#use wml::template Title="echoping details"

echo service

echoping assumes the remote host accepts such connections. Experience show that most Internet routers do and many hosts also. However, some Unices are not shipped with this service enabled and, anyway, the administrator is always free to close it (I think they shouldn't). echoping has therefore less chance to succeed than ping or bing. (On a typical Unix box, "echo" service is configured in /etc/inetd.conf but see the CERT advisory.)

What does it measure?

echoping simply shows the elapsed time, including the time to set up the TCP connection and to transfer the data (but excluding the time for the - possible - DNS call). Therefore, it is unsuitable to physical line raw throughput measures (unlike bing). On the other end, the action it performs are close from a HTTP request and it is meaningful to use it (carefully) to measure Web performances.

UDP and inetd

With UDP servers you can have surprises: the first test is quite often much slower since inetd has to launch the process. After that, the process stays a while so the next texts run faster.

A nice example

There are many, many traps when measuring something on the Internet. Just one example: 'echoping -w 0 -n 4 a-sunOS-machine' and you'll see the first test succeed in a very short time (if you are close from the machine) and all of the others take a much longer time (one second). With '-w 1' (wait one second between tests, the default), everything works fine: it seems the sockets on SunOS need time to recover :-)

To measure performances on the Internet you can also see

Unix

MacOS

MS-Windows

(I have little knowledge of that environment and I tested nothing.)

Windows-NT

echo and other services can (apparently) be provided within 'Simple TCP/IP Services' which can be enabled through the Network Control Panel

Web clients

You can ping or traceroute on the Web. See Freenix, fr.net (with Autonomous Systems handling) or Multiple Traceroute Gateway.

Use all of them with care, the result is not obvious to interpret.

And don't forget to read RFC 1470 ("Tools for Monitoring and Debugging TCP/IP Internets and Interconnected Devices"), specially its "Benchmark" section and the Richard Stevens' books (all of them), published by Addison-Wesley.