mirror of
https://framagit.org/bortzmeyer/echoping
synced 2024-11-18 15:26:17 +00:00
108 lines
4.1 KiB
Plaintext
108 lines
4.1 KiB
Plaintext
Some details about echoping
|
|
------------
|
|
|
|
|
|
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
|
|
<http://www.cert.org/advisories/CA-96.01.UDP_service_denial.html>.)
|
|
|
|
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 :-)
|
|
|
|
A graphical interface:
|
|
|
|
If you have the Perl/Tk <http://pubweb.bnl.gov/~ptk/> package, you can
|
|
use a (quite rough and completely unmaintained) windowing interface,
|
|
"echoping.ptk". To use it, you should define FLUSH_OUTPUT at the
|
|
beginning of echoping.c (this seems to work on only a few Unices,
|
|
including DEC's OSF/1). This interface has not yet been updated for
|
|
echoping 2's new features (like HTTP support).
|
|
|
|
To measure performances on the Internet you can also see:
|
|
|
|
Unix:
|
|
|
|
- bing, a bandwidth measurement tool <ftp://ftp.lip6.fr/pub/networking>
|
|
- ping, probably available with your system
|
|
- traceroute, idem (otherwise, see <ftp://ftp.ee.lbl.gov/>)
|
|
- ttcp, the best measurement tool but it needs some control over the
|
|
two machines <ftp://ftp.arl.mil/pub/ttcp> (nothing to do with
|
|
the T/TCP protocol)
|
|
- treno (evaluates available bandwidth for TCP)
|
|
<http://www.psc.edu/~pscnoc/treno_info.html>
|
|
- spray is a tool which I dont't know very well. It is available on some
|
|
machines (Sun, OSF/1).
|
|
I've also heard of but never tried:
|
|
- NetPerf <http://www.netperf.org/netperf/NetperfPage.html>
|
|
- a suite of Bandwidth Measuring programs from gnn@netcom.com
|
|
<ftp://ftp.netcom.com/~ftp/gnn/bwmeas-0.3.tar.Z>. These are several
|
|
programs that measure bandwidth and jitter over several kinds of
|
|
IPC links, including TCP and UDP.
|
|
|
|
Macintosh:
|
|
|
|
- TCP Watcher, a very nice "swiss-army knife" tool, to test ping, DNS, echo.
|
|
It includes an echo server. Available on Info-Mac in "comm/tcp".
|
|
|
|
MS-Windows:
|
|
|
|
(I have little knowledge of that environment and I tested nothing.)
|
|
|
|
- WSNUTIL. Seems to be an echo client and server.
|
|
<http://www.ccs.org/winsock/xref-e.html#echo_clients>
|
|
- echox32. An echo server.
|
|
<http://www.winsite.com/info/pc/win95/misc/echox32.zip/>
|
|
- cfinger. An echo client and server.
|
|
<http://www.winsite.com/info/pc/win3/winsock/cfing13b.zip/>
|
|
|
|
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
|
|
<http://www.freenix.org/cgi-bin/traceroute.iphtml>,
|
|
<http://www.tracert.com/> or
|
|
<http://www.fr.net/internet/trace.html>.
|
|
|
|
|
|
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.
|
|
|
|
|
|
$Id$
|