Ethereal-users: [Ethereal-users] Timing accuracy problem when logging USB port

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

Date Prev · Date Next · Thread Prev · Thread Next
Date Index · Thread Index · Other Months · All Mailing Lists
From: Tomas Brännlund (KI/EAB) <tomas.brannlund@xxxxxxxxxxxx>
Date: Wed, 7 Sep 2005 15:48:47 +0200
Hello!
I wonder if someone could help me with a problem.

We made some tests with a mobile terminal connected to a PC via USB. The mobile terminal was connected to internet. We ran ping tests from the computer and at the same time we logged the USB port with Ethereal. We ran the Ping tests from an MS-DOS window. When we compared the Ping result presented on the MS-DOS window with that logged with Ethereal there was a difference. It seemed like Ethereal truncated the result down to multiples of 10 milliseconds. To give an example: the MS -DOS window could present results ranging from 90ms up to 120ms. There were no steps, i.e. all values between 90 and 120ms seemed to appear. When looking at the ethereal results, they showed either 80ms, 90ms or 110ms, in those steps. Could someone please explain this behaviour. Which result should I trust?

Thanks in advance/Tomas Brannlund