic than the long-haul fibers used by commercial providers. Making connections between universities should in principle give considerably more reliable results for this measurement where we want to minimize any additional delays which we might misinterpret as a slower speed of light.

Available Machines

Please go ahead and try your own laptop if you wish. As long as you are on campus, it should work fine. The macs in Room 17 have been verified to work, and if you want to try to collect your ping data from home, the best option is to log into the shell.uoregon.edu server (which is a Unix machine and gives you a command-line prompt as soon as you log in) and run your ping commands there. If you do use shell, you will need to use a file transfer protocol like sftp to copy your raw files back to another machine for analysis.