Ping is a simple utility commonly found on systems using TCP/IP. Ping
allows you to do a basic check to see if a remote system is alive and
responding to TCP/IP, even if it is not accepting connections on
specific ports. Ping is also useful for measuring how "far away" a
remote system seems to be - lower reported numbers are an indication of
short round trip packet times.
Here is the detailed readme for ping: ping.txt
And here is a screen shot of ping testing the response time to
www.brutman.com:
Pinging to my local router (192.168.2.1) and then www.brutman.com
(A note about the screen shot - it was taken on a Windows XP system
running a special build of DOSBox that has networking support. This is
the best way to get screen captures. Your results on real hardware will
be similar.)
Note the reported times. Normal timer resolution under DOS is limited
to 55 milliseconds. This is how fast the BIOS timer clicks, and it
works out to about 18 times a second.
Ping can measure time down to 0.85 milliseconds. To do this it
reprograms the hardware timer to generate interrupts faster, and then
only passes the correct number of interrupts to the BIOS code.
This way BIOS keeps correct track of the time and everything else works
as it should, while Ping can get 1 millisecond accuracy while it needs
it.
This technique is highly accurate - try it!
Download!
Ping is included with the other mTCP based applications. They can be
downloaded from the main mTCP page
here.
Created July 31st, 2008, Last updated February 8th, 2010
(C)opyright Michael B. Brutman, mbbrutman@yahoo.com
